For the ideal Rankine cycle case where the feed pump and turbine are isentropic, and the electric
Question:
For the ideal Rankine cycle case where the feed pump and turbine are isentropic, and the electric motor on the feed pump and the electric generator are 100% efficient:
- Calculate the specific enthalpy and specific entropy of the refrigerant at the entry and exit of the feed pump, and the entry and exit of the turbine. Also calculate temperature at the exit of the turbine
Refrigerant: R134A
Boiler working pressure: 1200kPa (absolute)
Refrigerant temperature after boiling: 70.08C (5 below geothermal water)
Amount of heat available from geothermal water: directly proportional to 5 degrees drop of geothermal water
Geothermal water specific heat capacity: 4.2 kJ/kg.K
Boiler to turbine isentropic efficiency: 86.4%
Boiler feed pump isentropic efficiency: 84.76%
Condenser saturation pressure: 723kPa
Electric Generator Efficiency: 78.70%
Efficiency of electric motor driving boiler pump: 84%
Thermodynamics for Engineers
ISBN: ?978-1133112860
1st edition
Authors: Kenneth A. Kroos, Merle C. Potter