Electrical master plan for chemical engineers and managers

Petro‐Chemical and Refinery Master Electrical Plans and What a Good Electrical System Looks Like

Speaker:Vincent W. Wedelich, *PE, MBA,

Project Manager Power Distribution & Controls, Burns & McDonnell Engineering Co, Inc.

*Registered PE in Texas.

IEEE/AiChE Joint Presentation April 9, 2015 Rev. 0 For Educational, Safety, and Process

Improvement Purposes Only1

Your company should have a Zero Policy.

• “zero” safety incidents• “zero” power failures; with “fastest” power recovery

• “zero” flares and process leaks• “zero” process downtime



Get everybody on board to save bottom line

• Petro‐Chemical facility owners and refiners are advised to set a goal of “zero” power failure and “fastest” power recovery and share the goal with all the employees, including people working outside the plant.

• When a refinery/petro‐chemical facility shuts down, business profit is gone, thereby affecting everybody in the company, from the CEO to the maintenance worker.

• Any employees that offer key contribution in terms of ideas and innovations to increased reliability and availability of a power system should be offered financial incentive for avoiding power failures.

• The Power of Habit! By: Charles Duhigg Read it….IEEE/AiChE Joint Presentation April 9, 2015 Rev. 0 For Educational, Safety, and Process


Reference Data• Long term optimization of asset replacement in energy

infrastructures; Ype C. Wijnia, Martijn S. Kom, Saskia Y. de Jager, Paulien M. Herder 2006

• Refinery power failures: causes, costs and solutions; Patrick J Christensen, William H Graf and Thomas W Yeung Hydrocarbon Publishing Company 2013

• Integrating Advanced Relays On Medium Voltage Switchgear Safety Instrumented Systems (P66 and BMcD) IEEE PCIC 2013.

• OSHA 1910.119 Process safety management of highly hazardous chemicals

• Arc Flash Mitigation in a Chemical and Refining Facility Using IEC 61850 (CPChem/BMcD IEEE PCIC 2012)

• Many, many papers and studies published by IEEE.



Abstract:• The material used in this presentation was readily available

from the internet and IEEE presentations. This presentation is for educational, safety, and process improvement purposes only.

• Applicable to Refineries and Petrochemical facilities • Review of what an Electrical System Master Plan Study is:

– to identify system improvements related to reliability,– safety and maintainability for projected load expansion at the

refinery/petro‐chemical facility within the next 5 to 20 years. – This master plan and the ideas presented were geared towards

creating a good foundation for the future of the electrical system primarily through upgrade and replacement projects.

– Illustrate what a good electrical system looks like.



Bio

• Presenter: IEEE Houston Past Chair • Mr. Wedelich is an Associate level project manager and electrical engineer in the Houston T&D Power Distribution and Controls Department at Burns & McDonnell.

• His responsibilities include Power System Design and Project Management for the Industrial and refinery/petro‐chemical facility Markets.



Read the OSHA report on:THE 100 LARGEST LOSSES

• 1972–2011• Large Property Damage Losses In The Hydrocarbon Industry



What do (Refinery, Petrochemical, Gas Processing, & Terminals and

Distribution) have in common?

• EarthQuakes• Fires• Explosions• Hurricanes (flooding)• Vapor Cloud Explosions• Corrosion (pipe racks!!!) failing.• Mechanical Damage



Explosion

• Five people were killed and two seriously injured following an explosion at a plastics plant producing 200 million barrels per year of specialty grade PVC. The highway was shut and local residents evacuated. The explosion occurred in a reactor where vinyl chloride and vinyl acetate were being mixed. Up to 75% of the plant was destroyed in the explosion. The explosion was felt 4 miles away.

• Solution: Implement Safety Integrity Systems



Explosion

• A release of hexane created a vapor cloud which ignited on an electric motor causing an explosion. This resulted in damage to the unit and some 20 injuries. The plant was eventually replaced.

• Solutions: Implement Safety Integrity Systems and address Area Classification Issues



Explosion/Fire

• An accident occurred at one of the methylcellulose manufacturing facilities located at this site. At 16:26 an explosion occurred and was followed by a fire, which was extinguished at 23:11 the same day.

• Seventeen people who were working at the site were injured in this accident; three critically, five seriously and nine with minor injuries. There was one minor injury off site. Static electricity induced the ignition of methylcellulose powders, resulting in a powder dust explosion. All methylcellulose operations were suspended for two months before sequentially restarting.

