中低温热水发电系统循环参数和工质的选择

Cycle Parameters and Working Fluid Selection in Low-medium Temperature Hot Water Power Generation

针对热源为80～150℃热水的有机朗肯循环(ORC)发电系统,以发电功率和效率为评价指标,分别分析了以R134a、R123和R245fa三种工质为循环介质时的系统,确定了最佳循环参数和工质。一般来说,最佳蒸发温度对应着最大的输出电功,且随着热流体温度的升高而升高;当热源温度大于120℃时,R134a的系统不存在最佳蒸发温度,此时输出电功随着蒸发温度的升高而增大。对于80～135℃的热水,工质R245fa的发电功率最大;当热水温度超过135℃时,工质R134a的发电功率最大。工质R245fa的发电效率始终是最大的。

This paper presents the analysis on the selection of optimum cycle parameters and working fluid for organic Rankine cycle（ORC）in low temperature（80~150℃）hot water power generation system by testing R134a、R123 and R245fa as the working fluids respectively.The results show that output net power depends on the optimal evaporation temperature,and they increased with increasing tmperature of hot water;There is no optimum evaporation temperature for R134a when the temperature of hot water is above 120℃,and its power output increased with the rise of evaporation temperature.When the temperature of water is within the range of 80~135℃,the output net power of R245fa is the highest;within the range of 135~150℃,the output net power of R134a is the highest.The generating efficiency of R245fa is always the highest.