Thermodynamic Properties of 2,3,3,3-Tetrafluoroprop-1-ene (R1234yf) and Propane (R290) Mixtures: (p, ρ, T) Behavior, Saturated Liquid and Vapor Densities, Critical Parameters, and a Mixture Model

The (p, ρ, T) behavior of a refrigerant mixture of 50.00 mass% R1234yf and 50.00 mass% R290 was measured with the isochoric method. Along the six isochores (60, 121, 305, 500, 550, and 600 kg·m^-3), a total of 40 single-phase (p, ρ, T) data points were obtained at temperatures from 330 to 400 K and pressures up to 6.6 MPa. In addition, the phase boundary of this mixture was experimentally investigated by visual observation of the vapor-liquid meniscus, and a total of 17 saturated densities and the critical parameters were obtained. Additionally, five saturated densities were also determined from the inflection points of the isochores. According to the multifluid approximation approach, a thermodynamic mixture model was formulated for R1234yf/290 mixtures. The parameters of the mixture model were determined by fitting the experimental data obtained in this work and those available in the literature. Expected uncertainties (k = 2) in calculated values with the mixture model are 0.2% for bubble and dew point pressures, 0.2% for liquid densities, 0.4% for vapor densities, 1% for saturated liquid and vapor densities, and 1.5% for isochoric heat capacities in the liquid phase. The mixture model can also be applied to regions away from the fitted experimental data with reasonable accuracy because it extrapolates well to higher temperatures and pressures, and to lower temperatures.