Exergy Analysis of a New Proposed Cycle for Power Generation from Sabalan Geothermal Wells

In this paper a new combined flash-binary cycle is proposed for power generation from geothermal wells of Sabalan region in Iran, considering the temperature and pressure differences of wells. Using the real data of these wells, the proposed cycle is analyzed from the viewpoints of the first and second law and the optimum pressure values are calculated for two flash chambers. The results indicate that for R141b, as the best working fluid for the binary cycle the net output power, energy and exergy efficiencies of the proposed cycle are calculated as 17.11 MW, 14.35% and 53.38% respectively. The results of exergy analysis show that the condenser of binary cycle has the highest value of exergy destruction. The performance of the proposed cycle in the present work is compared with the previously proposed system for geothermal sources of Sabalan, and the results show that the net output power, energy and exergy efficiencies of the proposed cycle in this paper is 26.3 %, 31.8% and 23% higher than the corresponding values obtained for the previously proposed system.