ANALYTICAL MODEL OF WETTING THE POROUS MEDIUM

Abstract

The purpose of this article is to develop an analytical model for determining the weakening of the thermal insulation capacity of porous materials - mineral wool and polystyrene because of increased water content. In the dry state, it was assumed that the sample consists of a skeleton and air-filled pores without process moisture content. In the second shot, however, dry material skeleton and pores with dry air and moisture content were taken into account. In addition, the results of tests involving the process of absorbing moisture in different moisturizing environments for both types of materials were presented. Based on the adopted calculation model, the value of the heat conduction coefficient in the dry state was determined based on the sum of the products of the volume shares of individual components of the material sample, i.e. the apparent volume of the sample material skeleton and the volume of air pores contained. The results of the thermal conductivity coefficient λ obtained in this way are consistent with those obtained from measurements during the experiment. This allowed to determine the validation of the adopted calculation model.

Key words: humidity in porous materials, heat transfer coefficient, moisturizing