Working principle

SITESELECTION WORKINGPRINCIPLE

THERMAL POWER PLANT

☞ MAIN FLOW CIRCUIT(WORKING PRINCIPLE)

• Fuel and Ash circuit
• Air and Gas circuit
• Feed water and Steam circuit
• Cooling water circuit

☆ FUEL AND ASH CIRCUIT

In a steam power plant the coal is used as fuel and required to store. The fuel is used to generate steam. At first coal is stored at the plant and then coal is pulverised through crushers,sizers, dryers and magnetic separator. It is done for complete burning and extraction of heat from burning coal. The pulverised coal is feed into boiler where coal is burned. During the burning of coal produced heat and ash. Heat is used to produced steam from water and ash is collected to ash handling plant. The removal of ash from the furnace is necessary for proper burning of coal.

☆ AIR AND GAS CIRCUIT

Air is required for complete burning of coal. At first the fresh air is passed through the air preheater which raise the temperature of air. This hot air then feed into the boiler where the air burn the coal. During the burning process flue gases produces which is removed to atmosphere after removing the suspended particles at the precipritator. Normally two fans i,r, ID and FD fans are used for this purpose. They are used in pairs.

☆ FEED WATER AND STEAM CIRCUIT

Water is required for steam generation. The water from the water source is at first Demineralised and then fed into the boiler. Water converted into steam in boiler and passed through the super heater for rising the temperatur of steam. The super heated steam is then expanded in turbine, so the turbine rotates. After expanding in turbine the steam pressure falls down so this steam is condensed at condenser where steam converted into water. Then this condensed water is feed to the boiler through boiler feed pump. During this process a considerable amount of water is lost so for compensate it extra water is added to the feed water system.

☆ COOLING WATER CIRCUIT

To condensate the steam after passing through turbine a large amount of cold water is required which is fed from river or pondage. In the steam and cold water flows through different pipes where hot steam gives it temperature to the cold water and condensated. After passing through the condenser the water is fed back into the river or pondage.