Composites Enhance Heat Transfer in Paraffin/Melamine Resin Microencapsulated Phase Change Materials

To enhance the heat storage efficiency of microencapsuled phase-change materials (MicroPCMs), different mass fractions of expanded graphite (EG), graphene nanoplatelets, (GNs), and nanocopper were added to a MicroPCM of paraffin/melamine resin as heat transfer promoters. The thermal conductivities of the MicroPCM/nanocopper, MicroPCM/GN and MicroPCM/EG composites were measured by using heat flux methods and compared to that of MicroPCM. The melting temperatures and latent heat capacities of the MicroPCM and composite were tested. Furthermore, the heat transfer effect on the heat storage with different mass fractions of additives and different flow rates of heat transfer fluid were investigated. The addition of EG proved to be an effective method to increase the thermal conductivity and heat storage efficiency of MicroPCM without greatly reducing its latent heat storage capacity.