Chun-cheng Piao1, Masahiro Noguchi1
1Mechanical Engineering Laboratory, Daikin Industries, Ltd., 1304 Kanaoka-cho, Sakai, Osaka 591-8511, Japan
Tóm tắt
An 18-coefficient modified Benedict–Webb–Rubin equation of state for HFC-125 (pentafluoroethane) has been developed. Correlations of vapor pressure and saturated liquid density are also presented. This equation of state has been developed using experimental data for the relationship of pressure-volume-temperature of fluid, saturation properties, isochoric heat capacity data, and speed of sound data. The equation of state is valid in the superheated gaseous phase and the compressed liquid phase at pressures up to 68 MPa, densities to 1700 kg/m3, and temperatures from the triple point (172.52 K) to 475 K. This equation of state has been selected as an international standard formulation for HFC-125 based on an evaluation of the available equations of state by Annex 18 of the International Energy Agency.
