issue no.

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WÄRTSILÄ TECHNICAL JOURNAL

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Flexibility in dispatching Modelling power systems

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ENERGY

MARINE

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Smaller scale LNG deliveriesLogistics model can open new markets

Composite technologyWärtsilä solutions for seals and bearings

LNG conversions A viable option for environmental compliance

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COVER STORY

SMART POWER

GENERATION FOR

the oil and gas industry

DEAR READER

issue no. 01.2012 in detail

E-mail and feedback: indetail@wartsila.com

2 in detail

Flexibility in power generation . . . . . . . . . . . . . . . . . . . . .4

GD power plant conversions . . . . . . . . . . . . . . . . . . . . . . .9

Forecasting power demand . . . . . . . . . . . . . . . . . . . . . . 15

Facilitating smaller-scale LNG availability . . . . . . . . 21

System support enhances use of renewables . . . . . 26

Ancillary services secure power supply quality . . . 31

New composite seal and bearing technology . . . . . 34

LLC offers additional levels of redundancy . . . . . . . 40

Blending on Board improves lubrication . . . . . . . . . . 47

LNG conversion for marine installations . . . . . . . . . . 55

Wärtsilä 32 has greater power output . . . . . . . . . . . . 61

Publisher: Wärtsilä Corporation, John Stenbergin ranta 2,

P.O. Box 196, FIN-00531 Helsinki, Finland | Editor-in-Chief: Marit Holmlund-Sund | Managing Editor and Editorial Office:

Tarja Vuorela | English editing: Tom Crockford, Crockford

Communications | Editorial team: Kärt Aavik, Stephane Debiastre,

Niklas Haga, Marit Holmlund-Sund, Tom Kreutzman, Dan Pettersson,

Marialuisa Viani, Virva Äimälä | Layout and production:

Otavamedia Ltd., Kynämies, Helsinki, Finland | Printed: May 2012

by PunaMusta, Joensuu, Finland ISSN 1797-0032 | Copyright ©

2012 Wärtsilä Corporation | Paper: cover Lumiart Silk 250 g/m²,

inside pages Berga Classic 115 g/m²

ENERGY

MARINE

Contents

The Wärtsilä-powered Antelope Station facility is providing grid stabilisation services in West Texas, one of the USA's premier wind farm locations (more on page 26).

THIS ISSUE OF IN DETAIL is also available on iPad as a Wärtsilä iPublication app from Apple's Appstore, as well as in a browsable web version at http://indetailmagazine.com/.

WÄRTSILÄ CONTINUES to strive to provide, both for land and

sea based applications, power and propulsion solutions that

are reliable, sustainable and affordable. For these are the

shared demands of power plant and ship owners throughout

the world, and a few of Wärtsilä's innovations to meet the

current and future needs of its customers can be seen in this

issue of In Detail.

SMART POWER GENERATION is an outstanding example of

this far-sighted vision in not only responding to the present

situation, but in anticipating the likely requirements of the

energy sector in the years ahead. As utilities everywhere

continue to add renewable power sources, such as wind and

solar, to their systems, they seek also ways of adjusting their

generating capacity to the inherent variability in supply

that these new sources create. Traditional, conventional

systems are not designed for responding to such rapid

variations, and Wärtsilä is a pioneer in providing an

economically sound and technically feasible alternative.

SIMILARLY, WÄRTSILÄ'S LEADING ROLE in developing

multi-fuel engine technology is paying dividends in reducing

operating costs and helping the environment. One clear

example is illustrated in the use of oilfield associated gas to

generate power instead of being flared into the atmosphere.

IN THE SHIPPING AND OFFSHORE MARKETS too, Wärtsilä's

advances in engine technology are enabling the emergence of

liquefied natural gas (LNG) as a viable marine fuel. Despite its

obvious advantages in cost and environmental sustainability,

LNG has for years been looked upon as being impractical

for use in fuelling marine engines. Wärtsilä has shown

the world that this is not the case at all. On the contrary,

thanks to the company’s innovative thinking and dedicated

development work, LNG may well become the marine fuel

of the future. Conversions to gas powered propulsion are,

therefore, likely to increase rapidly as we look ahead.

THESE LARGE-SCALE DEVELOPMENTS, and the many

smaller-scale innovations that are presented in this issue of

InDetail magazine, not only provide Wärtsilä with business

opportunities, they are also reason for every employee

across the globe to be justifiably proud. Above all, they offer

our customers solutions that are

absolutely in line with the need

to meet tightening cost budgets,

and to comply with increasingly

stringent environmental

legislation.

I wish you enjoyable reading,

Frank Donnelly President, Wärtsilä North America Contributing editor to this issue of In Detail

iPad

Web

WÄRTSILÄ TECHNICAL JOURNAL | WWW.WARTSILA.COM

in detail 3

WÄRTSILÄ LOW LOSS CONCEPTNew Wärtsilä platform supply vessel design with LLC achieves the highest possible

Environmental Regularity Number without increasing installed engine power. PAGE 40

Blending on Board concept aids lubrication

After extensive testing, Blending on Board to be installed on a Maersk Line container vessel.

Upgraded Wärtsilä 32 engine

The Wärtsilä VS 465 design vessel being built for Atlantic Offshore will feature the higher-output Wärtsilä 32.

Reduced gas flaring after GD conversion

Successful co-operation with PETROAMAZONAS enables electricity to be produced from associated gas at Eden Yuturi.

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Fig. 1 – A pumping station on the Baku-Tbilisi-Ceyhan pipeline in Turkey. The pipeline, for which Wärtsilä has supplied engines, crosses several mountain ranges.

The oil and gas business is a multi-billion

dollar industry with a huge need for

prime movers – whether in the form of

combustion (reciprocating) engines or

combustion turbines (rotating machines) to

deliver electrical power or mechanical drive.

As oil and gas become more difficult

to recover and operators attempt to

extract more from existing wells, the

demand for investment in power

generation will continue to increase.

Smart Power Generation for the oil and gas industryAUTHOR: Junior Isles, Man in Black Media

The oil and gas industry has a tremendous need for prime movers that can provide electrical power or mechanical drive. With their high efficiency and fuel flexibility, combustion engines offer the most competitive solution.

The total investment in the upstream

segment is currently in the region of EUR

300 - 350 billion a year, a figure that is

expected to grow in the coming years.

The choice of whether to use rotating

or reciprocating machines is one that

operators need to consider carefully,

especially in the face of growing

environmental awareness and the need

for greater energy conservation.

Increasing energy demand continues to

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

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drive oil and gas exploration in regions such

as the Middle East, Russia, the Caspian and

Latin America. Underground gas storage

projects, and the development of gas

transport and distribution in Europe and

the U.S., are also increasing demand for

investment. For example, the U.K. is

planning to build many new underground

storage facilities to increase its severely

limited storage capability.

Applications

The market for combustion engines in

the oil and gas business can be split into

three segments: power plants, pumping,

and compression.

Power generation: Power plants are often

needed to provide power; the location can

be at an oil or gas field, a refinery, or even

at a compression or pumping plant in cases

when the compressor or pump is driven

by an electrical motor.

Such power plants are much the same as

in the electric utility industry. One of the

key differences, however, is the available fuel

to drive the power plant. Fuels can range

from associated gas to crude oil, have

varying quality and quantity, and often

cannot be burned in turbines.

This is where Wärtsilä’s technology comes

into its own. Wärtsilä has engines that can

run on gas or virtually any liquid fuel. It has

gas engines capable of running on normal

pipeline gas; liquid fuel engines that can run

on crude oil, heavy fuel oil (HFO) or light fuel

oil (LFO); and dual-fuel (gas-diesel) engines

capable of burning gas of varying quality

and liquid fuel at the same time. Gas-diesel

(GD) technology, which is unique to Wärtsilä,

is particularly well suited for oil field power

plants where there can be changes over

time in the quality of the associated gas, as

well as in that of the crude oil produced.

With engines ranging in size from 1 MW

to 23 MW, Wärtsilä can build oil or gas fired

power plants ranging from 1 MW up to 500 MW.

The modular design of Wärtsilä’s solutions

means that plant size can be increased by

adding additional units as the operators’

needs change.

Pumping: The same engines used for

generating electricity can be used for driving

pumps. Wärtsilä has large engines suited for

big pipeline projects. It has supplied engines

to projects such as the BTC Pipeline (see side

story) in Turkey, and the OCP Pipeline

in Ecuador.

An advantage of the Wärtsilä technology

is that its engines can run on the crude oil in

the pipeline without any refining or treatment.

Compression: Gas compression is a big

market for combustion engines. Gas

compression is a business worth several

billion dollars a year globally.

Smaller 0.5 - 2 MW engines are used for

small gas distribution lines, as well as in

the shale gas market, which are typically

very small fields.

Larger engines are used for underground

gas storage projects. Indeed, reciprocating

technology is better suited than centrifugal

technology for the high pressures needed

for underground storage.

Currently, the pipeline compression

sector has a prevalence of turbines driving

centrifugal compressors. The turbines used

for this application are typically 5-10 MW

but can also be bigger.

However, using combustion engines to

drive centrifugal compressors offers huge

savings in fuel. The arrangement would see

a gas engine driving the compressor directly,

or a power plant supplying electricity to

electrically driven compressors. Although

the latter would be a more expensive solution,

it would increase flexibility. Using a gas

engine in place of a gas turbine also provides

much better fuel efficiency. Lifecycle studies

of real cases show that such a solution could

deliver fuel savings of more than

EUR 100 million over a 20-year period.

Better efficiency

The efficiency argument presents a strong

case when comparing combustion engines

with other technologies. When a lifecycle

cost evaluation is made, the fuel cost over

the lifetime of a plant is many times that

of the capital expenditure cost.

Historically, operators of power plants,

and compression or pumping stations,

have paid little attention to fuel efficiency

as the fuel is often provided free of charge

from the owners of the field. With free fuel

meaning low operating costs, the main

impact on profitability is capital investment

i.e. the cost of equipment. Operators have

therefore opted for the cheapest equipment,

which is usually not the most fuel-efficient.

But this is changing. As energy prices

continue to increase, efficiency is becoming

an important part of the evaluation process.

In order to save energy, reduce the

environmental impact and cost, energy

efficiency programmes are now common

in the production of oil and gas.

As a traditional industry, oil and gas

operators have a tendency to use technology

they are familiar with. This often means that

when issuing tenders, only turbine

technology is specified, despite their much

lower efficiency compared to combustion

engines.

Although some larger gas turbines can

demonstrate efficiencies of around 40

percent, the smaller turbines (around 10 MW)

typically used in many applications have

an efficiency of about 30 percent or less,

depending on operating conditions.

Efficiency decreases during part-load

operation, and there is a significant drop-

off in power as the ambient temperature

increases. Gas turbines also lose output

and several percentage points in efficiency

due to wear between overhauls.

By comparison, Wärtsilä’s gas and diesel

combustion engines have shaft efficiencies

of around 45-48 percent. Efficiency above

40 percent is maintained even at loads as

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low as 50 percent. Gas engines lose virtually

no efficiency over time, and liquid fuel

engines lose only about one percent between

overhauls of the fuel injection system.

Unlike combustion turbines, combustion

engines do not derate over time but

maintain full output during their lifetime.

Fuel flexibility

The ability to burn almost any liquid or

gas fuel in a Wärtsilä engine can help to

drastically reduce the cost of fuel, even from

a purely logistical standpoint.

The ability to run on a wide range of fuels

is why combustion engines are playing a

major role in the drive to reduce flaring.

Gas flaring is a practice that is coming

increasingly under the spotlight due to

environmental concerns and the need for

energy conservation.

In 2010, Wärtsilä became the first solution

provider to become a member of the Global

Gas Flaring Reduction Partnership (GGFR).

The GGFR was formed by the World Bank

in 2002 to support the efforts of oil producing

countries and companies to increase the use

of associated natural gas, and thus reduce

flaring and venting. It estimates that over

138 billion cubic meters (or 4.9 trillion cubic

feet) of natural gas is being flared and vented

annually.

This is equivalent to 25 percent of the

United States’ gas consumption, 30 percent

of the European Union’s gas consumption,

or 75 percent of Russia’s gas exports. The gas

flared yearly also represents more than

the combined gas consumption of Central

and South America.

At a gas price of about USD 4 per million

Gas engines: Wärtsilä gas engines are

suited to normal pipeline quality gas.

They are spark-ignited (SG) engines

that use the lean-burn Otto cycle.

In this process, the gas is mixed with air

before the inlet valves. During the intake

period, gas is also fed into a small pre-

chamber, where the gas mixture is rich

compared to the gas in the cylinder. At

the end of the compression phase the gas/

air mixture in the pre-chamber is ignited

by a spark plug. The flames from the

nozzle of the pre-chamber ignite the gas/

air mixture in the whole cylinder. After

the working phase, the cylinder is emptied

of exhaust and the process starts again.

Oil-fired engines: Wärtsilä liquid fuel

engines can run on crude, heavy fuel

oil (HFO) or light fuel oil (LFO). In the

diesel process, liquid fuel is injected into

the cylinder at high pressure by camshaft-

operated pumps. The fuel is ignited

instantly due to the high temperature

resulting from the compression.

Combustion takes place under constant

pressure with fuel injected into the cylinder

during combustion. After the working

phase, the exhaust gas valves open and

the cylinder is emptied of exhaust gases.

With the piston in its upper position, the

inlet valves open just before the exhaust

gas valves close, and the cylinder is filled

with air. In Wärtsilä engines the inlet

valves close just before the piston reaches

the bottom dead centre. This method,

Wärtsilä engine technology

Fig. 2 – Wärtsilä's gas-diesel technology offers the opportunity to reduce flaring of associated gases, thereby enabling fuel savings and a reduction in greenhouse gas emissions.

Btu, the value of the gas flared in oil fields

and refineries today is around USD 20

billion a year. This wasted associated gas

could produce 65 GW of electricity a year.

With Wärtsilä’s gas-diesel technology,

associated gas can be used for power

generation or gas re-injection at the oil field.

Its fuel sharing technology allows

the engines to cope with variations in gas

quantity and quality.

Reliability

Another key benefit of using combustion

engines is the high reliability they provide.

Oil and gas are highly valuable

commodities and any failure in, for example,

pump or compression equipment can have

serious financial consequences.

Operators, therefore, always install spare

or backup engines or turbines to ensure

there is no interruption in oil or gas

production.

There is a general perception that a

turbine is more reliable than an engine due

to its fewer moving parts. However, modern

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

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medium speed engines have been proven to

provide reliability equal to that of turbines.

With the clear benefits of better

reliability, greater fuel flexibility and lower

operating costs, it is time for the oil and

gas industry to change its conservative

mindset and focus on using the more

efficient and environmentally friendly

solutions that combustion engines provide.

called “Miller timing”, reduces the work

of compression and the combustion

temperature, which results in higher

engine efficiency and lower emissions.

Dual-fuel engines: Fuel flexibility and

high efficiency are the main advantages

of the dual-fuel technology. They can

be characterised as “anything in, and

anything out”. They can run on crude

and other liquid fuels as well as gas of

varying quality, and can be used for

power generation, combined heat and

power, pumping or compression.

Wärtsilä dual-fuel engines are unique

because they have two different injection

systems. A micro pilot injection system

injects a very small amount of liquid

fuel when the engine is operating in

gas mode. The micro pilot system is of

the common rail type, which allows

for very small injection amounts.

This makes it possible to meet very

stringent emission regulations, which

would be impossible if a normal injection

system were used. A conventional injection

system is used when the engine is run on

liquid fuel. The engine transfers from gas

to fuel oil operation (LFO, HFO) at any

load instantaneously and automatically.

Because the gas is injected to the

engine at high pressure, the engine

is not sensitive to the methane

number or other gas components.

Fig. 3 – One of four Wärtsilä pumping stations in the Turkey section of the BTC Pipeline.

Pumping for BTCAs one of the longest of its kind in the world,

extending across three countries from the

Caspian Sea to the Mediterranean coast,

the Baku-Tbilisi-Ceyhan (BTC) Pipeline is

described as one of the great engineering

endeavours of the new millennium.

Designed for the transport of 1 million

barrels (50 MTPA) of crude oil per day, the

pipeline is of regional and international

significance and is the main export route

for Azeri crude to world markets.

Commissioned in 2006, the state-of-the-

art pipeline was built by a consortium led

by B.P. It extends from Baku on the Caspian

Sea, through Azerbaijan, Georgia and Turkey,

to the port of Ceyhan on the Mediterranean

coast of Turkey. From here the crude is

further shipped via tankers to European

markets.

Much of the route through which

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Fig. 4 – BTC pump station with five pump sets driven by Wärtsilä 34SG engines.

the pipeline passes is mountainous. From

the lesser Caucasus Mountains on the border

with Georgia, the pipeline heads west across

the Anatolian Plateau before crossing south

through the Taurus Mountains. At this point

it follows a steep descent to the Cukurova

plain on the north shore of the Gulf of

Iskenderun.

The Anatolian Plateau forms the

principal landform on the route. The terrain

comprises a number of broad plains at

elevations between 1500 m and 2000 m

above sea level, and upland mountains

rising to 3000 m. With a total length of

1769 km, the major portion (1076 km) of

the pipeline’s route is located in Turkey.

Pumping oil across such a vast distance

and high elevations called for the installation

of eight pumping stations – two in

Azerbaijan, two in Georgia and four

in Turkey.

The BP consortium awarded the entire

design and construction of the Turkish

section of the pipeline, including the

pumping stations, to BOTAS, the Turkish

Petroleum Pipeline Corporation.

In 2002, BOTAS awarded a contract to

Wärtsilä for the equipment for the four

stations in Turkey. The scope of the contract

covered the supply of nineteen 18-cylinder

Wärtsilä 34SG engines in V-configuration

with selective catalytic reduction (SCR)

systems, a starting air system, lube

oil systems for the engine, and for the

pump and gear box, cooling radiators,

auxiliary modules for heat exchangers

and filters, air intake ducts, exhaust gas

systems, and pump seal oil systems.

The BTC pump stations in Turkey,

installed along the pipeline from the Georgia

border down to the Ceyhan Marine Terminal,

are designated PT1, PT2, PT3 and PT4 and

are at elevations of 2140 m, 1720 m, 2028 m

and 1595 m, respectively above sea level.

The gas fired reciprocating engines offer

several significant benefits. Compared to

gas turbines, reciprocating engines have

the main advantage of retaining high

efficiency at high altitude. A reciprocating

engine has an efficiency of about 40 percent

compared to less than 30 percent for a gas

turbine driver. Gas turbines experience a

significant loss of power at higher altitudes

and are further handicapped by a steep drop

in efficiency at deviations from the design

point.

Following more than five years of

operation, BTC and Wärtsilä are considering

modernising the engine automation

system with the introduction of a torque

measurement system. This would allow the

engines to automatically adjust according

to the flow of oil in the pipeline.

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

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Fig. 2 – Gas re-injection combined with power generation.

Fig. 1 – The Wärtsilä solution for re-injecting associated gas into the oil well. This maintains the pressure, enhances oil production, and can even be used as a means of storing gas for later use.

Wärtsilä s gas-diesel (GD) technology was introduced in 1987 with the Wärtsilä 32GD, the first gas engine in the Wärtsilä portfolio. This technology has been used mainly in offshore applications, but has later found applications in the power plant sector.

GD technology makes it possible to run

a power plant on either associated gas or

crude oil, where the gases could contain

heavy hydro-carbons, or heavy fuel oil to

provide the operator with fuel versatility

and security against gas supply disturbances.

The system accommodates daily/frequent

variations in gas quality and quantity.

GD- power plants

In power installations, the economic viability

of gas is becoming ever more apparent.

