AUTHOR=Shojaeinasab Chatroudi Ilia , Atashafrooz Meysam , Mohammed Hayder I. , Abed Azher M. , Talebizadehsardari Pouyan 

TITLE=Heat transfer enhancement and free convection assessment in a double-tube latent heat storage unit equipped with optimally spaced circular fins: Evaluation of the melting process

JOURNAL=Frontiers in Energy Research

VOLUME=Volume 11 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2023.1097382

DOI=10.3389/fenrg.2023.1097382

ISSN=2296-598X

ABSTRACT=To overcome the weak conduction heat transfer of phase change materials (PCM), this investigation aims to assess the behavior of a double-tube latent heat storage unit with circular fins through charging process. The influence of free convection in the presence of fins with various arrangement and size are studied comprehensively. The geometrical characteristics of the fins i.e. the size and number of the fins are assessed to optimize the performance of the fins. Moreover, a sensitivity assessment is performed on the characteristics of the heat transfer fluid passing through the inner tube i.e. the Reynolds number and temperature. It is shown that the charging time diminishes by 179% in the case of using nine fins with a height of 15 mm evaluated with that of the finless case considering the same volume of the PCM. Moreover, the thermal recovery rate improves from 20.5 W to 32.9 W by adding the mentioned fins to the system. The use of a higher number of fins improves thermal behaviour to the PCM because of the higher fins’ area. The melting time and heat storage rate change by 76% and 71%, respectively, for the system with 19 fins evaluated with those of the system with 4 fins. Moreover, the outcomes indicate a higher heat storage rate using a faster flow and inlet temperature of the working medium.