Numerical study of the influence of the convective heat transfer on the dynamical behaviour of a phase change material wall

In construction, the use of Phase Change Materials (PCM) allows the storage/release of energy from solar radiation and internal loads. The application of such materials for lightweight construction (e.g., a wood house) makes it possible to improve thermal comfort and reduce energy consumption. The heat transfer process between the wall and the indoor air is convection. In this paper, we have developed a numerical model to evaluate several convective heat transfer correlations from the literature for natural, mixed and forced convection flows. The results show that the convective heat transfer highly influences the storage/release process in case of PCM walls. For the natural convection, the numerical results are highly dependent on the correlation used and the results may vary up to 200%. In the case of mixed and forced convection flows, the higher is the velocity, the more important is the storage capacity.

► We study effect of inside convection correlation on energy stored in PCM wall.
► We developed a 1D conduction model for multilayer walls, with phase change material.
► Correlations have been constructed for mixed convection in all flow regimes.
► Up to 200% variation of energy stored in PCM layer, depending on convection correlation.
► Ventilation can increase the energy stored in the PCM layer.