Performance enhancement of a shell-and-coil ice storage enclosure for air conditioning using spiral longitudinal fins: A numerical approach

This study carries out a series of complex unsteady three-dimensional (3D) computational analyses that were validated by experimental tests to examine the performance enhancement of a cylindrical shell-and-coil ice storage enclosure by employing various spiral longitudinal fin geometries covering the heat transfer fluid (HTF) tubes throughout the transient process of solid-liquid phase change. The phase change material (PCM) in this work was selected to be water and the tubes and fins were chosen to be made of copper alloy. To study how this type of fin accelerates the charging process, several dimensionless parameters related to the spiral longitudinal fin geometries were defined, which included dimensionless fin length (<i>Ω</i>), count (<i>Ψ</i>), and thickness (<i>Φ</i>) parameters. Additionally, the impact of fin orientation was evaluated. The findings suggested that raising <i>Ω</i> from 0 to 0.719 reduces the solidification time by 42.29 %. Similarly, changing the <i>Ψ</i> from 0 to 6 expedites the process by 50 %. Regarding the changes of <i>Φ</i>, it was observed that even though the freezing dynamic was not sensitive to this parameter in the first half of the process, the effect was more pronounced throughout the second half. Furthermore, with identical heat transfer areas, horizontal fins outperformed the vertical ones by a marginal difference of 3.58 %, which was found to be because of the better distribution of fins within the container.