关键词: 有机朗肯循环, 经济性能, ?效率, 目标函数, 有机工质, 优化

Abstract: A comprehensive evaluation criterion combined economic performance and exergy efficiency has been used for the working fluids optimization of organic Rankine cycle (ORC). The objective function of economic performance is defined as the ratio of the required heat exchanger area to the total output power,and the comprehensive evaluation function is the weighted sum of the objective function of economic performance and the exergy efficiency. In the calculation,the heat source of the ORC system is 95℃ geothermal water,and the heat inputs are identical. The working fluid used in the system is varied and the evaporating temperature or condensing temperature is changed in each calculation process. The objective function values and the exergy efficiency are calculated and then the comprehensive evaluation function values of them become available. The results show that from the point of view of economic performance,each system has an optimum evaporation temperature. The economic performance rises with the decrease of condensing temperature and the relation between them is quadratic. In the ranges of evaporating temperature and condensing temperature,R113 and R245ca present better economic performance than other work fluids while the exergy efficiency of R161 is highest. The comprehensive evaluation function shows that the R161 has the best working performance.

Key words: organic Rankine cycle, economic performance, exergy efficiency, objective function, organic work fluid, optimization