A gas-turbine power plant operates on the regenerative Brayton cycle between the pressure limits of 100 and 700 kPa. Air enters the compressor at 30°C at a rate of 12.6 kg/s and leaves at 260°C. It is then heated in a regenerator to 400°C by the hot combustion gases leaving the turbine. A diesel fuel with a heating value of 42,000 kJ/kg is burned in the combustion chamber with a combustion efficiency of 97 percent. The combustion gases leave the combustion chamber at 871°C and enter the turbine whose isentropic efficiency is 85 percent. Treating combustion gases as air and using constant specific heats at 500°C, determine
(a) the isentropic efficiency of the compressor,
(b) The effectiveness of the regenerator,
(c) The air€“fuel ratio in the combustion chamber,
(d) The net power output and the back work ratio,
(e) The thermal efficiency, and
(f) The second-law efficiency of the plant. Also determine
(g) The second-law (energetic) efficiencies of the compressor, the turbine,
and the regenerator, and
(h) the rate of the energy flow with the combustion gases at the regenerator exit.

Transcribed Image Text:

Diesel fuelCombustion chamber 1 700 kPa 260°C Compressor Turbine 100 kPa リt 30°C