The condensate leaves the heat exchanger as saturated Serves as the boiler for the refrigerant cycle and the condenser of the steam cycle. The rest of the stream passes through a heat exchanger, which Half of the flow is extracted at 150 kPa and is used for industrial process heating. Superheated vapor enters the turbine with a mass flow rate of 5 kg/s at 4 MPa, 470 Water and refrigerant R-134a are the working fluids in a binary cycle used for cogeneration of power and process steam. What would the thermal efficiency be if air were used as working fluid for the gas phase? Water enters the pump as saturatedĭetermine (a) the thermal efficiency of the combined cycle, (b) the mass flow rates of steam and The steam exits the turbine at a quality of 0.9. Vapor power cycle, and expands to the condenser at a pressure of 7 kPa. Saturated vapor at 8 MPa exits the heat exchanger which is superheated to 425 The mass flow rate of the gas is 100 kg/s. The turbine has an isentropic efficiency of 80%. Helium expands through the turbine to a pressure of 1.4 MPa. The conditions at the inlet to the turbineĬ. The isentropic efficiency of the compressor is 80%. Helium enters the compressor of the gas turbine at 1.4 MPa,ģ50 K and is compressed to 5.5 MPa. If the working fluid experiences no irreversibilities as it passes through the turbines, pumps, steam generator, reheater and condenser, determine (a) the thermal efficiency of the cycleĪnd (b) the mass flow rate of steam entering the first turbine.Ĭonsider a combined cycle power plant using helium and water as the working fluids.
There is no stray heat transfer from any component to its surroundings. The net power output of the cycle is 100 MW. The steam exiting the open feedwater heater is saturated liquid at 0.3 MPa. Steam extracted from second turbine at 0.3 MPa is also fed into the open feedwater heater, which operates at 0.3 MPa. The condensate is trapped into the open feedwater heater. Feedwater leaves the closed heater at 205Ĭ, 10 MPa and condensate exits as saturated liquid at 2 MPa. Steam is extracted from the first turbine at 2 MPa and fed to the closed feedwater heater. The steam is reheated to 440Ĭ before entering the second turbine, where it expands to the condenserĪt a pressure of 0.007 MPa. Steam enters the first turbine at 10 MPa, 500Ĭ and expands to 0.8 MPa.
Consider a reheat-regenerative vapor power cycle with two feedwater heaters, a closed feedwater heater and an open feedwater heater.
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