Vol. 28 No. 1 March 2005

Geographical Distribution

Advanced Control Features

Petrol Depot Automation System

Control System for Diesel-Electr ic

Locomotive

Gravimetric Feeder Control for feeding coal

in power plants.

A prototype system comprising hardware, firmware,

software and networking was designed catering to

the identified Input / Output requirements (600 nos.)

and control loops (6 nos. ) of Unit 1 and Unit 2 of

Vijayawada Thermal Power Station (VTPS). The

prototype system was installed and commissioned at

VTPS in March 2003. It has been working

satisfactorily since the time of commissioning.

Omega System has been already used in the

development of the following control applications :

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A NEW-GENERATION CONTROL

A N D I N S T R U M E N TAT I O N

PLATFORM (OMEGA) FROM BHEL

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BHEL has recently completed a mega project for the

design, development, implementation and site

testing of a state-of-the-art Control and

Instrumentation (C&I) Platform, code named

as a significant step in the direction of

achieving self-reliance in the high-tech and

emerging area of C&I. The Omega System has been

tested and commissioned at Vijayawada Thermal

Power Station.

The project comprised two phases. Phase-I,

spanning over 2½ years, was aimed at design of

system architecture, development of hardware,

firmware and software, including development of a

prototype C&I system and site testing. Phase-II,

spread over two years with an overlap of 6 months

with Phase-I, focused on design, development and

implementation of advanced control algorithms.

The system architecture of Omega Control and

Instrumentation Platform has been designed

catering to a wide range of applications in Power and

Industry Sectors. The main features of Omega

System are :

Open Architecture

Omega,

Modular Scalability

Enterprise-Wide Solutions Omega model control room

BHEL DEVELOPS & TEST-

COMMISSIONS INDIA's FIRST

T H Y R I S T O R - C O N T R O L L E D

SERIES CAPACITORS

BHEL has proven its capability in the area of Flexible

AC Transmission Systems (FACTS) by test-

commissioning India's first indigenously developed

Thryristor Controlled Series Capacitors (TCSC)

recently, at 400 kV sub-station of PGCIL at

Ballabgarh, Haryana. The TCSC is installed at

Ballabgarh end of the 400 kV Kanpur–Ballabgarh

line. The basic purpose of this installation is to

improve power flow and system stability using in-

built damping controller.

The project was jointly funded by BHEL, PGCIL

and Department of Information Technology (DIT),

and executed by BHEL. The project was executed

in two phases. The first phase was undertaken as a

commercial project and involved installing 35%

(27% + 8%) Fixed Series Capacitors, which was

commissioned in mid-June 2002 and has been in

service since then. The second phase of the project

was undertaken as development project for

conversion of the 8% fixed series capacitor bank to a

variable one (TCSC) and thus enhance the

maximum compensation level.

The system was successfully tested in both open and

closed loop up to its maximum capacity. The

system will be shortly put in continuous operation.

There are only six commercial TCSC installations in

the world, including the one commissioned recently

The TCSC system developed & commissioned

by ABB at Raipur in the 400 kV Raipur-Rourkela

double-circuit line.

With this achievement, BHEL joins the select group

of the few companies in the world, like ABB and

Siemens, who can offer this technology.

S E L E C T I V E C A T A L Y T I C

REDUCTION SYSTEM FOR

MINIMISING NOx EMISSION

DEVELOPED

Combustion of coal in pulverized form is the most

widely used process for power generation.

However, coal-fired power plants are one of the

main sources of the polluting NOx emission from

coal combustion process. In view of this, BHEL has

developed Selective Catalytic Reduction (SCR)

system to reduce the level of NOx by around 95%.

In the selective catalytic reduction method, the NOx

concentration in the flue gas is reduced through

injection of ammonia in the presence of a catalyst at

the optimum temperature of between 300 C and

400 C. The reaction products are elemental

nitrogen and water vapour. The reaction is

selective, which means that oxidation of ammonia

and sulphur dioxide should not occur.

The efficiency of NOx reduction is dependent upon

several factors such as NOx concentration at the inlet

of the catalyst, flue gas temperature, the ratio of

ammonia injection, oxygen concentration, and

catalyst properties. An increase in ammonia

injection leads to increased NOx reduction, but the

amount of ammonia which reacts with nitrogen

oxide, depends on the activity of the catalyst. The

un-reacted ammonia leaving the stack is called

ammonia slip.

The selectivity of the catalyst defines the extent to

which the desired reaction occurs. A decrease in

selectivity allows unwanted reactions such as the

oxidation of sulphur dioxide to sulphur trioxide to

occur. The un-reacted ammonia will react with

sulphur trioxide in the presence of water. The

unwanted product is ammonium bisulphate, a sticky

compound that can cause corrosion.

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Scheme of SCR plant at Fuel Evaluation Test Facility (FETF)

at BHEL-Tiruchirapalli

In order to evaluate the efficiency of the system, an

SCR plant has been set up at Fuel Evaluation Test

Facility at BHEL-Tiruchirapalli. The catalyst has

been developed by Ceramic Business Unit (CBU) of

BHEL (at Bangalore).