At the same time, emission issues related to

the use of liquid fuels are becoming more

complex. Not surprisingly, therefore, the

use of gas to generate power is rapidly

increasing, although in order to convert

older LFO /HFO operated installations to

natural gas, there needs to be a reliable

Gas-diesel conversions for power plant applicationsAUTHORS: Jyrki Anturaniemi, Project Proposal Manager, Project Proposals , S olut ion Management

Sergey Cheprasov, Project Manager, S ervices Projects Nor th America

Heikki Huhtala, Project Manager, S ervices Project Centre Finland

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supply of gas available. Nevertheless,

the conversion of a HFO plant to natural

gas offers several benefits that make this

upgrading feasible for many customers.

Currently, a conversion project can be

offered using most of the Wärtsilä 32,

Vasa 32 and Vasa 46 engines. Typically,

the two main drivers for fuel change are:

Reduced emissions and fees

Reduction of fuel costs.

The GD conversion concept

Wärtsilä's gas engine portfolio (GD, SG and

DF types) is well known, and if the current

total running hours are, for example, less

than 10,000 hours, a GD conversion is

feasible. In any case, the number of engine

parts that need to be changed is limited.

Diesel engines provide one of the best heat

rates, while GD engines in addition to this

also enable the use of most gas types

available on the market.

There are a number of factors to take into

account when considering a gas conversion.

The most logical place to start is to establish

whether or not the existing engines on site

can be converted, or if they should be

exchanged for new ones. Converting an

existing engine is usually economically more

feasible than installing a new one, especially

since a conversion basically brings the same

benefits as a new engine. For example, the

same warranty is granted as for a brand

new engine. Furthermore, there are also

savings to be made on maintenance costs

since the running hours are reset to zero

(0). However, with smaller installations,

e.g. below 10 MW, it would most likely be

more cost effective to install new engines.

The plant equipment required for

operating on gas can be divided into six

main areas:

Gas delivery

Gas compressor

Fig. 3 – W2W: The Waste To Wire schematic process.

Well

Water

Separator

Crude oil

Gas Pre

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Co

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Tre

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High pressure gas

High gas pressure oil

Control

Electrical feed.

Each gas conversion is installation specific,

and requires a basic engineering evaluation

before a detailed offer and scope can be

given. The scope can encompass a turnkey

delivery that includes the installation and

commissioning of the plant. The plant’s gas

supply and gas line connection to the gas

delivery system is normally the

responsibility of the customer. The most

important benefits of such a conversion are

lower emissions, improved plant efficiency,

and the fact that all the work can be done

on site.

Currently there is an upsurge in demand

for gas conversion installations, based on an

increase in gas supply. In countries without

pipeline gas, liquefied natural gas (LNG)

offers a potential alternative solution.

Gas conversions are yet another example

of Wärtsilä´s ability to help owners and

operators throughout the lifecycle of their

investment, and the company can offer

a broad variety of possibilities to meet

each customer´s specific requirements.

Wärtsilä is also supporting its customers

in gas conversions by providing relevant

training courses on gas operation

Eden Yuturi Conversion Project

In 2008, PETROAMAZONAS EP (PAM), an

Ecuadorian state owned oil company,

initiated a mission named “Optimisation

Generation Electric- OGE” that they also

nominated as a Waste to Wire, or Well to

Wire (W2W) project.

During the crude oil extraction process,

crude oil, water, and associated gas

come to the surface, where they are then

separated at the production facilities (see

Fig. 4 – Associated gas supply characteristics.

Figure 3). Given the unstable condition

of the associated gas (both in terms of

composition and supply) it is usually

vented or flared. The World Bank-led

‘Global Gas Flaring Reduction Partnership’

estimates that globally this amounts to

approximately 150 billion cubic meters of

gas each year, causing some 400 million

tons of carbon dioxide emissions. That is

equivalent to 30 per cent of the European

Union’s total gas consumption. It is

important to point out that associated gas

is quite different to natural gas, in that

its composition and volumes change

significantly over time. If you add to this

the fact that the supply of associated gas

is extremely unstable (see Figure 3), it

becomes clear why in most cases the oil

companies prefer to simply vent or flare it.

In order to reduce gas flaring at the

Eden Yuturi site, PETROAMAZONAS EP and

Wärtsilä entered into a joint development

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agreement aimed at developing an integrated

"gas/crude" product, able to cope with the

dynamic condition of associated gas. In

line with the technological developments,

PAM and Wärtsilä jointly developed the

Clean Development Mechanism (CDM)

programme as a means to co-finance the

project. The objectives of the project are to

mitigate the environmental impact through

reducing the exhaust and noise emissions;

to develop and implement a flexible solution

that will adjust to the challenging conditions

of associated gas; and to replace the use of

diesel/crude oil for power generation by

utilizing the associated gas.

Technology

Thanks to Wärtsilä's multi-fuel technology,

associated gas can be converted to electricity

instead of being continuously flared into the

atmosphere. This technology offers a unique

degree of fuel flexibility, permitting the

engines to run on any combination of liquid

fuel and associated gas. This is essential for

oil and gas companies operating in

environments where the associated gas

volumes and composition are constantly

changing. This flexibility in the utilization of

associated gas serves to maximize power

production while, at the same time, reducing

greenhouse gas emissions.

Although the first phase of the project has

been completed, PAM and Wärtsilä are

already looking at taking the "energy

efficiency" concept to a next phase by

developing new state-of-the-art technological

features. The overall goal is to eliminate any

waste, thereby allowing PAM to reduce

the "carbon footprint" per barrel of crude

oil extracted.

The Project Outcome

The conversion of the Eden Yuturi power

plant from crude oil-fuelled to associated

gas-fuelled operation enabled PAM to

utilize associated gas that was being flared.

Four 18-cylinder Wärtsilä Vasa 32 low nox

gas (LNGD) engines in V-configuration

generating 20 - 24 MW power were

converted, and the hand-over to PAM took

place in November 2011. Every 1 million

cubic foot per day of flare gas optimised for

power generating represents approximately

160 barrels of crude oil per day. Thus,

PAM expects to save up to 640 barrels

thanks to the project. As PAM likes to say:

it increased the net crude oil production

by an average of one well without having

gone through the drilling process.

The PETROAMAZONAS EP and Wärtsilä

co-operation succeeded in developing an

"in-house" Ecuadorian Project Team and

Project Implementation Structure capable of

taking a project from an idea to commercial

operations. This has been duly recognized

by the government of Ecuador, which has

now decided that this vehicle should be used

to implement energy efficiency projects

throughout the country's petroleum sector.

Furthermore, technological solutions

were developed and implemented that

focused on mitigating the challenges of

quantity and quality fluctuations in the

delivery of associated gas. At the same

time, PAM’s power supply matrix was

re-engineered so that today more than

60 MW of capacity has been installed to

operate with associated gas. This will be

increased to 70 MW in phase three. The

other critical technical achievement of the

project has been the transformation of

isolated power generation systems towards a

distributed power system, by installing low

environmental impact underground cables.

Wärtsilä's multinational team can reflect

on a successfully implemented solution for

PAM. It has also created an international

benchmark for oil sector energy efficiency

and consequently, a business model that

focuses on long term sustainable prosperity.

Carbon Finance

The gas conversion is expected to save

over 1Mt of CO2 emissions over 10 years

by using previously flared gas for power

generation. In parallel with Wärtsilä's

delivery of the gas conversion project, the

Development and Financial Services group

at Wärtsilä assisted PAM in the successful

registration of the project under the UN’s

Clean Development Mechanism. During the

2 ½-year process Wärtsilä's carbon finance

experts guided the PAM CDM team in the

CDM registration process, and arranged

the sale of Certified Emission Reductions

from the project. The income from the

Certfied Emission Reductions provides

an ancillary income stream for PAM over

at least 10-years and was one of the key

elements in the investment decision.

Aksa Samsun conversion project

Aksa Enerji Uretim A.S, a part of Kazanci

Holding, is one of Wärtsilä’s biggest

customers in Turkey. This energy sector

company operates diesel and gas power

plants, wind farms, hydro-electric plants,

solar energy, biogas and landfills, as well

as distributing and selling electricity.

The company made an agreement with

Wärtsilä in early 2000 for the supply of a

120MW power plant, equipped with seven

18-cylinder Wärtsilä 46 engines, to the

Turkish city of Samsun on the Black Sea.

The Samsun region has industry, but is also

an agricultural area and the local authorities

pay considerable attention to environmental

impacts. The emission levels from the big

factories and power plants were, therefore,

of high concern already at that time and

the Wärtsilä power plant was equipped

with SCR and SOx scrubber systems.

With the tightening of Turkey’s

environmental legislation, the company

was anxious to convert the engines to

use more environmentally friendly fuel.

At the same time, however, it had to be

kept in mind that the rated output from

the engines could not suffer any losses.

Additionally, operating costs needed to be

Fig. 5–6 – Gas Flaring at Eden Yuturi before and after the GD conversion.

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

13in detail

Fig. 7–8 – Aksa Samsun before and after the GD conversion.

reduced to make the plant’s operations more

economical. Since the engines were running

for only 5000 hours each, only minor

modifications to the engines were preferred.

Wärtsilä’s suggestion for the challenge was

a GD concept, which could cope with all

the requirements with improved engine

efficiency, yet still be able to provide not

only back up fuel flexibility with HFO and

LFO, but also natural gas/HFO fuel sharing.

As the undersea natural gas pipeline from

Russia already exists in the city of Samsun,

the set up was clear, and the GD concept

was proposed as a means of continuing the

plant’s operation under the tight emission

laws. The EEQ contract to convert six of the

power plant’s engines to GD operation was

signed in November 2009, and the project

team’s involvement began accordingly. The

seventh engine was relocated to Cyprus

by Aksa Enerji during the execution of the

GD conversion project in order to make

room for the first Wärtsilä 50SG engine.

Safety is the driving force

Safety is imperative when using high pressure

gas as a main fuel. The fuel oil system, gas

detection and automation system, and the

fire fighting system were designed according

to stringent safety regulations. Different

ratings and areas of Ex-zones were

determined, and even the access road to the

power house building had to be changed

due to the compressor house design and

location. Ex-proof components were

considered for all electrical and automation

parts, when located inside the Ex-zone.

A new gas feed arrangement with double

wall piping, a new HFO injection system, a

control oil system for 370 bar pressure, and

a new improved engine control were added

to the engine. Basically, therefore, very minor

modifications to the engine itself were

required.

For external systems, the conceptual

design was made through close co-operation

between Wärtsilä and Aksa Enerji A.S

Uretim. A ‘Safety Concept with a Cause &

Effect’ study was made by Wärtsilä and Aksa

Enerji based on the Wärtsilä GD concept and

local regulations, and this was used as a

design and execution guideline. The safety

concept emphasizes all the necessary aspects

and measures included in the GD power

plant concept to achieve an acceptable

safety level.

An optimal gas feed system based on

the local conditions was calculated and

designed by Wärtsilä experts together with

Aksa Enerji A.S Uretim’s gas department.

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The gas itself is good quality Russian

natural gas with high low heat value

(LHV), a low consistence of inert gases,

and high methane number (MN). Two high

pressure gas compressors supply the six

Wärtsilä 46GD engines via an engine wise

gas valve skid, which is also able to share

the load upon request from the Wärtsilä

plant control system. The gas feed piping

inside the power house is double walled

to enable proper ventilation for the safe

evacuation of any possible gas leaks. A

reliable, sufficient, and safe gas feed into

the engine is an important factor, but the

gas blow down and venting cannot be

overlooked. Because of maintenance or

other planning reasons, the gas flow must

be able to be led out (blow down) from the

system back to the gas grid. This must be a

safe and controllable operation. There is a

further need for emergency venting of the

gas flow into the atmosphere, which has

to be well planned so that it is activated in

accordance with the plant controls, etc.

A project specific gas valve skid was

tailored by the project team to achieve the

optimal reliability and performance for

operation with a very low, <2 bar, pressure

drop over the skid. The gas valve skids

were further located inside the gas tight

individual cabinet, which is continuously

ventilated and furnished with gas detection

equipment that issues a gas alarm in case

of any leak or malfunction of the skid.

Testing and commissioning took place

in autumn 2011, engine by engine, by the

Wärtsilä commissioning team assisted by

the Aksa Enerji team. Start up of the GD

engine is carried out using LFO or HFO,

and then ramped up to 25% to 30% on

fuel sharing mode prior to change over

to full gas operation with an HFO fuelled

pilot. After a few days tuning, the 17 MW

was reached with very good heat rate

figures. Furthermore, the key issue, the

exhaust gas emissions, were accepted by

the local authorities, who are continuously

monitoring the plant’s exhaust gas emissions

via engine wise emission sensors installed

on each exhaust gas stack. So, in other

words, the production of electricity can

continue with far lower levels of exhaust

gas emissions, while providing financial

benefits through lower operation costs. An

additional advantage is that HFO no. 4, or

even no. 6, can be used as a pilot fuel to

reduce the operational costs even more.

New automation

No conversion project is without a

challenge or a surprise of some kind. This

is especially true when something new

has to fit into an existing environment.

The engine and plant automation and

monitoring systems were renewed totally, so

old panels, sensors, etc were disconnected

and removed prior to assembly of

the new ones, which were also partly

interconnected to the existing systems. In

addition, considerable quantities of safety

equipment, including detectors, sensors,

limit switches, and so on, were installed

based on the required safety concept. Once

the dismantling and installation work

was finalised, the software needed to be

updated to the final revision, and once

again this was based on the safety concept

and the final setting of the equipment.

Overall, however, through close and

open co-operation with the customer, the

Wärtsilä organizations in Finland and

Turkey, and other stakeholders meant that

no major surprises occurred - even though

the project specific and tailored design

was developed during the project itself.

Fuel flexibility

Wärtsilä products are flexible and easily

adaptable for utilizing gas as a main fuel.

This makes the converting of power

plants to gas operation very interesting,

for example in terms of lower operation

costs, less exhaust gas emissions, fuel

flexibility, and short payback time. This

is especially important now when the

gas grids are expanding and emission

levels are being tightened globally. The

GD concept requires very few engine

modifications, and provides considerable

benefits with real fuel flexibility.

Fig. 9 – Pressure testing of the gas pipeline.

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

15in detail

Fig. 1 – In a wind integration study for the Mid Western United States, the PLEXOS® simulations quantify the ability of Wärtsilä Power Plants to load follow against rapidly changing wind output.

The modelling of power systems AUTHOR: Kimi Arima, Advisor, Advisory S ervices, Marketing and Business Development

How does one quantify the value of flexibility? For this one would have to model an entire power system, insert flexible power generation, and observe the results. Wärtsilä has a tool that can do just this.

Dispatching

Dispatching could be concisely described

as the act of continuously optimising the

operation of the power system from one

minute to the next. In the context of a

developed and complex power system,

the responsibility for dispatching usually

resides with the system operator. To be

able to optimise the power system, the

system operator is continuously engaged

in three activities that define dispatching:

forecasting, planning, and controlling.

Forecasting is the task of finding out the

expected load demand and what generating

assets are available to meet that demand.

For traditional longer-term forecasting,

considerations include seasonal variations

in load demand, macro-level weather

patterns and their effect on demand, as

well as planned outages of large generating

units. Shorter term forecasting involves

daily load variations and, which is of

increasing importance in many systems,

the output of intermittent renewable power

generation. The result of forecasting is a

net load curve, that is, the forecasted load

demand less the forecasted output from

intermittent renewable power generation.

This is the part of demand that needs to be

met with dispatchable power generation,

i.e., generating units that can be started

and stopped as and when needed.

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Based on the forecast, the system operator

can plan which generating units will be

used to meet expected net load demand

at each point of the coming day. One

approach is to rank the units in the system

in ascending order of their marginal cost

of generation, known as a merit order.

Renewable sources come first, as they

have no fuel costs. These are followed by

nuclear and coal plants, which typically

have very low marginal operating costs,

notwithstanding the emission costs imposed

on coal plants in some countries. Next come

CCGTs, combustion engines, and OCGT

plants running on gas, while possible oil-

fired units come last, as their fuel costs

are the highest. Having planned which

generating units need to be running and at

which times, the system operator accounts

for start up times and ramp up rates to

see when each generating unit needs to be

started up. In case a generating unit has

to be started up twice during the day, the

minimum uptime and minimum downtime

also have to be taken into consideration.

Finally, contingencies, such as a

malfunction in a big generating unit, or a

forecasting error, also have to be accounted

for. Some generating units are needed to be

at the ready in case of an unexpected shift,

positive or negative, in net load demand.

Reserve requirements are system-specific,

and can be met with a combination of

spinning and non-spinning generating units.

In many countries, the planning phase

takes place on the market. Plant owners bid

their production onto the market, whereby

a merit order is established according to

bid prices. Reserves can also be organised

via separate market mechanisms.

In parallel with forecasting and planning,

continuous controlling is needed to keep

frequency stable throughout the grid, and

maintain stable voltage locally. Routine

control chiefly revolves around the dispatch

plan based on forecasts and the merit

order. If actual demand deviates from

the forecast too much or too quickly, for

whatever reason, reserves will be called

upon to regulate generation as needed.

The goal of dispatching is two-fold. The

first objective is to ensure security of supply.

In the short term, this is achieved mainly

by successful controlling of the system.

In the longer term, forecasting accuracy

needs to be maintained, and reserves

capable of meeting both the scale and speed

of unexpected variations are required.

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00 01 02 03 04 05 60 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23Hour

Dispatchable

Wind

Solar

Fig. 2 – Net load curve, actual data in a Spanish power system. Notice the difference between the smooth curves of aggregate demand and the output of dispatchable power generation.

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

17in detail

Fig. 3–4 – The generation curves in the graph to the left are the result of one hour resolution, whereas the actual generation data in the graph to the right shows generation on a 10 minute interval basis. The surge in wind output and subsequent rampdown of CCGT output between 6 and 7 am is almost invisible in the one hour resolution forecast.

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The second objective of dispatching is to

minimise total system costs. The merit

order approach is an important tool here.

Quite a lot also depends on the accuracy

of forecasting – both long term and short

– as unneeded start-ups will inevitably

manifest themselves in the form of higher

operation and maintenance costs.

Emerging challenges in dispatching

Today, many system operators face

challenges due to the growing share of

intermittent power generation in their

systems. While well established and robust,

the traditional methods of dispatching

are ill equipped to cope with the demands

imposed by increasing levels of variability

in both generation and demand. As most

power systems have traditionally consisted

only of dispatchable power generation, the

conventional dispatching methods have not

been developed to account for variability

in generation, at least not on today’s scale.

There are numerous challenges regarding

power system dynamics that must be

overcome in the coming years if targets for

renewable power generation, and reductions

in emissions, are to be met. Firstly, the

variability of intermittent renewable power

generation has a magnifying effect on load

changes for dispatchable generation. The

smooth curves of aggregate load demand

hide behind them violent shifts in the net

load demand. These rapid shifts entail

more cyclic – i.e., start-ups, ramps – as well

as part-load operation for dispatchable

units, with obvious cost implications.

Secondly, traditional tools for system

and feasibility analysis do not take these

kinds of phenomena into account. Typically,

forecasts and models used for analysing and

optimising power systems are based on an

hourly resolution, i.e., load demand, and

the corresponding generation is considered

24 times in a day. This approach does

not reflect the stresses imposed on the

system by intermittent generation. Indeed,

when comparing the result of a dispatch

model with an hourly resolution to actual

grid data on a ten minute resolution, the

discrepancies can be striking (see Fig. 3-4).

The forecasting challenge is compounded

by the fact that, due to basic mathematics,

increasing forecast error is an inevitable

by-product of the increasing variability

in generation. Thus, either decisions

have to be made based on forecasts less

reliable than previously, or decisions are

made on the same level of reliability but

with less time for implementation.

Thirdly, the interplay of shortened

forecasting horizons and rapid shifts in net

load demand, combined with the relative

inflexibility of traditional dispatchable

power generation, leads to unit commitment

issues. Starting up a plant is costly, especially

if the wind picks up again and the start

up turns out to have been unnecessary.

