Keywords: binary, exergy analysis, geothermal, pressure optimisation, geothermal power, geothermal energy, binary power plants, thermodynamics, Turkey, geofluid flow rate, reservoir temperature
Exergy analysis and pressure optimisation of geothermal binary power plants
Binary geothermal power plants are used for power production from moderate temperature geothermal reservoirs (85-170°C). In performance analysis of those plants, the second law of thermodynamics is used like in other conventional power plants. In this paper, the exergy analysis and pressure optimisation methods are described for binary power plants. The method described is applied to a hypothetical geothermal reservoir for Turkey and a performance analysis is made of the binary power plant and its major equipment. The computer software developed is used to show the variations of performance criteria. According to the results, overall first and second law efficiencies of the hypothetical binary power plant have been determined to be 9.065 and 34.94% respectively for a reservoir temperature of 150°C and geofluid flowrate of 250 kg/s.