• Solutions: Resolve the Area Classification Issues



Hurricane(Flooding)

• This petrochemical facility sustained damage during Hurricane Ike. Storm surge, flooding and high winds caused significant damage at the site. Force majeure was declared and the most heavily damaged portion of the plant remained off line for 152 days.

• Solutions: Coastal sites: The flood maps need to be updated and electrical equipment needs to be raised into elevated Power Control Room’s. Have an alternate power source.



Explosion

• A massive explosion occurred in an ammonium nitrate storage warehouse of a fertilizer plant just outside the southern French city of Toulouse. The warehouse contained approximately 300 tons of off‐specification ammonium nitrate crystals. The explosion had the strength of a 3.2 magnitude (Richter Scale) earthquake, left most of the plant in ruins and caused damage to surrounding areas. Thirty people were killed in the blast and approximately 3,000 people were injured.

• Solutions: Address the (Area Classification Issues)



Explosion• An explosion and fire occurred in an olefins unit at this

petrochemical plant. The incident originated at the cracked gas compressor in the olefins unit and was caused by a failed air assisted check valve on a five inch diameter, 500 psi discharge line from the compressor.

• Upon closure of the check valve, one of the pins holding the two‐piece check valve stem broke and allowed it to open in the opposite direction. This led to a gas leak, ignition, explosion and ensuing fire at the partially enclosed compressor building. The explosion damaged a line to the quench tower, which fed the fire. The fire was allowed to burn itself out.

• About 30 workers were treated for minor injuries.

• Solutions: Address the (Safety Integrity Systems, and the Area Classification Issues)



Fire/Explosion

• A vent connection failed on a compressor suction line, releasing gas which led to a violent explosion with widespread damage. This was believed to be a fatigue failure due to vibration.

• Fatigue failures due to vibration!! Vibrations and corrosion is setting the industry up for major issues.

• In electricity networks almost all parts are vibrating at 100 Hz, resulting in metal fatigue.



Aging Infrastructure• The oldest assets in operation are about 60 years old, the

average age of the asset base is about 30 years.

• However, assets do not have perpetual lives, as normal wear and tear takes it toll.

• In the energy distribution systems, the assets are relatively old.

• Distribution companies expect a large number of assets to fail because they reach their end of life in 1 to 21 years from now (current year 2015).



Aging Infrastructure• Vibration and corrosion influences build up over time, and

nobody knows for certain how fast deterioration will take place.

• The best estimate for the lifespan is between 40 and 80 years, depending on the type of asset.

• This means we can expect at least part of the asset base to reach end‐of‐life within 1 to 11 years.

• End‐of‐life is defined as a non‐repairable failure of the asset.



Aging Infrastructure

• The failing assets will have to be replaced, which would potentially double the total workload in this 20 year period.



Aging Personnel

In parallel, to aging equipment , engineering staff retires after about 40 years in service. As most of them were employed during theseventies, we can expect a large part of them to retire in the year 2016. About half of the work force will retire by year 2013). IEEE/AiChE Joint Presentation April 9, 2015

Rev. 0 For Educational, Safety, and Process Improvement Purposes Only

20

One in Five

• One in five young people will need to become an engineer if we have any chance of addressing severe skills shortages and rebalancing the economy towards advanced manufacturing, new research has warned.

• There is no getting away from the fact that women are substantially under‐represented in manufacturing at a time when industry needs to be tapping into every potential talent pool to access the skills it needs.



Demand is high and is getting higher for qualified engineers

• With the number of baby boomers retiring in 2017 and in 2022 . . . the big fear is that . . . there are not enough individuals coming into the workforce to replace everybody, especially in the engineering fields.

• The dilemma of a shortage of skilled engineers has become a prime topic of discussion across the country.

• The present‐day labor market for most United States‐born engineering graduates remains relatively competitive in a time of high unemployment after large manufacturers and firms have consolidated operations during the recession.

• Many engineers also have to compete with highly qualified candidates in China and India.

• But recruiters indicate that demand for engineers and a more technically inclined workforce in the U.S. is only expected to grow.



