A numerical investigation of a heat transfer augmentation finned pear-shaped thermal energy storage system with nano-enhanced phase change materials

Abstract

Thermal energy storage using latent heat and phase change materials is a frequently utilized technique in energy storage systems. It is critical to search for various thermal enhancement approaches in order to further improve the poor thermal conductivity of phase change materials in these systems. Two primary thermal enhancement approaches (fins and the use of a nano-enhanced phase change material (NePCM)) are discussed in this study for a pear-shaped TES system. The TES unit is filled with n-octadecane PCM incorporated with Al2O3 nanoparticles and equipped with fins. Different concentrations of Al2O3 (such as 0, 3, and 6 vol%), fin shapes (2-fin, Y-shaped fin, and T-shaped fin), and fin materials (aluminum, copper, and steel) are tuned to obtain an optimal heat transfer and acceleration of PCM melting process. The results indicated that when a dose of 6 % of Al2O3 nanoparticles and copper fins are utilized, the melting time is lowered by 14 % and 32 %, respectively, compared to pure PCM with steel 302 fins. Additionally, the best choice for accelerating energy storage in a pear-shaped unit is to equip it with a Y-shaped copper fin. The use of steel 302 fins causes a dominance of the heat transfer irreversibility compared to the fluid friction irreversibility. Nonetheless, two rectangular aluminum fins may be considered a more cost-effective option due to the moderate difference in performance between the cases, the fact that aluminum is cheaper and lighter than copper, and the simplicity and convenience of producing the two rectangular fins.