Download - Report Taqa
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