Comprehensive analysis of melting enhancement by circular Y-shaped fins in a vertical shell-and-tube heat storage system

To overcome the weak thermal conduction of the phase change materials (PCM), the present investigation aims to study the effect of circular Y-shaped fins added to a vertical double-pipe latent heat providing a higher heat transfer rate compared with conventional circular fins. The PCM is located in the annulus, while the hot water flows inside the internal tube to charge the PCM. Different independent geometrical factors of the fins involving the length of the stem and the angle of the tributaries to the horizontal line and the number of fins are analyzed after validating the code against experimental data. The impact of the working fluid’s Reynolds number and temperature (as input parameters) are assessed as a sensitivity analysis to control the output (i.e. melting time and rate). The results show that for the base case with nine Y-shaped fins, the storage rate improves by ~12% compared with the conventional circular fins with a similar height. The findings show that the charging period reduces by ~43% and the energy storage rate enhances by 70% for the best configuration of the fins. For the optimal case, increasing the Reynolds number of the working fluid from 500 to 2000 results in 31% reductions in the melting time. Moreover, raising the working fluid’s temperature from 45℃ to 55℃ reduces the melting time by ~44%.