Electrical Power Generation Notes2

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Vinayaka.B.G. Asst.Professor, Dept E& E , BI ET, Davanagere

UNIT 2

Syllabus: Diesel electric plants. Gas turbine plants. Mini, micro and bio generation. Concept of

distributed generation.

DIESEL POWER PLANT

A generating station in which diesel engine is used as the prime mover for the

generation of electrical energy is known as Diesel power station.

Diesel power plants produce power from a diesel engine. Diesel electric plants in

the range of 2 to 50 MW capacities are used as central stations for small electric

supply networks and used as a standby to hydro electric or thermal plants where

continuous power supply is needed. Diesel power plant is not economical

compared to other power plants.

The diesel power plants are cheaply used in the fields mentioned below.

1.

Peak load plants

2.

Mobile electric plants

3. Standby units

4.

Emergency power plants

5.

Starting stations of existing plants

6. Central power station etc


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4.3.2 Advantages of diesel power plants

1.

More efficient than thermal plant

2.

Design, Layout etc are simple and cheap3.

Part load efficiency is very high

4.

It can be started quickly

5.

Simple & easy maintenance

6.

No problem with fuel & dust handling

7.

It can be located in the heart of town

8.

Less cooling water required.

4.3.3 Disadvantages

1.

There is a limitation for size of a diesel engine

2.

Life of plant is comparatively less

3. Noise pollution is very high

4.

Repair cost is very high

5.

High lubrication cost


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Apllications Of Diesel Power Plant:

Emergency plant: To maintain the essential services when the supply from

the grid is not available. Starting auxiliaries: They are used to start the auxiliaries in steam power

stations.

Mobile Plants: Mobile diesel plants mounted on trailers are used for

temporary and emergency purposes.

Peak load plants:A diesel plant can be started and loaded quickly, so these

plants can be used as peak load plants. Standby plants:They can be used as standby plants when supply from grid

is not available.

Remote Places:They can be used in remote locations where supply the grid

is not available.

4.3.1 General Layout of Diesel power plants


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General Layout of Diesel power plants

Figure shows the arrangements of the engine and its auxiliaries in a diesel power

plant. The major components of the plant are:

a) Engine

Engine is the heart of a diesel power plant. Engine is directly connected through a

gear box to the generator. Generally two-stroke engines are used for power

generation. Now a days, advanced super & turbo charged high speed engines are

available for power production.

b) Air supply system

Air inlet is arranged outside the engine room. Air from the atmosphere is filtered

by air filter and conveyed to the inlet manifold of engine. In large plants

supercharger/turbocharger is used for increasing the pressure of input air which

increases the power output.

c) Exhaust System

This includes the silencers and connecting ducts. The heat content of the exhaust

gas is utilized in a turbine in a turbocharger to compress the air input to the

engine.

d) Fuel System

Fuel is stored in a tank from where it flows to the fuel pump through a filter. Fuel

is injected to the engine as per the load requirement.


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e) Cooling system

This system includes water circulating pumps, cooling towers, water filter etc.

Cooling water is circulated through the engine block to keep the temperature of

the engine in the safe range.

f) Lubricating system

Lubrication system includes the air pumps, oil tanks, filters, coolers and pipe lines.

Lubricant is given to reduce friction of moving parts and reduce the wear and tear

of the engine parts.

g) Starting System

There are three commonly used starting systems, they are;

1) A petrol driven auxiliary engine,

2) Use of electric motors,

3) Use of compressed air from an air compressor at a pressure of 20 Kg/cm

h) Governing system

The function of a governing system is to maintain the speed of the engine

constant irrespective of load on the plant. This is done by varying fuel supply to

the engine according to load.


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GAS TURBINE POWER PLANT:

With a neat schematic diagram, explain working of a gas turbine power plant.

With a neat sketch, explain working of a gas turbine power plant.

Explain working of a gas turbine power plant, with a neat sketch,

With a neat block diagram, discuss principle operation of open cycle gas turbine

plant. Why is its efficiency low?

Explain principle of working of a gas turbine plant also explain open cycle andclosed cycle gas turbine plant

Discuss the methods of increase the thermal efficiency of gas turbine plant

Explain how the use of regenerator, intercooler & reheater in gas turbine plants

help in improvement of thermal efficiency.

DEC 08. 8 M

JUNE 10. 10 M

JUNE 11. 10 M

JUNE 09. 9 M

DEC 09.10, 6 M

JUNE 11, 8 M

JUNE 11, 8 M


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With a neat sketch, explain the principle of operation and working of bio-

generation plant.DEC 08. 8M


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MICRO GENERATION

Micro generation is the small-scale generation of heat and power by individuals,

small businesses and communities to meet their own needs, as alternatives or

supplements to traditional centralized grid-connected power. Although this may

be motivated by practical considerations, such as unreliable grid power or long

distance from the grid, the term is mainly used currently for environmentally-

conscious approaches that aspire to zero or low-carbon footprints. It differs from

micro power in being principally concerned with heavy, fixed power plants rather

than high mobility

DISTRIBUTED GENERATION:

Explain the concept of distributed generation

When small generators of capacities around 2 - 50 MW output are installed

at typical points in the area such that each of these generators supply

power to a small number of consumers nearby then it is called distributed

generation.

The generators may be operated through renewable energy sources such

as solar, wind or gas turbines, small hydro or micro turbines as these are

most economical choices.

JUNE 09. 5M
http://en.wikipedia.org/wiki/Low-carbonhttp://en.wikipedia.org/wiki/Micropowerhttp://en.wikipedia.org/wiki/Micropowerhttp://en.wikipedia.org/wiki/Low-carbon


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Dispersed generation is use of still smaller generating units of less than 500

kW and use for individual houses or small business. The distributed or

dispersed generators may be standalone or grid connected depending on

the requirement.

Distributed generation proves to be economical as it requires to

transmission network and reduced need of distribution equipments.

Another advantage is this generation is portable or compact as compared

to big power stations located far away from consumers. Also they are

modular and reloadable.

The fuel cells and micro gas turbines are two new types of techniques

evolved in distributed generation.

The main challenge is to upgrade existing technology and to promote

development, demonstration of new and upcoming technologies for

widespread adaptation of distributed generation.


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Electrical Power Generation Notes2

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