Similarly, shutting down a plant is risky

since, due to minimum downtime, the

plant will not be able to help for some time

should the net load demand suddenly

increase. Due to inadequate flexibility, in

many systems the response to this issue

has been an increase in partial loading.

The fourth point is that the combined

effect of all the above challenges undermines

the cost objective of dispatching. Costs are

impacted by increased wear and tear due to

violent shifts in net load demand; even more

wear and tear due to unnecessary start-ups

as a result of decreased forecasting accuracy,

decreased total system efficiency and, thus,

increased fuel costs due to partial loading.

Finally, these challenges also have a

negative impact on emissions. Partial

loading, besides increasing fuel costs,

also increases the emissions per unit of

electricity generated. Moreover, modern

emissions reduction technologies don’t

operate at optimum levels in unstable

conditions. In other words, during

start-up, shutdown, and steep ramp,

emissions are invariably higher than

during stable operation at full load.

A tool for the job: PLEXOS®

PLEXOS® is electricity market and power

system modelling and simulation software

developed by Energy Exemplar, an

Australian software company (for more

information on PLEXOS®, visit their website

at www.energyexemplar.com). The main

reason for selecting PLEXOS® as the tool to

demonstrate the value of flexibility is its

accuracy or, as it is known in the context

of modelling, its resolution. As noted

above, the difference between one hour

and ten minute resolutions can be striking,

and PLEXOS® is capable of even higher

resolutions, if necessary. Consequently,

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Fig. 6 – PLEXOS® gives a wide range of output.

Fig. 5 – A PLEXOS® model requires vast amounts of quality data.

PLEXOS® is able to offer a very realistic and

accurate picture of, for instance, how a

proposed plant would actually operate as

part of the power system in the future.

In order to build even a rudimentary

model of a power system, immense amounts

of data are required (see Figure 5). It bears

mentioning that typical models with

one hour resolution do not incorporate

the dynamic features of the various

technologies present in the power system.

Nevertheless, on ten minute resolution

– as well as in real life – these properties

make all the difference. That is why our

models include start-up and shutdown

times, ramp rates, and minimum up

and down times for all technologies.

The amount of output available from

PLEXOS® is even more impressive than the

data required as input (see Figure 6). For the

purposes of this article, the most important

outputs are, firstly, the total generating costs

for the system, and then the running profile,

operational efficiency, and CO2 emissions

of each generating unit in the system.

Case study: Spain 2020

As of late 2011, Spain was already one of

the leading countries of the world with

respect to installed capacity of wind and

solar power. Nevertheless, the government

has set an ambitious agenda to more

than double renewable output by 2020.

Thus, we decided to see how the Spanish

system would cope with the challenges.

As it is important to analyse how the

system would cope with challenging

conditions, output from hydro reservoirs

was modelled according to the year 2005,

which was somewhat drier than average.

Furthermore, modelling was focused on

a week of the year that was identified as

having higher than average variability in

wind power output. This week was then

simulated using ten minute resolution

for two separate cases. The first case

constituted the Base Case, whereas for the

second case nine gigawatts of Flexicycle

capacity was added to the system.

In the Base Case, the effects of the

compound intermittency of wind and

solar are clearly visible (see Figure 7). After

satisfying the previous evening’s peak,

CCGT plants quickly shut down for the

night. As wind output increases in the early

morning, and especially after solar output

starts to grow around 6 am, the pumped

storage load climbs to over five gigawatts.

Due to the prohibitive start costs, it is

Plexos

Cost information

Consumable prices • Lube oil • Water • Etc.

Fuel prices Emission prices

Grid information

Transmission network • Lines (transfer capacity) • Nodes (generator / load points) • Interconnections

Market information

Market information • Market mechanisms • Real bid information for model verification

Reserves • Regulation up / down • Spinning • Non-spinning

Load and production profile library• Uncertainly (forecast error)

Load profiles • Load demand

Intermittent profiles• Wind• Solar

Power Plant profile library

Power Plants types • Coal • Nuclear • OCGT, CCGT • Etc.

Power Plants features• Efficiencies• Dynamic features• O&M costs• Etc.

Plexos

Power plants

Production by plant • Generation • Fuel offtake • Efficiencies • CO2 emissions • Loading factor • Etc.

Costs by plants • Generation • Emission • Operation & Maintenance • Start-up and shutdown • Etc.

Reserves • Provision of reserves • Etc.

Power system

Balance of system • Total generation • Load demand • Unserved energy • Dumped energy

Grid

Transmission system • Power flows • Losses total / per line • Bottlenecks (overloads), if any • Voltages

Energy market information

Energy • Prices • Marginal prices • Income by plant / company

Reserve marketinformation

Reserves • Reserve margin requirements • Prices • Provision by plant • Income by plant

Optimising total generating costs of the system with the

generation fleet

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

19in detail

Fig. 8 – Base Case operating profile for a single day. Notice the sharp fluctuations in CCGT output and the heavy reliance on pumped storage hydro capacity.

Fig. 7 – Base Case distribution of capacities in the Spanish power system model for 2020 (RoR = run-of-river, R = reservoir, PS = pumped storage).

cheaper to run 5 GW of CCGTs on partial

load and use the excess electricity to run

pumped storage hydro plants in reverse,

than it would be to shut them down.

This has a considerable impact on

total system efficiency. The roundtrip

efficiency for a typical pumped storage

hydro plant is around 70%. Thus, running

a CCGT on partial load, i.e., with poor

efficiency, and then ‘recycling’ that

electricity through a pumped storage

facility yields very poor overall efficiency.

Consumption catches up with the

renewable output around 10 am, after which

fluctuations in renewable output are met

with a combination of CCGT and hydro

power. Between 5 and 6 pm, an increasing

number of CCGT plants are started up to

compensate for the decreasing solar output,

and then subsequently ramped up to meet

the evening peak. Reservoir hydro and

pumped storage hydro are also needed to

meet demand between 7 pm and midnight.

It is worth pointing out that, because

of their low efficiency as compared

to CCGTs, the nine gigawatts of OCGT

plants in the system remain completely

unused throughout the day.

Projected generation fleet in 2020: 119 GW

CCGT 25 GW

FLEXI-CYCLE™

OCGT3-9 GW

COAL8 GW

NUCLEAR7 GW

WIND35 GW

HYDRO-RoR4 GW

SOLAR12 GW

HYDRO-R13 GW

HYDRO-PS6 GW

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Fig. 9 – Operating profile with 9 GW of Flexicycle™ added to the system. Notice the difference from the Base Case in CCGT and pumped storage profiles.

A dramatic change occurred when nine

gigawatts of Flexicycle capacity was added

to the system (see Figure 9). Immediately

noticeable is the generation profile from 6

am to 10 am. In the Base Case, CCGT plants

were kept running, despite the impact on

total system efficiency, as they were needed

for the evening peak, and it would have

been too expensive to shut them down

only to start them up again in the evening.

At 9 GW, however, the Flexicycle capacity

is capable of covering such a large share

of the evening peak that no additional

CCGTs plants are needed. Consequently,

CCGTs don’t need to be kept on minimum

stable load through the afternoon, and are

shut down instead. The remaining CCGTs

get to do what they do best, namely run

on full load throughout the evening.

During the afternoon, the benefits of

combustion engines are clearly visible.

Between 11 am and 5 pm, Flexicycle plants

cover four major peaks in net load demand,

ramping from below 1 GW to 5 GW and back

again in less than one hour. Moreover, due

to the negligible start cost and excellent part

load efficiency of the Flexicycle, the ramps

and starts had no impact on system level

costs. In fact, adding 9 GW of Flexicycle

reduced the system level costs by 4.3% as

compared to the Base Case, delivering

annual savings of USD 633 million.

As for the CCGTs, the addition of 9 GW

of Flexicycle decreased their generation

by 34%. For the CCGTs that remained in

use, however, the operating profiles were

considerably smoother, and the average

load increased from 87.5% to 90.6%. It

should be noted that the most impressive

increase was achieved with 6 GW of

Flexicycle, whereby the CCGT average load

rose to 93.9%. In other words, the addition

of Flexicycle enabled a more optimal

running profile for the other generating

units in the system, in this case CCGTs.

SUMMARY

The future impact of intermittency needs

to be analysed on a much finer resolution

than traditional methods are capable

of delivering. In addition to optimising

dispatch, tools such as PLEXOS® can be

used to analyse how our current power

systems should be improved to be better

able to respond to future challenges. In

doing so, valuable insight for strategic

decision-making can be accumulated.

By balancing rapid shifts in net load

demand and optimising the operating

profiles of other generating units in the

system, the addition of flexible capacity,

such as Flexicycle, to a power system can

help to mitigate many of the problems and

costs related to intermittency. In the future,

with further increases in variability likely,

such flexibility can have tremendous value.

And, with PLEXOS®, we can show it.

Flexicycle™The new Flexicycle solution combines the advantages of a flexible simple

cycle plant with the superb efficiency of a combined cycle plant.

The Flexicycle solution is based on combustion engines with heat recovery

and steam turbine for combined cycle operation. The plant is capable of instant

switching between the dynamic and fast simple cycle mode and the highly

efficient combined cycle mode, enabling competitive operation on the energy,

capacity & ancillary services markets.

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WÄRTSILÄ TECHNICAL JOURNAL 01.2012

21in detail

Gas is increasingly becoming the fuel of choice for thermal power plants. Many regions do not have access to natural gas via pipelines, but liquefied natural gas (LNG) can be transported cost efficiently from one part of the world to another.

The world’s economically recoverable

natural gas reserves have increased

substantially during recent years. This is

largely thanks to shale gas, and the advances

made in developing efficient methods

for extracting it. As a result, according to

industry experts, there are now reserves of

natural gas for more than 200 years. With

this abundance of gas, it seems likely that

gas prices will remain competitive over

the long term. Add to this the fact that

natural gas is the cleanest of all fossil fuels,

and its popularity is easy to understand.

Transporting LNG

Liquefied natural gas (LNG) is an obvious

way to transport gas where pipelines

are not available. The traditional way to

distribute LNG is to use dedicated ships that

are as large as possible. These large ships

transport LNG from major liquefaction

facilities located in a handful of places

around the world to the LNG import

facilities, which are not that numerous

either. Since many ships are not designed

to transport partial loads, these import

facilities need to have tanks large enough

Fig. 1 – The Bahrain Vision is a small scale LNG carrier with a capacity of 12,000 m3. It has been in service since November 2011.

Delivering LNG in smaller volumesAUTHOR: Sampo Suvisaari, General Manager, Power Plants, Central America and the Caribbean

Phot

o: C

ourt

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of I.

M. S

kaug

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ocat

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Bah

rain

.

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to receive the full cargo from an LNG ship.

While this large-scale approach

keeps transportation costs down, the

problem is that it creates limitations.

Firstly, the receiving terminals need to

be relatively large. A receiving terminal

of say, 160 000 cubic meters, requires a

very significant investment. For a power

plant having a 100 MW of capacity, this

160 000 m3 would represent about half

a year’s consumption, which is far too

much for an efficient use of capital.

The most common solution to this

problem has been to build LNG import

terminals only at locations where the

gas consumption is large enough, thus

completely ruling out smaller disconnected

locations, such as islands or small

countries. However, this is now changing.

Smaller-scale transportation

The transportation of LNG on a smaller

scale is already happening in several

places around the world, most typically

using trucks. LNG trucks are essentially

vehicles having a pressurised LNG tank.

These are offered by many manufacturers,

and come in different sizes. In some

countries even multi-unit trailers are used.

Unfortunately, this solves only regional

and not overseas transport requirements.

Another method is to use dedicated LNG

containers. This makes it possible to use

the same container for both marine and

road transport. The disadvantage is the

relatively small capacity possible, which

only makes sense for smaller power plants.

Using smaller vessels to transport LNG is

not yet common, but it is already happening.

Norway has been one of the early users

of small vessels for the distribution of

LNG, since the geography of the country

is attractive for marine transportation,

even in quantities as small as 1000 m3.

The Caribbean, on the other hand,

needs slightly larger scale transportation

capacity. Vessels of around 10,000 m3

are ideal for many locations, but such

vessels are not yet shuttling back and forth

from island to island. There needs to be

LNG sources that make LNG available for

smaller vessels, and in order for this to

happen, their business model needs to

take smaller scale vessels into account.

By trying to load smaller vessels from

the same loading bays as the larger ones,

valuable dock time would be utilized for a

smaller volume sale. LNG export terminals

Fig. 3 – Unloading an LNG truck can be a one man operation. The LNG tank in the truck is at a higher pressure than the recipient allowing LNG to flow from it without the need of any pumps. A clever, simple system.

Fig. 2 – LNG truck unloading at a small two-tank LNG storage facility.

Phot

o: C

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Dom

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an R

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Phot

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Dom

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WÄRTSILÄ TECHNICAL JOURNAL 01.2012

23in detail

need, therefore, to have additional loading

bays dedicated for these smaller vessels.

An analogy could be trains and trucks.

Trains are more cost efficient for cargo

transportation, but that does not mean

that trucks are not needed, or that they

are cost prohibitive. Both are essential

for a functioning transportation system.

In the same way, LNG needs to be

transported using both cost efficient large

vessels, as well as flexible 10,000 m3 small-

scale vessels that reach more places.

Hub and spoke concept

A natural solution for improving the

efficiency of transporting LNG on a smaller

scale is to use a hub. The hub can be a

new, or even an existing LNG terminal.

It can be land-based or floating. Smaller

vessels could make ‘milk runs’ to several

locations, or back and forth trips to a single

location, which would keep the distances

relatively short. The trips of the smaller

vessels are the spokes, hence the name ‘hub

and spoke’ for this distribution model.

At present this distribution model is not

yet applied in the Caribbean. Nevertheless,

due to the imminent widespread demand

for gas, it would be surprising if this

concept does not materialize within the

next few years. On the other hand, as

several new LNG export terminals have

been announced in the region, including

several terminals in the Gulf of Mexico

and one in Colombia, some of the export

terminals themselves may become regional

small-scale LNG distribution hubs.

Boil-off gas

Liquefied natural gas needs to be at a

very low temperature, approximately

-160 degrees Celsius. No matter how well

insulated the LNG tank is, the liquid will be

constantly producing boiling off gas, which

needs to be taken into account. Different

tanks handle boil-off gas in different ways.

Let us have a look at the different tank types:

Pressurised small-scale tanks

LNG can be stored in cylindrical metal tanks,

which are essentially spherical tanks that

are made longer. This is a geometrically

strong shape, and the tanks are made to

resist pressures of typically up to 8-10 bar

(116-145 psi). The benefit of having such

pressure resistance is that the boil-off gas,

which is inevitable no matter how good

the thermal insulation, can remain in the

tank. An increased amount of boil-off

gas will simply increase the pressure and

temperature inside the tank. The length

of time that this can be sustained depends

on the tank specifications, and on how

full the tank is. The less fuel there is, the

more space there is for boil-off gas. Some

manufacturers claim their tanks can stay

idle for three weeks and more without the

need for venting the boil-off gas. When the

excess pressure is controlled by releasing

gas through a control valve, the evaporation

inside the container lowers the temperature

and keeps the container in equilibrium.

The benefit of having a tank that can

withstand pressure is that the tank does

not need a reliquefication system at all.

The boil-off gas will be used in parallel

with the consumption of the LNG. As a

result, the tank arrangement is extremely

simple, having no compressors or rotating

equipment of any kind. It simply consists

of the tank, an emergency pressure relief

valve, regasification heat exchangers, and an

outgoing gas pressure stabilisation valve.

Pressurised small-scale LNG tanks come

in different sizes, ranging from very small

tanks for vehicular use, up to larger tanks of

several hundred cubic metres, and even up

to about 1000 m3 in capacity. Their size is

limited by transport constraints and weight.

For example, a tank of 1000 m3 is over

45 metres long and 6 metres in diameter.

Typically, many tanks are placed side by

side to get to the desired overall volume.

Even larger pressurised LNG tanks of

10,000 m3 and more do, however, exist.

The pressure resistance of the larger tanks

Phot

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hart

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nd G

asen

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ocat

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Øra

term

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in N

orw

ay.

Fig. 4 – A small scale LNG storage system can consist of a large number of prefabricated tanks. Ambient air evaporators seen in the back on the right side of the image.

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tends to be smaller, about 4.5 bar (65 psi),

as the weight and cost of the tank steel

would otherwise become cost prohibitive.

These larger pressurised tanks have so far

been used only on ships and barges, due to

transport limitations.

Atmospheric pressure tanks

Traditional large land-based LNG tanks are

designed for atmospheric pressure only.

These tanks are built on site over flat base

concrete foundations, and their tops have

such a large area (the diameter can be

over 60 metres) that even a small internal

pressure inside the tank would create a

strong upward force against them. These

tanks are not designed to withstand such

upward forces, and the pressure inside the

tank has to be maintained equal to the

outside atmospheric pressure. The only

way to ensure this is to have a system to

compensate for the boil-off gas, by

converting this gas back into liquid form via

a reliquefaction system.

A natural gas reliquefaction system has

to be sophisticated due to the cryogenic

temperatures that it needs to create, and

it is therefore an important cost element.

For this reason, atmospheric pressure tank

technology is typically selected for LNG

storage tanks larger than 30,000 m3, while

storage tanks smaller than 30,000 m3 are

built using several pressurised tanks.

Atmospheric pressure tanks can be built

in three different ways; single containment,

double containment and full containment.

Each type has its own advantages and

disadvantages, and selection is dependent

on the location.

Safer than LPG and oil fuels

Liquefied Petroleum Gas, or LPG as it is

known, has been used for a very long time

all around the world as domestic gas. It is

distributed in small bottles, or by trucks

to somewhat larger domestic tanks. The

concept is widely accepted. LPG is not

cryogenic and can be maintained in a liquid

state at normal ambient temperatures by

controlling the pressure.

When LNG and LPG are compared many

people will instintively think that LNG is

more dangerous, due to its cold nature. In

fact, LNG is less risky than common LPG.

LNG does not ignite easily, and in liquid

form does not ignite at all. It can only burn

within a narrow air-to-gas mix range.

Natural gas is also lighter than air, and will

dissipate in the atmosphere in case of a

leak. Should a leak occur, it will not leave

any greasy residues as oil spills do. All will

evaporate, which is a very desirable quality

for a fuel to be used in the Caribbean.

The worldwide safety track record of LNG

has been exemplary over the last fifty years

and more.

Floating or land-based?

A floating storage and regasification unit

(FSRU) is a ship or barge that is fitted with

LNG tanks and the required heat exchangers

(gasifiers) for converting the liquid to gas.

If the gas is used onshore, it is transported

to land by a gas pipeline, which has to be

at least partially flexible.

An FSRU may also be placed next to the

gas consumer, such as a gas power plant,

thereby avoiding the need for a submarine

gas pipeline. Instead, a submarine power

transmission line is all that is required.

Fig. 5 – Vertical LNG tanks at a factory in the Dominican Republic. Vertical tanks are used even in areas where hurricanes are common.

Phot

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. Loc

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anto

Dom

ingo

, Dom

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WÄRTSILÄ TECHNICAL JOURNAL 01.2012

25in detail

The question of whether to use floating

or land-based gas storage is largely

determined by the proposed site, and

the proposed marine conditions. Both

solutions have their distinct merits.

CONCLUSION

As the use of gas fuel increases throughout

the energy market, the entire infrastructure

for ensuring adequate supplies are available

to both large and small markets is in need

of rapid development. For fragmented

markets, such as the Caribbean islands,

transportation and storage issues are of

prime importance.

20000

18000

16000

14000

12000

10000

8000

6000

4000

2000

0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

LN

G S

tora

ge

ca

pa

cit

y in

m3

Full load operation in days

50 MW

100 MW

LNG storage capacity (base load operation)

Fig. 6 – LNG is loaded into distribution trucks at the AES LNG import terminal in the Dominican Republic. The large 160,000 m

3 LNG tank in the background

is an atmospheric pressure tank with a reliquefaction system.

