Combined Cycle Power Plant and study of its working mechanisms

Abstract

The combined cycle power plant or combined cycle gas turbine, a gas turbine generator generates electricity and waste heat is used to make steam to generate additional electricity via a steam turbine. The gas turbine is one of the most efficient one for the conversion of gas fuels to mechanical power or electricity. The use of distillate liquid fuels, usually diesel, is also common as alternate fuels. More recently, as simple cycle efficiencies have improved and as natural gas prices have fallen, gas turbine have been more widely adopted for base load power generation, especially in combined cycle mode, where waste heat is recovered in waste heat boilers, and the steam used to produce additional electricity. This system is known as a combined cycle. The basic principle of the combined cycle is simple burning gas in a gas turbine produces not only power which can converted to electric power by a coupled generator but also fairly hot exhaust gases. Routing these gases through a water cooled heat exchanger produces steam which can be turned into electric power with a coupled steam turbine and generator. This type of power plant is being installed in increasing numbers round the world where there is access to substantial quantities of natural gas. A combined cycle power plant produces high power outputs at high efficiencies(up to 55%) and with low emissions. In a Conventional power plant we are getting 33% electricity only and remaining 67% as waste.