Amirkabir University of Technology AUT Journal of Mechanical Engineering 2588-2937 9 1 2025 01 01 Solidification enhancement of phase change material in a triplex tube latent heat energy storage unit using longitudinal-parabolic fins 65 82 5620 10.22060/ajme.2024.23620.6146 EN Farhad Moheiseni Department of Mechanical Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran Zahra Mehrdoost Department of Mechanical Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran Journal Article 2024 10 20 This paper numerically investigates the solidification performance improvement of phase change material in a triplex tube latent heat thermal energy storage unit by introducing an innovative longitudinal-parabolic fin. A numerical model based on the enthalpy-porosity approach is employed to simulate the discharging process. Simulation results reveal that the longitudinal-parabolic fins outperform the conventional straight fins in effectually increasing the phase change performance of the latent heat thermal energy storage unit. The complete discharging time of the triplex tube latent heat thermal energy storage unit with the proposed fin was reduced by up to 38.5% compared to that of the unit with straight fins. The study also investigates the influence of geometric parameters of the designed fin to achieve superior phase change material discharging efficiency. Effects of radial pitch and angular pitch of the longitudinal-parabolic fins on energy discharge time are studied by examining various cases under the constant total fins volume. Results infer that the radial pitch of parabolic fins has a moderate impact on solidification time improvement, while the angular pitch has a remarkable impact on reducing energy discharging time. Decreasing the angular pitch from 120° to 60° reduces the solidification time by 52.3%. The maximum of saving discharge time for the most efficient fin design is 61.8% in comparison with straight fins.

https://ajme.aut.ac.ir/article_5620_382e85354381aebd5340b9eb123dcf2c.pdf