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

Abstract

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.

New Experimental Vapor-Liquid Equilibria Data and Thermodynamic Modelling for R1234yf/propane/R32 as low-GWP Mixtures in Heat Pump Applications

“…Moreover, saturated vapor phase densities at temperatures above 338 K are estimated with errors between 0.6 and 4% and saturated liquid densities report relative errors between 0.7 and 6% (the latter is the point at 320 K). As highlighted in Appendix A (Table 9), lower deviations are obtained between the model and experimental data from Akasaka [25] for vapor phase densities at lower temperatures, while deviations between 4 and 7.8% are obtained in the subcooled liquid region; PR-WS model predicts vapor phase density very accurately, as shown by the comparison against experimental data from Brown et al [24] (deviations in the range 0.6 to 2.5 %), while, in line with the typical limitation of cubic Equations of State, it is inherently less accurate in the liquid density region, as confirmed by the deviations against data from Zhong et al [22], reporting discrepancies in the range from 7.7 to 9.3% of the actual density value.…”

“…In order to better validate the calibrated PR-WS model, density predictions are compared against the experimental data by [22], [23], [24] and [25]. Figure 10 represents the comparison between experimental data by Akasaka [25] and the predictions by this work: although it is expected that the cubic PR models fail to properly predict the critical point behavior and liquid densities, the version calibrated in this work has acceptable deviations for preliminary heat pump cycle simulations: predicted critical point is at 362 K and 41.4 bar against the 359.7 K and 38.8 bar experimentally determined by Akasaka [25]. Moreover, saturated vapor phase densities at temperatures above 338 K are estimated with errors between 0.6 and 4% and saturated liquid densities report relative errors between 0.7 and 6% (the latter is the point at 320 K).…”

“…Zhong et al [20] and [21], which covers only temperatures below 300 K with a total of 105 data point, while two different sources exist for p--T data, Zhong et al [22], [23] and Brown et al [24], the latter related to the gas phase. Very recently (after measurements were completed in the present work), Akasaka et al [25] collected 40 new single-phase (p,  T) data in the high temperature region between 330 and 400 K and a total of 17 saturated densities for a 50%mass R1234yf and 50%mass propane mixture. Moreover, they also proposed a new Helmholtz-based thermodynamic model applicable to this binary mixture at any composition, currently representing the state-of-the-art and most accurate reference for R1234yf and propane.…”

Vapor-phase (p, ρ, T ) Behavior of Difluoromethane (R32)+ Trifluoroiodomethane (R13I1), Pentafluoroethane(R125) + R13I1, and R32 + R125 + R13I1 mixtures: Experimental Measurements Based on the IsochoricMethod and Verification with a Generalized VirialEquation of State

“…Figure 1 shows the experimental apparatus used in this work for measuring the (p, ρ, T ) behavior based on the isochoric method. This apparatus was successfully employed in our previous studies for pure fluids and mixtures, e.g., Higashi et al [10], Higashi and Sakoda [11], and Akasaka et al [12,13]. These references discuss the details of its structure, measurement procedure, and expected uncertainties, which are summarized below.…”