TAQA TAQA (250 MW) plant is the 1st biggest lignite fired plant as a

single unit of independent power producer category in India

It is located in uthangal , 4okm west of cuddalore, 12km from

neyveli township to the west of NLC TPS ll.

TAQA supplies power to :

Cuddalore

Dievakurichi

Perambalore

TS ll Neyveli.

Primary fuel lignite is being supplied to the project under 30

year contract with neyveli lignite coorporation.

Total area: 212 acres.

MAIN EQUIPMENTS:

Boiler( benson type, drumless, 5400c ,175 bar)

Auxiliary boiler(2650c,15.8 bar)

Turbine(single flow HP , combined IP-LP)

Generator (250MW,50Hz,18kV).

ESP (electrostatic precipitator).

Cooling tower

DM plant.(500m3)

Ash handling plant

Lignite handling plant.

Condensate storage tank(400m3)

Raw water reservoir(52000m3)

Ash pond.

Chimney(220m)

DAY 1:Safety measures

HAZARDS IN THERMAL POWER PLANT:-

1.NOISE:

Many locations in the power produces noise more than

90decibal which causes damage to human ears.

2.CHEMICAL:

Toxic: Chlorine used for treating water. To detect chlorine

leakage the thermal plant is provided with detectors.

Flammable: LSHS and LDO which are used as fuel

Explosive: LPG which is used for initial ignition and LDO

Corrosive: Acids like H2SO4 which is used in four bay system.

3.HEAT: Regions like furnaces and boiler where large amount of

heat is employed ,if not controlled properly can cause hazardous

situations.

4.DUST: The effluents from the boiler known as fly ash causes

hazardous situations if not maintained properly as per the permitted

limit.

PRECAUTIONS TO BE TAKEN:

Wear helmet

Wear safety goggles

Wear nose masks

Wear boots

Be aware of the assembly points in the industries in case of

emergency

Basic knowledge about first aid

Do not operate instruments without prior knowledge about it.

Day 2: LIGNITE HANDLING PLANT

Lignite, the primary fuel is transported by trucks from mine-1A stock pile

to the wagon loading facility at vadalur. By means of conveyor the lignite

is brought inside the plant which is then separated into two.

One part is taken into the main feed via INLINE MAGNETIC SEPERATOR

(ILMS) ,then into CRUSHERS which consists of rollers ,then again into

ILMS 2 for removing remaining metal particles.

The other part is taken into stock pile which can be used as main feed if

there is lack of lignite supply (generally happens during rain).

WAGON

6 HOPPERS

STORAGE AREA

TRANSFER THROUGH TRUCKS

GROUND HOPPER

PADDLE FEEDER

1A-CONVEYOR

CRUSHER

2A-CONVEYOR

TP (Transfer point )

3A-CONVEYOR

SHUTTLE CONVEYOR

6 BOILER BUNKER

A

WATER AND AIR CYCLE

WATER CYCLE:

Main water supply is from the raw water reservoir using

12 borewells( 8 working, 4 standby)

Water is then supplied to DEMINERALISATION PLANT for

the removal of impurities and dissolved minerals.

Water then reaches CONDENSATE STORAGE TANK.

Then to the DEAIRATOR for the removal of dissolved

gases.( dissolved oxygen causes damage to the turbine)

Water is then supplied to the ECONOMISER

Water wall tubes

COLD SUPPORTER TUBES

CYCLONE SEPARATOR (separates steam from water)

A

SUPER HEATER 1

SH 2

SH 3

HP TURBINE

RE-HEATER

LP TURBINE

CONDENSOR

Water from the condenser is supplied back to the

deaerator.

AIR CYCLE:

FORCED DRAFT fan supplies in the pressure.

RAP (regenerative air preheater)

It is then supplied into the boiler.

ESP (electrostatic precipitator)

INDUCED DRAFT fan.

Chimney

DAY2:ASH HANDLING PLANT The Burn out material which is of micro scale and can be

easily mixed with the atmosphere is called ASH. In the ash handling

plant, the ash which is emitted from the furnace of the boiler is

removed.

There are two types of ash removed namely

Fly ash

Wet ash

FLY ASH REMOVAL:-

In fly ash removal the main equipments used are ESP

(Electro Static Precipitator) and ash transmitters. Initially the flue gas

from the boiler is passed through cathodic and anodic coils of the

ESP which absorbs the positive and negatively charged ash particles.

Those particles are collected in transmitter through the hopper due

to gravity. The transmitter is maintained at the pressure of 3 kg/cm2.

The collected ash is transferred to the ash silo with the help of

compressed air from air compressor.

The flow process is as follows :

FURNACE COMPRESSED AIR

dry ash

ESP FLY ASH TRANSMITTER

ID FAN VALVES CONTROLLED BY

PNEUMATICS

CHIMNEY

SILO

TRANSFER TO CEMENT FACTORY

WET ASH REMOVAL:-

The Sand particles which is in the coal gets separated while burning

in the furnace due to gravity. Those particles contain considerable amount of

moisture and they are flushed out to the ash pond. If needed they are

transported through lorries.

