关键词: 汽液相平衡, 二元混合工质, 三元混合工质, HFC/HC, 推算

Abstract: A method is presented to predict the vapor-liquid equilibria (VLE) for binary and ternary HFC/HC mixtures using PR equation of state and van der Waals (vdW) mixing rule. The binary interaction parameters kij is predicted by the difference-correlation model, which is assumed to be the difference between the mixing factors ki of the pure components. The values of ki of 10 HFCs and 3 HCs have been obtained according to VLE correlation for 39 binary mixtures in authors' previous works. In this work, this prediction method is further verified with 11 new binary systems (HFC236ea / HC290、HFC152a / HC600、HFC125 / HC600a、HFC143a / HC600、HFC227ea / HC600、HFC152 / HC290、HFC125 / HC227ea、HFC125 / HC290、HFC134a / HC290、HFC134 / HC290、HFC134 / HC600a), and then extended to predict VLE properties of ternary HFC/HC mixtures, which are HFC32 / HFC125 / HFC134a, HC290 / HC600a / HFC32, HFC125 / HFC143a / HFC134a, HFC32 / HC290 / HFC227ea and HFC32/HFC125/HC290. The predicted results are compared with the experimental data reported in literatures. The overall deviations of pressure and vapor composition are 2.23% and 0.0086 for the HFC32 / HFC125 / HFC134a system, 8.33% and 0.014 for the HC290 / HC600a / HFC32 system, 1.43% and 0.0054 for the HFC125 / HFC143a / HFC134a system, 0.40% and 0.0071 for the HFC32 / HC290 / HFC227ea system, and 1.71% and 0.0089 for the HFC32 / HFC125 / HC290 system, respectively. The comparison shows very good agreement between predicted and experimental results, validating the feasibility of the method to predict VLE properties for binary and ternary HFC/HC mixtures.