Use of Integrated Single and Triple flashes with Organic Rankine cycle to Generate Power from Sabalan Geothermal Wells

Using high-performance thermodynamic cycles to generate power from existing heat sources is an effective strategy for sustainable energy development. In this study, a new integrated cycle (triple flash and single flash combined cycle with Organic Rankine cycle) based on different real temperatures and pressures in Sabalan geothermal power plant is proposed and analyzed from thermodynamic and exergy viewpoint. A comprehensive parametric study is performed by EES software and then, the proposed cycle is optimized for four considered working fluids relative to the flash chambers’ pressure (or valve 1, 2 and 3 pressures), the evaporator temperature, and the pinch point temperature difference of evaporator. The results show that isobutane is the most suitable fluid for the Rankine cycle. The power generation, thermal and exergy efficiency, in this case for optimum condition, was calculated to be 23073 kW, 19/73%, and 75.67%, respectively. In optimum condition and compared to other studies which has similar wellhead for Sabalan geothermal power plant, the proposed cycle had better performance from energy and exergy viewpoints.