HFC32／HFO1234ze二元混合工质的热物性模型

Thermophysical Properties Model for Binary Mixtures Working Fluid of HFC32/HFO1234ze

在实验数据基础上,建立了适用于HFC32/HFO1234ze二元混合工质的PR方程模型,并对实验数据、模型计算结果和Refprop 9.0计算结果进行了比较分析;作出了定温度下泡、露点压力随混合比的变化关系图以及定压力下饱和温度随混合比的变化关系图,分析得出HFC32/HFO1234ze二元混合工质属于非共沸工质,存在温度滑移,500 kPa压力下混合物在0.27/0.75处温度滑移达到最大为12.7℃;选取状态参考点后,作出了不同混合比下的混合工质的logP-h图,得出了随混合比变化混合工质的热力学性质的变化趋势,为系统的设计提供基本的热力学数据;最后,以R410A循环性能为基准,对不同混合比下混合工质的"相对循环性能"(COP_(mix)/COP_(R410A))进行了分析,为家用空调制冷剂的替代和系统的优化提供方向。

In this study, a PR state equation for the binary mixture working fluid of HFC32/HFO1234ze was proposed based on experimental data. The prediction results of the proposed state equation were compared with the experimental data and the values calculated from Refprop 9.0. Then the variation of the bubble and dew pressure at various concentrations under the constant temperature, as well as that of the bubble and dew temperature at constant pressure was depicted by the proposed PR state equation. It was concluded that the binary mixture of HFC32/HFO1234ze is an azeotropy working fluid and the temperature glide is as high as 12.7~C at the pressure of 500 MPa and the mixture concentration of 0.25/0.75. The pressure-enthalpy figure was obtained based on the state reference point and the variation tendency of thermophysical properties of the binary mixture at various concentrations was also conducted, which can provide basic thermophysical data for the design of thermal systems. Finally, the relative coefficient of performance （COPmix/COPR410A） for the mixture at different concentrations was analyzed and COPR410A was considered as a basic standard value. This analysis provides guidance for the refrigerant substitution and the optimization of domestic air-conditioning systems.