Optimization simulation of the melting process in a rectangular heat storage unit with fin heat transfer

This paper presents a numerical investigation into the effects of different fin structures on the thermal management efficiency of rectangular PCM thermal storage units. Three fin configurations were analyzed: straight fins, T-shaped fins, and Y-shaped fins. For straight fins with a length of 37 mm, the melting time was 4070 seconds. The optimal T-shaped fin design, featuring a vertical section length of 32 mm and a horizontal section length of 40 mm, reduced the melting time to 3770 seconds. Using the Box-Behnken design for optimization, the best-performing Y-shaped fin had an angle of 36.5°, an insertion depth of 17 mm, and an extension length of 20 mm, achieving the shortest melting time of 3620 seconds. Compared to the straight fin, the Y-shaped fin reduced the melting time by 20.6%, significantly enhancing thermal storage efficiency. These findings demonstrate that the Y-shaped fin structure substantially improves heat storage performance in PCM systems.