Discharging process expedition of NEPCM in fin-assisted Latent Heat Thermal Energy Storage System

Latent Heat Thermal Energy Storage Systems (LHTESS) which work based on energy storage and retrieval during solid-liquid phase change is used to establish balance between energy supply and demand. The main restriction for these systems is the weakness of thermal conductivity of common PCMs. Different enhancement methods is applied to LHTESS in order to overcome this problem. In present work, the method of adding nanoparticles to pure PCM and making Nano-Enhanced Phase Change Material (NEPCM) and using Y-shaped fin with suitable array are applied to accelerate solidification process. The two mentioned methods are analyzed separately. The effects of nanoparticles volume fractions on solidification rate are studied and geometry parameters, which are fin branch angle, length and thickness, are changed to find the best fin array. Copper particles and water are used as nanoparticles and PCM, respectively. Aluminum Y-shaped fin system is implemented in LHTESS. The numerical approach which is used in this paper is Standard Galerkin Finite Element Method. In this work, Y-shaped fin structure has been employed in order to enhance the performance of LHTESS during discharging process, also the efficiency of nanoparticle dispersion in PCM and adding fin with different structures on LHTESS performance have been studied from the viewpoint of either discharging expedition or maximum energy storage capacity. Also, adaptive grid refinement is used in numerical procedure which are proposed as the novelties here. Results indicate that by considering both parameters of full solidification time and maximum energy storage capacity, applying Y-shaped fin with suitable array demonstrates better enhancement in comparison to adding nanoparticles.