Thermal Conductivity Enhancement of Phase Change Materials Using Metal Wire Woven Porous Structures for Thermal Energy Storage

Abstract

In the present work, the thermal conductivity of paraffin wax has been increased using low-cost and lightweight aluminium wire metal foam structures. The designed metal wire foam structures have uniform-sized circular pores forming a convective spring-like network for faster heat transfer. The paraffin wax can easily infiltrate the designed wire woven foam structures even at a lower porosity (~75 vol %). The latent heat thermal energy storage (LHTES) systems which can store up to 500 kJ of thermal energy have been designed using the PCM-wire-woven metal foam composite material. The heating of these composites is carried out both in convection and conduction modes, and their effect has been studied. The effect of using a polymer (acrylic), and a galvanized iron (GI) sheet to encapsulate PCM-metal wire foam composites is also evaluated. Increasing the pore diameters in the wire woven structures, and its effect on the thermal efficiencies of the LHTES system is calculated. The thermal efficiency of the LHTES ranged from 67 to 92 % using an acrylic sheet, and 72 to 77 % using the GI sheet. The heat extraction using cold water could be continued for 8-9 cycles in acrylic, and 5-6 cycles in GI sheet capsulation.