Fig. 7 – This chart shows the required net LNG storage capacity for 50 MW and 100 MW base load power plants and the respective number of days they can operate on full load. Some additional capacity may be needed for unloading flexibility.

Phot

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ourt

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of T

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Power generation is changing, with coal fuelled plants being phased out and more ‘green’ sources being introduced. Antelope Station in Texas is one of the new breed of US power plants designed to cope with these changes.

With the increasing use of solar power

and wind generation, power plants such as

the Antelope Station facility are needed to

stabilize the system and to respond quickly,

reliably, and economically. These factors

give an advantage over the use of older, gas

turbine combined and simple cycle plants.

With many of the older, coal fuelled

power plants likely to be permanently closed

and new and ever more stringent emission

regulations being enacted, Wärtsilä's

combination of low heat rate and quick start

capability is becoming increasingly

important.

Already, several coal fuelled plants have

been mothballed, and experts estimate that

some 50,000 MWs of coal capacity will be

permanently shut down by the year 2020.

Until this coal capacity is replaced by either

modern GTCC technology or the Wärtsilä

FlexicycleTM

technology, plants such as

Antelope will be used to dispatch power

Fig. 1 – Antelope Station owned by Golden Spread Electric Cooperative (GSEC).

Providing fast wind following response

AUTHORS: Dennis Finn, Business Development Manager, Wär tsi lä Nor th America

Anna Jarowicz, Project Manager, Wär tsi lä Nor th America

Chauncet Thomas, Project Control ler, Wär tsi lä Nor th America

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

27in detail

for an increasing number of hours.

Antelope Station is owned by Golden

Spread Electric Cooperative (GSEC), and

is located in windy and arid West Texas

(Figure 1). GSEC is a consumer-owned

public utility providing power to 16 member

distribution co-operatives that serve more

than 213,000 retail consumers.

West Texas is one of the premier wind

farm locations in the USA. The average wind

farm capability worldwide is in the 40%

range, but some in the West Texas area have

achieved 70% capability rates. Texas also has

a number of older coal fuelled power plants,

so the need for plants like Antelope Station

will continue. Quick-start generation works

well in meeting this type of electric

requirement, while such power plants are

also fuel efficient and use almost no water.

GSEC contracted for the Wärtsilä

equipment in November, 2009, and all

deliveries were completed by November,

2010. The EPC was contracted to The

Industrial Company (TIC), who in turn

entered into a joint venture with Zachary

Engineering for site engineering needs.

This same combination of TIC and Zachary

had previously performed the EPC for the

Plains End Two facility in Colorado.

All contractual dates were met, and

the Antelope Station plant began commercial

operations on June 25, 2011.

Antelope Station consists of eighteen

20-cylinder Wärtsilä 34SG generating sets in

V-configuration operating in simple cycle,

with a gross plant output of 168 MWs.

The major equipment supplied by Wärtsilä,

in addition to the gensets, includes the

medium voltage switchgear, radiators,

controls, and a selective catalytic reactor

(SCR) including an oxidation catalyst.

Due to the high 3350 feet (1020 meters)

elevation, the extreme ambient temperature

ranges from –100 F (-23 C) to +115

0 F (46 C)

locally, and the expectation to deliver full

power to the grid in less than five minutes,

some unique characteristics were included

in the design of the Antelope Station

facility. The high elevation and extremes

of temperature make it a challenge for any

power generating equipment to deliver

maximum output, particularly at the high

end of the temperature range. In order to

maximize the electrical output, GSEC

planned for two different cooling water

mixtures–one for high ambient temperatures,

and the other for low ambient conditions

where freeze protection is needed. This

option maximizes both the output and

the efficiency of the plant across the entire

temperature range. Antelope Station is the

only plant in the US with this capability.

Another unique characteristic is that the

control room is located away from the main

power house. This allows for easy expansion

of the control room and powerhouse, and

is a true modular concept for which

Wärtsilä is recognized.

Performance guarantees included the heat

rate, output, NOx emissions, PM emissions,

CO emissions, and VOC emissions. Another

Wärtsilä commitment was for the facility to

be able to achieve ramp up from shutdown

to full plant output in 5 minutes or less, with

the engine cooling water at 700C, and with

a fuel gas of methane number 80 or higher.

All Wärtsilä performance commitments,

including the 5 minute start-up, have been met.

Another performance characteristic that

is becoming very important is for the SCR

performance to be up to full guaranteed

effectiveness within 30 minutes of the

initiation of a plant start-up. Since many

local regulatory authorities presently have

a 30-minute window to meet emission air

permit limits, the environmental regulatory

agencies will likely reduce this time

Table 1 – Comparison of studies on new EPA regulations – Estimates of forced coal plant retirements.

StudyProjected coal capacity to retire or “at risk”

Criteria to identify coal capacity at risk

Models future revenues from energy and capacity

Models future cost of coal operations?

Distinguish merchant vs. regulated units?

Brattle, November 2010

50–65 GW by 2020

Regulated units: 15-year PV of cost > replacement power cost from a gas CC or CT; Merchant units: 15-year PV of cost > rev-enues from energy and capacity markets

Yes, based on dispatch against projected hourly prices

Yes, based on dispatch against projected hourly prices

Yes

NERC, October 2010

10–35 GW by 2018

Leveled cost @ 2008 CF > cost of re-placement power from a gas CC, or CT

NoNo projections except for future equipment costs

No

ICF, October 2010

75 GW by 2018 Unknown Unknown Unknown Unknown

Credit Suisse, September 2010

60 GWSize and existing controls No No No

ICF/INGAAA, May 2010

50 GW Age, efficiency and existing controls No No No

ICF/EEI, May 2010

25–60 GW by 2015

Cost of retrofitting coal plant compared to cost of new gas CC

Unknown Unknown Yes

Recent studies estimate 10–75 GW coal capacity at risk for retirement.

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Fig. 2 – A block of six engines are at full load output in five minutes or less after start-up.

Fig. 3 – Chart demonstrating full selective catalytic reduction (SCR) performance temperature in 25 minutes from cold start.

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

29in detail

allowance for future air permits. At this site,

a 25-minute time span was achieved with

the 20-cylinder Wärtsilä 34SG generating

sets in V-configuration under the adverse

conditions of a “cold” plant, in that it had

been out of service for three days, and with

low engine exhaust flow because the engine

was loaded to minimum load (40% of full

load rating) rather than being immediately

loaded to full load. This elapsed time was

shorter when the genset was immediately

ramped to 100% load rather than holding

at the minimum load, with time spans of

about 20 minutes.

With its state-of-the-art design, Antelope

Station is well-equipped to meet the current,

as well as the potential, requirements of

power generation. As a US first, it has the

capability to generate full output for

all eighteen engines in less than five minutes,

to firm up wind farms. It meets the strict

emission standards within 30 minutes,

attains full output at extreme temperatures

and high elevation, and can be easily

expanded at any time.

The five minute start-up capability

provided by the Wärtsilä technology, offers

owners the ability to technically control

the stability of their grid system.

The technology also provides great

economic benefits because the US markets

are reducing the clearing time on the

procurement of electricity. Markets are

moving from one-hour ahead procurement,

to 15 minute increments and in the future

will reduce these increments even further.

This means that a plant with the ability to

start and be at full output in five minutes

allows the owner to examine the market,

start up, and sell a 15 minute block of

electricity if the market price is advantageous,

then shut down and wait for the next market

price spike. The Antelope Station facility is

located in the State of Texas where summers

are extremely hot, so commercial and

residential air conditioning loads can spike

very high. In addition, there is a large amount

of agricultural irrigation, which adds a heavy

electrical load to the grid. During the

summer of 2011 there were several days

when the market price, which averages about

USD 50/MWh, spiked to the Electric Reliability

Council of Texas (ERCOT) system imposed

allowable maximum of USD 3000/MWh.

Plants with very fast start capability

responded to these spikes and earned their

owners significant revenues and profits.

Other utilities in Texas have noted the

economic benefit of those plants capable of

Fig. 4 – The SCR units, exhaust silencers, and station transformers at Antelope Station.

achieving a 5 minute start-up, and are in

the process of evaluating adding this type

technology.

Additional benefits of Wärtsilä's

technology are derived from the area that

the US electric industry defines as auxiliary

services. These auxiliary services include up

and down regulating, which is the plant’s

output response to system load changes.

The ability of this technology to change

between the minimum and full load outputs

at a 20%/minute rate when on automatic

dispatch, is superior to that possible by

existing competing plants, and is equal to

the newest simple cycle competing

technologies. A second auxiliary service is

black start capability, meaning the ability

to restart a grid that has blacked out. It is

not to be confused with black starting the

Wärtsilä power plant itself, since this is

a pre-requisite to black starting the grid.

The ability to provide this black start

capability for very little additional power

plant cost makes the Wärtsilä technology a

winner for this auxiliary service. Two other

auxiliary services are ready reserve and

spinning reserve, which the Wärtsilä quick

start capability provides. In the USA, some

markets are changing their old definition of

“spinning reserve” as requiring the power

plant generator to be actually spinning, to a

new definition of being at full plant output

in a specific number of minutes, with 10

minutes being the most common time span.

There is a significant cost benefit to owners

who do not need to be sitting at their

minimum plant load, where the plant heat

rate is at its very highest, but who instead

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can be sitting with power plant shut down

and able to qualify as spinning reserve. The

significance of being able to provide these

auxiliary services is that the plant owner,

in more and more grid systems in the USA,

receives revenues for these services separate

from, and in addition to, the revenues

received for the production of electricity.

The Antelope Station, and the economic

benefits Antelope Station and other similar

new Wärtsilä plants provide, represents

the continuous technology improvement

and market understanding that has been

developed since the first “large” natural

gas (NG) power plant was sold in the USA,

namely the Plains End One facility. Plains

Fig. 6 – Inside the engine hall at Antelope Station. Fig. 7 – The tank farm, which includes lube oil tanks, urea tanks, and cooling water storage tanks.

Fig. 5 – Inside the engine hall at Antelope Station.

End One began commercial operations

in May, 2002 and was really intended as

a pure peaking plant. It was sold based

on price/heat rate/water consumption,

without recognition of the benefits provided

in the areas of quick start and auxiliary

services. Wärtsilä was fortunate that the

Plains End One plant serves the Public

Service Company of Colorado (PSCO) grid,

and that PSCO was initiating a very large

addition of wind power into their system

at about the time that the plant went into

commercial operation. The wind power

coming into the grid caused grid instability,

due to the lack of dispatchability of the

wind, and it was found that the Wärtsilä

Plain End One plant was uniquely capable

of responding to provide grid stability,

even with a 10 minute start. At this same

time, the deregulation of the US electricity

market resulted in the recognition that

auxiliary services, which previously had

been provided by the integrated utilities and

not separately identified or paid for, were

now a missing component of the systems.

This needed to be addressed technically

with revenue accruing to the provider of

these services. Beginning with Plains End

One, Wärtsilä has provided a series of

improved plants to address these issues,

with Golden Spread Electric Cooperative’s

Antelope Station being the most recent

to go into commercial operation.

In part because of the need to replace

the coal plants, which are steadily being

permanently shut down because of

environmental regulations, and also because

of the need to have grid stability with the

increasing use of wind and solar power, the

US market will continue to push natural gas

fuelled power plants toward quicker starting

capability, and lower heat rates at both full

and part loading. Furthermore, the new

plants will need the ability to operate at

least a portion of the power plant generators

in synchronous condensing mode to help

provide grid reactive power requirements.

At the same time, plants with larger output

than Wärtsilä has traditionally provided,

are still wanted. The future market will be

served by Wärtsilä with both the simple

cycle plants similar to Antelope Station,

and by the FlexicycleTM

combined cycle

technologies.

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

31in detail

Fig. 1 – The frequency control of Wärtsilä 34SG engines is fulfilled according to regulations.

Ancillary services crucial for the Turkish gridAUTHOR: Daniel Nylund, Manager, Technology Development , Electr ical & Automation S ervices

High demands are placed on the control of power systems by volatile sources, such as wind and solar power. Changes need to be compensated by other power generation capacity, and ancillary services for securing quality are of increasing importance. Since September 2010, Turkey has been connected to the European grid, and has closely watched the evolvement of the European grid codes. Frequency and voltage control are now mandatory remunerable ancillary services in Turkey.

Ancillary services in the electricity supply

sector can be defined as the set of functions

related to the secure and reliable operation

of a power system. The functions may differ

from country to country, but typically

include:

Frequency control (primary control,

secondary control, tertiary control)

Voltage control

Black start and island operation capability.

Of these, frequency control (active power

control) and voltage control (reactive power

control) have lately taken precedence within

the Turkish power system. Power plants

that have an output exceeding 50 MW are

obliged to participate in primary frequency

control, while power plants of more than

100 MW can participate in secondary

frequency control, which is a commercial

Electricity cannot be stored in an economic way in large quantities. Therefore, the electrical power consumed should at all times equal the electrical power generated.

ancillary service. When it comes to

reactive power control, power plants with

an output of over 30 MW are affected.

Active power control

Active power control is designed to

re-establish the necessary equilibrium

between generation and demand in order to

maintain the frequency of the power system

within admissible bands. Active power

control includes primary, secondary and

tertiary frequency control, all operating

within different time frames.

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Fig. 3 – Primary frequency control curve.

Primary control(automatic)

Pprimary control

Psecondary control

f

Ptie lines

ftarget

Pscheduled tielines

Pscheduled

Ptertiary control

Pdispatched Pwanted Pproduced

fnominal

f–

+

+

+++

+

Secondary control(managed by TSO)

Tertiary control(managed by TSO &generation company)

Governor

GeneratorInterconnected

network

f

Load Frequency

Control

Fig. 4 – Reactive load limiter, technical characteristics.

Primary Frequency Control can be defined

as the automatic increase or decrease of the

output power of a generating unit due to

frequency deviations. Primary frequency

control actions are fast, being measured

in MW/seconds. A generator with Primary

Frequency Control will, under nominal

conditions, run at a slightly reduced output

in order to maintain a buffer of spare

capacity. It will then continually alter its

output on a second-to-second basis

according to the needs of the grid.

Secondary Frequency Control involves

centrally co-ordinated actions to return

frequency to its scheduled value. Secondary

frequency control actions are slower than

primary frequency control actions, and are

measured in MW/min. They are deployed

both during normal operations and after

primary frequency resources have arrested

frequency following major disturbances.

As long as the secondary reserve within

the system is not exhausted, the correct

behaviour of system frequency around the

nominal value is the result of the joint

operation of the primary and secondary

control functions.

Tertiary Frequency Control refers to

manual or automatic changes in the

dispatching and commitment of generating

units. This control is used to restore the

primary and secondary control reserves,

to manage congestion in the transmission

network, and to bring the frequency and

interchanges back to their target values.

It typically enters into action within 15

minutes after a disturbance. Tertiary reserve

is usually provided by non-spinning

generators that can be started and

connected to the grid within 15-20 minutes

after the order is sent.

Reactive Load Control

Reactive load control or voltage control, is

an ancillary service related to the provision

of reactive power to the transmission

network. System voltage levels are directly

related to the availability of reactive power.

If sufficient reactive power resources exist

in the areas where they are needed, system

voltages can be maintained in a reliable

manner. For this purpose, generators adjust

the injection or absorption of reactive

power. This maintains the voltage at the

point of connection to the transmission

grid within admissible bands around the

set point sent by the system operator.

Fig. 2 – Schematic representation of frequency regulation.

Sn= –25%

Pn= 100%

Pn= 30%

P/Sn

Q/Sn-0.2 0.0 0.2 0.4 0.6

1.0

0.8

0.6

0.4

0.2

Reactive load limiterTechnicalcharacteristics

f f

fG fGf0 f0

P (MW)

PGN Pset+ Q

Pset– Q

47.5 49.8 50–f0 50.0 50+f0 50.2 52.0

Pset

f(Hz)

Pset: Set value of unit output power f0: Frequency range where unit control system does not respond to frequency deviations (Dead band, Hz) Q: Primary Frequency Control Reserve Capacity fG: Amount of frequency deviation detected by the unit after dead band f: System frequency deviation amount

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

33in detail

To receive compensation for this ancillary

service, a generation plant has to sign a

reactive power control agreement with

TEİAŞ, the Turkish transmission system

operator. Reactive power remuneration is

based on the lost income caused

by the active power reduction.

The challenge

To be able to provide these services, power

producers need to install additional control

and measurement equipment, and new

functionalities are needed in the automation

system. It is not only functionality for

providing the services that is needed, but

also extensive testing methods need to be

supported. Typically changes are needed in:

PLC software

Automatic Voltage Regulator (AVR)

Power Monitoring Unit (PMU)

WOIS (Wärtsilä Operators Interface System)

Engine speed/load controller.

Additional signals to/from the control

system are also needed for activating

and monitoring the performance of

the generating sets. The monitoring

infrastructure is to be supplied by the power

producer, according to specifications

provided by TEİAŞ. The verification tests

are to be conducted by an accredited

company, and the test results need to be

approved by TEİAŞ.

Since the regulation concerns newbuilds,

as well as existing power plants, Wärtsilä

has developed a solution that is offered to

all new and existing customers. During the

development phase, the work has involved

a large number of people. People from

Wärtsilä Power Plants and Services, both in

Finland and Turkey, have worked together

to create an offering and solution for the

customer. The first field tests were carried

out in September 2011 at Antalya Enerji,

a power plant with six 20-cylinder and

six 16-cylinder Wärtsilä 34SG engines in

V-configuration. The tests were completed

successfully, and the certificates were

issued on 28 September 2011. This was

the first power plant with reciprocating

engines to receive such certification.

Turkey, with about 40 existing Wärtsilä

power plant installations, is an important

market for Wärtsilä. The implementation

of the solution into all installations will be

a great challenge in terms of resources.

Fig. 5 – Tests verify the transfer of reactive power.

DEFINITIONS Overexcited operationLagging operation of the generator to provide reactive power to the grid.

Underexcited operation Leading operation of generator to draw reactive power from the grid.

CONCLUSIONS

The movement towards increased

integration of renewable power sources

in the grid can be seen around the world.

Wind and solar power are highly volatile

in their contribution of power to the grid.

This in turn causes very high demands

on the control of the power systems, and

changes in power generation need to be

quickly compensated by other sources. The

ancillary services for securing the quality

are, therefore, getting more and more

attention. Since September 2010, Turkey

has been connected to the European grid,

and has closely watched the evolvement of

the European grid codes. The grid codes

in Turkey match the European ones in

many aspects, and the Turkish grid is now

implementing items that eventually will

become legally binding also in Europe,

once the network codes are finalised. Grid

codes are getting increased focus all over the

world, but Turkey is, in many aspects, ahead

of the field as regards implementation.

With the solution developed for the

Turkish grid codes, Wärtsilä is in a very

good position to offer a solution to its

customers in those countries still awaiting

changes in the regulation. Even though the

requirements may differ from country to

country, the base solution can be adapted

to fulfil the local requirements.

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Wärtsilä is currently the only supplier able to provide composite technology for both seals and bearings. This technology has been used to enhance marine solutions by providing longer life, easier maintenance and overall added customer value.

Wärtsilä’s seals and bearings business has

always been focused on providing the

appropriate product for the relevant

application requirement. With the ever

increasing demand for higher performance,

high reliability and rapid availability,

the emphasis today is on the further

development of products and solutions

through the use of the latest technologies.

Whilst new and improved material

technology developments can be tailored

to meet the demanding conditions found

within the modern marine propulsion

industry, compliance with all the major

international classification societies is

also critical. Wärtsilä’s composite seal and

bearing technology not only opens up a

new path for the customer, it also provides

a fresh look as to what can be achieved

to meet future operational demands.

