Enhancing thermal performance and optimization strategies of PCM-integrated slab-finned two-fluid heat exchangers for sustainable thermal management

Abstract

This research investigates the influence of phase change material (PCM) distribution, fin density, and PCM type on the thermal performance of a slab-finned cross-flow PCM heat exchanger (HEX). The aim is to develop a highly efficient PCM-HEX system for enhanced thermal intermittency management. Computational fluid dynamics (CFD) simulations are employed to analyze the dynamic behavior of the HEX. Three PCM configurations, 15 variations in fin densities, and three paraffin-based PCMs with distinct melting temperatures are considered. The results reveal that the Type II configuration enhances heating time at high set point temperatures (SPTs), while the Type I configuration extends heating time at low SPTs. Increasing the air mass flow rate (AMFR) reduces the overall discharged thermal energy by 18–19 % for Type II and III configurations and by 10 % for the Type I configuration, indicating the lower sensitivity of Type I to AMFR variations. It is also shown that decreasing the PCM domain's fin density extends the heating time at low SPTs. Additionally, using a PCM with a higher melting temperature enhances the heating time at high SPTs and increases latent energy discharge power. Tetracosane demonstrates the highest efficiency at 54.9 % and maximum total discharged energy reaching 112.4 kJ. The findings of this study have significant implications for the development of optimized PCM heat exchangers in various applications, enabling more efficient and impactful thermal management.