Refinery/petro‐chemical facility Shutdowns

from 2009 to 2012

From 2009 to 2012, there were over 1700 refinery shutdowns, or 1.2 shutdowns per day. IEEE/AiChE Joint Presentation April 9, 2015 Rev. 0 For

Educational, Safety, and Process Improvement Purposes Only 23

Causes of power disruptions from 2009 to 2012

Other causes, mostly fires that occurred at the refinery/petro‐chemical facility.

Unfortunately, over 60% of the causes of electrical disruptions are not specified. Most of the unspecified power failures were listed as “a power failure occurred at the refinery and caused flaring” or similar statements.



Flooding during Hurricanes

• Although high wind and debris are the most commonly cited causes of hurricane damage, for Gulf Coast refineries in the US, where hurricanes hit most often and hardest, the greatest hurricane damage is the result of flooding.

• It is not uncommon for a water line to be seen in refineries, the electrical equipment needs to be raised out of the water flood line.



Structural Integrity• It is important to understand that there is a difference between reliably

supporting piping & process equipment versus being able to “stand in place” with piping and process equipment.

• In many existing facilities, – previous expansions, – modifications, – the age of the structures – as well as unknown conditions such as materials, – have drastically reduced the overall reliability of the support structures.

• While these structures remain upright, that does not mean they have the same reliability they once did in the original state.

• In many instances, the “in‐place” condition of many of the support structures are – already well below current minimum standards of reliability, – not to mention “good practice” standards.



New steel is added to aging pipe racks, this can occur 3 and 4 times, the

engineers designing these pipe racks could not have anticipated this.



Key Issues LPG Fire

• Lack of Freeze Protection Of Dead‐legs: failure likely resulted from water trapped in the propane mix control station dead‐leg freezing due to low ambient temperatures.

• Lack of an Emergency Isolation Of Equipment

• Lack of Fireproofing Of Support Steel

• Lack of Fire Protection For High Pressure LPG Service

• Chlorine Release: change it to sodium hypochlorite system.IEEE/AiChE Joint Presentation April 9, 2015 Rev. 0 For Educational, Safety, and Process


Multiple unit shutdowns

• Since most refinery/petro‐chemical facility units are integrated and sometimes share the same power supply, power failures could lead to the shutdown of these integrated units and the production loss of many refined products, thereby magnifying potential damages.

• A facility in Alaska, experienced a power outage. The hydrocracker and another unit were shutdown.

• In a Texas, plant experienced an external power failure that knocked its plant and other refineries in the area offline.



Safety and Reliability Approval• Most companies care about three values: financials,

reliability and safety.

• For manageable optimization purposes, a single‐objective is pursued.

• The common way forward is to express safety and reliability in monetary values.

• What is the cost to the bottom line if it is not corrected?

• There is no acceptable monetary value that can be place on safety and saving lives.



Production loss and profit penalties

• When a power failure occurs, a refinery/petro‐chemical facility unit or units, or an entire facility must be shut down and production is lost.

• A refiner could post a loss instead of profit in a quarter, and adverse financial impacts are further magnified when refining margins are poor.

• For a rough estimate, a US Gulf Coast refinery/petro‐chemical facility with an average‐ sized FCC unit of 80K b/d will lose $68K/hour for a downed unit.



Case study• A facility (refinery/petro‐chemical facility up north), was down from 28 October to

20 November 2012 due to SuperStorm Sandy.

• According to the company, the expenses related to the storm were $56 million before tax.

• This loss did not include missed production for over three weeks.

• Based on the refinery’s nameplate gasoline production capacity of 145 000 b/d and distillate production capacity of 115,000 b/d,

• a utilization rate of 85% and average spot market prices of gasoline of $2.812/gal and $3.084/gal for distillates in New York Harbor during the shutdown period, estimated revenue loss was over $650 million.

• Net profit loss ranged from $5.3 million for cash margins of $1/bbl to $26.5 million for cash margins of $5/bbl.

• US refineries outside the East Coast should expect a bigger financial impact, since East Coast refiners are known to have much lower refining margins than their peers in other parts of the country.



Potential legal liabilities • Aside from missed production, outages prompt unnecessary flaring of

hydrocarbons to avoid unsafe conditions.

• Over the past 10 years, the US EPA has entered into settlements with 28 different refineries that are aimed at restricting emissions by the oil industry.

• The EPA has acquired consent decrees from 105 US refineries in 32 states and territories since December 2000.

• All of the settlements have involved at least one of four primary pollution types: NOx, SOx, benzene and volatile organic compounds (VOCs).

