THREE-DIMENSIONAL CALCULATION OF LONG-TERM CHANGE OF THERMAL CONDUCTIVITY DISTRIBUTION IN PLASTIC INSULATION FOAM

It is well known that the thermal conductivity of an insulation foam increases due to the emission of the blowing agents from the insulation foams and the transfer of the air into them. In this study, numerical simulation based on three-dimensional finite difference method is conducted to study the distribution of thermal conductivity within an insulation foam for a long-term. The influence of surface gas barrier and side seals on thermal conductivity change was examined. In addition, the time variation of thermal conductivity distribution for various types of plastic insulation foams are compared.