Brief Profile of the company
Combined Cycle Power Plant
Working of Gas Power Plant
Heat Recovery Steam Generator (HRSG)
Water Treatment Plant
Switch Yard Description
Merits & Demerits
• Under IPGCL i.e. Indraprastha Power Generation Company
Limited,2 Power Stations are in operation.They are as
1) RAJGHAT POWER HOUSE
2) GAS TURBINE POWER STATION (GTPS 1)
• Under PPCL i.e. Pragati Power Cooperation Limited, two
Power Station are in operation and they are:
1)PRAGATI POWER STATION(GTPS 2)
2)BAWANA POWER STATION(GTPS 3)
135 282 330
Units 4*250 (GT) +
2*67.5 (GT) 6*30 (GT) +
2*104 (GT) +
2002-03 1989-90 1986 & 1996 2002-2003
NCL,BINA GAIL HBJ
River Yamuna River Yamuna Treated water from
Sen Nursing Home &
Delhi Gate Sewage
To make Delhi-Power Surplus
To maximize generation from available capacity
To plan and implement new generation capacity
To set ever so high standards of environment
To develop competent human resources for
managing the company with good standards
• The gas turbine is comprised of three main
components: a compressor, combustor and a
• The air is, compressed in the compressor
(adiabatic compression-no heat gain or loss),
then mixed with fuel and burnt by combustor
under constant pressure conditions in the
•The resulting hot gas expands through the
turbine to perform work (adiabatic expansion).
• The Heat Recovery Steam Generator (HRSG) is a horizontal, natural
circulation, single pressure, water tube type steam generator with a single
• It is unfired type and uses Gas turbine exhaust gases as heat source.
• It has been designed to generate superheat steam at a pressure of 41.5
and a temperature of 512 degree Celsius at a Main Stream Value
• It consists of following section :
a) Superheater section
b) Evaporator section
c) Economizer section
d) Condensate Pre heater (C.P.H) and components
e) Steel chimney
•The steam coming out of turbine is
condensed and the condensate is
feedback to the boiler as feed water. Some
water may be lost due to blow-down,
leakage etc and to make up these losses
additional water called make up water, is
required to be fed to the boiler.
•The source of feed water contain
impurities that could lead to scale
•The water is passed through alum-dosed
clarifier which bonds impurities and thus
•Chlorine removes the algae and bacteria’s
from the water. These processes takes
place in clarifier from where water is sent
to D.M Plant (De-mineralized plant).
ACTIVATED CARBON FILTER:
Water from the clarifier first comes in the ACF. It absorbs some of
STRONG ACID CATION:
It consists of resin named hydrocarbon. It removes the acidic
impurities. This is recharged by HCl acid.
Here the gases available in the water i.e. oxygen, carbon dioxide
is removed upto 5-6%.
STRONG BASE ANION:
It consists of resin, OH-
.It removes the basic impurities. It is
recharged by NaOH. The pH is 8.5-9.5.
It consists of both resin, acid and basic. pH is maintained about
6.8-7.2.This is recharged by HCl & NaOH.
•Generator converts the mechanical
energy of turbine shaft into electrical
energy. Rotating field type generators are
employed which are ventilated by the fans
of rotor shaft or separately driven fans.
•At this power plant the requirements
of generator are:
•The class of generator under consideration is steam turbine-
driven generators, commonly called turbo generators. Generally
they have the ratings up to 1900MW but here 3000rpm,50Hz
generators are used of capacities 122MW.
For any power station, switchyard is an important part which bridges
the generating station and the distribution system i.e. via switchyard
the generated electricity is fed to the sub-stations. It connects the
GTPS to the northern grid.
The switchyard of Gas Turbine Power Plant is of 66KV.
The voltage generated is 11KV, which is then step up to 66KV by
generator transformer. This 66KV is fed to the 66KV switchyard.
