【摘要】 为了提高有机朗肯循环(ORC)系统中蒸发器换热效率,采用CFD软件FLUENT数值模拟计算方法与试验相结合,选取6种临界温度不同的待选工质,研究了工质进口速度、热空气进口速度、热空气进口温度、工质临界温度对蒸发器?效率、?损失率的影响,得出蒸发器换热效率最高的工质进口速度、热空气进口速度、热空气进口温度,进而得出各种待选工质的换热效果。研究表明:当工质进口速度为系统最小速度、热空气进口速度为系统最大速度时,蒸发器换热效率最高;待选工质临界温度越高,蒸发器换热效率越好;所有待选工质中换热效果:R245fa>正丁烷>异丁烷> R134a> R143a> R125。更多还原

【Abstract】 In order to improve the heat transfer efficiency of evaporator in ORC system,CFD software FLUENT numerical simulation method was used. Selecting six kinds of different critical temperatures for working fluids,the effects of inlet velocity of working fluid,inlet velocity of hot air,inlet temperature of hot air and critical temperature of working fluid on the exergy efficiency and exergy loss rate of evaporator were studied. The inlet velocity of working fluid,inlet velocity of hot air and inlet temperature of hot air with the highest heat transfer efficiency of evaporator were obtained. Furthermore,the heat transfer effects of various selected working fluids were obtained.The research shows that when the inlet speed of working fluid is the minimum and the inlet speed of hot air is the maximum,the heat transfer efficiency of evaporator is the highest and the heat transfer efficiency of evaporator increases with the critical temperature of selected working fluid. The heat transfer effect of all selected working fluids: R245 fa > n-butane > isobutane > R134 a > R143 a > R125.更多还原