Proposal and Analysis of a New Cycle for Power Generation from Sabalan Geothermal Wells

The wellhead pressure and temperature in the geothermal wells at a region are different. In this paper a new combined flash-binary cycle, considering the temperature and pressure differences of wells, for power generation from geothermal wells of Sabalan region in Iran, is proposed. Four appropriate working fluids are considered for the binary cycle and the proposed system is analyzed thermodynamically by the EES software using the real data of sabalan geothermal wells and the optimum pressure values are calculated for two flash chambers. The results show that to achieve the maximum output power, the optimum pressure for the first flash chamber is 800 kPa and for the second flash chamber is 92 kPa. Also, the results indicate that, among the considered working fluids for the binary system, R141b is the best fluid. For this working fluid the net output power of the proposed cycle is calculated as 17.11 MW. To compare the performance of the proposed cycle by cycle proposed in the previous research for geothermal sources of Sabalan by considering the well conditions as previous research, the results show that the net output power of the proposed cycle in this paper is 26.3 % higher than the corresponding value obtained for Sabalan geothermal sources in a previous research.