Theoretical modelling of heat transfer in non-homogeneous porous media

Abstract

The paper is focused on the study and analysis of heat transfer in geothermal substrates made up of non-homogeneous porous media. The paper analyses the influence of porosity on the heat transfer as a result of the combination of conduction and convection mechanisms that take place in non-homogeneous porous materials. As a result of the combined effect heat transfer is not homogeneously distributed throughout the cross section of the geothermal zone, generating instability in the thermal energy extraction. Besides, the presence of mass transport due to convective effects through the pores of the material represents an additional perturbation that influences the energy flow. The paper proposes a theoretical model to evaluate the energy transfer from the geothermal bulk to a heat exchanger to extract thermal energy from a geothermal substrate. The study can be applied to any geotectonic area made up of a compound of different types of materials. The resulting algorithms obtained in the modelling process allows scientist and technicians to easily apply a process that predicts thermal flow transfer within rather good accuracy.