A N O V E L B U R N E R F O R

“HERITAGE LOCO”

BHEL has recently developed a novel oil burner

suitable for “Heritage Locos which are used for

traction in narrow-gauge Mountain Railways. The

salient features of the developed burner are that it

neither requires an oil pump for atomization nor a

blower for supply of combustion air. The burner just

requires an oil tank at a height of 1.5 m to make the

oil to flow into the burner, and combustion air is

aspirated by suction created by steam ejectors in the

loco chimney. The burner was developed on a

request from M/s Golden Rock Railway Workshop.

The burner system has been fitted into a “Heritage

Loco” and successfully test-run.

The burner has been developed at the Liquid Fuel

Burning Test Facility at BHEL-Tiruchirapalli, by

simulating the loco conditions in a specially created

test rig.

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“Heritage loco burner test facility at BHEL-Tiruchirapalli”

IMPROVED PUMP HYDRAULICS

FOR 150 KHI SIGMA DESIGN

BOILER FEED PUMP DEVELOPED

BHEL, a leading supplier of boiler feed pumps in the

country, has recently designed, manufactured and

tested a prototype boiler feed pump of 150 KHI

Sigma design with improved hydraulic design for

achieving higher efficiency.

The improved hydraulic design was developed using

a state-of-the-art design software procured from

USA. Modified mechanical design of the pump was

carried out at BHEL, RC Puram. The existing semi-

cartridge design was modified to fully cartridgised

design which will considerably reduce the downtime

for maintenance at site. Based on the modified

hydraulic and mechanical design, a prototype boiler

feed pump was manufactured.

The performance evaluation of the pump was

carried out in two stages. Initially, a two-stage pump

(with Stages 1 and 10) was manufactured and tested.

An efficiency of 72.5% was observed for the two-

stage pump, which is close to the predicted value.

Following this, full-size prototype with 10 stages was

assembled and tested. Performance tests carried out

on the full-size prototype showed considerably

higher efficiency than currently being achieved with

the old hydraulic design. It was also noticed that the

pump was operating with relatively low hydraulic

noise and that its operation was smooth.

The CBU-developed honeycomb catalyst has been

tested for its performance at the SCR plant. The

NOx reduction capability was found to be of the

order of 90-95%.

Issued quarterly by the Corporate Office, Bharat Heavy Electricals Limited, BHEL House, Siri Fort, New Delhi-110049, Website : http://www.bhel.com

Editor : P. Jagannathan. Associate Editor : D. Roy. Designed & Printed at NIKHIL OFFSET, New Delhi-110020. Phones : 26812316, 26810097, Telefax : 26810458 For Private Circulation only

It is expected that with this successful development,

BHEL will be in a position to offer replacement for

old pumps, with pumps of the new design of higher

efficiency, as an R&M activity.

Boiler feed pump with improved pump hydraulics

Testing of the power conditioning system with AC loadTesting of cell stack assembly with the C&I system

CONTROL, INSTRUMENTATION

AND POWER CONDITIONING

SYSTEM FOR 5kW PEM FUEL

CELL POWER PACK DEVELOPED

Of the various fuel cell technologies being pursuedworldwide for generating power, PEM fuel cells showgreater promise for such application. Under NewMillennium Indian Technology Leadership Initiative(NMITLI) scheme sponsored by CSIR, BHEL, NCL,SPIC Science Foundation and Kirloskar Oil EnginesLtd.(KOEL) jointly took up the proposal to designand develop a 5 kW PEM fuel cell power pack. Itwas agreed that the cell stack development would becarried out by SPIC, the reformer by NCL & KOEL,and the C&I system by BHEL. The integratedpower pack has recently been developed, tested anddemonstrated with DC and AC loads using purehydrogen as well as reformats from fuel processoremploying LPG as primary fuel.

The C&I system developed by BHEL enablesproper operation, control and monitoring of thePEM fuel cell power pack including the powerconditioning circuitry. The complete C&I for thevarious sub-systems like stack, reformer, powerconditioning circuitry and the HMI (Human MachineInterface) has been realized using suitablemicroprocessor/microcontroller and associatedsensors/transducers and transmitters.

The C&I system consists of a Data AcquistionSystem, a controller and a desktop PC, all integratedinto a single unit with the capability of monitoring atotal of 140 channels for any mix of voltages,temperatures and currents. The Data AcquisitionSystem was realized by using a 140-channelelectronic multiplexer switch along with a desktopPC. A stand-alone controller, developed usingDynamic “C” language and an embeddedmicrocontroller system, is used for sequentialoperation of the power pack, as per pre-definedsteps, during the normal start-up & shut-downoperations. The desktop PC displays the acquiredparameters, stores logged data, and also sendscommands to the controller.

The major parameters monitored by the C&I systemare : individual cell voltages (82 cells), stack voltage,current and temperatures, cooling water inlet andoutlet temperature, reaction air temperature,inverter output voltage/current, etc.

The Power Conditioner, also developed by BHEL,converts the variable DC voltage output of the fuelcell stack to a single-phase voltage of 230 V AC,50 Hz. This DC voltage varies from 48 volts DC to80 volts DC. The stack has been rated to give apower output of 5 kW at 48 V DC. A variable ACload was designed and fabricated for testing thePower Conditioner.