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I N S I D E

Power Plants World Class Development of service

providers network forIndian thermal powerplants

Application of Variablefrequency drives for

Power plant Auxiliaries

- CII - Godrej GBC

Thermal Power PlantEfficiency & Boiler

Optimization

- Stephen K. Storm,

Storm Technologies, Inc. (USA)

Make Indian Thermal

March 2010The Monthly Newsletter No.1

Make Indian Thermal Power Plants World Class Development of service providers network for

Indian thermal power plants

CII-Sohrabji Godrej Green Business Centre (CII-Godrej GBC) is promoting theconcept of Make Indian Thermal Power Plants world class, with the support of

all the stake holders in Indian power sector. The main objective is to facilitatecontinuous performance improvement in Individual Indian thermal power plants

and help them in achieving the world class standards.

Indian thermal power plants offer enormous potential for efficiency improvement,however, the actual implementation of the efficiency improvement projects arenot taking place at the required pace. The following reasons have been

repeatedly highlighted in many of the CII forums by end users are:

FLack of awareness about the latest technological developments &performance improvement techniques

FVery limited or non availability of capable service providers for the Indianthermal power plants

Against this background, as part of the initiative of Make Indian thermal power

plants world class, CII-Godrej GBC has started facilitating the development ofservice providers network for Indian thermal power plants.

The U.S. Department of Energy (DOE) and its National Energy TechnologyLaboratory (NETL) and the India Mission of the U.S. Agency for InternationalDevelopment (USAID/INDIA) are supporting the initiatives related to the

development of the service providers network.

CII-Godrej GBC is taking up the following activities for facilitating thedevelopment of service providers network for Indian thermal power plants:

FAwareness creation - centre wise / unit wise training programmesand workshops for creating awareness about latest efficiencyimprovement techniques

FInformation dissemination through periodic news letter with technicalarticles on latest developments and case studies

FActing as a nodal agency for transfer of technologies and technicalservices

FFacilitation of demonstration of performance improvement projects inIndian thermal power plants

The monthly newsletter Power plant efficiency brought out with the solepurpose of disseminating information amongst the end users would throw lighton various technological developments, best practices from Indian &International thermal power plants. The newsletter will also highlight the currenthappenings in the power sector at national and international level.

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POWER PLANT EFFICIENCY

NEWSLETTER


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Application of Variable frequency

drives for Power plant Auxiliaries

BackgroundMotor-driven systems are often designed with safetymargins to handle peak loads and extreme conditions.

These excess margins lead to energy inefficiency insystems and increased power consumption. The ability to

adjust motor speed enables closer matching of motoroutput to load and results in significant reduction inenergy consumption.

The variable frequency drive varies the speed of the motorby changing the frequency and voltage of the motorkeeping the v/f ratio constant.

Variable speed drives are used for the following reasons:

1. To vary the capacity of the motor drivenequipment to match with the changing loadrequirements

2. To minimize the excess margin built in theequipment

3. For accurate and continuous process control

Previous StatusA condensate extraction pump of the fol lowingspecifications is in operation in a 250-MW thermal power

plant.

3 Capacity - 770 m /hr Head - 205 m Motor rating - 650 kW No of stages - 5The schematic diagram of the system is shown below.

Typically, all of the auxiliary equipments in power plants,such as pumps and fans, are designed with excessmargins to ensure reliability of the plant and also to meet

requirements during extreme operating conditions.

These excess margins lead to increased auxiliary power

consumption during the normal operating conditions ofthe plant. With the help of the variable frequency drives,the operating speed of the auxiliary equipment can be

optimized to reduce power consumption and to match

actual requirements.

A 250 MW thermal Indian power plant has installedvariable frequency drive for centrifugal equipments, suchas the condensate extraction pump (CEP) and seal air

fans. This has resulted in significant energy savings. Thedetails of the project related to installation of VFD for theCEP are given below.


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Parameters Values

2Discharge Pressure 21.3 kg/cm

2Deaerator Pressure 6.9 kg/cm

Flow 640 TPHMotor speed 1450 rpm (50 Hz)

Power Consumed 590 kWh

The operating parameters of the CEP at full load operating

conditions are given below.

The control valve is only about 60% open during normaloperating condition. This valve throttling leads to pressureloss across the valve and hence energy loss. The pressure

loss across the control valve is estimated as 7.5 kg/cm2based on pressure measurements taken before and afterthe control valve.

Performance improvement project

The operating conditions and the measurements clearlyindicate that there is an excellent potential to minimize thepressure drop across the control valve and reduce energy

consumption. This can be achieved by optimizing thenumber of stages of the pump or installing a VFD for thepump with feed-back control.

In addition to energy savings and better process control,installation of VFDs has the following benefits compared

to the stage reduction.

1. Maintenance costs can be lower, because lower

operating speeds result in longer life for bearingsand motors.

