Correlations of thermal conductivity for liquid refrigerants at atmospheric pressure or near saturation

• Literature survey of experimental thermal conductivity data for refrigerants.
• An equation based on the corresponding states theory is proposed.
• The influence of dipole moment is discussed.
• Classical predictive methods gave higher deviations.

A previously proposed general correlation relating thermal conductivity to reduced temperature is improved by the complete characterization of the refrigerant family. A total of 41 fluids and 1372 experimental points were considered. After analyzing the statistical effects, a new simple empirical correlation to represent the thermal conductivity of refrigerants is presented as a function of reduced temperature, molecular mass, acentric factor, and critical pressure. This equation gives an AAD = 6.5%. The influence of the dipole moment is also discussed and a slightly more complex equation, with an AAD = 6.1%, is presented. The refrigerants were then divided into four subgroups according to the different chemical halogen forming the compounds, and analyzed separately. To minimize the deviation between predicted and experimental data and to find the optimal coefficients for each family, a non-linear regression was performed. In this way, an AAD = 4.9% was obtained.