Energy, exergy, and economic analyses of geothermal power generation cycle with different organic fluids

In the present research, energy in the geothermal fluid is utilized to generate power. In the first case of power generation, the model of the geothermal double-effect instantaneous evaporation cycle is employed, and in the second one, the single-effect evaporation combined cycle and Rankine cycle with different organic fluids are utilized. The effect of several organic fluids in the combined cycle is examined. The SPECO method has also been applied in economic analysis. Given the analysis, net power generation is the highest for the combined cycle with water vapor and the lowest for the double-effect instantaneous evaporation cycle with a considerable difference. Increasing the separator pressure at constant evaporator temperature reduce the power generation cost for combined cycles. The lowest power generation cost is related to the combined cycle with operating fluid R113, and the highest amount of power generation cost is related to the combined cycle with ammonia fluid. The Exergoeconomic coefficient, which indicates the ratio of the purchase price components to the sum of costs associated with total exergy destruction and the cost associated with purchasing cycle components, is also the highest for the combined cycle with R113 and the lowest for the double-effect instantaneous evaporation cycle.