THE SOLIDIFICATION PROCESS OF NANO-ENHANCED PHASE CHANGE MATERIAL IN LATENT HEAT STORAGE UNIT

Abstract

NePCMs have been an advanced invention to improve the Thermal Energy Storage (TES) performance. Nano-enhanced Phase Change Materials (NePCMs) have been adopted to combat the inherently low thermal conductivity of Phase Change Materials (PCMs). The high conductivity nanomaterial is being added into the PCM to raise its thermal conductivity.

To investigate the enhancement of the NePCM during solidification process, a numerical analysis based on valid prediction models is being adopted along with ANSYS FLUENT Computational Fluid Dynamics for simulation. The NePCMs used are categorised into carbon-based, metal-based and metal oxide-based. Four conditions were studied which are orientation of the cylinder, morphology, concentration of the NePCM and the types of materials. Different conditions are expected to result in a variation of results and this study aims to find out the optimum condition that can enhance the solidification performance.

The results showed that morphology variation has a prominent enhancement effect in which Graphene Nano-Sheet (GNS) is 57.64% more efficient than pure PCM distinctly. This could be due to a higher thermal conductivity as 2-dimensional morphology has higher interfacial interaction due to larger surface. Copper enhanced PCM is 26.55% more efficient than PCM. 5% of nano-alumina is 21.75% more efficient than pure PCM. Diagonal orientation is 2.89% more efficient than vertical orientation.

Experimental study can be conducted to validate the simulated results for future work. Other potential materials can be used, and GNS-PCM, being the best composite, can be further studied in real life application such as incorporating this NePCM in cooling appliances.