Thermodynamic Analysis of Geothermal Power Generation Combined Flash System with Binary Cycle

Abstract

This paper will analyze a special energy conversion system of geothermal power generation with a flash system combined with binary cycle and suggests a mathematic model of thermodynamic calculation for such combined geothermal power plants in detail. With such a mathematic model, both the capacity and efficiency of the power plants are calculated. The results are given in a diagram which displays the optimum flash temperature for combined power generation system and the optimum design parameters determined by the temperature. The calculated result shows that when the average temperature of cooling water from the environment is 28°C, the maximum total capacity of hybrid flash-binary system is at least 20% higher than that of flash system or binary cycle separately with a geothermal water resource of 110°C. In addition, the power plants produce hot water of about 60°C for direct utilization.