Fig. 1 – The Sealift Inc's HSV 2 Swift is fitted with Wärtsilä Jetguard Seal – WFS1R-P-LJ.

New composite seal and bearing technology for better performanceAUTHOR: Andy Ford, Product Manager, S eals and Bearings

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

35in detail

Fig. 2 – The Wärtsilä Jetguard Seal – WFS1R-P-LJ for commercial new build and retrofit applications.

Fig. 3 – The Wärtsilä Enviroguard Seal - WFS1H-P-L for larger vessels in commercial applications.

Critical acquisitions

In order to comply with the vast range of

marine applications, Wärtsilä’s leading edge

global marine technology plays a key role

in the development and improvement of

its seals and bearings related products,

services and solutions. The strategic goal is

to ‘be recognised as the leading seals and

bearings solutions and services provider

in the marine industry’. The following

provides details of how this is achieved.

Wärtsilä has completed some major

acquisitions to aid its seals and bearings

business. These include Deep Sea Seals Ltd

and Japan Marine Technologies Ltd in 2003,

material technology and expertise from

Railko Marine in 2007, and most recently in

2011, Cedervall & Sons. These acquisitions

have added decades of experience and

comprehensive composite test equipment,

along with dedicated material scientists.

Wärtsilä relocated its

composites operations to a dedicated new

facility in Slough, England, and set about

the development of new, high-performance

materials for use in its evolving seals and

bearings portfolio.

New sealing solution launches in 2012

Wärtsilä Jetguard Seal -

waterjet sealing solutions

There are, of course, other water jet sealing

solutions available. However, based on

market feedback received, high quality is

essential, not only to aid extended time

between overhauls, but also to increase

overall in-service operational life. The new

Wärtsilä Jetguard Seal not only meets these

requirements, but is also streets ahead on

customer value.

The Wärtsilä Jetguard Seal design (Figure 2)

is based on the successful Maneguard seal

range. Comprehensive in-house testing has

proven its features by operating superbly

thoughout the arduous conditions that may

be encountered by water jets on shaft sizes

up to 410mm. To comply with high RPM and

possible negative water pressure differentials,

the water flush on the Wärtsilä Jetguard Seal

is directed effectively towards the seal

interfaces. The interfaces are made of Silicon

Carbide (SiC) to provide extended life, even

in abrasive laden waters. The seal has been

specifically designed with composite

components and offers a simple, lightweight,

corrosion free and cost effective solution.

Being a partially split design with an inflatable

seal, it also enables all wearing components

to be maintained without shaft removal.

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The Wärtsilä Jetguard Seal is now

specified as the first choice for the Wärtsilä

Midsize Waterjet range. Over the next four

years, it is expected that Wärtsilä jets alone

will account for some 300 new installations.

With an impressive fitted list for various

vessel types, the composite Wärtsilä Jetguard

Seal is likely to become and remain a leader

within the waterjet market.

The Sealift Inc's HSV-2 Swift, the wave-

piercing, aluminium-hulled, commercial

catamaran, is the most recent pilot vessel for

the Wärtsilä Jetguard Seal to date. The trials

have run very successfully under extreme

operating conditions.

Wärtsilä Enviroguard Seal

– water lubricated sterntube

(large size range) solutions

The new Wärtsilä Enviroguard Seal has

been specifically developed for the

commercial propulsion market to provide

a competitive high end product. Primarily

aimed at larger shaft sizes (Ø460-Ø820mm),

it is suitable for both open and closed water

sterntube system applications. As with

the Wärtsilä Jetguard Seal, the composite

material not only complies with long life/

reduced corrosion requirements, it is also

extremely easy to install due to its light

weight. In addition to the introduction

of composite housings, the new sealing

interface combination of advanced

composite running against phosphor bronze

has proven to be highly resistant to abrasive

conditions during in-house tests carried out

by the seals and bearings development team.

Highly abrasive water conditions were tested

for 1400 hours, using maximum pressure

and a maximum seal compression state (in

accordance with ‘Identification of levels and

composition of particulate contamination

in sea water samples by M.R.O. Hargreaves,

Tech Memo Nav Eng 1019 (M) (1983),

Royal Aircraft Establishment West

Drayton’). Results confirmed a perfect

trial with zero interface wear, the ability

to run up to 150 rpm (depending on shaft

size), and increased axial capability for

large shaft movements or the thermal

expansion of interfacing equipment. The

composite Wärtsilä Enviroguard Seal is

also equipped with an inflatable seal to

enable overhaul of the seal while afloat.

General features and benefits of Wärtsilä

composite seal technology include:

“Hard” sealing contact materials

(face and seat) are selected for their

suitability for a water lubricated

application where abrasives are

frequently present

Closing force at the face is generated by

an elastomeric element or helical springs.

Can accommodate large and

repeated shaft movements

The seal is “pressure balanced” so that

changing draft will automatically

adjust the closing force to an ideal value

Static Inflatable seal - activated to allow

maintenance of the seal without

dry docking

Composite material prevents galvanic

corrosion

Simple lightweight installation

No shaft / sleeve wear

Proven capability in aggressive

environments

Vibration-tolerant

Long lasting - 15 years +

In-house production method enables

quick turnaround.

Composite bearing solutions

Wärtsilä composite bearings cover both

oil and water lubricated applications. Since

2006, more than 1300 Wärtsilä composite

bearing installations have been carried out.

Wärtsilä’s seals and bearings development

team is constantly aiming to improve its

products and materials via ongoing testing

and validation trials. All of this is for one

goal; superior product performance that

meets the market need.

One such development is the new

composite bearing material, Envirosafe

- launched for pilots in 2011.

Envirosafe - water lubricated composite

bearing sterntube solution

Installing a water lubricated composite

bearing seal system not only eliminates the

environmental impact from the propulsion

shaft line, it also brings other benefits.

Composite materials are non-metallic and

have been specially designed to cope with

extreme operating conditions, such as high

loads, speeds, temperature fluctuations

Fig. 4 – The Wärtsilä Envirosafe Composite Bearing - WCS for commercial and military applications.

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

37in detail

and dirty conditions. Depending on the

application and grade, composite materials

can operate dry, partially lubricated, or fully

lubricated in oil or water (even emulsified).

This is clearly demonstrated with Wärtsilä’s

new water lubricated propeller shaft

bearing solution. It fits both new build and

retrofit applications, and is particularly

suited to naval and other ocean going

vessels, as well as offshore installations.

The Envirosafe water lubricated bearing is

Property Envirosafe Polyester nylon laminate

Compressive Strength (MPa) ISO 604 (Radial) 120 180

Compressive Modulus (MPa) ISO 604 (Radial) 1400 4100

Swell (water @ ambient temp) RTM 307 0.2% 1.0%

Thermal expansion (x10-5 / oC) ASTM E-831 (Radial) 2.0 6.0

Maximum Operating Temperature (oC) 150 80

Table 1 – Material properties of Envirosafe vs. superseded material.

Fig. 5 – Hydrodynamic test results of the new material.

based upon Wärtsilä core technologies that

enable the thermosetting of cresylic resin

together with filament winding to produce

a material that runs on a water equivalent to

oil/white metal combination. Compared to

existing alternatives, the new material has

improved the stability and hydrodynamic

running capabilities. It already has class

approval for ABS, LR and DNV, and is

available in various split & un-split

configurations based on in-situ serviceability

requirements for both commercial and

military applications. Scopes of supply also

vary from raw billet through to fully

machined assemblies, including housings.

The material properties compared to

the former polyester/nylon laminated

material, can be seen in the table below:

Continued development, validation, and

testing has been carried out within Wärtsilä’s

comprehensive bearing test facility to

improve the Envirosafe material, and to

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0

Co

eff

icie

nt

of f

ric

tio

n

-10 10 30 50 70 90 110 130 150

rpm

Test 1

Test 2

Test 3

Test 4

Envirosafe Bearing 6 bar bearing pressure, 2:1 L:D ratio bronze (LG4) shaft

Reducing coeff

Full hydrodynamic operation

Hydrodynamic operation begins

Quicker hydrodynamic operation after each test using the same bearing material

Improved operation after each test

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certify its performance advantages over

currently available bearings. Each trial

carried out has demonstrated excellent

performance, with hydrodynamic operation

and extremely low wear being achieved at

very low shaft speeds. During trials, four

separate tests were carried out starting from

a max of 200 rpm, and reducing for each

test. Figure 5 illustrates how improved

Fig. 6 – Envirosafe bearing wear after 1000 (of total 2000) hours in gritted seawater.

Fig. 7 – Envirosafe bearing wear and shaft wear test results after 2000 hrs.

hydrodynamic operation is achieved after

re-testing the same material in each case.

Wear testing

In order to compare the wear (and therefore

establish the life) of the new material against

those in current use, an arduous test

programme was undertaken on the Wärtsilä

test rig. The performance of various bearing

materials was analysed. The tests were

undertaken in highly abrasive (silica) loaded

sea water conditions against stainless steel.

As can be seen from the results shown in

Figure 6, initially the rubber material

performance was similar to that of the

polyester/nylon and Envirosafe composite.

However, over time the wear rate increased

rapidly resulting in the test on the rubber

0.60

0.50

0.40

0.30

0.20

0.10

0.00

We

ar

in m

m (D

TI)

0 200 400 600 800 1000 1200

Test duration in hours

Journal wear tests in simulated coastal seawater5 bar pressure - 50 rpm - stainless steel shafting

Previous material

Rubber

Envirosafe

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

39in detail

material having to be terminated at around

850 hours.

The Envirosafe material exhibited a more

linear (steady state) wear result. The test in

this case was continued to 2000 hours.

The bearing was still capable of further

operation. It is worth noting that the new

bearing took almost four times as long to

reach the same wear down level as the

rubber bearing.

Figure 7 shows that the condition of the

shaft sleeve was not heavily worn. As the new

material is relatively harder than rubber, the

material does not allow abrasive particles to

embed in its surface, therefore maintaining

a hydrodynamic water film and greatly

increasing both bearing and shaft sleeve life.

Based upon the test work completed,

Envirosafe has demonstrated

Consistent and predictable

hydrodynamic performance improves

over time.

Potentially increased bearing service

life and longer docking cycles.

Improved wear in abrasive water

conditions when compared to

competitive materials

Fig. 8 – Wärtsilä composite bearing installations by operating segment.

Reduced shaft removal requirements.

Potential reduction in total ownership

costs.

Operational capability on multiple

shaft liner materials.

Lower thermal expansion than

predecessor material

(reduced by 3 times).

Good thermal stability (up to 150°C).

Lower swell factor (up to 5 times lower

than competitors).

Low risk (may be run dry).

Classification Society approvals from

major societies

Composite technology does not only exist

in water lubricated applications. The Wärtsilä

portfolio also includes Sternsafe and

Steersafe, specifically developed for oil

lubricated sterntubes and rudder bearing

systems with various lubricated

requirements.

The development programme undertaken

by Wärtsilä in utilizing modern technology

and new materials to improve seal and

bearing performance is ongoing. It mirrors

similar work going on throughout the

company’s R&D organisation to find ways

of increasing operational efficiency and

reducing costs for its customers, and is part

of the company’s overall policy of being

a total solutions provider to the marine

and offshore industries.

45%

8%8%

7%

7%

25%

Merchant

Cruise & FerrySpecial Vessel

Other

Navy

Offshore

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Wärtsilä has developed a platform supply vessel design which achieves the highest possible Environmental Regularity Number (ERN) score without increasing the installed engine power. Benefits for ship owners and operators include fuel savings and lower levels of emissions as a result of reduced losses in the vessel’s electrical system, improved dynamic positioning capability in both normal and failure scenarios, reduced weight and space requirements, and increased levels of safety for crew members.

To avoid the occurrence of rig impacts in

operations in the offshore sector, as well

as other similar incidents resulting from

loss of the propulsion power required to

maintain station, conventional marine

power-supply configurations in offshore

vessels equipped with dynamic positioning

(DP) systems consist of a split main

switchboard divided by bus tie breakers.

In the worst single failure condition,

shown in Figure 2 - failure of Bus A - two

out of the vessel’s four gensets have become

unavailable and power to all thrusters and

the propulsion system on the faulty side of

the main 690V switchboard has been lost.

Power for all systems connected to the 450V

and 230V switchboards on the faulty side

has also been lost.

Low Loss Concept – a unique solution

In Wärtsilä’s patented Low Loss

Concept (LLC) system (Figure 3), the

main switchboard is constructed with

four separate sections, each of which is

connected to the output of one genset.

Thrusters are connected to the four

switchboard sections in such a way that

each drive is fed by two gensets. Using this

Fig. 1 – The Wärtsilä VS PSV 485 MKIII design platform supply vessel features the Wärtsilä Low Loss Concept solution.

Wärtsilä LLC helps achieve highest possible ERN numberAUTHORS: Inge Skaar, Director, Project Development and Naval Architecture, Wär tsi lä Ship Design

Kjell Angeltveit, Global Discipl ine Leader Electr ic and Automation, Wär tsi lä Ship Design

Margareth Urheim, Naval Architect , Hydrodynamics, Wär tsi lä Ship Design

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

41in detail

configuration, even if one main switchboard

section fails completely, the thrusters can be

driven using just a single supply. While this

feature makes the LLC solution unique, other

subsidiary and auxiliary systems installed

in the vessel have to be constructed in the

correct way, a Wärtsilä design speciality.

Even with the loss of one genset, the

sophisticated construction techniques

employed in LLC and Wärtsilä’s frequency

drive systems allow thrusters or other

propulsion systems to be driven while the

450 V or 230 V switchboard sections remain

available. A figure of 99 for the “d” element

in the vessel’s ERN is therefore possible. This

condition is shown in Figure 3. While engine

auxiliary systems are designed to meet the

demands for higher levels of redundancy, no

increase in the size of either gensets or

thrusters is required, and in some cases they

can even be smaller.

Achieving the same ERN with conventional technology

To achieve the same ERN number for worst

single failure in a conventional system, the

vessel’s two forward tunnel thrusters would

have to be more than doubled in size from

1000 kW to 2100 kW. Each of the four

gensets would also need to be approximately

40% larger, with outputs of 2440 kWe rather

than 1580 kWe. This configuration is

shown in Figure 4.

The need to increase genset output and

thruster size results in a heavier and more

expensive configuration, which is more

costly to operate. On the electrical side,

the additional power demand could mean

that a high-voltage system, rather than

Fig. 2 – Conventional switchboard failure.

1580

kWe

1580

kWe

1580

kWe

1580

kWe

Bus A

(port)

TT FWD 11000 KW

PROPULSION PS

2300KW

AZIMUTH FWD

880 KW

PROPULSION SB

2300KW

TT FWD 2 1000KW

Bus B

(STBD)

690kV / 60Hz

G1

MM

MM

M

G3G2 G4

One of the two main switchboard sections and two generators, TT FWD 1, PROPULSION PS and AZIMUTH FWD are unavailable in worst single failure.

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a low-voltage one, could be required.

As well as restricting access to the vessel’s

power plant - personnel with the training

required to operate such systems are hard to

find - other possible consequences of having

to install larger gensets and thrusters include

increased initial levels of investment,

increased operating costs, and the need

to provide more space for generating

equipment and power transformers.

Improved station-keeping capability

The Wärtsilä VS 485 PSV MKIII vessel

design features the Wärtsilä LLC solution

with the gensets and thrusters shown in

Figure 3, giving an ERN of 99,99,99,99.

If this vessel was equipped with the

conventional switchboard solution

shown in Figure 2, it would have an ERN

of 99,99,99,55. To achieve the highest-

possible ERN of 99,99,99,99 with a

conventional switchboard solution, the

gensets and thrusters would have to be

significantly larger and heavier, would

cost more and would occupy additional

space. This option is shown in Figure 4.

Although DNV’s ERN is one way of

defining a vessel’s ability to maintain

its station in different weather and sea

conditions, another way of doing this is

to use a DP capability plot. Three DP plots

are shown in Figure 5. The green envelope

represents the Wärtsilä LLC solution when

one switchboard has failed (Bus A1 out of

operation) as is shown in Figure 3. The blue

envelope in Figure 5 also represents the

Wärtsilä LLC solution, but in the case where

the most important thruster - the forward

tunnel thruster - has failed.

While both these failure cases result in

an ERN with 99 for the “d” element, i.e.

the highest possible result, the blue envelope

shows that losing the forward tunnel thruster

results in a lower DP capability than the

loss of one of the vessel’s four switchboards.

This means that for the Wärtsilä LLC

solution on this vessel, the worst single

failure condition (and the condition that

yields the fourth ERN number) involves

the loss of this propulsion device.

Wärtsilä LLC solutions offer many benefits

The red envelope in Figure 5 represents

the conventional switchboard solution

when one of the vessel’s switchboards has

failed (Bus A is out), with the loss of the

forward tunnel thruster, main propulsion

on the port side, and also the forward

azimuth thruster. The red envelope is also

a clear demonstration that DP capability

in the worst single failure condition in

a vessel equipped with a conventional

switchboard solution is much lower than

in a vessel equipped with the Wärtsilä

LLC solution, as this enables all thrusters

and gensets to remain available.

Fig. 3 – Switchboard failure with the Wärtsilä Low Loss Concept.

W9L20

1580 kWe

W9L20

1580 kWe

W9L20

1580 kWe

W9L20

1580 kWe

LLC Unit1600 kVA LLC Unit

1600 kVABus A1

690V/ 60Hz Bus Link

Bus A1

Bus A2 Bus A2

G G G G

TT FWD 1 1000kW

PROPULSION PS

2300kW FWD AZIMUTH

880kW

PROPULSION SB

2300kW

TT FWD 21000kW

M M

M

M M

One of the four main switchboard sections and one generator are unavailable in worst single failure. All thrust-ers and the remaining three generators are still available.

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

43in detail

In addition to offering ship owners and

operators higher levels of redundancy and

safer operation, offshore service vessels

equipped with sophisticated Wärtsilä

LLC solutions are able to operate in harsh

conditions with less installed power. LLC

transformers add impedance to onboard

power distribution arrangements, and

short-circuit currents are therefore

reduced, thus improving safety levels.

Overall power levels also mean that

engines will be running at higher loads and

correspondingly higher levels of efficiency.

Vessels equipped with Wärtsilä LLC also

have increased operational flexibility as

gensets can be taken out of service, thereby

reducing accumulated running hours

and associated maintenance costs.

Fig. 4 – Conventional solution with larger generating sets and thrusters.

Fig. 5 – Alternative Dynamic Positioning (DP) plots.

LLC – Bus A1 out

– Wind [knots]

LLC – FWD Tunnel out

– Wind [knots]

Conv – Bus A out

– Wind [knots]

2440 kWe

Bus A

(port)

TT FWD 12100 KW

AZIMUTH FWD

880 KW

PROPULSION SB 2300KW

TT FWD 2 2100KW

PROPULSION PS 2300KW

Bus B

(STBD)

690kV / 60Hz

2440 kWe

2440 kWe

2440 kWe

Forward tunnel thrusters and all generators/engines for conventional solution must increase power to comply with same DP plot as for LLC in worst single failure.

G1

MM

MM

M

G3G2 G4

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Environmental Regularity Number (ERN)Defining a vessel’s ability to maintain its position

Developed in the 1970s by Det Norske

Veritas (DNV), the Environmental

Regularity Number (ERN, also ern) is

a theoretical way of defining a vessel’s

ability to maintain its position in different

weather and sea conditions. As only

lateral forces are involved - wind, waves

and current come in on the beam - the

calculations involved are relatively simple.

The ERN consists of four groups of

integers, each of which is stated by

DNV to reflect “the probable regularity

for keeping position in a defined area”.