• Furthermore, all of the violations involved one or more four key refinery/petro‐chemical facility components: the FCC unit, SRU, flares and heaters/ boilers.

• Excessive flaring can lead to environmental concerns and incur fines imposed by environmental agencies.



Potential legal liabilities

• A facility in Texas paid over $87 million in fines issued by OSHA along with undisclosed amounts in civil suits related to an explosion and subsequent fire at its Texas City, Texas, refinery/petro‐chemical facility that resulted in 15 worker deaths and over 170 injuries.



A Reliable Electrical Supply

• Electricity is the lifeblood of the refinery/petro‐chemical facility operation.

• Optimal design and excellent construction mean nothing if the plant cannot receive a consistent and reliable power supply.



Managing Electrical Outages



In handling risk management

• A refinery/petro‐chemical facility must install the most reliable equipment available in the market that can withstand disruptions caused by – weather, – power surges, – blackouts, – and any other outside elements.

• Since no equipment is perfect, reliability engineers and operators still need to prepare for worst‐case scenarios as well as the most frequently occurring possibilities.



Crisis Management

• When a problem does arise, the second part of the strategy — crisis management — comes into play.

• This involves the recovery technologies that allow for safe shutdown and continued operation, and the restart methods that will not lead to the same problem that caused the previous failure.



Prevention and protection

• One of the most important preventative measures a refinery/petro‐chemical facility can take is to have an efficient maintenance program.

• Studies show that the failure rate of electrical equipment is three times higher for components that are not part of a scheduled preventative maintenance program.



Reliability of systems

Everyone in this room, is smart, and can without a doubt, show that the reliability is not as bad as it looks, (using monte‐carlo type tools). In affect they can kill key improvements by using statistics and math. This is short term thinking.

A safer more reliable, facility will return higher profits.

Reward your employees who bring you safety ideas, and optimization ideas.



Radial Feed System• A Radial Feed System supplies electrical power via a single lineup of

components from a supply bus, such as the utility supply, to the final utilization equipment.

• In simplified terms, one feeder supplies one or more distribution transformers which in turn supplies one or more motor control centers or distribution panels.

• These motor control centers and distribution panels then supply individual motor or other branch circuit loads. There is no duplication of equipment.

• Failure of any single component will cause an outage to all loadsdownstream of the failure point and loss of production.

• In addition the electrical equipment must be shut down to perform routine maintenance.

• System investment is the lowest of the circuit arrangements, operation is simple, and reliability is as good as the quality and maintenance of the components. IEEE/AiChE Joint Presentation April 9, 2015

Rev. 0 For Educational, Safety, and Process Improvement Purposes Only

45

Dual Feed System• Various Dual Feed Systems are available and provide multiple paths to supply all or

parts of the distribution system.

• A primary selective system provides dual feeds on the primary or upstream side of a transformer.

• A secondary selective system provides dual feeds on the lower voltage side of a pair of transformers but not all the utilization equipment is redundant.

• Some power systems incorporate both primary and secondary selective options.

• Dual Feed Systems provide multiple ways to supply most components except for the final utilization equipment – individual starters to motors for instance.

• On properly designed Dual Feed systems, most maintenance can be performed following proper switching of loads without affecting refinery/petro‐chemical facility operations.



Dual Feed System• However, pumps and compressors that are not redundant (un‐

spared) will require operations interruptions for maintenance.

• On Dual Feed systems with normally‐closed ties or automatic transfer schemes, a power outage or significant loss of production should be minimized for a single feeder or transformer failure.

• Operation of the system is more complicated and initial installation cost is higher than for a Radial Feed System.

• The main advantage of a Dual Feed system is that because of the multiple paths to provide electrical power, the electrical system has a high degree of reliability and availability which results in an overall lower LPO exposure than for a Radial System.

• This is important for critical process or utility operations.



Loop‐Feed or Ring‐Bus System

• A Loop‐Feed arrangement is sometimes used on primary distribution systems to feed multiple loads from different sources.

• Generally, it is a system that can be manually‐configured to isolate portions of the loop for maintenance or repair.

• A ring‐bus system includes multiple sources and loads in a normally‐closed loop system with protective relaying designed to automatically isolate faulted sections.



Combinations of Radial, Dual Feed, and Looped Systems

• Combinations of the above systems are present in most facilities.

