含HFC混合物的气液相平衡计算模型评价

Evaluation of vapor-liquid equilibrium models for refrigerant mixtures containing hydrofluorocarbons

含氢氟烃(HFC)混合物是一类很有前景的替代工质,其气液相平衡性质的准确描述非常重要。该文对23种有代表性的含HFC二元和4种三元混合工质,采用PR状态方程结合vdW混合规则及其改进形式,以及两种GE-EoS型混合规则进行了相平衡性质研究,详细分析了各模型对二元体系,以及应用于三元体系相平衡性质预测时的适用性。结果表明:简单的vdW混合规则对多种二元体系的计算精度较低,而SV、MHV1、WS混合规则均可准确再现各二元体系的相平衡性质。vdW、MHV1、WS混合规则结合优化得到的二元交互作用参数可以较好地用于文中三元体系的预测,SV混合规则对三元体系的适用性不佳。

Mixtures containing hydrofluorocarbons （HFC） are promising alternative refrigerants, so accurate descriptions of their vapor-liquid equilibrium （VLE） properties are very urgently needed. The VLE properties of 23 representative binary and 4 representative ternary mixtures containing HFC＇s were calculated using the Peng-Robinson （PR） equation of state combined with the van der Waals （vdW） mixing rule, the Stryjek Vera （SV） mixing rule which is a modification of the vdW mixing rule, and two GE-EoS type mixing rules （MHV1 and WS） to investigate their abilities to accurately describe the VLE properties of binary and ternary systems. The results show that the vdW mixing rule is too simple to provide accurate descriptions for many binary systems, while the SV, MHV1, and WS mixing rules can accurately describe the VLE properties for all binary systems. The results also show that the vdW, MHV1, and WS mixing rules satisfactorily predict the VLE properties of these ternary systems with some parameters optimized from the binary data, while the SV mixing rule fails to do so.