Simulation of the phase change process of paraffin waxes with and without Al foams for advanced hybrid thermal energy storages.

The use of the latent heat absorption phenomenon related to the melting process of a suitable Phase Change Material (PCM) can be considered an effective way to improve the energy storage capabilities in many applications. In order to simulate the possible advantages of hybrid water thermal energy storages, advanced simulation tools are strongly needed. Nevertheless, in many cases, the lack of accurate experimental measurements limits the reliability of the simulation results. In this paper, a Trnsys Type developed to simulate the loading (melting) and unloading (solidification) processes of paraffin waxes for hybrid thermal energy storages is presented. It permits to monitor the phase change processes with and without the use of metal foams to enhance the poor heat transfer properties of the paraffin waxes. The model was validated against some data collected during experimental tests on a paraffin wax having melting temperature of 40 °C in a hybrid water thermal storage unit.