An effective thermal conductivity model for the three-phase porous media based on the numerical simulation

Heat conduction in the porous media (PM) with gas-liquid-solid three-phase has been numerically investigated. The validation of the adopted numerical method is performed by comparing the effective thermal conductivity (ETC) obtained from the simulation results with the experimental data. The results show that the ETC of the PM increases with increasing solid volume fraction (ϕs) and liquid saturation degree (Sr). Sr has a weaker effect on the ETC compared to ϕs. Similar variation laws of the ETC with Sr and ϕs are found for systems with different solid and liquid thermal conductivity. In this work, the PM is simplified as a circuit network. The modeling for the ETC is performed by defining a weighted harmonic parameter (η) to connect the serial and parallel models. η is closed as a function of Sr, ϕs and the thermal conductivity of the solid and liquid phases. The predictability of the model is evaluated. The results demonstrate that the model can provide accurate estimations for the ETC of the three-phase PM.