Phase change material heat transfer enhancement in latent heat thermal energy storage unit with single fin: Comprehensive effect of position and length

In this study, the comprehensive effect of position and length of the fin in a latent heat thermal energy storage (LHTES) unit with a single fin on the melting and solidification of the phase-change materials (PCMs) was explored by transient numerical simulations. By analyzing the liquid-solid interfaces, temperature distributions, velocity vector and phase change rate, the melting and solidification characteristics of PCM and heat transfer enhancement mechanism of the fin with various length ratios and height ratios were understood in detail. The results illustrated that the total melting time was significantly reduced by increasing the fin length and lowing the fin position simultaneously. On the other hand, lowering the fin position would result in non-uniform temperature distribution during the solidification process. More importantly, considering the contradiction in fin position between melting and solidification, an optimal position of the fin corresponding to different fin lengths was suggested. Besides, a disparity between heat storage/release and phase transition was quantitatively discussed.