Answer Happy

1. As the Specialist Engineer for ACWA Power Company, you have
been tasked with designing an upcoming combined cycle power plant
in Jazan economic city. The combined cycle power plant can be
modeled as consisting of a simple gas turbine cycle acting as the
topping cycle for a simple vapor power cycle (see Fig. 9.23). Air
enters the compressor of the gas turbine at 25°C, 100 kPa with a
volume flow rate of 30 m3 /s. The compressor pressure ratio is 12
and the turbine inlet temperature is 1700 K. The compressor and
turbine each have isentropic efficiencies of 88%. The air leaves
the interconnecting heat exchanger at 500 K, 100 kPa. Steam enters
the turbine of the vapor cycle at 7 MPa, 480°C, and expands to the
condenser pressure of 7 kPa. Water enters the pump as saturated
liquid at 7 kPa. The turbine and pump efficiencies are 90 and 70%,
respectively. Provide a table listing the properties (p and h) at
all states for the two working fluids. Determine:
(a) the mass flow rates of the air and steam each in kg/s.
(b) the net power developed by the gas turbine cycle and the
vapor cycle, respectively, each in kW.
(c) the thermal efficiency of the combined cycle.
(d) the number of such combined cycle power plants need to reach
an overall power output of 3800 MW.
lin Combustor Gas turbine Compressor Turbine w gas Air inlet Exhaust លាហហហហហា លាហលាប់ Heat-recovery steam generator Turbine Wap Vapor cycle Steam Pump Condenser Condensate Fig. 9.23 Combined-cycle district heating plant.