The format of an ERN is a series of four

numbers ranging from 0 to 99. ERNs are

stated in shipping registers in the form

ern (a, b, c, d), in which a represents the

optimal use of all thrusters, b represents

the minimum effect of a single-thruster

failure, c represents the maximum

effect of a single-thruster failure, and

d represents the effect of the worst-

case single failure(s). In a guidance

note, DNV says: “The fourth number

d shall represent the case where stop

of the redundancy group resulting in

the largest reduction of position and

heading keeping has occurred. (106)”

In practical terms, a represents the

probability that a vessel will be able to

maintain a required position at a certain

location in the North Sea when all its

systems are fully operational, b indicates

the probability that it will be able to

maintain its desired position if the least-

effective thruster fails, c indicates the

probability that it will be able to maintain

position if the most-effective thruster

fails, and d indicates the probability

that it will be able to maintain position

in the worst-case single failure. The

highest possible ERN rating - a score of

99 for a, b, c and d - is 99.99.99.99.

Assumptions during calculation

ERN calculations assume that the forces

resulting from wind, waves and current

are coincident, with the magnitudes of

wind and waves being of equal probability

(103), and are intended to reflect a ‘worst-

case situation’. For monohulls, a guidance

note by DNV says this is normally when

the weather is on the vessel’s beam (104),

and the ERN is based on this situation

“regardless of the vessel’s ability to select

other headings in operation. (104)”

Current is assumed to have a

constant value of 0.75 m/s without

differentiation into wind-induced and

tidal components. ERNs are evaluated

at the incidence angle of forces causing

the maximum load on the vessel (104),

and for a balance of forces while the

vessel is maintaining both position and

heading (105). According to DNV: “Thus

there shall at the same time be a balance

of forces and a balance of moments,

i.e. including all moments generated

by the thrusters, and those caused by

environmental forces” (105). DNV also

states “The ERN shall be based upon the

thrust output that is under control, in

the most efficient control mode. (107)”

Note: The reference numbers above

are as given in Section 7 of the DNV

publication Rules for classification

of Ships, Part 6 Chapter 7, Dynamic

Positioning Systems, July 2011, including

amendments made in January 2012.

DET NORSKE VERITAS (DNV) is an

autonomous and independent foundation

with the objectives of safeguarding

life, property and the environment,

at sea and onshore. DNV undertakes

classification, certification, and other

verification and consultancy services

relating to quality of ships, offshore

units and installations, and onshore

industries worldwide, and carries out

research in relation to these functions.

Wärtsilä LLC is a fresh approach

to supplying power to the variable

frequency drives used in electric

propulsion systems in marine

applications. In addition to energy-

efficient power distribution, it offers

high levels of redundancy.

Featuring a transformerless design,

the benefits of LLC include superb

system availability. All power applications

between 5 MW and 70 MW are covered

in both the low-voltage and medium-

voltage versions, and LLC is particularly

effective in vessels such as OSVs, whose

operating profiles require variable speeds

and dynamic positioning capabilities.

Low-voltage LLC systems have already

been installed on approximately

100 vessels and medium-voltage

installations are in the pipeline.

The invention on which the Wärtsilä

LLC is based was made in 2003. The first

complete LLC system was delivered in

2004 and installed on the ‘Normand

Skipper’, a platform supply vessel. The

main patent for LLC was granted in

2006, and patents have subsequently

been obtained by Wärtsilä for both

the Quattro LLC design and for LLC

in medium-voltage applications.

Saving weight and offering higher levels of efficiency

Traditional solutions for electrical vessel

propulsion systems consist of two or

more propulsion units - a number

of generating sets and a drive system

consisting of a propulsion transformer, a

frequency converter for speed control,

and a propeller system. The transformers

in such systems are heavy and occupy

significant amounts of space, and

platform supply vessels of medium

size employ at least four propulsion

units, sometimes as many as seven.

LLC eliminates the need for propulsion

transformers by allowing genset power

to be applied directly to the frequency

The Wärtsilä

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

45in detail

Low Loss Concept (LLC)converters used for speed control.

This approach means that system efficiency

is 2-4% higher than in traditional

transformer-based systems, in which each

propulsion unit consists of a propulsion

transformer, a frequency converter for

speed control and a thruster unit. In LLC,

current levels supplied to the frequency

converters from the switchboards are 10%

lower than in conventional solutions, and

the transformers required are also smaller

and lighter.

Low levels of total harmonic distortion, fuel savings and weight reductions

The LLC solution employs transformers

in which the main windings are phase

shifted by 30º to cancel the 5th and 7th

harmonic currents introduced into the

network by rectifying bridges. The bridges

are supplied from the two phase-shifted

sides of the LLC transformer, with each

side providing 50% of the required power.

An LC (tuned circuit) filter combined with

a filter winding in the LLC transformer

results in total harmonic distortion (THD)

of less than 5%, and the majority of the

harmonic currents pass through the

transformer, not through the generators.

This also means that LLC transformers

can be smaller and lighter than those

employed in conventional power-supply

configurations.

Lower electrical losses in the system result

in better fuel economy, thereby reducing

the overall levels of emissions, and the

need for auxiliary systems. Depending

on the type of vessel and its operational

profile, the reduction in electrical

losses can yield annual fuel savings of

between EUR 30,000 and EUR 100,000.

In traditional systems, the use of low-

voltage components is restricted to

applications with a maximum of around

10 MW installed propulsion power. By

using LLC, propulsion systems can be

designed for higher installed power using

low-voltage (690 V) components, reducing

equipment weight and saving valuable

space. In some applications, weight

reductions of 35-40% can be achieved.

A wider range of potential applications with Quattro LLC

Quattro LLC extends the range of

applications for the LLC concept. Four

LLC transformers connected in a ring

configuration maintain a constant

30º phase difference between the

electrical distribution bus bars.

While Quattro LLC was originally

designed for medium-voltage power

distribution, it extends the low-voltage

power range up to a total of 20 MW

propulsion power. Components for

low-voltage power distribution are

significantly cheaper than medium-

voltage components and crew training

is less costly. There is also a shortage

of personnel trained to operate

medium-voltage equipment.

With medium-voltage components

(6600 V), installed propulsion power

using traditional design configurations

can be in the range 30-40 MW. LLC

enables the use of standard medium-

voltage components in large vessels and

offshore platform applications equipped

with up to 70 MW of installed power.

Advantages of the Wärtsilä LLC concept

1. Reduced losses in the vessel’s electrical system (15-20%) result in fuel savings and lower levels of emissions.

2. Higher levels of availability when a major failure occurs increases thruster robustness.

3. Less-severe consequences in the worst single failure case mean that LLC solutions offers improved DP capability.

4. Increased operational flexibility and availability through a segregated, two-section switchboard and bus connections via buslinks.

5. Significant increase in levels of personnel safety because of the reduced likelihood of short circuits.

6. No inrush current at thruster start-up as the transformers are always energised.

7. Reduced weight and space requirements as the usual thruster transformers are not required.

8. Additional flexibility in vessel design as the LLC phase-shift transformers do not need to be located close to the electric drives

for which they provide power. They also feature secondary windings which can be used to supply some of the vessel’s auxiliary

power requirements.

9. More efficient power distribution in damage scenarios.

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SOURCE DOCUMENTS:

• Rules for classification of Ships, Part 6 Chapter 7, Dynamic Positioning Systems, July 2011, including amendments made in January 2012

(http://exchange.dnv.com/publishing/RulesShip/2012-01/ts607.pdf)

• Station Keeping Criteria for DP Vessels.pdf ( http://www.dynamic-positioning.com/dp2004/design_ubisch.pdf)

• Low Loss Concept Comparison Study 2010.pdf ( http://www.dynamic-positioning.com/dp2010/newapps_vankeep.pdf)

Assessing station-keeping capability in vessels with DP systems

Analysis procedure

Steps involved in analysing the station-keeping capability typically involve:

1. Defining the operating environment and vessel heading

2. Calculating the global surge, sway and yaw loads due to wind, waves and currents

3. Determining the required output of each installed thruster based on appropriate thruster allocation algorithms

4. Determining the available thrust from each thruster

5. Calculating the total available thrust and comparing this to the global environmental load. For the intact condition,

the global environmental load must be less than, or equal to, 80% of available thrust. For the damage condition,

the global environmental load must be less then 100% of the available thrust.

6. Repeating the above for different headings and/or operating environments.

Dynamic positioning (DP) systems are

designed to maintain vessel position

within an acceptable watch circle under

defined operating environments. In

practical terms, this means countering

mean environmental loads and

dampening out low-frequency surge and

sway motions, reducing the likelihood

of unplanned impacts with stationary

installations such as drilling rigs or

other offshore oil and gas facilities.

Vessel station-keeping characteristics

are usually presented using capability

plots - polar diagrams in which envelopes

depict a vessel’s ability to maintain its

position in a specific environment with

a particular combination of thrusters.

The grid on which the plots are

displayed indicates wind speed. The

speed of the current is usually fixed,

as is the relationship between wind

speed and wave height - wind speed

is the easiest parameter to measure.

Each plot depicts the vessel’s ability

to withstand wind speeds from

different headings, coupled with a

defined current and waves of height

determined by the wind speed. All

three environmental forces normally

act on the vessel in the same direction.

Calculations carried out to obtain each

capability plot include: the effect of wind

forces acting on the vessel; the effect of

wave drift forces and current drag forces;

and propeller, rudder and thruster

efficiencies in different directions.

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

47in detail

Blending on Board (BOB) is a new concept developed by Maersk Fluid Technology Inc with whom Wärtsilä has a co-operation agreement for the joint marketing and sales of the system. BOB optimises the overall lubrication performance of large bore diesel engines. It also enhances operational flexibility and independency.

Traditional cylinder and engine lubrication

Two-stroke cross-head diesel engines

typically use at least two different oils

besides the fuel oil: the general system

oil, which serves as the lubricating and

cooling oil for engine components; the

special cylinder lubricating oil, which

lubricates the piston ring/cylinder liner

contact; and the servo oil, which in Wärtsilä

two-stroke engines is the system oil.

The cylinder lubricating oil is

specially formulated with additives

to fulfil three main purposes:

To create a sufficient oil film between

the running surfaces of the cylinder liner

and the piston rings to minimize friction

and wear of the components

To clean the piston, piston rings, and

cylinder liner from deposits, which is

achieved by the special detergency and

dispersancy properties of the additives

To prevent cold corrosion by

neutralizing the acidic species created

during engine operation. The main acid

to be neutralized is the sulphuric acid

produced from the sulphur content

of the fuel burnt in the engine.

Cylinder lubricating oil is injected into

the cylinder via the cylinder lubrication

system (on Wärtsilä two-stroke engines,

e.g. the CLU-3 or the Pulse Lubrication

System). The cylinder lubricating oil and

system oil are separated in two-stroke

cross-head engines by stuffing boxes.

The system oil usually remains for a long

time in the engine as it is consumed in only

relatively small quantities. During

Blending on Board – innovative engine lubrication management AUTHORS: Shamba Jumaine, Tribology Exper t 2-stroke, S ervices Del ivery Management

Markus Zehnder, Innovation Manager 2-stroke, S ervices S olution Management

Andreas Wiesmann, GM Innovation & Business Development , S ervices S olut ion Management

Phot

o: C

ourt

esy

of M

aers

k Li

ne.

Fig. 1 – The Maersk Line's container vessel EDITH MÆRSK with a 14-cylinder Wärtsilä RT-flex96C main engine will be fitted with Blending on Board in 2012.

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High sulphur fuel, harsh operating

conditions, and long-term low or ultra-low

load operation require increased cylinder oil

performance for neutralisation, detergency

and dispersancy. Extended engine operation

with very low sulphur fuel, MDO or MGO,

is also required.

Operators usually address these conflicting

requirements by using two different cylinder

oils (typically 40BN and 70BN) – sometimes

also with a new in-between BN cylinder oil

(typically in the range of 55-60BN) – and

a sulphur dependent feed rate adjustment

according to the engine manufacturer’s

recommendation. This enables them to cope

with the variability of the fuel’s sulphur

content, in particular in reduced engine load

operation.

These traditional measures are working

compromises for operating engines under

more or less normal conditions, and in

combination with heavy fuel oils having

sulphur contents of between 0.8% and 3.5%.

The Blending on Board concept

Looking at the main purposes of cylinder

operation, depending on the condition

and wear of the components, the oil loses

its initial properties and cleanliness. Even

though the oil consumption through the

stuffing boxes, as well as from leakages and

during oil separation is small, topping up of

the system oil sump, and in certain cases

a complete oil change, is necessary due to

the ageing of the oil. Depending on

the condition of the engine and the oil

treatment plant, the daily system oil

consumption is between a few litres and

approximately ten litres per cylinder.

Depending on the engine type, design,

and cylinder lubricating system type, the

recommended feed rate for Wärtsilä two

stroke engines under normal engine operating

conditions is between 0.8 and 1.1 g/kWh at

CMCR. For the latest engine type additions in

the portfolio, this feed rate will be further

reduced.

In order to match the properties of the

commercially available cylinder oil with the

sulphur content (S%) of the currently used

heavy fuel oil, Wärtsilä recommends in its

engine operating instructions that oils with

BN70 for sulphur contents >1.5% and BN40

for sulphur contents <1.5%, be used. In

addition to these standard oils, other oils

with BN levels between BN40 and BN70 are

available on the market.

When engines are continuously operated

at lower loads below 60% contracted

maximum continuous rating (CMCR),

and with fuels having high sulphur content

(e.g. sulphur content higher than 3% in

the HFO with a 70 BN lubricant), the

neutralisation performance of the standard

cylinder lubricating oil is not sufficient at

the same low feed rate. For this reason,

Wärtsilä recently recommended feed rate

adjustments for different combinations

of lubricating oil BN levels and fuel

sulphur content. A Technical Bulletin (TB

RT-113) was published to communicate

this recommendation to customers.

Requirements for flexible operation

Today’s requirements in shipping often call

for the vessel’s main engine to have highly

flexible operation capabilities, while at the

same time maintaining high reliability.

Versatility, in terms of the engine’s operational

load and different fuel oil qualities, is of

paramount importance for operational costs.

Furthermore, constraints related to Emission

Control Areas and new fuel regulations call

for more cylinder lubrication adaptability

to ensure reliable piston running.

lubrication – building an optimal oil film

for piston running, neutralising sulphuric

acid from fuel combustion, and cleaning –

a better alternative (both technically and

commercially) to the traditional measures

would be to maintain the cylinder oil

feed rate at the most optimal level under

almost all operational conditions, while

simultaneously adjusting the cylinder

oil’s properties to the actual conditions.

This is exactly what is achieved with the

innovative Blending on Board concept. It

provides a unique, flexible solution to these

challenging requirements. The concept is

to keep the cylinder oil feed rate constantly

low while adjusting the concentration of the

additives in the oil. This results in a wide

base number range from 40BN to 120BN.

Furthermore, it is adapted to the actual

heavy fuel oil sulphur content, to other

fuel types used in relation to the relevant

regulations, and to the engine load pattern.

With a Blending on Board installation,

the used system oil is transferred from

the main engine, and optionally also the

auxiliary engines (up to 10% of the total

2

1.8

1.6

1.4

1.2

1

0.8

0.6

0.4

0.2

0

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

Sulphur content in HFO (%)

LO

FR

(g

/kW

h)

BN 40

1

5

2

34

BN 50BN 60 BN 70

1. BN 40 curve

2. BN 50 curve

3. BN 60 curve

4. BN 70 curve

5. Sulphur break point

Fig. 2 – Recommended feedrate adjustments at loads <60%, based on fuel sulphur content (S%) and cylinder oil in use.

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

49in detail

used oil volume), and is then blended

with a specially formulated cylinder oil

additive. The result is customized cylinder

oil for each vessel’s specific operating

conditions, thus reducing a vessel’s lube

oil consumption by 10%-50%, depending

on the currently used feed rate. With the

now frequent transfer of system oil to the

blender, the vessel is able to replenish the

engine sump with fresh oil, without any

waste oil disposal, which results in a cleaner

engine and better engine performance.

Installing the Blending on Board system

The solution has been designed in a

modular way in order to allow easy

installation. The BOB system consists of

a blender with a blender control panel, and

an XRF analyzer (either with or without

the ability to detect cat fines).

The product names are:

SEA-Mate® Blender B3000

SEA-Mate® Analyzer M2000

(without cat fines detection)

SEA-Mate® Analyzer M3000

(with cat fines detection)

The system is compact enough to be

transported through a normal door. Some

modifications to the existing piping and

tank allocation are necessary, but no new

tank installations are required. The Blending

on Board system is ABS and Lloyds

Register approved.

The SEA-Mate® Blender is a compact,

robust, reliable and easy-to-use piece of

equipment, designed to fit an engine room’s

environment. It is connected to the “Used

System Oil Tank for BOB” and the “Additives

Tank” on one side, and the “Blended Cylinder

Oil Tank” and/or “Day Tank” on the other side.

The operator onboard enters the following

values on the screen of the blender control

panel:

The used system oil’s BN level – this can

be determined beforehand from

the Analyzer

The additive’s BN level – this needs to be

entered just once at the beginning, unless

a different additive product is purchased

at a later stage

The target BN level for the new batch of

blended cylinder oil – the value can be

determined from Blending on Board

instructions (and in the future will be

an integrated function in the blender

control panel)

The amount in tonnes for the new batch

of blended cylinder oil.

120

110

100

90

80

70

60

50

40

30

20

10

00.5 1 1.5 2 2.5 3 3.5 4 4.5

Ble

nd

ed

oil

BN

HFO S% content

Fig. 4 – Target BN levels for the blended cylinder oil for different fuel S%.

Fig. 3 – SEA-Mate® Blender B3000.

The cylinder lubricating oil is blended from used system oil and additives for achieving the required BN level and oil properties.

The product is based on a blender and an analyzer, which are installed onboard the vessel.

Some modifications to the existing piping and tank allocation will be necessary.

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After pushing the “Start” button, the blender

completes the required blending on its

own. Optionally, the operator can also

set the blender operation on automatic,

which will repeat the blending process with

the set values, once the blended cylinder

oil tank reaches a set minimum level.

The SEA-Mate® Blender B3000 is equipped

with all class-required features for safe

maritime operation.

The SEA-Mate® Analyzer is an integrated

part of the Blending on Board installation.

It is an advanced XRF technology based

analyzer that provides state-of-the-art

onboard or on site analysis capability for

lubricants and fuels. It also provides

the operator with a whole new level of

awareness and knowledge regarding the

importance of lubrication oil, engine

condition and monitoring. It is designed in

a robust way, gives the user clear on-screen

guidance and instructions, and provides

analysis results within only six minutes.

The analyzer is supplied together with

a bar-code reader and all required sample

bottles and bar-code labels for sampling

locations and bottles. This enables the easy

handling of sampling and provides unique

management for analysis data. The software

offers various possibilities for trending,

reporting, as well as data export.

The SEA-Mate® Analyzer is available

in two different versions. The SEA-Mate®

M2000 is designed for analyzing lubricants

and fuel sulphur only, while the SEA-Mate®

M3000 is intended for analyzing both

lubricants and fuels, and it includes the

detection and measurement of cat fines

in the fuel. Besides BN levels of lubricants,

various elements can be detected and

accurately measured in lubricants and fuels.

The XRF technology enables the detection

and measurement of total iron (Fe), which

makes the SEA-Mate® Analyzer a unique

tool, most especially in monitoring the

condition of the cylinder and piston

components, as it enables the detection

of both abrasive and corrosive wear.

The analyzers were tested in long field

tests, and measuring results from the SEA-

Mate® Analyzer were compared with results

from professional land-based laboratories

run from the same samples. The latter

comparison showed a very good correlation

(R2>0.95) between the laboratory results

and the SEA-Mate results.

Installation of the Blending on Board

system is relatively simple and can be done

without interrupting the vessel's commercial

operations. After installation of the SEA-Mate®

Fig. 6 – The principle of the Blending on Board system.

