Enhanced PCM melting performance in shell and tube latent heat thermal energy storage systems using optimally positioned porous fins
Alireza Jaberi, Siamak Hossainpour
Abstract
Heat transfer enhancement is crucial for overcoming the low thermal conductivity of PCMs in LHTESS, with fins being among the most effective strategies. However, solid fins can impede buoyancy-driven flow during the melting process. To overcome this limitation, the present study explores the replacement of solid fins with porous fins at various locations within the LHTESS, aiming to identify the optimal fin placement for maximizing the melting rate. Four distinct fin configurations are analyzed, and fin porosity is evaluated at three porosity levels. The results highlight the critical influence of fin positioning on the melting behavior of PCMs when solid fins are replaced with porous alternatives. Optimal melting performance is achieved by replacing the lower-mounted solid fins with porous fins, resulting in up to 21 % reduction in the overall melting duration and a corresponding 26.6 % increase in stored power. The optimal fin configuration depends on the system's charge level scenario; under a complete charge condition, replacing the lower-mounted fins with porous ones yields superior melting performance, whereas, for a partial charge level of 90–95 %, better results are obtained by replacing the side-mounted fins. Specifically, in this sub-maximal charging scenario, the charging time can be reduced by up to 33 %.