2. Eliminating the throttling valves and dampers alsodoes away with maintaining these devices and allassociated controls.

The details of the operating condition of the CEP aftinstalling the VFD are given below.

Financial analysis

The annual savings achieved is Rs 4.52 million (USD 0.million). The investment made for installation of VFD is

6.00 million (USD 0.12 million). The simple paybaperiod is 16 months.

Replication Potential

In a typical 250-MW thermal power plant, the auxiliapower consumption for the CEP is around 0.27% of t

total plant output. The savings that can be achieved installing an HT VFD varies from about 15-20%.

This project has high replication potential in majority of tcaptive and utility thermal power plants in IndConsidering the present installed capacity of the co

based thermal power plants in India, the replicatipotential of this performance improvement project estimated to be as high as 30 MW.

CEP Parameters With HT VFD drive

2Discharge Pressure 17.5 kg/cm

2

Deaerator Pressure 6.9 kg/cmFlow (TPH) 640

Motor speed 1250 rpm (42 Hz)

Control valve CD14 position 95%

Power Consumed 440 kWh

Benefits of the project

Energy Savings achieved

Electrical Energy Saving 1.26 Million Units

Annual Savings Rs 4.52 Million/ yearSaving of Coal 671 Tons/ year

Reduction of CO2 Emissions 2460 Tons/ year

3. A soft starter for the motor is no longer required.

4. Controlled ramp-up speed in a liquid system celiminate water hammer problems.

5. The ability of a VFD to limit torque to a usselected level can protect driven equipment thcannot tolerate excessive torque.

In view of the above-listed additional benefits, the plainstalled a HT VFD for the CEP, even though it costs mu

more than stage removal.

03


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Thermal Power Plant Efficiency &

Boiler Optimization

Stephen K. Storm

Storm Technologies, Inc. (USA)

Around the globe, we all bear the responsibility of usingour energy resources wisely. However, one of the

greatest challenges we face is the conversion of

affordable fossil fuels into electricity as efficiently and

cleanly as possible. Electric power generation from coal

is the most affordable energy on the planet and we must

use it responsibly in our effort to achieve sustainable

power generation growth. Coal will continue to serve as a

primary source of energy worldwide, and it will be the

bridge to our future, as we develop new means of

renewable energy and other means of generating

electricity. An example of a responsible, yet mutually

beneficial, climate change program in the power sector isthe Performance Optimization and Efficiency Program

supported by Storm Technologies at selected power

plants in India over the past several years.

Storm's program reviews power plant performance by

inter-relating the variables of performance with fuel quality,

operations and maintenance (O&M), and plant reliability.

Sustaining optimum plant performance and reliability is a

must for all plants, even if they have not been rehabilitated.

An introduction, or refresher course, on best practices

for O&M of existing and future coal-fired generating plants

in India is worthy of the resources needed to implementsuch a program.

Storm Technologies' introduction of the best practices is

an important paradigm shift in the O&M of the existing fleet

and future coal-fired generating plants in Asia, as well as

the United States. The main objective of the program is to

demonstrate the importance and the environmental

benefits of combustion and boiler optimization and overall

plant efficiency/heat rate improvement.

Storm Technologies' program has been used by the U.S.

Department of Energy to promote Best Practices underthe Asia Pacific Partnership on Clean Development and

Climate (APP). The program included fourteen

comprehensive areas of evaluation including pulverizer

systems, fuel lines, burner performance, as well as total

combustion airflow measurement, furnace exit flue gas

profiling, and measurement and monitoring at several

points between the boiler and the stack.

The basic purpose of the program's protocol utilized w

to provide a process for the plant to periodically test, tu

and comprehensively evaluate opportunities for pla

efficiency and heat rate improvement. It should also

noted that the program was purposely designed f

replication at the Indian super thermal power plan

selected for demonstration. Some of the typic

challenges today's plants are faced with in India a

related to plant efficiency, fuel conservation, reduc

generation and limited coal supplies. Taking these in

consideration, the key to the program is essentia

identification of opportunities for improvement throug

the implementation of a performance preservatio

program.

Program Overview

Quite often, there are numerous low-hanging fru

opportunities for combustion and plant efficien

improvement, and some of these include coal pulverizand burner performance, the opportunity to improve low

furnace heat absorption, reduce furnace exit g

temperatures, reduce carbon in ash levels, as well

reducing air in-leakage, both upstream and downstrea

of the air heater, to name a few. Most of these factors at t

boiler influence heat rate and efficiency, generation a

environmental performance. In an effort to evaluate t

previously identified opportunities for improvement,

series of performance tests were completed.

