PONDICHERRY POWER CORPORATION LIMITED (PPCL)
Introduction:
Pondicherry Power Corporation Limited (PPCL) produces 32.5MW power by combined power plant. The combined power plant consists of Gas Turbine Generator and Steam Turbine Generator. The Gas Turbine Generator has a capacity of 22.9MW and Steam Turbine Generator has a capacity of 9.6MW.
Combined power plant process:
The Gas Turbine Generator (GTG) utilizes any one of the following fuels.
The fuels are:
- Natural Gas system
- Naphtha system
- High speed Diesel System
In this Naphtha and High speed Diesel system are auxiliary system. At present the plant uses natural gas as its Fuel. Gas Authority of India Limited (GAIL) supplies the natural gas. The gas from GAIL has a pressure of 6.8 kg/cm2.
Then the gas pressure is reduced to 3-3.5 Kg/cm2. This gas is given to Gas Booster Compressor, where its pressure is increased to 17-18 kg/cm2. This gas goes to Gas conditioning skid, where the gas is conditioned, filtered and then send to Gas Turbine.
Then the gas enters the combustion chamber. In the combustion chamber the gas and air are mixed and fired. The hot exhaust gas enters the Gas Turbine (GT) and rotates the Turbine blades. The turbine blades are connected to a common shaft and hence the Shaft rotates. So the alternator also rotates and hence power is produced. The power produced by the Gas Turbine Generator (GTG) is 22.9MW.
The exhaust gas from the GTG is send to Heat Recovery Steam Generator (HRSG) through ducts. The HRSG uses the exhaust gas as its fuel. A water tube boiler generates the steam. This steam is send o Steam Turbine (ST), which rotates the turbine blades and shaft. The shaft is attached to alternator that produces power. The Steam Turbine Generator (STG) produces a power of 9.6MW.
The exhaust steam from the turbine is condensed into water in condenser and collected in hot well. The water from the hot well is sent to Deaerator by condensate extraction pump. This water is send to the boiler by Boiler Feed Pump (BFP) and the cycle continues.