Vapor phase pvTx measurements of binary mixtures of difluoromethane (R32) and 2,3,3,3-tetrafluoroprop-1-ene (R1234yf)

The pvTx properties of binary mixture of difluoromethane (R32) and 2,3,3,3-tetrafluoroprop-1-ene (R1234yf) in the vapor phase were measured at temperatures from (298 to 383) K and at pressures from (475 to 5686) kPa covering the mole fractions of xR32 = (0.119, 0.259, 0.449, 0.698, 0.874) by using a Burnett apparatus. The combined expanded uncertainties of temperatures, pressures, mole fraction and density are estimated to be 24 mK, 1.6 kPa, 0.01 and within 0.2% (k = 2) over the entire temperature and pressure ranges, respectively. Based on the experimental data of this work, a virial equation of state was developed with the absolute average deviation of compressibility factor lower than 0.19% for each composition and this equation shows physically reasonable behaviour of the second and third virial coefficients. Furthermore, the relative deviations of the experimental data from the multi-parameter equation of state of REFPROP 10.0 are less than 0.6% for the mixtures.