Saturday, September 4, 2010

Important Balance of Plant Packages for Thermal Power Plants

1. Coal Handling System
Coal is the fuel used to heat up the water in the boiler to produce steam. The coal delivered to the site is stored in bunkers and delivered to the pulverizer by conveyor belts. The pulverized coal is further transferred to the ball mill where its is converted into a powder form. This entire system is called the coal handling system of the power plant.

2. Ash Handling System
Burnt coal produces bottom ash and fly ash. The bottom ash is falls through the grate of the furnace into a silo where it is mixed with water to produce ash slurry. This slurry is then pumped out of the boiler furnace into an ash pond. The fly ash moves along with the flue gases and is trapped by an electrostatic precipitator. The trapped ash is then pnuematically sent to the ash storage area.

3. Cross Country Pipeline
Water for the power plant generally comes from a river, sea, lake reservoir or an STP plant of a city. The distance of water source to the power plant may be quite large and hence a cross-country pipe line is required along with a pumping station.

4. Water Treatment Plant
Water required by the power plant needs to be free of any suspened particles as well as dissolved salts. Hence the water is generally passed through a pre-treatment plant, RO plant and a De-mineralisation plant before being used in the boiler, turbine, etc.

5. Cooling Tower
Cooling water is required to convert the exhausted steam from the turbine back into water to create back pressure and improve thermal efficieny of the plant.Hence cooling tower is required to cool the heated water passing through the condensor.

6. Switchyard
The electrical network where the power is transferred along different routes.

7. Railway Siding
Coal needs to transferred from the coal mine to the power plant by means of a train. The train enters the power plants and dumps the coal into a underground bunker. Power plant owner needs to erect the railway tracks for the train to reach the power plant.

8. Transmission Line
The power needs to be evacuated by means of high voltage transmission line to the purchaser of power such as State Electricity Board.