Hybrid heat transfer enhancement for latent-heat thermal energy storage systems: A review

The potential of phase-change materials (PCMs) for application in the fields of thermal energy storage and thermal management is well recognized, due to their remarkable energy storage density and negligible temperature variation during operation. However, these materials do face the primary challenge of low thermal conductivity which necessitates incorporation of heat transfer enhancement techniques. Heat transfer enhancement in these systems has been a subject of interest for numerous studies, many of which have focused on employing only one enhancement technique. Very few studies have investigated the combination of two or more techniques. This combination of techniques is referred to as hybrid heat transfer enhancement. This paper provides a review of the major studies on the hybrid heat transfer enhancement techniques. It was found from the study that best enhancement is achieved via the hybrid application of the heat pipe with fins or metal foam. It was also found that the hybrid use of nanoparticles with fins or metal foam is more efficient than the use of nanoparticles alone within the same containment volume. Further research is recommended to explore other possible hybrid enhancement techniques which could lead to improved performance of PCM-based systems. (C) 2019 Elsevier Ltd. All rights reserved.