Effect of graphite fin on heat transfer enhancement of rectangular shell and tube latent heat storage

•Graphite fin is potential for heat transfer enhancement in a latent heat storage application.•Working condition including inlet HTF temperature and HTF flow rate plays an important role in the thermal behavior of latent heat storage.•Increasing fin thickness improves the heat transfer rate and reduces the thermal resistance while sacrificing an amount of heat capacity. Graphite is a promising material for application in thermal storage systems owing to its high thermal conductivity and extreme lightweight. In the current study, research on rectangular graphite-finned latent heat storage is conducted and numerically simulated. The effects of the fin material, fin thickness, inlet heat transfer fluid temperature, and water flow rate are considered to be related to the thermal performance of the charging and discharging process of a phase change material (PCM). To evaluate the thermal behavior of the proposed heat storage, the heat transfer rate, total thermal resistance, and liquid fraction are investigated. The results demonstrate that varying the inlet water temperature has a significant effect on the thermal response of the latent heat storage when compared to the effect of the heat transfer fluid flow rate. This research also offers fin material alternatives to the conventional copper fin. Regarding graphite fins, an increase in the fin thickness of 0.5 mm can enhance the heat transfer rate by approximately 14%, although the PCM volume is reduced by 4%. The results also revealed that the melting time could be reduced by 50% using graphite fins.