• The incoming Utility power and perhaps the primary distribution system in the plant are usually some form of Dual Feed, Looped, or Ring‐Bus system for reliability and maintainability.

• Critical utility or common facilities that can never be shutdown, such as boiler plants, effluent systems, sulfur removal plants, plant air compressor systems, or the like, almost always require 2 or more sources of power (usually Dual Feed system) with careful consideration of load arrangement for maintainability.

• The electrical availability, operational reliability and maintenance requirements are balanced against installed capital costs.

• It should be noted that installation of a radial fed system connected to a secondary selective system does cause problems trying to schedule maintenance for the secondary selective bus.



Formulating strategies to mitigate power failures

• Every processing unit within an oil refinery/petro‐chemical facility was meticulously designed and planned on the assumption that it would receive a constant power supply.

• With that in mind, it is necessary to consider the steps that could be taken to ensure 24/7 production from every process.

• Risk management and crisis management must be practiced to maximize productivity of the plant.



Impacts of refinery/petro‐chemical facility power failures



Power independence

• Onsite power generation via combined heat and power (CHP) units and microgrids are worth consideration.

• The latest CHP and microgrid technologies can be incorporated into the design of a new refinery/petro‐chemical facility power grid that can be combined with other renewable energy generation units as a way to improve power supply security and reduce plant carbon footprint.



Get everybody on board to save bottom line

• Petro‐Chemical facility owners and refiners are advised to set a goal of “zero” power failure and “fastest” power recovery and share the goal with all the employees, including people working outside the plant.

• When a refinery/petro‐chemical facility shuts down, business profit is gone, thereby affecting everybody in the company, from the CEO to the maintenance worker.

• Any employees that offer key contribution in terms of ideas and innovations to increased reliability and availability of a power system should be offered financial incentive for avoiding power failures.

• The Power of Habit! By: Charles Duhigg Read it….IEEE/AiChE Joint Presentation April 9, 2015 Rev. 0 For Educational, Safety, and Process


Major Equipment In Electrical Systems

• Generators• Motors • Power & control cables • Transformers • UPS• Battery chargers • Battery banks • Switch gear & control gear • Panels • Lighting



Transformers• Almost every malfunction is a result of the failure of the device’s insulation system.

• The insulation is what keeps the transformer in electrical balance and, when the insulation ceases to function, the entire transformer is susceptible to immediate failure.

• Faults, heat and mechanical damage will lead to insulation failure, but the electrical engineer can avoid these issues by selecting a unit capable of withstanding expected operating and fault conditions.



Cables • A refinery/petro‐chemical facility will use miles of cable for power

distribution, motor operation and process control.

• Its ability to transport signals and current will impact the entire refinery/petro‐chemical facility’s ability to operate.

• Protection of all the cables is vital for any part of a process.

• Cables will suffer from degradation to their insulation through heat and contamination.

• Parts of a cable that heat up from excessive current or external factors will be vulnerable to water trees and short circuits.

• Cables surrounded by polymer insulation are especially vulnerable to the damage caused by water trees.




Cables: An electrical cable comprises two or more wires running side by side and bonded, twisted, or braided together to form a single assembly, the ends of which can be connected to two devices, enabling the transfer of electrical signals from one device to the other.



Switchgear

• Switchgear is a combination of electrical enclosures, buses, protective relays, circuit breakers, fuses, controls and indicating devices that are used to distribute power to and protect other electric equipment.

• Receiving power from generators or transmission cables, they will distribute their power to other switchgear (or switchboards) and motor control centers.



Switchgear• Arcing is a major threat to switchgear safety and reliability.

• Major arc flashes and blasts will ruin the switchgear and nearby equipment, and endanger nearby workers.

• An arcing event can cost a refinery/petro‐chemical facility as much as $15 million per incident.

• Plant engineers should select arc‐resistant models that utilize quick sensing and switching to de‐energize arcs.



Motor control center

• A motor control center (MCC) is used to group a number of combinations of motor controllers together with a common power bus.

• A MCC gives operators easy and safe control over a number of different motors throughout the facility.

• Motor controllers serve several key functions: starting or stopping the motor it controls, interrupting the current of the motor, and providing overcurrent protection.




Panels: is a component of an electricity supply system which divides an electrical power feed into subsidiary circuits, while providing a protective fuse or circuit breaker for each circuit in a common enclosure.



