Ramendra summer training presentation

Brief Profile of the company Combined Cycle Power Plant Working of Gas Power Plant Heat Recovery Steam Generator (HRSG) Plant Overview Water Treatment Plant Generator Transformer Switch Yard Description Specifications Merits & Demerits Bibliography

• Under IPGCL i.e. Indraprastha Power Generation Company Limited,2 Power Stations are in operation.They are as follows :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)

STATIONS BAWANA POWER STATION

RAJGHAT POWER STATION

GTPS PRAGATI POWER STATION

Station Capacity (MW)

1500(Planned)

1000(Installed)

135 282 330

Units 4*250 (GT) + 2*256 (ST)

2*67.5 (GT) 6*30 (GT) + 3*34 (WHRU)

2*104 (GT) + 1*122 (WHRU)

Year of Commissioning

2002-03 1989-90 1986 & 1996 2002-2003

Coal Field/Gas

GAIL HBJ Pipeline

NCL,BINA GAIL HBJ Pipeline

GAIL HBJ Pipeline

Water Sources

Rithala Sewage treatment plant

River Yamuna River Yamuna Treated water from Sen Nursing Home & Delhi Gate Sewage Treatment Plants

To make Delhi-Power Surplus To maximize generation from available

capacity To plan and implement new generation

capacity in Delhi To set ever so high standards of

environment Protection 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 turbine.

• 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 combustion chamber.

•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 drum.

• 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 kg/cm2 and a temperature of 512 degree Celsius at a Main Stream Value (MSV).

• 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 formation.

•The water is passed through alum-dosed clarifier which bonds impurities and thus removed.

•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 the impurities.

STRONG ACID CATION:It consists of resin named hydrocarbon. It removes the acidic impurities. This is recharged by HCl acid.

DEGASIFIER: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.

MIXED BED: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 requirementsof generator are:POLES=2FREQUENCY=50HzSPEED=120f/P=3000rpm

•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 system. 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 measurement/protection/control.

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: SwitchyardEarthing is provided to protect personally from shocks and hazards from electrical equipments.

9)MULSIFIER: They are used to protect the transformer against fire.

Specifications of SF6 circuit breaker:1) Rated voltage 72.5kV2) Rated frequency 50Hz3) Rated current 2000A4) Impulse voltage (peak) 325kV5) Rated breaking capacity

a) Symmetrical 25KAb) Asymmetrical 28KAc) Making (peak) 64KAd) Short time (for 1 sec) 2.5KA

6) Rated Pressure 5.5 bars7) Total mass of ckt breaker 900kg8) Total SF6 gas content 3.7kg

Specifications of 66KV Isolators and earthing switches:1) No. of Pole 032) Installation Outdoor3) Rated Voltage72.5KV/66KV4) Rated Current1250 Amp5) Rated Frequency 50 Hz

Specifications of 66KV Current Transformer:1) No. of Course 42) Rated Voltage 72.5KV/66KV3) Rated Current 2000-10004) Rated Frequency 50Hz5) Total Creep age distance 1700mm6) 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

Merits: Low operation and maintenance cost Less space is occupied Less gas storage Cheaper fuels like natural gas

Demerits: 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

• Merits: They can respond to rapidly changing loads without

difficulty A portion of steam generated can be used as a

process steam in different industries Steam engines and turbine can work under 25% of

overload continuously Cheaper fuels

• Demerits: Maintenance and operating cost are high Large quantity of water is required Problem of ash removing Unavailability of good quality coal

Links referred :http://www.hrsgdesign.com/design0.htmhttp://ipgcl-ppcl.gov.in/

http://www.osha.gov/SLTC/etools/electric_power/illustrated_glossary/

substation.html#Equipment