Viscosity and Thermal Conductivity Model of HFOs and HFO/HFC Mixtures Based on Friction Theory

Hydrofluoroolefins (HFOs) are a category of environmentally friendly refrigerants. The transport properties such as viscosity and thermal conductivity of pure HFOs and HFO/HFC mixtures are essential for the investigation of flow and heat transfer characteristic of fluids. Therefore, it is necessary to provide the viscosity and thermal conductivity calculation method of HFOs and HFO/HFC mixtures. In this work, the viscosity and thermal conductivity models of HFOs including R1234yf, R1234ze(E), R1234ze(Z), R1243zf, R1336mzz(Z), and R1336mzz(E) were established based on the friction theory (FT) and Peng–Robinson (PR) equation of state, and the overall ARD between the experimental values and those calculated from the model is 1.6% and 2.0%, respectively. The viscosities and thermal conductivities of HFO/HFC mixtures were predicted using mixing rule and the established FT model. Results show that the established FT model has good predictive ability for the viscosity and thermal conductivity of HFO/HFC mixtures.