Abstract
The pressure-density-temperature-composition (p-ρ-T-x) data of binary refrigerant mixtures containing R-134a (1,1,1,2-tetrafluoroethane), R-1234yf (2,3,3,3-tetrafluoropropene), and R-1234ze(E) (trans-1,3,3,3-tetrafluoropropene) were measured in both the vapor and liquid phases using a two-sinker, magnetic-suspension densimeter. The specific samples in this study comprised two compositions of approximately (0.3/0.7) and (0.7/0.3) mole fraction for each of the following three binary refrigerant blends: R-1234yf + R-134a, R-134a + R-1234ze(E), and R-1234yf + R-1234ze(E). Single-phase vapor densities were measured over a temperature range of (253 to 293) K and pressures from approximately (0.04 to 0.5) MPa. Single-phase liquid and supercritical densities were measured over a temperature range of (230 to 400) K and pressures up to 21 MPa; for refrigerant blends containing R-1234yf, the maximum pressure was limited to approximately 12 MPa. Overall relative combined, expanded (k = 2) uncertainties in density ranged from 0.043% to 0.418%, with an average uncertainty of approximately 0.06%. Here, we present measurement results, along with comparisons to available literature data and to default equations of state and mixture models included in REFPROP.