三角转子膨胀机在有机朗肯循环中应用分析

APPLICATION ANALYSIS OF WANKEL EXPANDER FOR ORGANIC RANKINE CYCLE

基于中低温太阳能驱动的有机朗肯循环应用背景,分析三角转子机械作为膨胀机的运行特征,通过建立含泄漏影响的运行过程热力学模型对膨胀机性能进行计算,分析以R245fa为工质在单个膨胀周期内膨胀机内部的热力学性能,包括进气角度、形状因子、偏心距和轴距系数等型线设计参数对膨胀机性能的影响。结果显示,三角转子膨胀机可实现较大的膨胀压比,所讨论的因素会对质量流量、输出功率、膨胀压比和容积效率产生影响,适当选择结构参数可优化膨胀机的性能。

The operation mechanism of the Wankel expander in organic Rankine cycle are analyzed theoretically and the performance of the expander is simulated by developed thermodynamics model considering leakage among chambers. With R245fa as the working fluid,several thermodynamic parameters of the expander are discussed in a completed working cycle,and the structure parameters of chamber profile including shape factor,rotor profile,intake angle,eccentric distance and wheelbase coefficient are discussed as well. The results show that the Wankel expander can achieve a large expansion ratio,and all the discussed factors can take significant impacts on working performance induding mass flow rate, output power, expansion pressure ration, and volumetric efficiency. Therefore,it is necessary to select optimized parameters for satisfiing performance of the expander in future application.