Study on solidification characteristics of bionic finned phase change heat exchanger and multi-objective optimization design

• Published in: Journal of energy storage Vol. 86; p. 111105
• Main Authors: Wang, Zhen, Wang, Yanlin, Yang, Laishun, Song, Lei, Jia, Huiming, Ren, Yunxiu, Yue, Guangxi
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2024
• Subjects: Multi-objective optimization; Prediction relation; Solidification characteristic; Tree-shaped perforated fins; Solidification characteristic; Prediction relation; Tree-shaped perforated fins; Multi-objective optimization
• ISSN: 2352-152X; 2352-1538
• DOI: 10.1016/j.est.2024.111105

The investigation into bionic fin structures marks a frontier in phase change heat transfer research. This study presents an innovative tree-shaped perforated bionic fin structure, exploring the synergistic heat transfer processes of conduction and convection during solidification. Leveraging the enthalpy-porosity technique, a numerical model was developed to delve into the flow dynamics and heat transfer behaviors of the bionic fins throughout solidification. This model scrutinizes the influence of perforations on the thermal efficacy of latent heat storage (LHS) systems, delineating the principles governing the effects of perforations on heat transfer. To further dissect the multifaceted effects of perforations on LHS, the response surface methodology (RSM) evaluated the repercussions of variations in perforation size and number on the phase change material's (PCM) fill volume and the discharge duration of the storage units. Findings reveal that perforations substantially augment the role of natural convection in the initial phase of solidification, albeit at the cost of diminished thermal conductivity. In scenarios where the tree-shaped perforated fins comprised one or two layers, perforations beneficially contributed to the concurrent enhancement of natural convection and thermal conductivity, whereas additional layers of perforations proved to be counterproductive. In comparison to bulkier rectangular fins, the introduction of one, two, and three layers of perforations increased the PCM fill volume by 0.86 %, 0.94 %, and 1.19 % respectively, while discharge times were curtailed by 52.76 %, 52.56 %, and 51.99 %. To optimize the thermal performance of LHS units, a regression model was devised via RSM, accompanied by the application of the non-dominated sorting GA-II (NSGA-II) algorithm for a multi-objective optimization of the tree-shaped perforated fin LHS systems. The resultant Pareto optimal set demonstrated a 1.02 %–1.24 % rise in PCM fill volume and a 50.85 %–51.74 % decrease in discharge time, showcasing the strategic enhancements achievable through perforation adjustments. •Bionic perforated fins were utilized to enhance phase change heat transfer.•Phase change material natural convection is enhanced through perforation.•Perforation area exhibits a U-shaped trend of PCM discharging time.•Pareto optimum demonstrates a reduction in discharging time by 51.74 %.