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

Abstract

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.

Thermal conductivity enhancement of paraffin by adding boron nitride nanostructures: A molecular dynamics study

“…It is true and a common phenomenon in many experiment studies when some high thermal conductivity fillers (e.g. graphene, CNTs, expanded graphite and carbon fiber) are added into paraffin [5][6][7]17]. And the paraffin-based PCM composites still have the relatively high latent heat, though the latent heat is a marked decrease after adding other materials.…”

“…However, the low thermal conductivity of paraffin seems to greatly restrict its further developments and applications in the large scale. Thus, a mass of researches and investigations have been carried out and performed in order to enhance the thermal conductivity [5][6][7][8][9][10][11][12][13][14][15][16][17].…”

Review of latent thermal energy storage systems for solar air‐conditioning systems

“…To solve this problem, some researchers added metal coatings, 197 expanded graphite, 198,199 graphene oxide, 200,201 and nanotubes 182 to the capsules. All capsule materials suffer from a low thermal conductivity, especially organic capsule materials.…”

“…All capsule materials suffer from a low thermal conductivity, especially organic capsule materials. To solve this problem, some researchers added metal coatings, 197 expanded graphite, 198,199 graphene oxide, 200,201 and nanotubes 182 to the capsules. Compared with ordinary mPCM with the same concentration, the heat transfer coefficient of mPCM slurry with a metal coating increased by more than 10%.…”

Preparation and characterization of sodium thiosulfate pentahydrate/silica microencapsulated phase change material for thermal energy storage

“…19 In order to overcome the problems of inorganic hydrated salt, MicroPCM have received great attention for thermal energy storage in recent years. 20,21 MicroPCM are tiny core-shell structure capsules, which have PCM core surrounded by a shell that prevents the PCM from leaking during the solid-liquid phase change process. 22,23 The advantages of MicroPCM are as follows: preventing leakage of the melted PCM during the phase change process, increasing heat transfer area and controlling the volume change of PCM as phase change occurs.…”