An improved PCM heat storage technology utilizing metal foam

Having a uniform temperature for electronics is part of thermal management in order to avoid hot spots and reduce thermal stresses in electronic systems. In many applications, thermal energy storage is required to receive, store, and subsequently release heat. The major disadvantage of phase change materials (PCMs) is their low thermal conductivities, which drastically slows the phase change process and causes a wide temperature range within PCMs. Metal foams possess thermal conductivities that are an order of magnitude higher than PCMs, and can be imbedded in PCMs. The random internal structure and high porosity of metal foam enhance and accelerate the phase change process without significantly reducing PCMs´ heat storage capacity. Unlike traditional PCM systems, the distribution of the foam ligaments in PCMs makes the melting and solidification processes more uniform and less dependent on the location inside PCMs. In this paper, the performance of a PCM combined with aluminum foam storage system is investigated experimentally. Transient temperatures were measured at strategic locations in the PCM-foam matrix to assess the phase change process. The pure PCM was also tested separately to serve as a base case. The results established the significant phase change process enhancements in terms of time and temperature uniformity.