Experimental Study of Varying Heat Transfer Fluid Parameters within a Latent Heat Thermal Energy Storage System Enhanced by Fins

Abstract

Latent heat thermal energy storage (LHTES) systems can be used to combat the limited collection and long-term storage of renewable energy sources. The key component of an LHTES system is its phase change material (PCM), which thermally stores energy. Despite extensive research on thermal conductivity enhancement within PCM, little attention has been paid to the heat transfer fluid (HTF) within the system. This study aimed to observe the impact of variable HTF flow rates and temperatures on the speed of charging and discharging an LHTES system enhanced with annular fins. Two copper fin configurations of 10 and 20 annular fins were tested within an LHTES system with Rubitherm RT-55 PCM. The configurations were tested during charging processes with HTF parameters of 65 °C and 70 °C at 1, 2, and 3 gpm. Discharging processes were tested with HTF parameters of 15 °C and 20 °C at 0.5, 1, and 1.5 gpm. The system energy response and PCM temperature were recorded throughout the tests. The results of the study revealed that a higher flow rate produced a shorter processing time, but furthermore, that a larger temperature gradient between the PCM and HTF caused a more significant decrease in charging and discharging times.

Heat Transfer Enhancements Assessment in Hot Water Generation with Phase Change Materials (PCMs): A Review

“…Fins are typically extended on the PCM rather than the HTF side to enhance efficiency [42]. Fins facilitate heat transfer within these systems, and increasing their number and size can significantly enhance system performance [43,81,82]. This assertion is supported by studies such as Hosseine et al [83], which propose that fin length is a critical parameter capable of augmenting absorbed energy and reducing melting temperatures.…”

“…SWHS typically comprises three key components: the solar collector, storage tank (optional in some systems), and heat transfer fluid (HTF-with good thermal conductivity) [41]. HTF serves as a medium for energy transfer in heat exchange systems, whether PCM is employed or not [42,43]. Typically used in hot water generation, HTF, such as water [44], facilitates human consumption in various applications [45].…”