Multifluid MixtureModels for the Binary Mixturesof Trifluoroethene (R-1123) with Difluoromethane (R-32), 2,3,3,3-Tetrafluoroprop-1-ene(R-1234yf), and Propane (R-290)

This work presents mixture models for the thermodynamic properties of the mixtures of R-1123 with R-32, R-1234yf, and R-290, which are potential refrigerants for next-generation air conditioning systems. The models are based on the multifluid approximation and employ accurate Helmholtz energy equations of state for the pure fluids. The mixing parameters of the models are determined by fitting experimental data for the (<i>p</i>, ρ, <i>T</i>) behavior and vapor–liquid equilibrium. The range of validity of the models is approximately temperatures from 273 to 400 K and pressures up to 7 MPa. Typical uncertainties (<i>k</i> = 2) in this range are 0.3% for liquid densities, 1.5% for vapor densities, and 1% for bubble-point pressures. The mixture models exhibit qualitatively correct behavior in the critical and extrapolated regions; this is demonstrated by plots of several thermodynamic properties over wide ranges of temperature and pressure.