Measurements and correlation of vapor-liquid equilibrium for difluoromethane (R-32) + 2,3,3,3-tetrafluoroprop-1-ene (R-1234yf) and pentafluoroethane (R-125) + propane (R-290)

Abstract

A new set of recirculation-analytical type vapor-liquid equilibrium (VLE) apparatus was built, and the verification experiment of the R-125+R-290 system was carried out along three isotherms in the range of temperature from 273.15 K to 293.15 K. The experimental data is consistent with the literature data, which proves the reliability of the experimental system and method. In the temperature range of from 273.15 K to 358.15 K, the VLE measurement of the R-32+R-1234yf system was carried out along eight isotherms. The VLE data above 333.15 K was reported for the first time, and the measurement uncertainties of temperature, pressure, mole fraction were determined. Using the PRSV equation of state (EoS) combined with the W.S. mixing rule and NRTL activity coefficient model, the experimental VLE data of the R-32+R-1234yf system were correlated, and the temperature-dependent binary interaction parameters (BIP) within 273.15 to 343.15 K is obtained. For the R-32+R-1234yf system, the average relative deviation of the pressure ARD(p) is 0.34%, and the average absolute deviation of the vapor phase mole fraction AAD(y) is 0.0050. The experimental data in this work are in good agreement with the literature data.