Liquid Thermal Conductivity of Ternary Mixtures of Difluoromethane (R32), Pentafluoroethane (R125), and 1,1,1,2-Tetrafluoroethane (R134a)1

The thermal conductivities of ternary refrigerant mixtures of difluoromethane (R32), pentafluoroethane (R125), and 1,1,1,2-tetrafluoroethane (R134a) in the liquid phase have been measured by the transient hot-wire method with one bare platinum wire. The experiments were performed in the temperature range of 233 to 323 K and in the pressure range of 2 to 20 MPa at various composi- tions. The measured data are correlated as a function of temperature, pressure, and composition. From the correlation, we can calculate the thermal conduc- tivity of pure refrigerants and their binary or ternary refrigerant mixtures. The uncertainty of the measurements is estimated to be \20.