HEAT SOURCES IN A POROUS MEDIUM

摘要

Porous materials are usually treated as homogeneous substances in which the classical differential Fourier equation can be applied for the description of heat transfer processes. However, this approach can lead to substantial errors due to mass transport processes that in such media occur simultaneously with heat conduction. The mass transport consists mainly in the flow of gas or liquid through pores, vapor absorption and condensation in capillaries, diffusion of water vapor present in the air or of other gases the fill the pores. These mass transport processes generate heat sources which have been shown [1, 2, 3 ] to significantly distort temperature fields in porous media. In the present paper, equation will be derived that determine heat source densities associated with various mass transport processes. Next, effect of the processes on temperature fields will be estimated and a generalized equation formulated for the case of heat transfer in a porous medium.