Numerical investigation of enhanced thermal performance in phase change materials (PCMs) via nanoparticles across diverse regenerator configurations

Abstract

This study investigates the use of CuO-enhanced Paraffin wax (RT-55) in a horizontal co-axial regenerator, addressing the challenge of low thermal conductivity in Phase Change Materials (PCM). The focus is primarily on examining the influence of CuO nanoparticles on the thermal and energetic performance of the regenerator. The research begins by exploring the impact of CuO volume fraction on both the total melting time and energy density. Subsequently, the study incorporates the addition of 3 wt.% of nanoparticles to diverse regenerator configurations, including non-uniform longitudinal fins, eccentricity, and combined fins with eccentricity. The objectives are twofold: firstly, to evaluate the effect of nanoparticles on power densities across various geometries; secondly, to assess the implications of natural convection within each configuration upon nanoparticles addition. The results demonstrate that while the nanoparticles enhance the power density of the system, they concurrently modify the storage capacity of the Latent Thermal Energy Storage System (LTES). Furthermore, the impact of nanoparticles varies depending on the regenerator’s configuration, owing to the influence of natural convection. Therefore, it was demonstrated that in the eccentric case, which experiences the highest impact of natural convection, the total melting time is increased by 2% when nanoparticles are added. Conversely, the finned and combined cases show a 4% and 8% reduction in the melting time with the addition of the same amount of CuO nanoparticles.