Fig. 5 – SEA-Mate® Analyzer M3000.

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

51in detail

Blender and making the necessary piping

and tank adaptations, the total system is

commissioned by a senior engineer and

the crew is trained to use and operate

the blender and analyzer.

Co-operation with Maersk Fluid Technology

The Blending on Board concept and the

SEA-Mate® Blender and Analyzer products

were invented, designed and patented by

Maersk Fluid Technology (MFT), a subsidiary

of the A.P. Moeller-Maersk group. Both

the concept and the system products have,

within the past four years, been installed in

25 Maersk Line container vessels, of which

eleven have Wärtsilä two-stroke main engines.

After analyzing the technical feasibility

of the Blending on Board concept, and its

potential as a new flexible engine lubrication

management approach for the market,

Wärtsilä and MFT entered into a co-operation

agreement in the beginning of 2011 for

the joint marketing and sales of the system.

An extensive field testing and approval

process, for both the system capabilities and

the performance of various BN levels of

blended cylinder oils with different system

oils and additives, was also initiated.

Field test results

Wärtsilä followed the strict and demanding

product market introduction process

determined for oil applications. This

procedure was started by an independent

LOQUS laboratory analysis of the blended

cylinder oils, and a comparison of the

findings with the properties of commercially

available cylinder oil products. The

laboratory analysis was followed by

extensive field testing throughout 2011.

Various combinations of blended oils at

different BN levels, with different operational

loads and different fuel sulphur contents,

were tested and the condition of the piston

running components subsequently checked.

All tests were concluded successfully with

very positive impact on the engine operation

and cylinder lubrication costs. Different

cylinder oil additives from different oil

suppliers and many different operational

patterns were tested. These field test

activities have resulted in numerous

"Letters of No Objections" and the full

endorsement of the Blending on Board

concept and operation by Wärtsilä.

When operated in harsh conditions (high

sulphur content of the heavy fuel oil, low

engine load leading to lower temperatures,

high humidity in the scavenge air, etc.),

two-stroke engines are more prone to

corrosion attacking the cylinder liners and

piston rings.

To reduce the corrosion, Wärtsilä and

other engine designers recommend

increasing the cylinder lubrication oil feed

rate in order to increase the neutralisation

effect. Once the Blending on Board

equipment is in use on a vessel, the

reduction in corrosion can be achieved by

adjusting the BN of the lubricant, and not by

increasing the cylinder oil feed rate.

In one of the field tests, it was observed

that with the correct BN adjustment, and

the blended oil having a high BN level of 105,

the maximum corrosive wear was decreased

by 48%.

In addition to these effects, a fast recovery

of the engine's cleanliness was observed

after the introduction of Blending on Board

on a 9000 TEU container vessel with a

12-cylinder Wärtsilä RT-flex96C main engine.

The majority of the used system oil was

replenished with fresh system oil, and the

used oil was utilized for the blending of

the required cylinder oil. Thanks to the

Blending on Board process, the system oil

is regularly refreshed, thus keeping the system

oil in its optimal condition and the engine

components clean.

Furthermore, as regards engine

cleanliness, it was also observed that the

lifetime of the vital engine components, such

as bearings, hydraulic components in

the RT-flex system, piston crowns, etc, can

be prolonged as a result of running on fresh

system oil.

References for Blending on Board

Blending on Board has already been used

and extensively field tested for several years

on a total of 25 Maersk Line container

vessels. Based on the promising results as

described above, and the clear benefits as

summarized at the end of this article,

Maersk Line decided to rollout the concept

to another 26 vessels during 2012, all of

which are powered by Wärtsilä RT-flex96C

engines. Pilot installations for other ship

owners and a power plant are also in

the pipeline.

Wärtsilä engine lubrication management services

Along with the sole supply and installation

of the SEA-Mate® Blender and Analyzer

products, Wärtsilä is offering a variety

of services and lubrication management

concepts in order to meet the different

Fuel Sulphur Al + Si Fe Pb Cu V Ni Cr Zn Ca

M2000 X X X X X X X X X

M3000 X X X X X X X X X X

Detection range/

PPM100–60 K > 5 0–5 K

0– 1000

0– 1000

0– 1000

0– 1000

0– 1000

0– 10,000

100– 50,000

Table 1 – Detection capabilities and measurement accuracy of the SEA-Mate® Analyzers.

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Main Engine

Cylinder oil Day Tank

Cylinder oilstorage tank

(Former Cylinder oil storage tank)

BOB Additive storage tank

(Former Spare Cylinder oil tank)

BOB Base oil tank

Aux. EngineMain Engine Sump

Cylinder Oil Transfer Pump

Blending on Board unit

Fig. 7 – The layout and flow diagram of the Blending on Board system.

needs and requirements of vessel or plant

operators. Some examples include:

Analysis of an operator’s current engine

lubrication approach, performance,

consumption and overall costs, and

consulting for overall optimisation

measures

Analysis of the vessels’ piping and tank

arrangements, and the design of required

adaptations prior to the installation of

the Blending on Board equipment

Blending on Board installation,

commissioning, and crew training

Support for the technical management

in implementing the new Blending on

Board concept, including assistance in

finding the optimal cylinder lubrication

feed rate, and managing the overall

lubrication performance and costs

Analysis of trends and special findings,

and expert recommendations

Arranging the supply and supply

agreements for system oil and additives

“We consider SEA-Mate Blending on Board to be a ground breaking innovation, which will change the lubrication procedure for larger bore engines and bring significant cost savings for the operator. It will reduce cylinder oil consumption by up to 50% and reduce waste-oil volumes by up to 80%. Blending on Board will take ship-owners to the next level in terms of better engine operation, smarter lubrication management, and reducing the environmental footprint.”

"With the recent new Maersk Line BOB orders we hope to get the attention of others in shipping, as well as in other onshore industries,” says Jens Byrgesen, Managing Director of MFT, who along with technical manager, Henrik Weimar, is driving the product’s development and commercialization.

for smaller ship operators

Full engine lubrication performance

agreements, to provide continuous

optimisation of the overall lubrication

costs.

Flexible concepts

For full operational flexibility of a vessel,

Wärtsilä recommends the installation of

the complete Blending on Board system,

including the blender and analyzer.

Depending on the fleet's operating routes,

alternative concepts can be decided upon

in consultation with the customer. For

example, Wärtsilä can also provide on-the-

spot analyzing services for regular fuel and

lubricants in ports, if vessels are regularly

returning to the same port. Or, if vessels are

operated on short routes between two ports

and always bunkering the same quality

of fuel, a "blending ashore" service can be

set up by the operator or by Wärtsilä.

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

53in detail

Summary of customer benefits

Technical benefits

Obtaining the optimal constant low

cylinder oil feed rate by variable BN

blending, matching the fuel sulphur

content

Just-in-time onboard production

of the correct, fit-for-purpose,

cylinder oil

Controlled cylinder liner and

rings wear during harsh operating

conditions, such as slow steaming

Engine “cleanliness” and reduction

of deposits (crankcase, liners, piston

rings, servo) due to the regular

replenishment of new system oil

in both the main and auxiliary engines

Reducing maintenance

and the need for oil separator

discharging

Reduced frictional losses with positive

effects on fuel oil consumption

Up to 1% improvement

Improved environmental footprint

due to reduced lube oil consumption

and the reduction of waste oil volumes

Lower harmful particulate

emissions and up to 80% less waste oil.

300

250

200

150

100

50

00 15 30 45 60 75

Load % CMCR

Fe

(pp

m)

–17%

–48%

BOB 79 BN BOB 105 BN

Total Iron content of piston underside drain oil during operation with BOB cylinder lubricant.

Fig. 8–9 – Condition without BOB. Fig. 10–11 – Condition with BOB installed.

Fig. 12 – During a field test on a 12-cylinder Wärtsilä RTA96C engine at different loads, the correct level of BN in the blended cylinder oil resulted in substantial reductions of corrosive wear.

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Estimated savings and payback times per year with Blending on Board:

For the below case calculation, the following parameters were used:

Engine type 7-cylinder Wärtsilä RT-flex96C

Yearly running hours 6000

Cylinder lubrication system (CLU3 or CLU4) CLU3

Average engine load 50%

Cost standard system oil (USD/t) 1550

Cost standard cylinder oil (USD/t) 2000

Cost additives (BP, XOM, PC) (USD/t) 3500

Cost fuel price (USD/t) 600

Areas of cost savingsApprox. savings in USD/year

Cumul. Savings in USD/year

Payback times in years

Annual savings from cost difference between standard cylinder oil and blended cylinder oil and from reduced feed rate (0.1 g/kWh assumed)

110,000130,000 < 2.5

Annual savings from reduced system oil losses through separator discharging, due to extended discharge intervals

20,000

Annual savings from reduced maintenance and spare parts costs due to better component condition and TBOs

50,000 180,000 < 2.0

Annual fuel savings of 0.5% due to impact of reduced friction and optimal viscosity coming from frequent replenishment of system oil and cleaner engine.

60,000 240,000 < 1.5

Commercial benefits

Producing blended cylinder oil from

used system oil plus additives results in

lower total costs compared to using

commercial cylinder oils

Re-cycling of used system oil, instead of

disposing of it, reduces overall lube oil

consumption and BN usage

Less separator discharges, thus additional

savings

Bunkering additives for a longer period

of operation creates operational flexibility,

as there is no need to buy commercial

cylinder oil in expensive ports. Improved

supply security by the sourcing of

system oil.

Payback time on investment is usually

within 2 years, depending on engine type

and operating conditions.

In addition to the overall Blending on

Board concept benefits, the SEA-Mate®

Analyzer provides the following benefits:

Early wear detection (liner scuffing) with

access to wear metal, cat fines (M3000)

and BN information

Supports the Blending on Board

process, feed rate optimisation and

TBO extensions

Analysis of HFO for cat fines and fuel

sulphur level (confirm HFO prior to

bunkering)

Supports the Blending on Board

process and operation of the fuel

treatment plant

Analysis results generated in 6 minutes

Quick support, reduced external oil

analysis costs

Analysis that includes all lubricated

systems (maneuvering systems,

ancillaries)

Quick support, and reduced

external oil analysis costs

Analysis of used lube oil and fuel oil

can be done onboard instead of using

laboratory services

Reduced external oil analysis costs

Ability to trace each sample point’s

history, and to forecast problems by

observing trends

Supporting professional

lubrication management

Ability to confirm lube and fuel separator

efficiency through cat fine measurements

(M3000)

Support for improved performance,

discharges and maintenance can

be carried out when needed

Measurement of key elements (Ca, V, Cr,

Fe, Ni, Cu, Zn, Pb, S). Cat fines detection

only with the Analyzer SEA-Mate® M3000

tests Si and Al down to 5ppm combined.

Cylinder oil feed rate reduced to a

minimum, thanks to the ability of

knowing the true iron wear in the

cylinder. The XRF analyzer allows

continuous monitoring of various engine

fluids, including the analysis of true Fe

content; both corrosive and abrasive

iron wear.

Example of a customer business case

Customer specific business case calculations can be made by providing the customer’s installation

and operational parameters. The following influencing parameters can be considered in the

calculations on a monthly basis: fuel sulphur level, engine load, current used cylinder oil BN,

current used cylinder oil feed rate, current price levels for system and cylinder oils:

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

55in detail

New environmental regulations relating to operating within Emission Control Areas (ECAs) come into effect in 2015. The marine industry is actively seeking ways to comply. Converting to gas fuelled propulsion is an increasingly viable option.

There are a number of reasons why a gas

conversion makes sense, though customer

needs naturally vary. Such needs can be

everything from emphasizing the green

image of the company, to purely economic

reasons. However, in a majority of cases,

the main drivers for converting to gas are

the significant emission reductions,

the consequentially reduced fees, and

the reductions in fuel costs.

The year 2015 is rapidly approaching, and

with it the new emission reduction

requirements within Emission Control Areas

(ECAs). For shipowners and charterers

operating in these areas, there are mainly

three solutions available; low sulphur fuel

(MDF), SOx scrubbers, or liquid natural gas

(LNG).

The price of LNG at major import terminals

is today very cost competitive. Interest in

expanding the existing infrastructure is

vibrant, with investment proposals for small

scale LNG facilities being reported almost

daily. However, in order to build a solid

business case, the price of the fuel is the

most important parameter in the analysis.

Having an agreed LNG price level at an early

stage with a gas supplier, would remove

this uncertainty and significantly increase

the success probability of the project.

In practice, all vessels can be converted

where available space exists for the LNG tank.

Nevertheless, the prime target vessel types

can be listed as being; RoRo/RoPax, product/

chemical tankers, container vessels with LNG

containers, and bulkers.

Fig. 1 – The Bit Viking owned by Tarbit Shipping after becoming the world’s first merchant ship to undergo a LNG conversion.

LNG conversions for marine installationsAUTHORS: Sören Karlsson, General Manager, Ship Power Technology

Mathias Jansson, LNGPac Product Manager, Ship Power Technology

Jens Norrgård, General Manager, Project Proposals , S ervices

Jens Häggblom, Project Proposal Manager, S ervices

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LNG storage

A key factor for the success of a gas

conversion is finding sufficient space for

storing the gas onboard the vessel. Wärtsilä

has developed tools for calculating the

required dimensions and weights in order

to find an optimal solution. Conceptual, as

well as in depth, studies can be made based

on customer requests. For the Wärtsilä gas

engine portfolio, gas storage in the form of

LNG can be considered the most attractive

alternative due to the high energy density

of LNG and, therefore, the relative

compactness of the storage required.

Currently, LNG is also being developed for

use in road vehicles, with considerable

less installed power, and it can be

anticipated that LNG will increasingly

dominate the marine market.

Daily gas consumption can easily be

calculated based on the existing operating

profile. In order not to incur unnecessarily

high capital costs, the LNG storage tank

should be kept as small as possible and

instead more frequent bunkering intervals

should be considered. The existing liquid

fuel storage system would continue to work

as a backup system if necessary.

The LNG storage location can be freely

selected onboard the vessel, and either

vertical or horizontal tanks, on open deck or

below deck, can be selected. When storage

is above deck, the requirements set by the

classification societies are slightly lower.

Additionally, for the conversion, installation

on an open deck is very straightforward,

and some of the system ventilation

requirements can be circumvented.

The LNG storage tanks and any additional

steel structures may have an impact on

the vessel’s stability. These vessel stability

criteria, with new LNG tanks installed, can

be analysed in-house by Wärtsilä as part of

the initial feasibility study. For vessels with

a very high stability, the rolling behaviour

and crew comfort can even be improved.

Converted or new engines?

The second step in the process is to check

whether or not the existing engines onboard

can be converted, or if they should be

exchanged for new Wärtsilä dual-fuel

engines. Generally speaking, converting

an existing engine is recommended and is

economically more feasible than installing

new ones - especially when keeping in mind

that a conversion basically brings the same

benefits as new engines. For example, the

same warranty is granted as for a brand new

engine, in addition to which there are also

savings to be made on maintenance costs

since the running hours are reset. However,

with smaller generating sets, say below 2 MW,

it might be more cost effective to install

new engines.

At present a conversion can be offered for

basically all Wärtsilä 32, Vasa 32 and

Wärtsilä 46 engines.

Wärtsilä is actively considering

expanding its portfolio of conversions,

and in the future it may even be possible

to convert two-stroke engines.

If the existing engines aren’t suitable for

conversion, the only option is to replace

them with new ones. When doing this

one may need to replace the gearbox

and some of the auxiliary equipment as

well, should it prove that the capacity of

the existing equipment isn’t sufficient.

Unless it’s a question of replacing old

engines with new ones, a DF-conversion

will usually mean a lowering of the total

output onboard. If the utilisation of the

available power onboard is normally

in the lower range, this is in most cases

acceptable. In other cases it may prove to

be quite critical and has to be compensated

for in some way, like for instance,

omitting the use of shaft generators.

Another important consideration is,

of course, the age of the installation. A

DF-conversion is a fairly large investment,

and if the vessel is near the end of its

service life, there is a big risk that a

conversion would never pay itself back.

From vision to offer

Developing a LNG conversion solution, from

a vision to a completed project, will involve

a number of progressive steps. We have,

therefore, made a model of how to handle

the Proposal Management (see Figure 2).

MARINE LNG SALES PROJECT DEVELOPMENTStructure of offering (sales) process

RFP (Request for Proposal)

RFP from client

Leads / Opportunities developed with the client

Pre-study

Concept study from GA drawings and data provided by client

Budgetary proposal for equipment delivery.

Go / No Go decision

Pre-study follow up

Possible ship check

Possible update of budgetary proposal

Preliminary time schedule Go / No Go decision

Agreement on feasibility and basic design

Feasibility

Broad engineering, design work and report for determining feasibility

Engineering package for submittal to the flag authorities and class society for concept approval Go / No Go decision

Basic design

Build plan and schedule in cooperation with client

Engineering deliverables needed to secure a ship- yard contract

Turn key proposal preparation

Obtaining firm offer from selected ship- yard and other sub suppliers

Preparation of turn key proposal

Preparation of contract draft

Presentation of proposal

Submittal and presentation of detailed proposal and contract draft

Fig. 2 – Typical lead times for the major tasks in the sales process.

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

57in detail

Since almost all vessels are in some way

unique, it is very difficult to have ready-

made concepts for all types of LNG

conversion projects. Therefore, one always

has to start with a desktop study, which later

leads in turn to a “pre-study”. A pre-study

can include everything from a ship check to

a lot of engineering hours, just to determine

if the concept can be applied or not, is

feasible or not, or even possible or not. By

carrying out these pre-studies, Wärtsilä

can support the customer with consulting

services, and already at an early stage give

recommendations as to the feasibility of

the project. This includes sometimes

recommending that for a specific vessel,

it is not economically feasible.

The pre-studies/conceptual plans are

made internally by Wärtsilä naval architects

and system experts, or in co-operation

with external engineering partners, to

arrive at the most applicable solution.

Developing the optimal LNG conversion

solution together with the customer involves

more than just Wärtsiläs' own propulsion

machinery systems. The engine conversion

work itself is a very straightforward activity

for Wärtsilä, and is today seen internally as

“daily business”. Neither is the time needed

for the engine conversion a bottleneck

in the LNG conversion schedule, nor is it

the most expensive part of the project.

In addition to the engine technology,

engineering/naval architecture, and

the equipment, there are a number

of other aspects to be considered

when developing the LNG conversion

solution. These include: minimizing

the yard time in order to reduce

losses in charter revenues

site location for the conversion work

pre-selection of shipyards that are

suitable to both parties

external stakeholder requirements

(autonomy of tanks, shore-based fuel

bunkering systems, safety, classifications

and flag states, etc).

In practice, the entire conversion schedule/

project is developed and planned during

the sales phase.

As can be seen from Figure 3, the cost

of the engines and auxiliaries is just 1/5 of

the total price. The biggest price impacts

come from the autonomy of the tanks,

the complexity of the project (design &

engineering), and of course, the installation

work. The latter needs to be considered very

thoroughly since not all shipyards have the

capacity to undertake these conversions.

As pointed out earlier in this article,

the year 2015 is rapidly approaching,

and with it the new emission reduction

requirements within Emission Control

Areas (ECAs). This means that owners and

operators need to quickly start considering

which technology to use. There is only

one year remaining before action must be

taken if one wants to comply with the new

legislations. A time schedule for developing

such a project can be seen in Figure 4.

Project execution and risk management

A conversion project is managed by certified

Project Managers with the aid of a dedicated

project team. A project process utilizing the

gate/milestone principle is used. It involves

the project team early enough in the

sales stage and this, together with a work

breakdown structure, planning and

follow up routines, ensures full control

of all phases of the project execution.

