Thermodynamic Properties of Muiticomponent Refrigerants

In recent years, increasing attention has been focused on the use ofhalogenated hydrocarbon mixtures as working fluids in vapor compressionrefrigeration systems, e.g. heat pumps. This paper discusses phase rules,applied to the equilibrium of the vapor and liquid states of such mixtures.Mixtures of ideal behavior, those that obey Raoult's law, and those withdeviations from the law are included. Their behavior may analytically beapproximated by different ~quationsof state developed during the pastcentury. An overview on the type of equations is given along withexperiment«! datJ. they approximated. Those equilibrium data are summarizedto a table of investigated binary fluid mixtures. A selection of them werecorrelated with the De Santes equation of state. This equation pridictesboth the vapor and liquid volumes with satisfactory accuracy up to thevicinity of the-critical point. Thermodynamic properties of ternary fluidmixtures, comprised of the correlated binaries, are simmulated with the DeSantes equation of state and compared with experimental data. Mixing rulesare reviewed and suggestions of incorporating a coefficient for the ternarymixture are made to fit the experimental data better.