Analytical model to calculate the temperature increase in a low conductive material covered by a highly conductive layer

Paper in proceeding, 2014

There is a lack of measurement methods that can be used to determine the thermal conductivity of vacuum insulation panels (VIPs) on the construction site. With the transient plane heat source (TPS) method, the thermal properties of an isotropic material can be evaluated after a short measurement period. Heat is supplied in the TPS sensor which raises the temperature in the sensor. The thermal properties of the material are calculate based on the temperature increase. A novel analytical solution of the TPS method makes it possible to use the method on a low conductive material covered by a highly conductive layer. The aim of this study is to investigate the applicability of the analytical solution by comparing it to a numerical calculation model and TPS measurements. Five different setups were tested with good agreement between the analytical solution and the numerical calculation model. The TPS measurements deviated from the calculated temperature increase which could be explained by uncertainties regarding the influence of the contact surface between the sensor and material.