A Model of Moist Polymer Foam and a Scheme for the Calculation of Its Thermal Conductivity
Open Access
Abstract
This paper proposes a method for determining an effective value of the thermal conductivity for moist, highly porous rigid polymer foams. The model of moist foam based on an ordered structure with interpenetrating components was developed in accordance with the moisture distribution in the pore space. With small moisture content, isolated water inclusions are formed, and the pore space is considered as a binary system (vapor-gas mixture and water) with isolated inclusions. With an increase in moisture content, isolated water inclusions merge, forming a continuous layer, and pore space is considered as a binary system of interpenetrating components. The thermal conductivity of the vapor-gas mixture is represented as the sum of the thermal conductivity of the dry gas and the thermal conductivity of the vapor caused by the diffusion transfer of vapor in the pore space, taking into account the coefficient of vapor diffusion resistance. Using the proposed scheme of calculation, a computational experiment was performed to establish the influence of the vapor diffusion, moisture content, and average temperature of the foam on its thermal conductivity.Keywords
Funding Information
- Ministerstwo Edukacji i Nauki (S/WBiIŚ/1/16 (Bialystok University of Technology) and 2017-WNET/KNT/ZB/1 (State Higher School in Biala Podlaska).)
This publication has 11 references indexed in Scilit:
- An Analysis of Relations for Determining the Thermal Conductivity of Rigid Polymer FoamsInternational Journal of Applied Mechanics and Engineering, 2018
- Effective conductivity of Voronoi’s closed- and open-cell foams: analytical laws and numerical resultsJournal of Materials Science, 2017
- Effective Thermal Conductivity of Open Cell Polyurethane Foam Based on the Fractal TheoryAdvances in Materials Science and Engineering, 2013
- Determination of capillary tortuosity coefficient in calculations of moisture transfer in building materialsInternational Journal of Heat and Mass Transfer, 2013
- Estimation of effective thermal conductivity enhancement using foam in heat exchangers based on a new analytical modelBrazilian Journal of Chemical Engineering, 2010
- A whole range hygric material model: Modelling liquid and vapour transport properties in porous mediaInternational Journal of Heat and Mass Transfer, 2010
- Numerical investigation of conductive heat transfer in high-porosity foamsActa Materialia, 2009
- Effective thermal conductivity of moistened insulation materials as a function of temperatureInternational Journal of Heat and Mass Transfer, 2008
- Determination of effective thermal conductivity for polyurethane foam by use of fractal methodScience China Technological Sciences, 2006
- An assessment of expressions for the apparent thermal conductivity of cellular materialsJournal of Materials Science, 1994