Energy and exergy analyses of various configures for combined flash-binary cycles using Sabalan geothermal wells

In Iran, Sabalan geothermal power plant has been utilized with two wells having different and mass flow rates and thermal properties. In this study, in order to achieve the maximum power, four new configures; a single flash-binary, a double flash (I)–binary, a double flash (II)–binary and a triple flash-binary cycles were examined. These four configurations were initially investigated considering the effective parameters of energy and exergy analysis, and then optimization was performed using three working fluids. The results show that in the optimum state, the double flash (II)–binary using isobutane shows better results compared to the other three configurations. Furthermore, for the optimum case, the net power of 23084 kW, the thermal efficiency of 19.74%, the exergy efficiency of 75.7%, and the exergy destruction rate of 6250 kW were obtained which show an improvement in terms of energy and exergy for the Sabalan geothermal power plant compared to the previous studies.