Consider a combined gass steam power plant that has a net power output of 450 MW. The pressue ratio of the gas turbine cycle is 14. Air enters the compreeor at 300K and the turbine at 1400K. The combustion gases leaving the gas turbine are used to heat the stream at 8 Mpa to 400C in a heat exchanger. The combustion gases leave the heat exchanger at 460K.
An open feed water heater incorperated with the steam cycle operates at a pressure of 0.6 MPa. The condenser pressure is 20 KPa. Assuming all the comression and expansion processes to be isentropic.
Determine
- The mass flow rate ratio of air to stream
- The required rate of heat input in the combustion chamber
- The thermal efficienct of the combined cycle.