Study on the Interaction Coefficients in PR Equation with vdW Mixing Rules for HFC and HC Binary Mixtures

摘要

The Peng-Robinson equation of state with the van der Waals mixing rules was used to correlate vapor-liquid equilibrium (VLE) data for HFC/HC, HFC/HFC, and HC/HC binary mixtures. The interaction parameter k{sub}(ij) was obtained for every binary mixture. It was assumed that k{sub}(ij) has contributions from the two components, and each component has its own constant contribution factor k{sub}i for the mixture, and the values of k{sub}(ij) indicate the degree in difference of properties between the two components. Therefore, the interaction parameters k{sub}(ij) is proposed as: k{sub}(ij) = k{sub}i - k{sub}j. The values of the mixing factor k{sub}i for Hydrofluorocarbons (HFCs) and Hydrocarbons (HCs), including propane, isobutane, n-butane, R23, R32, R125, R143a, R134a, R152a, R227ea R236fa, R236ea, and R245fa, were obtained by least-square fitting. In total, 39 refrigerant binary mixtures were analyzed on the basis of this method, and the results showed good agreement with experimental data. The overall average absolute deviations of pressure and vapor mole fraction are 1.3% and 0.0089, respectively.