The Flow process is as follows:

FURNACE

SLAG WATER FROM COOLING TOWER

FEED CONVEYOR

LOADED IN FLESHING POINT

LORRY

SLAG SUMP

ASH POND

DAY3:Demineralisation plant

12 borewells supply the water into the water reservoir whose

capacity is 52000 m3 and 5m depth.(8 working and 4 standby)

Water is then taken into a common sump.

Next stage consists of: 1. hyden pump 2.jockey pump. 3.cw

make up pump 4.dm feed pump 5.seal water pump

In DM plant, water is first passed through DUAL MEDIA FILTER

consisting of sand , pebbles which removes impurities in water.

ACTUATED CARBON FILTER where chlorine is removed from the

water. Actuated carbon absorbs the chlorine and odour.

The chlorineless water is passed into the SAC( strong acid

cation resin)

SBA ( strong base anion resin)

SBA ll

MIXED BED RESIN.

ULTRAFILTRATION(for the removal of suspended silica

particles)

DM storage tank

CONDENSATE STORAGE TANK.

FLOW PROCESS

RAW WATER

DUAL MEDIA FILTER (DMF) CONTAINS SAND AND PEBBLES

ACTIVATED CARBON FILTER (ACF) TO REMOVE Cl

STRING ACID CATION (SCA) REMOVES SALTS

DEGASER WATER TANK

WITH TOWER

STRONG BASE ANION MAINTAIN TDS

MIXED BED (MB)

ULTRA FILTER ( UF) 3 UF

DM STORAGE TANK

CONDENSER WELL

DAY4:BOILER AND TURBINE

BOILER

• STEAM GENERATORS :Generates steam at desired rate, desired

pressure, and temperature by burning fuel. It is a the

combination of furnace, super-heater, re-heater, evaporator,

economizer, air pre-heater, along with various auxiliaries such

as pulverizes, burners, stokers, dust collectors, ash-handling

equipment, chimney or stack. Boiler is part of steam generator

where phase change occurs from liquid to vapour at constant

pressure and temperature. We will discuss boiler in this

following.

• DIFFERENTS TYPES OF BOILERS ACCORDING TO RELATIVE

FLOWS

A) Fire tube boiler.

B) Water tube boilers.

• TAQA’S BOILERS

The boiler user is drum-less one, which is once-threw

• ACCESSORIES

• Feed pump

• Economizer

• Super heater

• Re- heater

• Raph (regenerative air pre-heater)

• Scaph (Steam coil air pre-heater)

• Induced draught fan & forced draught fan

• Chimney

1)Feed pump is used to supply demineralised water to

pipe tubes, around the boilers.

2) Economizer are mechanical devices used to reduce

energy consumption, or to perform another useful

function such as preheating a fluid(water). It consists of

thermal fluid boilers or steam boiler, with exhaust gases

through a common chimney. An indirect contact or

contact condensing economizer will recover the residual

heat from the combustion products using series of

dampers, depending on the demand for make-up water

and process water. The efficiency of heat produced is

directly linked to boiler efficiency. The percentage of

excess air and the temperature of the combustion

products are two key variables in evaluating this

efficiency.

3) Super-heater is a device used to convert saturated

steam or wet steam into dry steam. There are different

types of super-heater. Three super-heaters are used in

this boiler heating water to required temperature

4) Re-heater is a device that reheats the high pressure turbine exhaust steam to 546OC with pressure about 36 . bar to intermediate pressure turbine.

5) Raph and Scaph: These are air pre-heaters used in boilers. Flue gas coming out of economizer is further utilized for pre-heating air before supplying to the combustion chamber .Air pre-heater is mainly used for supply air to burners. The gas coming will be at a temperature of about 500 degree Celsius which is used to heat the normal atmospheric air to 100-200 degree Celsius. 6) Induced draught fan & forced draught fan: These fans

are used to push and pull air into and out of the boiler

furnace. The pressure has to maintained negative inside

the boiler to attain maximum boiler efficiency.

7) Chimney: The chimney is 240 meters tall and is used to leave the gases to atmosphere at a temperature of 120-150 degree Celsius.

TURBINE :- A turbine is a rotary mechanical device that extracts energy from

a fluid flow and converts it into useful work. A turbine is

a turbomachine with at least one moving part called a rotor

assembly, which is a shaft or drum with blades attached. Moving

fluid acts on the blades so that they move and impart rotational

energy to the rotor. Three types of turbines are used here namely

high pressure (HP) turbine, intermediate(IP), low pressure

turbine(LP).The turbine shaft rotates a t a speed of 3000 rpm and

turbine are supplied with lubricating oil. Oil control system for

controlling the valve adjustments.

HP & IP & LP TURBINES connected by common shaft

GENERATOR generator circuit breaker for protection

SWITCH YARD

CONDENSOR HOT WELL MAKE UP WATER FROM

DM PLANT

EJECTOR

GSC

LP HEATER ( 3 LPH )

HP HEATER ( 2 HPH )

ECONOMISER COIL

SUPER HEATER - 540 0C & 175 bar

HP TURBINE - 536 0c & 171 bar – at inlet

360 0c & 38.4 bar – AT outlet

RE HEATER

IP TURBINE - 535 0C & 34.2 bar

LP TURBINE

CONDENSOR