MAJOR EQUIPMENT IN ELECTRICAL SYSTEMS

Switchgear & control gear : switchgear is the combination of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. Switchgear is used both to de‐energize equipment to allow work to be done and to clear faults downstream



Motors

• As far as consumption of electric energy goes, nothing in a refinery/petro‐chemical facility comes close to the amount of power provided to motor‐driven devices.

• Motor‐driven equipment will typically account for 70% of energy consumption in refineries, so special attention must be paid to their proper selection and operation.




Motor: a motor, is a machine designed to convert one form of energy into mechanical energy



Protective relays

• Relays are essential to any electrical system.

• Pick one kind of relay, so that you can develop a reliable, intelligent data collection system.

• Do not allow any capital project team to implement multiple relay manufactures. It complicates the entire system.

• They are used in all parts of the system, from the generators and substation to the transmission lines and load.

• Protective relays detect abnormal system conditions and direct the circuit breakers to operate in the proper manner, to correct any abnormality.



Grounding

• A properly grounded (earthed) system will protect equipment and personnel from exposure to fault currents.

• Well‐placed and ‐designed grounding will divert any faults to earth or a grounded bus.

• It is utilized throughout an electric system for equipment such as transformers and motors, and on conductive structures like storage tanks and pipes.



Inadequate Lightning Protection• In Port Arthur, Texas, facility experienced lightning that led to a power

outage and also stated a fire. The lightning caused a crude unit, two hydrotreaters and a delayed coker to shut down.

• Unlike the above experience, in July 2009, a refinery/petro‐chemical facility in Pasadena, Texas, experienced a lightning strike that disabled all power to the Tank farm, which resulted in loss of feed to the refinery’s crude unit. The feed was restored with a backup generator, and the refinery was able to run using backup power and keep operations online despite the loss of power to the tank farm.

• A facility in Los Angeles CA experienced a power surge caused by lightning, which caused the hydrocracking unit to trip. Emissions of sulphur dioxide and hydrogen sulphide were released during the flaring caused by the shutdown.



Lightning Protection

• Fixed Angle Method• Rolling Sphere Method• Proper grounding



Introduction to Lightning Protection

i. Notes continued:

» Aluminum materials shall not be used where they come in to direct contact with earth. A bimetallic connector shall be installed not less than 10” above earth level.

» Aluminum conductors shall not be attached to a surface coated with alkaline base paint, embedded in concrete or masonry, or installed in a location subject to excessive moisture.




– Air Terminal height

• The tip of an air terminal shall not be less then 10 inches above the object or area it is to protect.

– Zone of protection

• To determine the zone of protection, the geometry of the structure shall be considered.




– Location of devices

• There are set distances that an air terminal can be installed apart from each other on a roof peak or at the edge of the roof that is pitched or flat.– Within 2’ of the edge of the roof

– 20‐25 ft. maximum spacing along the ridge.



Recovery and restart

• Preventative and protective measures will make great strides towards decreasing downtime arising from power failures.

• But if a failure does occur, it is necessary to minimize loss in production and resume normal operation as quickly as possible.

• Even if the units are running at reduced rates, flaring can be reduced and production will not completely halt.



Backup generators

• When the power goes down, all the units have to stop.

• On‐site generators give operators the ability to continue running units when the primary power goes down.

• These units are not usually used as the primary power due to fuel costs.




Generator: a generator is a device that converts mechanical energy to electrical energy for use in an external circuit.

The source of mechanical energy may vary widely from a hand crank to an internal combustion engine. Generators provide nearly all of the power for electric power grids.



Uninterruptible power supply • UPS is a device that acts as a backup power source.

• It is designed to detect power dips and power failures, and initiate a battery backup power once a problem is detected.

• A UPS should only be used in an environment that it is rated for.

• UPS system loads consist of – digital control systems, – programmable logic controllers, – critical process instruments, – fire and gas alarm panels, – safety shutdown systems, – process equipment control panels (boiler controls, compressor

controls, and so on) – and other critical electrical loads.




UPS: An uninterruptible power supply, also uninterruptible power source, UPS, is an electrical apparatus that provides emergency power to a load when the input power source, typically mains power, fails

UPSINPUT OUTPUT

SpikesInterruption

Harmonics

Under Voltage

ContinuousCleanFiltered

CriticalLoads



3‐ UPS COMPONENTS1. Normal Electric Source

2. Rectifier (Charger)

3. Battery.

4. Inverter.

5. Static Transfer Switch (STS).

6. Maintenance Bypass Switch (MBS).

7. Bypass Electric Source.STS

Critical Load

BypassSource

NormalSource



4‐ How UPS Works?

