Development of multilayer interacted characteristic melting region for large-scale horizontal latent heat storage investigation

The development of thermal energy storage (TES) technology has aroused extensive attentions due to its considerable energy-saving benefits. In the current work, the strategy of multilayer interacted characteristic melting region (MCR) was established to characterize large-scale horizontal latent heat thermal energy storage (LHTES). Based on the shell-and-tube configuration, the influence of multilayer interaction was numerically investigated and the single-tube approach was found to be inapplicable to characterize the melting performance of horizontal LHTES devices. Furthermore, the characterization strategy with MCR was applied to reexamine typical eccentric design and quite different rules were concluded. The melting performance of cases with intersection angles ranging from 60 degrees to 120 degrees and the tube eccentricity ranging from 0 to 0.6 were established and compared. For the design of eccentric side fins, horizontally spreading heat transfer structures was found to be a better choice, which extended the area dominated by the natural convection above the tubes. The full melting time of the case with the intersection angle of 90 degrees was reduced by 2.9 % and 6.2 % compared with the case with intersection angles of 60 degrees and 120 degrees, respectively. The eccentric tube arrangement was found to have negative influence on the melting performance for large-scale horizontal LHTES devices. The full melting time of the case with the fin-tubes eccentricity of 0.6 was increased by 23.3 % compared with the concentric design.