Enhancement of Hybrid PCM Thermal Storages Using Aluminum foams

The latent heat absorption phenomenon associated with melting of a suitable Phase Change Material (PCM) can be an effective way to improve the Thermal Energy Storage (TES) behaviour in many applications. However, the most suitable PCMs to be used in HVAC and refrigeration systems find intrinsic limitations due to their poor heat transfer capabilities. This work experimentally studies the use of aluminum foams as heat transfer medium to improve the overall heat transfer of paraffin waxes that can be possible PCMs to be implemented in hybrid sensible-­latent water TESs. The experimental tests were run in a dedicated setup designed, developed, and built at the Department of Management and Engineering of the University of Padova to study the water hybrid TES. The experimental results are presented in terms of loading and unloading times at constant water tank temperature. The effects of the use of aluminum foams as enhancing heat transfer medium were studied by comparing the loading and unloading processes of a paraffin wax with melting temperature around 40 °C, with and without metal foams, in a water thermal storage unit. The effects of three different foams with 5, 20, and 40 Pores Per Inch (PPI) were investigated.