Effects evaluation of fin layouts on charging performance of shell-and-tube LTES under fluctuating heat sources

Abstract

The previous studies focus on the heat storage process of shell-and-tube latent thermal energy storage (LTES) under steady heat sources, without considering the fluctuating and intermittent characteristics of the most available heat sources in real applications. The effect of different fin sizes and locations on the charging performance of shell-and-tube LTES still keeps unclear under fluctuating heat source, and it is critical to improve the heat storage rate and density due to the low thermal conductivity of phase change materials (PCM). Consequently, this study aims to investigate the charging performance of a shell-and-tube LTES considering different fin layouts. Firstly, the effects of different fin number and configurations on heat storage process are performed under fluctuating heat sources. The case with comprehensive performance of high melting rate and large heat storage capacity is obtained. Then the effects of critical parameters on the charging process, including the fin angle, fin thickness, fin height and deviation distance of tube under fluctuating heat sources are further analyzed based on this case, and the results are compared with that of steady heat source. Results indicate that the fin height is the dominant factor influencing the heat storage rate and density under both steady and fluctuating heat source conditions, while the total melting time is shorter and the heat storage capacity is smaller, and the heat storage capacity is less obvious with the variation of fin parameters under the fluctuating heat source. In addition, the effect of downward deviation distance of tube on heat storage capacity is much obvious under fluctuating heat source than that of steady heat source.