An equation of state for the thermodynamic properties of 1,1,1,2,3,3-hexafluoropropane (R236ea)

Abstract

A new equation of state expressed explicitly in the Helmholtz free energy for the thermodynamic properties of 1,1,1,2,3,3-hexafluoropropane (R236ea) was presented in this paper. The equation uses temperature and density as independent variables and is valid from 240K to 412K with pressures up to 6.0MPa. The results from the equation of state were compared with the available experimental data. The uncertainties in density of the equation of state are estimated to be 0.1% in the compressed liquid region, and 0.5% in the vapor region. The uncertainties in vapor pressure are 0.2% at temperatures from 280K to 370K, and 0.4% at temperatures outside of this range. The uncertainty in speed of sound is 0.1% in the vapor region and 2% in the liquid region. The equation of state shows reasonable extrapolation behavior at higher pressures and temperatures.