Modified Gas Turbine Power Plant
A modified gas turbine cycle may have in addition to above an intercooler, a regenerator and a reheater. Such a gas turbine power plant is shown in Figure. Such a system is used to improve the performance of the plant.
A regenerator is used to heat the compressed air by the exhaust hot gases of the turbine before discharged to the surroundings. It reduces the amount of heat to be added in the combustor, thus it reduces the specific fuel consumption.
Compression is divided into two or more stages with intercooler in between the stages. It reduces the work of compression.
Expansion of hot gases is divided into two or more stages with a reheater in between the stages. The reheater is also called as auxiliary combustor. In the reheater, additional fuel is burnt to raise the temperature of gases before supplied to gas turbine. It increases the work output of the turbine.
Net effect of the combined cycle is to increase to shaft work, reduce fuel consumption per kWh and increase the efficiency of the plant.