| 초록 |
Hydrofluorocarbons (HFCs) have been considered as promising alternative refrigerants in place of chlorofluorocarbons (CFCs) since their ozone depletion potentials (ODP) and global warming potentials (GWP) are low. The HFCs binary mixtures may have good potential for altermative refrigerants because of HFCs are stable and inflammable. Vapor-liquid equilibrium data are required as one of the most important types of basic information in evaluating the performance of refrigeration cycles and determining their optimal compositions. In this work, we measured VLE data for two binary systems of 1, 1, 1, 2, 3, 3, 3-Heptafluoropropane(HFC-227ea)+1, 1, 2, 2-tetrafluoroethane(HFC-134a), + 1, 1-difluoroethane(HFC-152a). The experimental data were correlated with Modified Huron-Vidal(MHV) mixing rule combined with the Peng-Robinson-Stryjek-Vera equation of state and the NRTL excess free energy model. In addition, the nonideality of HFC-227ea + HFC-134a, HFC-152a, and iso-butane was discussed by the excessgibbs energy. The NRTL parameters obtained by these mixing rules and second virial coefficients and fugacity coefficients were presented.
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