Natural convection heat transfer analysis of a nano-encapsulated phase change material (NEPCM) confined in a porous square chamber with two heat sources

Abstract

This study focuses on the thermal behavior and performance of an insulated porous cavity containing square tubes, one as the hot block and the other as the cold block. The cavity is filled with a Nano-Encapsulated Phase Change Material (NEPCM) that combines the advantages of phase change materials (PCM) and nanofluid. The main purpose of this research is to examine the heat transfer mechanisms, phase change process, and overall thermal performance of the system. The governing equations of the NEPCM suspension are transformed into a dimensionless form and solved using the finite element approach. Various parameters, including nanoparticles concentration, fusion temperature, Darcy number, Rayleigh number, and Stefan number, are investigated to assess their impact on the system's thermal and dynamic performance. The results reveal that the optimal heat transfer performance is achieved when the NEPCM fusion temperature is set to 0.5. Moreover, a smaller Stefan number significantly improves the system's performance. Additionally, including NEPCM particles generally improves heat transfer, with a 33% increase in mean heat transfer observed when the volume fraction was raised from 0% to 2%.