Power
Plant
Boiler
Accessories
An huge quantity of fuel is used in thermal power plant and very large quantity of heat is carried by the exhaust gases. The heat carried by the exhaust gases per hour from 100MW plant is of the order of 75 x 106 Kcal as 25% heat remains in the exhaust gases. This loss can be halved by installing economizers in the flue gases. In the present age of costly fuel, it has become necessary to conserve the fuel by utilizing the wasted energy to the atmosphere. This is done in all modern power plants by incorporating economiser and air pre heater. By increasing the temperature of feed water passing through the economiser using waste heat of gas, the quantity of heat given per kg of steam generated in the boiler is reduced.
Similarly the temperature of the air is also increased by passing through the air pre heater using remaining waste energy of the gases. The preheated air increases the combustion efficiency in the furnace and reduces the fuel loss. In both equipments the quantity of fuel is reduced the extracting the heat from the exhaust gases
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