A gas turbine power plant developing 250 MW of electrical power employs a single-shaft gas turbine reheat cycle having the following data:
Total compressor pressure ratio = 30
Total ambient conditions = 1 bar & 300 K
polytropic efficiencies for both compressor and turbine = 0.9 each
Total turbine inlet temperature of both turbines = 1600 K each
Pressure loss in both combustors = 2% of entry pressure each
Total turbine exhaust pressure = 1.05 bars
Mechanical efficiency of assembly = 0.98
Combustion efficiency of both combustors = 0.97
Alternator power output = 250 MW
Actual air-fuel ratio = 25
Lower calorific value of fuel = 42 MJ/kg
Take, Cpa = 1.005 kJ/kg-K,
Cpg = 1.16 kJ/kg -K.
Work out the following:
(i) Sketch the system and show the process on T-s diagram
(ii) The plant specific work in kJ/kg.
(iii) The mass flow rate of air required in kg/s.
(iv) The specific fuel consumption in kg/kWh.
(v) The actual thermal efficiency