Liquid thermodynamic-transport property coupling: Linking thermal conductivity to density using hidden scale invariance

Thermal conductivity is a key thermophysical parameter in the energy transfer process and is important for the design and optimization of heat transfer equipment. This work monotonically linearizes the logarithm of the reduced thermal conductivity with respect to the reduced density of 95 pure fluids and 66 mixtures (including ternary and quintuple mixtures) based on hidden scale invariance. Quasiuniversality is used to make the images of different fluids as a function of the reduced thermal conductivity vs the reduced density coincide. A generalized predictive model for the liquid thermal conductivity is constructed. The average absolute relative deviation of the 26 327 pure fluid thermal conductivity experimental data is 3.6%, and the average absolute relative deviation of the 7033 mixtures experimental data points is 4.8%. In addition, the critical enhancement of thermal conductivity is considered. The new model contains only four global parameters, no specific fitting parameters for pure fluids and no interaction parameters for mixtures.