Chapter 13 Gas Turbine Power Plants

the combine cycle, and the thermal efficiency of the combined
cycle.
13.24 A combined gas turbine and steam power plant (see Figure
13.11) draws in air at 1 atm and 300°K, and the compressor discharges
it at 12 atm and an enthalpy of 670 kJ/kg. In the combustor
the enthalpy of the air is raised to h 03 = 1515 kJ/kg. The expansion
in the gas turbine reduces the enthalpy to 858 kJ/kg, and,
upon exiting the boiler, the exhaust gas has an enthalpy h 05 = 483
kJ/kg. The steam pressure at the throttle of the steam turbine is 80
bar, and the pressure in the condenser is 0.08 bar. The enthalpy of
the steam at the turbine inlet is h 06 = 3138 kJ/kg and at the exit is
h or = 2105 kJ/kg. The enthalpy of the water leaving the condenser
is 174 kJ/kg, while that leaving the pump is 184 kJ/kg. If
the combined plant produces 100 MW of power, determine the
mass flow rate of steam, the mass flow rate of air, and the thermal
efficiency of the combined cycle.