Impact of Using Different Numbers of Fins on Heat Transfer Augmentation in a Phase-Change Material Helical Coil Latent Energy Storage System

Latent heat thermal energy storage (LHTES) using phase change materials (PCM) is a promising way to store energy. The primary problem with PCMs is their low heat conductivity, which causes the charge and discharge processes to take a long time. This study presents an experimental study using fins on helical coils to overcome this issue. The effect of different numbers of fin, changing heat transfer fluid (HTF) inlet temperature and flow rate, are investigated in the charging and discharging processes. Temperature variations in different regions are measured by thermocouples and imaged by a thermal camera to illustrate the PCM melting and solidification. Temperature fluctuation, mean temperature response (MTR), Stefan number (STE), thermal imaging, and the discharge process‘s heat power supply are used as metrics to examine the impact of different parameters. Results indicate that using 15, 25, and 35 fins can decrease the charging by about 11.2, 18.2, and 29.5%, respectively, and the discharging process by about 6.31, 11.9, 20.9%, respectively. Also, An increase in temperature and flow rate of HTF in the charging remarkably increases the full charge time. Nonetheless, a drop in the flow rate and temperature of the HTF intake has lengthened the discharge.