| 초록 |
Azeotropic mixtures are attractive as refrigerants because they behave very nearly as pure materials. The method for predicting azeotropic composition and pressure was very useful and valuable. In this study, we derived a simple equation from the fundamental equation of equilibria and activity coefficient model (NRTL model) for predicting azeotropic composition and pressure. The VLE data for the binary mixtures of hydrocarbon (iso-butane) and HFCs (HFC-32, HFC-134a, HFC-152a, and HFC-227ea) were used to test this equation. These mixtures were selected as a promising alternative refrigerants in place of chlorofluorocarbons (CFCs) because of their low ozone depletion potentials (ODP) and global warming potentials (GWP). HFCs are stable but expensive, on the other hand, hydrocarbons are flammable but very cheap. The mixtures of these two compounds may have good potential for alternative refrigerants. In this work, we presented activity coefficient model parameters and the deviation between calculated and experimental values of azeotropic compositions and pressures.
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