The switchyard has the double bus bar system i.e. one is main bus
and the other one is secondary bus.
Some of the functions are:
Change voltage from one level to another
Switch transmission and distribution circuits into and out of the grid
Measure electric power qualities flowing in the circuits.
Eliminate lightning and other surges from the system.
1) ISOLATORS: They are designed to open a ckt under no load. Its main purpose is to
isolate portion of the ckt from the other & is not intended to be opened while current
is flowing in the line.
2) CIRCUIT BREAKERS: It is a piece of equipment which can break the circuit
automatically under faulty conditions and make the circuit either manually or by
remote control under faulty conditions. They can be classified as
i. oil ckt breaker
ii. Gas(SF6) ckt breaker
iii. Air-blast ckt breaker
iv. Vaccum ckt breaker
The switch yard has gas (SF6) or Sulphur Hexa Fluoride ckt breaker.
3)INSULATORS: All the insulators are made of porcelain metal parts. They are free
from radio interference. They support the conductors (bus bar) and confine the
current to the conductors.
4)BUS COUPLERS: Breakers are used as
a bus coupler. They provide coupling
between the two bus bar of zones.
5)CURRENT TRANSFORMER: C.T is an instrument t/f used
for protection & metering of high values of currents.
C.T is used for reducing a.c from higher to lower value of
6) POTENTIAL TRANSFORMER: They are used to increase
the range of voltmeters in electrical substations and
generating stations. They are also called voltage t/f.
7)LIGHTINING ARRESTORS: It is a protective
device used to protect the station, equipments
against atmospheric discharge.
8)EARTHING LINKS: Switchyard
Earthing is provided to protect
personally from shocks and
hazards from electrical
9)MULSIFIER: They are used to protect the transformer against fire.
Specifications of SF6 circuit breaker:
1) Rated voltage 72.5kV
2) Rated frequency 50Hz
3) Rated current 2000A
4) Impulse voltage (peak) 325kV
5) Rated breaking capacity
a) Symmetrical 25KA
b) Asymmetrical 28KA
c) Making (peak) 64KA
d) Short time (for 1 sec) 2.5KA
6) Rated Pressure 5.5 bars
7) Total mass of ckt breaker 900kg
8) Total SF6 gas content 3.7kg
Specifications of 66KV Isolators and earthing switches:
1) No. of Pole 03
2) Installation Outdoor
3) Rated Voltage 72.5KV/66KV
4) Rated Current 1250 Amp
5) Rated Frequency 50 Hz
Specifications of 66KV Current Transformer:
1) No. of Course 4
2) Rated Voltage 72.5KV/66KV
3) Rated Current 2000-1000
4) Rated Frequency 50Hz
5) Total Creep age distance 1700mm
6) Short time Current Rating 25 KV for 1 sec
• Specifications of Potential Transformer:
1) Type WH 72.5-17
2) Standard IEC
3) Year of manufacturing 1986
4) Weight 300kg
5) Minimum Temperature 10 degree Celsius
6) Maximum Temperature 50 degree Celsius
7) Frequency 50Hz
8) Voltage factor 1.5
9) Maximum Rating 1000-500 VA
• Specifications of 66KV Lightning Arrestor:
1) Rated Voltage 60KV
2) Power frequency Reseal Voltage 60KV
3) High Current Impulse 100 K Amps
4) Class of Arrestors 10 K Amps for heavy duty
5) Total creep age distance 1700mm
Low operation and maintenance cost
Less space is occupied
Less gas storage
Cheaper fuels like natural gas
Temp. of combustion chamber is too high, which results in
shorter life time.
Gas turbine has low thermal efficiency
Has starting problem
Efficient only in combined cycle
They can respond to rapidly changing loads without
A portion of steam generated can be used as a process
steam in different industries
Steam engines and turbine can work under 25% of
Maintenance and operating cost are high
Large quantity of water is required
Problem of ash removing
Unavailability of good quality coal
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