Melting heat transfer characteristics of a composite phase change material fabricated by paraffin and metal foam

Paraffin has a great potential as the phase change material (PCM) to be applied in many energy-related applications, such as thermal energy storage and thermal management, due to its appropriate phase change temperature and large latent heat. The heat transfer characteristics during phase change of paraffin play a very important role in determining the thermo-fluidic performance of the systems. However, the drawback of small thermal conductivity of PCM hampers its application. In the present study, the composite PCM was fabricated by using copper foam to enhance the thermal conductivity of paraffin, and an experimental setup was built to study the phase change heat transfer characteristics of composite PCM. The evolvement of solid-liquid interface and temperature variation during the melting process were experimentally investigated, and the experimental results were compared with the numerical results obtained by the two-temperature energy model. It was indicated that there was a quite large temperature difference between the ligament of copper foam and paraffin, which was due to the thermal non-equilibrium effect in heat transfer between the paraffin and copper foam. Good agreement between the experimental and numerical results showed that the heat transfer characteristics could be well depicted by the two-temperature energy model, which can be further used to depict the heat transfer in thermal energy storage or temperature management using composite PCM. (C) 2015 Elsevier Ltd. All rights reserved.