STS

Critical Load

BypassSource

NormalSource

Normal ModeAuto Bypass

Manual Bypass

Power Outage(Battery Mode)

FAILURE




Battery banks: a container consisting of one or more cells, in which chemical energy is converted into electricity and used as a source of power




Battery charger : A battery charger or recharger is a device used to put energy into a secondary cell or rechargeable battery by converting current from AC to DC.



What we have found during site visits

• Pipe racks are severely overloaded. When performing laser scans it can be seen that the pipe racks are in fatigue, bending beyond the calculated values.

• Corrosion is causing pipes and pipe racks to fail.

• Area classification issues, there are to many to count.– Hydrogen pipe/Control Valve in close proximity to a new PCR.– Conduit Seals not installed or installed incorrectly.– Arcing and sparking devices in areas that need explosion proof devices.

• New equipment added that now creates an area classification issue.

• SIS and SIF systems are not in place.

• Aging personnel, leaving behind young untrained personnel. IEEE/AiChE Joint Presentation April 9, 2015 Rev. 0 For Educational, Safety, and Process


What we have found during site visits

• Mis‐coordination of circuit breakers and fuses.

• Undersized equipment (voltage or current).– Cannot withstand the short circuit current– Cannot withstand the continuous current.

– I have heard CEO’s say: we don’t have this problem in our facility do we? (radial feeds to critical process units? Can’t be). It is our jobs to inform our supervisors, they trust the line managers, the maintenance crews, etc.. To inform them of safety and reliability issues.



An electrical master plan addresses

• The reliability and safety of the existing electrical system.

• A report should be created to mitigate (short/long term) plan to improve the reliability and the safety of the electrical system supported by justification.

• Electrical cable and equipment needs to be reviewed to see if the support structures are in good shape.



A Master Plan should include:• Recommendations of applying best practices and equipment assessment.

• Develop an accurate system model (ETAP, SKM, Easy Power etc..) data collecting from the site visit to figure out some of the reliability or safety issues such as:

– Substation configuration (radial or redundant) – Under rated equipment– Overload equipment– Voltage Dip – Single Point of Failure– Short Circuit capability– Replacing of oil switches and protection relays– Future substation or equipment capability



Long Range Plan Theories

• Long Range Plan Theories – Equipment Consolidation– Equipment Modernization– Equipment Maintainability

• Long term goal, add substations as new load dictates– Existing study must show that limited existing capacity exists

– New load must be required– Envision one substation per area



Goal of the Master Plan is to:

• Determine the strengths and weaknesses of existing system.

• Determine the load growth potential.

• Perform a reliability analysis.

• List recently completed projects.

• List identified problems from survey.IEEE/AiChE Joint Presentation April 9, 2015 Rev. 0 For Educational, Safety, and Process


Master plan should clearly • List code related issues.

• List grounding issues.

• List lighting issues.

• List area classification issues.

• List maintenance department and operator complaints, confirm these complaints.

• List bad actors.IEEE/AiChE Joint Presentation April 9, 2015 Rev. 0 For Educational, Safety, and Process


System Studies• Can transmission system increases (larger transmission transformers) – bring more capacity to a distribution substation?– Limitation is the switchgear bus

• Can the system utilization be improved through power factor correction?

• Can how the feeders are fed from the distribution substations be optimized to isolate outages?

• Can how the unit substations are fed from feeders be optimized to isolate outages?



Safety

• Entire system analyzed for shock and arc flash hazards.

• Problem areas are identified and corrected– Equipment Replacement– Settings Adjustments– Other arc flash mitigation techniques



Spare Equipment

• Identify long lead items that have sufficient risk of failing that extended downtime could be avoided by having spare equipment onsite– Transformers– Breakers– Etc.



Improve Maintainability

Redundancy study of unit substations• Insure A & B pumps are fed from different substation sources

(Switchracks, and or MCC’s) at a minimum but ultimately different substations.

• Evaluate turn around schedule versus unit loads to ensure substations can be shut down for maintenance.

• Improve equipment maintenance through equipment design.

