Experimental and Numerical Analysis of Bio-Based PCM Integrated with Metal Foam

The growing demand for efficient energy storage drives research on thermal storage, including the use of Phase Change Materials (PCM). Bio-based PCMs (bio-PCM's), derived from renewable resources, offer environmental advantages such as biodegradability and reduced reliance on fossil fuels. Their high latent heat capacity and stable phase change behavior make them promising for applications in building energy efficiency, thermal storage, and solar energy utilization. However, a major limitation of PCMs, in general, is their low thermal conductivity, which reduces their efficiency. To overcome this challenge, structures such as metal foams can be incorporated into PCM to enhance heat transfer. Studies indicate that parameters such as porosity and metal foam density affect the melting performance of PCM. Therefore, this study experimentally and numerically investigates the thermal performance of pure PCM (bio-PCM, specifically palm wax), as well as numerical analysis of this PCM when embedded in a copper foam. The objective is to quantify the impact of these high-conductivity structures on heat transfer efficiency, phase change behavior, and thermal management, contributing to sustainable energy applications. The experimental setup includes a 100x100x22mm3 reservoir, where acrylic walls are heated by a planar electric resistance. A NIKON D5300 camera with a macro lens evaluates the liquid fraction of PCM over time. The setup is thermally insulated with polystyrene and a fiberglass blanket to minimize heat losses. Numerical results with pure PCM showed that, in the early melting stage, conduction is the dominant heat transfer mechanism. As the process progresses, the melting front acquires a convex shape due to the influence of natural convection. Moreover, numerical results indicate that incorporating copper foam accelerates the melting of PCM, reduces the temperature gradient, and may, therefore, be used to improve the system's performance.