Influence of Rotational Speed on Melting Time in Latent Heat Storage Systems

Incorporating a spinning mechanism into a latent heat energy storage (LHES) unit can significantly influence its thermal behavior and overall efficiency. Inserting rotation introduces novel mechanisms that can enhance heat transfer and optimize the overall performance of LHES systems. The shell and tube system are used as LHTES. Varying the rotational speed has an important role in the charging process, but there is an inconsistency related to the impact of changing the rotation speeds on melting time. This study provides a systematic and comprehensive approach to addressing the discrepancies found in previous research regarding the relationship between rotational speed and melting time. It fills the research gap by conducting a detailed analysis of a specific range of rotational speeds (0.1–3 rpm). Additionally, it highlights the gradual influence of rotation, starting with a negligible effect in the initial phases and evolving into a crucial factor in enhancing melting once a certain liquid fraction is reached—an aspect not previously explored in the literature. Seven main cases have been defined with different rotational speeds to choose the best case that would result in the shortest complete charging time. The results indicated that increasing the rotation speeds from 0.1 to 1 rpm and 3 rpm shortened the charging time by 41% and 47%, respectively. Also, it is found that the positive influence of rotation starts at 0.51% of liquid fraction.