• i.e. Draw out breakers are easier to maintain than bolt‐in breakers.



Equipment Consolidation

• Evaluate equipment and proposed projects keeping in mind the goal of equipment consolidation

• I.e. instead of multiple smaller switchracks or MCC ‘s or buildings, consolidate like equipment into larger buildings (Power Control Rooms).



Modernize Old Equipment

• Equipment Replacement– Old equipment that can not meet existing standards or be modernized should be replaced.

– Cable Busses– Old Switchracks– Obsolete equipment should be replaced



Modernize equipment

• Add new relays, breakers, etc. to equipment that the core is still functional but better technology exists for components.

– Relay replacement projects– Breaker replacement projects



Not everything is the same.• One facilities bad actor may not be an issue at another

refinery/petro‐chemical facility.

• Oil switches might fail for a variety of reasons,

• PILC cable with pot heads connect to the oil switch, might have issues.

• SF6 might work better in colder climates.

• Some maintenance crews love PILC, others hate it and want it all out of the ground.



Refinery/petro‐chemical engineers and managers need to know the following:• What are the lessons learned for refinery/petro‐chemical engineers and

managers when dealing with SIS systems or a lack of a good SIS system in place? – Complexity of operations and the pressure to control the number of operators

makes it more and more important to have a reliable SIS.

• What are the lessons learned for refinery/petro‐chemical engineers and managers when dealing with electrical distribution systems or a lack of a good redundant electrical distribution system in place? – Relief scenarios involving electrical distribution faults are complex and can be

worst case.

• In your opinion what do refinery/petro‐chemical engineers and managers need to know about master planning and making a petrochemical system safe and reliable? – PHA/LOPA should be extended to involve electrical distribution faults.



Understand the Power Requirements

• Total Connected Load

• Running Load– Rule of thumb in industrial facilities 90% of load rotating and 10% of load static.

• Utility Required Power Factor

• Utility Required Harmonic Distortion



Understand the Utility Connection

• Voltage Level Available from the Utility

• Utility Requirements for Connection– Most utilities have documents with their requirements for connection

– The utility will normally want to approve the one line and layout.

– Utility may require some space and equipment inside the substation for metering.



Understand the Internal Electrical Distribution

• Routing Power Cables in the Facility– Cable Tray– Duct Bank– Air Insulated Conductors

• Unit Substation Size– 25‐MVA max for 15‐kV– 15‐MVA max for 5‐kV– 2.5‐MVA max for 480‐V

• Unit Substation Voltage Levels– 15‐kV

• 7.5‐kV– 5‐kV

• 2400‐V– 480‐V



Understand your Unit Substation Equipment

• Power Center• Transformers• Switchgear• Motor Controllers



Understand the Power Centers

• Locating– Classified Area– Blast Zone

• Prefab– Elevation– Shipping Issues

• Site Built– Building Penetrations– Equipment Access



Understand the Transformers• Transformer Sizing

– Connected Load– Running Load

• Transformer Impedance– Short Circuit– Arc Flash

• Transformer Grounding– High Resistance Grounding

• 5‐kV• 2400‐V• 480‐V

– Low Resistance Grounding• 15‐kV• 27‐kV• 38‐kV



Understand Your Switchgear• Medium Voltage (38‐kV, 27‐kV, 15‐kV, 5‐kV)

– Metal Clad– Arc‐Resistant– Nema 3R– Shelter Form

• Low Voltage (600‐V)– Metal Enclosed– Arc‐Resistant– Nema 3R



Understand Your Motor Control Centers (MCC)

• Medium Voltage (5‐kV only)– Metal Enclosed– Arc Resistant– Nema 3R (Outdoor)

• Low Voltage



Understand the Electrical Loads

• Motors– Pump– Compressors– Fans

• Variable Frequency Drives• Other Loads



Understand Your Motors

• Motors– Medium Voltage Motors

• Induction • Synchronous

– Low Voltage Motors• <250‐hp



Understand Your Substation Configuration

• Radial• Primary Selective• Double Ended

– Tie Open– Tie Closed

• Other Variations



Questions?

• Vincent W. Wedelich *P.E. MBA• [email protected]• 832‐214‐2804 main• 832‐932‐9236 cell

• *licensed professional engineer in Texas.



Electrical master plan for chemical engineers and managers

Engineering

Transcript of Electrical master plan for chemical engineers and managers