Experimental investigation of latent energy storage systems with the tree-pin-shaped fin

Abstract

The inefficient heat conduction of the phase change materials is the major bottleneck that hinders the large-scale application of latent thermal energy storage (LTES) systems. In this study, an innovative tree-pin-shaped fin was designed and assembled in a lab-scale shell-and-tube LTES unit, in which adipic acid was used as the phase change material. Moreover, a LTES unit with conventional longitudinal fins was tested under the same conditions for comparison. The temperature evolutions and thermal performance of the two units were studied during the charging and discharging processes. The experimental results suggested that the tree-pin-shaped fins significantly increased the charging and discharging speeds and enhanced the temperature uniformity in the LTES unit. Compared with the LTES unit with the longitudinal fins, the LTES unit with the tree-pin-shaped fins shortens the charging time by 44.6% and the discharge time by 50.6%. Furthermore, the tree-pin-shaped fin exhibited a structural feature that it did not restrain the natural convection when the LTES was placed at any orientation. The results of this study will provide a reference for the development of the LTES system.