Measurements of PVTx Properties for Binary Mixtures of HFC-32 (CH2F2) and HFC-134a (CH2FCF3)

An experimental study of pressure-volume-temperature-composition(PVTx) properties for binary mixtures of HFC-32 and HFC-134a was conducted in the range of temperatures from 243 to 473 K, pressures up to 16.7 MPa, densities from 9.5 to 1065 k g . m - 3 , and compositions from 0.39 to 0.89 mol fraction of HFC-32, with uncertainties of 8 mK, 1.7 kPa, 0.04%, and 0.001 mol fraction, respectively. A constant-volume method was used for the present measurements either with a spherical vessel approximately 270 cm3 in its inner volume or with a cylindrical vessel approximately 138cm3 in its inner volume. The present data were compared with the Piao equation of state for this substance.