Estimation of the thermal properties of PCMs through inverse modelling

The application of Phase Change Materials (PCMs) is promising to improve the energy efficiency of buildings. However, although the great interest that PCMs have gained, their practical application in the building sector is still very limited. One of the obstacles to the diffusion of PCMs is the lack of information regarding their thermo-physical properties. In the present work, a method for estimating the specific heat-temperature curve of a PCM through inverse modelling was presented. This method combined experimental data with a numerical tool that was capable of simulating multilayer walls with the inclusion of PCM materials. The experimental setup consisted in a sample of PCM which was subjected to controlled temperature variations on its surfaces. Given the measured surface temperatures of the sample as boundary conditions and the known thermo-physical properties of the material to the model, the specific heat-temperature curve which minimised the difference between measured and simulated heat fluxes was found through an optimisation algorithm. Results were validated against tests on different samples and discussed in comparison with a low-speed DSC measurement.