Numerical study of phase change material microencapsulated in a typical multilayer wall for a hot climatic zone

Abstract

AbstractA phase change material (PCM) allows releasing and absorbing energy at the phase change transition. They are employed in building walls to maintain internal thermal comfort and optimize thermal energy storage. However, the hottest cities in Morocco suffer from overheating during peak days. Consequently in this article, the purpose is to evaluate the thermal performance of incorporation of the PCM n‐octadecane paraffin in a typical multilayer wall at three different locations for a Moroccan hot climate zone. Numerical simulation is developed in a two‐dimensional transient in addition to mathematical modeling using the enthalpy‐porosity approach for three wall types. An implicit finite volume method is used for the numerical solution. The effects of PCM location, PCM type, and mass fraction (varying between 15% and 35%) are studied and compared with the reference case (without PCM). The evaluation of mass fraction variation is based on two determining factors of the wall panel's thermal inertia: the time delay and amplitude attenuation. The surface heat fluxes will then be used to quantify the capacity of the multilayer wall to store and release energy. The results showed that to ensure the thermal performance of the wall, it is useless to exceed 20% of mass fraction for all types of multilayer walls. It is shown that the incorporation in a solid matrix of hollow brick is the most optimal scenario, and it makes it possible to have a reduction in the internal surface flux of 32% with a temporal phase shift of 3 h.