Sufficient resourcing in the planning

and design phase minimizes the risks of

costly mistakes, and schedules should

contain buffers for the unexpected. The

dedicated project team normally consists

of a Project Manager, Project Engineer, Site

Execution Manager and Team Leaders in

the following disciplines; Naval architecture,

Process design, Electrical and Automation,

Classification, Engine conversion, LNG

storage and feed system,

and Steel outfitting. Team leaders would

manage the engineering tasks assigned

to the internal and external trusted and

carefully selected suppliers. A frame

agreement with selected shipyards enables

the development of long-term co-operation

and the best use of previous experience.

Surveys, engineering, project management, Naval architecture & system engineering integration

Installation work & material (Shipyard)

Automation & control system

Engine conversion & auxiliary system components

Fuel gas system (LNG storage, bunkering, process equipment)

l system

Fuelproc

Enginesystem

12%

6%

20%

31%

31%

Fig. 3 – Cost split for the major tasks in a LNG conversion.

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2012 2013 2014 2015

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

Vision

RFP

Desktop study

Pre-study

Concept development

Contract negotiations

Signing of contract

Project lead time

Deadline Q1/2015

Fig. 4 – A typical project schedule, including a zoom of the actual conversion schedule.

Engineering, design, planning

Manufacturing

Piping, cabling, equipment installation, hull modifications

Engine conversion

Commissioning test run & sea trial

LNG conversion time schedule(Typical for a single main engine merchant vessel, starting from date of order)

0 5 10 15 20 25 30 35 40 45 50 55 60 65

Weeks

Duration

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

59in detail

During the conversion, the most effective

work division between the yard and

Wärtsilä is that both parties focus on their

own key competence areas, and together

work towards finalising the conversion.

Interface handling between the different

parties is crucial for the success of a

conversion, due to the short lead time

involved. Therefore, detailed and defined

specifications and areas of responsibility are

the key to a successful engineering result. A

document management system that is open

and available for all involved engineering

parties enables revision handling and better

interface communications. Engineering

review meetings with subcontractors, the

yard and the customer, guarantees that no

additional change requests to the design

appear during the actual installation work

at the yard.

Laser scanning of the vital parts of the

vessel can be recommended if the added

values are seen as being crucial. Scanning of

the structure is dependent on the available

drawings and CAD models of the vessels.

The classification and quality assurance

of all engineering work and equipment

installed in a conversion is the responsibility

of the project team working closely with

the classification societies. Classification

requires a project specific Failure Mode and

Effects Analysis (FMEA). The HAZOP or FMEA

would be based on the already available

FMEAs of the engine and gas fuel feed

system. During the project execution, close

co-operation with the classification society

is crucial in order to ensure that all class

requirements are met and fulfilled as a result

of the conversion. The Wärtsilä project team

carries total responsibility for ensuring

that all equipment installed has the correct

quality assurance, material certificates,

and Non Destructive Testing (NDT).

Any required SOLAS update would be

the responsibility of the owner of the ship.

Training of the crew and ship owners, as

required by the classification society, can

be carried out by the training experts at

the Wärtsilä Land and Sea Academy.

The conversion work at the yard is

managed by the site manager, who is part

of the project team. Further to the actual

installing of all new equipment

commissioning, the quay and sea trials

of the vessel are the responsibility of

the site manager.

Tailoring a service agreement

After conversion, the propulsion train can

be operated as normal. However, Wärtsilä

can also offer improved reliability and

assistance based on the customer’s needs

and preferences. By teaming up as partners

at an early stage, maintenance schedules can

be jointly developed, which often results in:

Improved reliability and availability

- ‘what we can measure we can manage’.

Extended maintenance schedules,

but in a controllable way.

Optimisation of the maintenance

planning and execution - doing the

maintenance at the right time and place

to ensure economic benefits

(lifecycle management).

Reduced risk exposure for the customer.

Long term savings in Operation &

Maintenance costs due to improved

lifecycle costs.

Improved fuel consumption as an

additional plus from assuring optimal

running values.

As a reference, it can be mentioned that

the majority of the LNG carrier operators

with dual-fuel engines onboard have service

agreements with Wärtsilä to ensure improved

and stable revenue flows from their

investment.

Case study and references

Wärtsilä performed the first conversion of

a marine vessel from heavy fuel oil (HFO) to

liquefied natural gas (LNG) operation when

the MT Bit Viking was converted in 2011.

The total scope included the installation of

two 500 m3 LNG fuel storage tanks (LNGPac)

on the ship’s deck, converting the two

existing Wärtsilä 46 engines to Wärtsilä 50DF

engines, the installation of two LNG

Fig. 5 – LNG tanks and components required for a LNG conversion.

Complete

vessel conversion:

Engine conversion

LNG tank(s) and

foundation

LNG/NG double

walled piping

Gas detection

and fire suppression

Inert plant/N2 storage

and control air

Bunkering station(s)

Automation and

control system

Exhaust pipe gas

burst disc(s)

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bunkering stations, all the LNG and gas

piping onboard, updating the vessel’s

automation, and the gas detection system.

Furthermore, the classification documents

were updated as required. This included,

among other things, updating the stability

handbook and docking plane. The vessel

was handed back to the owner after

successful quay and sea trials.

The project started in the summer of 2010

with the signing of the project contract.

The engineering, procurement, and

manufacturing started immediately thereafter

and continued into the summer of 2011. The

conversion work was finalised in autumn of

2011, and the project was completed in

October 2011. The conversion of the engines

to DF operation was carried out in just six

weeks.

Since 2005, Wärtsilä has converted 40

diesel engines to dual-fuel engines in land

based power plants around the world.

A Wärtsilä 50DF engine has already

accumulated more than 40,000 operating

hours following a conversion. The Bit Viking

engine conversion was Wärtsilä's first marine

engine to be converted to dual-fuel operation.

CONCLUSIONS

The key driver in the increasing interest in

LNG as a marine fuel, on a global level, is

the increased focus on reducing emissions.

In whichever way the customer prefers to

address future trends regarding fuel prices

or emission abatement methods, Wärtsilä

can meet such needs for both new buildings

as well as gas conversions. A documented

way of working, and means of handling the

complex tasks and processes efficiently, have

been developed and are continuously being

improved. An already established track

record of completed turnkey conversion

projects is available, including the SOX

scrubber conversion of the Containership

VII vessel, and the LNG conversion of the

Bit Viking. The long-term commitment

to this strategy can be further exemplified

by the acquisition of Hamworthy to add

even greater strength to the company’s

environmental capabilities. The lead time

from idea to completion may require up

to one and a half years, and starting such

discussions in good time is essential if the

potential 2015 deadline is to be met.

Fig. 6 – Lifting of the LNG tanks aboard the Bit Viking during the conversion.

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

61in detail

The Wärtsilä 32 engine is now available with improved performance. It features best-in-class power density and fuel economy across a broad operating range. Its rated power is 15 percent greater than before.

The upgraded Wärtsilä 32 is now available

in the 6, 8 and 9 cylinder in-line series,

and the 12 and 16 cylinder V series. It

produces 580 kW/ cylinder at 750 rpm,

while the total rated engine output

ranges between 3.5 and 9.3 MW.

Its excellent fuel flexibility allows the

Wärtsilä 32 to operate on heavy fuel oil

(HFO), light fuel oil (LFO) and liquid bio fuel

with a broad range of fuel viscosities, from

2.0 cSt up to 730 cSt HFO (at 50 °C/122 °F).

The engine is able to operate efficiently and

economically on low sulphur fuel oils

(<0.1% S), making it suitable for operation

in emission-controlled areas.

It fulfils the IMO Tier II regulations as set

out in Annex VI of MARPOL 73/7. It can also

be equipped with a Selective Catalytic

Reduction (SCR) catalyst, such as the

Wärtsilä Nitrogen Oxide Reducer (NOR).

This means that, already today, the engine

is IMO Tier III compliant.

Background

The cylinder output of the Wärtsilä 32 engine

has been increased six times since 1980. In

1980, the first 32 engine had 308 kW/ cylinder,

while the current version has 500 kW/

cylinder at 750 rpm.

For more than 30 years, Wärtsilä 32 bore

engines have been the preferred choice of

yards, operators and owners, with more

than 4000 engines having been delivered

to the marine market alone. It has a proven

track record in a wide range of vessel

applications, including as a main engine,

both direct mechanical drive as well as

diesel electric, and as an auxiliary engine.

It can be optimised for either constant

speed or along a combinatory curve.

In the merchant fleet, its’ typical

applications include use as the main engine

on different types of tankers and container

vessels. In the offshore sector, the reliability

of the Wärtsilä 32 has made it the most

popular medium-speed engine Fig. 1 – After the latest upgrade, the Wärtsilä 32 has the best performance in the market .

The Wärtsilä 32 engine – making the good even better AUTHORS: Asko Vakkila, Manager, Product Information

Mika Harjamäki, Product Manager, Wär tsi lä 32

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for offshore service vessels and drilling

vessels. Similarly, in the cruise and ferry

sector, the Wärtsilä 32 has proven to be

the most favoured engine of its size. In

auxiliary electric production, the Wärtsilä

32 is widely utilized in all vessel categories

where high auxiliary load is needed.

Project and schedule

The upgraded Wärtsilä 32 is based on the

same well-proven technology and design

principles as the current Wärtsilä 32 engines.

It is a turbo-charged 4-stroke diesel engine

with direct fuel injection and charge air

cooling. The cylinder bore is 320 mm and

the stroke is 400 mm.

Because the basic technology was already

in place, the project proceeded very rapidly.

Development began after official approval in

October 2009, and the first 6-cylinder proto

engine was started successfully at the Vaasa

factory’s test run cell in September 2010.

The project proceeded on schedule and

within the budget.

The Wärtsilä 32 pilot sales release took

place in November 2010 and the first

customer order was received in April 2011.

The Type- and Engine International Air

Pollution Prevention (EIAPP) tests with

classification societies were completed

by the end of September 2011.

Assembly of the first pilot engines began

during August and the testing was

completed at the Vaasa factory by the end

of October 2011. The Ship Power business

unit took delivery on 19 October 2011.

The project itself was closed in the end of

January 2012.

Design and development

It was clear from the start that the most

suitable way to improve the power density

and product cost ratios was to increase the

firing pressure. For this, it was necessary

to optimise the combustion and to utilize

the latest high efficiency turbo charging.

The firing pressure has been increased from

21 MPa to 23 MPa.

However, while increasing the firing

pressure, it was also necessary to ensure

that the engine’s proven reliability was

maintained and that the prospective

commonality with gas engines could be

ensured. This meant the redesign of several

smaller and bigger components. Great

attention has also been paid to the noise and

exhaust gas, both of which are important

environmental aspects.

Main components

The engine block is based on the proven

design of the established Wärtsilä 32, with

the cylinder head bolts’ thread size being

increased from M56 to M60. The bore for

the cylinder liner is increased to enable

the future usage of a gas engine´s cylinder

liner with larger cylinder bore (340 mm).

The camshaft bearing diameter has been

increased from 190 mm to 230 mm and

the centreline is moved 20 mm downwards

to give more space for better serviceability.

The cam profiles are new and performance

has been optimised.

The cylinder head casting is common to

that of the gas engines. The design has been

strengthened in many ways, for example

by improving the flame plate. Great

attention has also been paid to easing the

serviceability. The crankshaft has a new

strengthened design with thicker crank

webs. The engine covers have improved

noise reduction and are common with those

for gas engines. The connecting rod design

is the same three-piece design, known as

Fig. 2 – The proto engine being started in a test run in Vaasa, Finland.

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

63in detail

the “marine-design”, as with the former

Wärtsilä 32, but the material has been

changed and is now harder than before.

The three-piece design reduces the

height required for piston overhauling.

A piston overhaul is possible without

touching the big-end bearing, while the

big-end bearing itself can be inspected

without removing the piston.

Fuel injection system

The conventional fuel injection system

has been upgraded with increased fuel

injection pressure and volume. The Wärtsilä

32 engine is designed for continuous

operation on HFO as well as LFO. A pre-

heated engine can be started directly on

HFO provided that the external fuel system

has the correct temperature and pressure.

Charge air and exhaust gas systems

Due to the increased charge air pressure

ratio and efficiency, a new version of

turbochargers has been introduced.

Both turbocharger types are connected

to the engine lubricating oil system. The

re-designed charge air cooling system

provides better engine performance

and commonality with gas engines.

The exhaust system will remain quite

the same as earlier, and the exhaust waste

gate/ by-pass system design is identical

with the one that is used in gas engines.

For offshore sector use, a design having a

charge air blocking device will be available.

The various changes to the charge

air system, as shown above, have led

to a new design for the insulation

box, heat- and noise coverings.

Fig. 4 – The fuel injection system in a hot-box (pump shelf).

Fig. 3 – Wärtsilä 32 cylinder head is now stronger and easier to service.

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Starting air system

The starting air system has also had several

new improvements due to the standard

installed slow turning system, a new main

starting valve, and the turning device. The

overall functional speed of the system

is faster. Great attention has been paid

to ease of assembly and thus also to the

serviceability, and last but not least, to a

strong commonality with gas engines.

Automation

The UNIC C2 engine control system is

used on the upgraded engine without

major changes. However, some of the

features that were optional earlier, are now

available as standard. These include:

engine slow turning

temperature monitoring systems for

cylinder liners and big end bearings.

The UNIC C2 automation system is an

embedded engine management system.

The system is specifically designed for

the demanding environment associated

with engines, thus the design pays special

attention to temperature and vibration

endurance. This allows the system to be

directly mounted on the engine, which

allows for a very compact design without

requiring the components to be mounted in

dispersed external cabinets or panels. It also

allows the engine to be delivered fully tested

at the factory. Thanks to the pre-tested

configuration, the engine or generating

set can be operational with a minimum of

commissioning and installation work.

The modular and standardized interface

provides the designer of the off-engine

automation systems with an easily re-usable

design. For example, it allows the conversion

of diesel engines to dual-fuel or common

rail with a minimum of modifications.

The critical parts of the UNIC system are

either redundant or very fault-tolerant to

guarantee high safety and availability in all

circumstances. In particular, parts like the

communication and power supply are fully

redundant to allow single failures without

interruptions to the engine’s operation.

Validation and performance

Testing of the Wärtsilä 32 started in

September 2010, when the fist proto 6-

cylinder in-line Wärtsilä 32 engine was

delivered from the factory. The official

start up of the engine was arranged

for the very next morning after the

engine was put in the test cell.

The engine was already performing

well with the first specification, and full

output was reached the same day as the

official start. The engine was moved to

the engine laboratory in October.

When testing began, the main focus

was on optimising engine performance

for constant speed applications. The target

was to have values for the performance

manual before the end of October. The

time schedule was tight but nevertheless,

the values were given to the product

engineering project team before the

deadline. The fuel consumption, emissions

and thermal load were according

to expectations. A load acceptance

optimisation test was also performed in

order to reach the 3-step loading target.

Testing continued until the beginning of

2011 with product validation tests, such as

vibration, stress, temperature and pressure

pulse measurements. To achieve extended

maintenance-free operation - and with it

maximized revenue-earning capability – it

is vital to get the best possible knowledge

about the components concerned.

After these optimisation and validation

tests, it was time to perform an endurance

Fig. 5 – The Wärtsilä 32 from the rear. Fig. 6 – The control system is the brain of the engine.

WÄRTSILÄ TECHNICAL JOURNAL 01.2012

65in detail

test on the Wärtsilä 32 engine.

The first 1000 hours endurance test

at an output of 580 kW/ cylinder was

completed just before midsummer in 2011.

Currently, the laboratory engine has

accumulated close to 2250 running hours,

with another 1500 more hours expected

before the end of 2012.

Based on these experiences, we can

proudly say that the Wärtsilä 32 engine

performs excellently, and is a world-class

performer amongst 32 bore size engines.

The target of developing the most powerful

engine in its class has been achieved.

Benefits to the customer

As already stated earlier, Wärtsilä 32 bore

engines have been the preferred choice of

yards, operators and owners since the 1980s.

As from 2012, the upgraded Wärtsilä 32

continues that tradition.

The main drivers for the design were

high power density, product costs and

commonality with gas engines. In simple

terms, this means more power with fewer

cylinders to overhaul.

The engine is designed for long periods

of maintenance-free operation and has

overhaul intervals of up to 24,000 hours

with low consumption of spares. This, and

the maintenance-friendly design, serves to

reduce downtime, promote scheduling, and

cut operating costs. Together with dynamic

maintenance planning and service

agreements, the overhaul interval time for

the Wärtsilä 32 can be extended even further,

thus minimizing maintenance costs and

maximizing the revenue-earning capability

of the vessel.

The Wärtsilä 32 has been designed to

operate reliably on a range of fuels, including

HFO, MDO and liquid bio fuels, and even with

the poorest quality of heavy fuel. In all cases

it has shown proven reliability, high power

density, and low fuel consumption over

a wide load range. Additionally, the high

degree of commonality with gas engines

makes future conversions to, for example,

dual-fuel very easy.

Constant development and the search for

improvement are central to Wärtsilä's

philosophy as a total solutions provider. In

making the Wärtsilä 32 engine even better

than it is already, this strategy is once again

emphasised. At the same time, Wärtsilä's

industry leading global support network

is being similarly enhanced and broadened

to ensure full lifecycle support for its

customers' installations.

REFERENCE: Bergen, Norway

The Wärtsilä 32 engine with extra power output is introduced

The VS 465 is equipped with the upgraded Wärtsilä 32 engine.

The Bergen Group's BMV shipyard in Norway is to build a Wärtsilä VS 465 design vessel for Atlantic Offshore, part of the Atlantic Maritime Group. Included in the order is the complete diesel electric propulsion system from Wärtsilä, comprising 6-cylinder in-line Wärtsilä 32 and 20 (two of each) generating sets, the electric and automation systems, the frequency drives, the gear and controllable pitch propeller, the tunnel thrusters, as well as a retractable thruster. This will be the first installation of the upgraded Wärtsilä 32 engine with its power output increased from 500 to 580 kW/cylinder. While the external dimensions remain unchanged, this represents a power increase of 15 percent over the earlier version of the

engine, which was originally introduced in the 1980s. The Wärtsilä 32 now covers a power range from 3 MW to 9.3 MW. In the VS 465 vessel, the needed cylinder output is 550 kW/cylinder at 720 rpm and the total rated output per engine is 3300 kW. The total rated mechanical output of the main diesel generating sets (2 x Wärtsilä 32) is 6600 kW.

The new ship will also feature Wärtsilä’s Low Loss Concept (LLC), a proven energy efficient and highly redundant power distribution system for electric propulsion applications. The combination of the higher engine output and LLC means that fuel consumption and exhaust gas emissions will be minimized.

Time

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45°N

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45°E 90°E 135°E

WÄRTSILÄ NETWORK

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The information in this magazine contains, or may be deemed to contain “forward-looking statements”. These statements might relate to future events or our future financial performance, including, but not limited to, strategic plans, potential growth, planned operational changes, expected capital expenditures, future cash sources and requirements, liquidity and cost savings that involve known and unknown risks, uncertainties and other factors that may cause Wärtsilä Corporation’s or its businesses’ actual results, levels of activity, performance or achievements to be materially different from those expressed or implied by any forward-looking statements. In some cases, such forward-looking statements can be identified by terminology such as “may,” “will,” “could,” “would,” “should,” “expect,” “plan,” “anticipate,” “intend,” “believe,” “estimate,” “predict,” “potential,” or “continue,” or the negative of those terms or other comparable terminology. By their nature, forward-looking statements involve risks and uncertainties because they relate to events and depend on circumstances that may or may not occur in the future. Future results may vary from the results expressed in, or implied by, the following forward-looking statements, possibly to a material degree. All forward-looking statements made in this publication are based only on information presently available in relation to the articles contained in this magazine and may not be current any longer and Wärtsilä Corporation assumes no obligation to update any forward-looking statements. Nothing in this publication constitutes investment advice and this publication shall not constitute an offer to sell or the solicitation of an offer to buy any securities or otherwise to engage in any investment activity.