These included measurement of:

FGross Turbine Cycle Heat Rate

FMill / Fuel Line Performance

FTotal Airflow Measurement & Calibration

FFurnace Exit Gas Profiling

FF lue Gas and F l y ash Me asu re me n t f

Performance Evaluation

Ultimately, the goal of such an evaluation is to determin

the stealth losses and/or the unaccountable loss

impacting heat rate performance. What is different abo

this program as compared to most combustion tunin

programs is that the protocol used at the participatin

Indian power plants evaluates the entire boiler syste

with the fuel lines and combustion airflow paths regarde

as the inputs.


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Furthermore, furnace exit profiling and flue gas

measurements from the boiler to the stack are also used to

evaluate overall performance.

Considering the comprehensive nature of such a

program, Storm Technologies has developed a simplified

Annual Plant Performance Longevity and Evaluation

Program (APPLES) to help establish such testing

protocols. The development of the standards for

performance can take time and requires a true team effort.

However, once completed, the plants enhance their ability

to maximize load generation and performance while

simultaneously improving environmental performance. It

is not untypical to find thermal plants operating between

5% 10% lower than the plants design thermal efficiency

and this correlates with a tremendous opportunity for heat

rate improvement, fuel savings, as well as overall CO2

emissions reduction. Quite often, many of the deviationsare not related solely to the turbine. However, boiler

performance and auxiliary horsepower consumption are

equally as important and often neglected.

Recently, Storm Technologies presented the project

completions of work completed in India at POWER-GEN

Asia. Based on the facts collected thus far, over the past

year and the result of the program identified, on average a

deviation of ~124,000 tons of CO2 was identified (on

average for each of the two 210-MW units).

For two thermal plants with 6 units each, the potential for

reduced CO2 emissions would be on the order of

~744,000 tonnes of CO2/year. It should also be noted

that, by reducing CO2 emissions, the program has

demonstrated how fuel consumption can also be

substantially reduced. By implementation of

recommendations on these units, payback for the

program investments yielded short-term payback with

respect to efficiency improvement and improved

generation performance and is gaining a substantial

amount of attention in the country.

By demonstrating the capability to improve load

generat ion, reducing fue l consumpt ion and

simultaneously improving environmental performance,

the benefits of the program are obvious.

Key Points of the Program

Some key points that were instrumental in the program

success were:

FTeam training and the personnel commitment

FInstallation of comprehensive diagnostic testi

ports was essential

FOptimization of the excess oxygen as proven

the furnace exit was required to validate actucombustion performance

FPulverizer performance and fuel balance is

critical component of the optimization program

FTotal airflow management is mandatory

FBurner tolerance and mechanical maintenance

the firing system is essential

FBoiler efficiency and air in-leakage measuremen

are critical to the support of the teamF

Once again, it should be noted that efficien

opportunities also resulted in the plants ability

simultaneously improve plant capacity and redu

emissions.

Achieving energy efficiency within thermal power plants

a mandatory requirement for sustainable and responsib

power generation and demands a fundamental an

proven approach which has been demonstrated by

small group of Indian coal-fired power plants who are

be commended for their leadership by example.

For more information about

Storm Technologies, Inc., you can visit

or

Contact Stephen Storm at

www.stormeng.com

[email protected].


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About CII, CII Godrej GBC

CII is a non-government, not-for-profit, industry-led and industry-managed organisation, playing a

proactive role in India's development process. Founded over 113 years ago, it is India's premier

business association, with a direct membership of over 6500 organisations from the private as well

as public sectors, including SMEs and MNCs, and an indirect membership of over 90,000companies from around 350 national and regional sectoral associations.

The Government of Andhra Pradesh, CII, and the House of Godrej, with the technical support of the

United States Agency for International Development (USAID) have launched the CII-Sohrabji

Godrej Green Business Centre to offer much needed Green Services to Indian industry.

Cll-Godrej GBC is a Centre of Excellence in Energy Efficiency, Green Buildings, Renewable

Energy, Water, Environment & Recycling and Climate Change activities in India.

CII-Godrej GBC is promoting the concept of Make Indian thermal power plants world class. The

main objective is facilitating continuous performance improvement in thermal power plants andthere by achieving world class standards. As part of this, CII-Godrej GBC is also facilitating

development of a service provider's network for Indian thermal power plants.

Supported by USDOE, NETL & USAID/India

The U. S. Department of Energy's (DOE), National Energy Technology Laboratory (NETL) is

providing technical support for power plant efficiency improvement on the Greenhouse gas

Pollution Prevention (GEP) Project of the India Mission of USAID. CII-Godrej GBC is supporting the

GEP Project by developing a service provider's network for Indian thermal power plants.

This technical bulletin has been developed as part of the information dissemination programme of

this effort.

Survey No 64, Kothaguda Post, Near HITEC City,

Ranga Reddy Dist., Hyderabad - 500 084

Tel: +91 40 23112971-73, Fax: +91 40 23112837

www.greenbusinecentre.com

S Karthikeyan

[email protected]

For further information, Please contact

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