{"title":"Thermal performance in latent heat thermal energy storage with annular heat source using different shape fins","authors":"Xiangqiang Kong, Wanke Hou, Xichun Miao, Yijian Zhang, Ying Li, Jianbo Li","doi":"10.1016/j.solener.2025.113397","DOIUrl":null,"url":null,"abstract":"<div><div>For a latent heat thermal energy storage (LHTES) unit, its heat transfer performance can be significantly enhanced by increasing the fin surface. The LHTES unit with an annular heat source (AHS) is proposed for different shape fins and structural parameters. A corresponding numerical simulation has been conducted. The results show that pipe diameter ratio <em>γ</em> has the greatest influence on the heat transfer power <em>Φ</em>, followed by the outer and inner fin type in the charging and discharging processes. The increase of <em>γ</em> from 0.55 to 0.7 leads to <em>t</em><sub>c</sub> decreasing by 62.65%, the charging power <em>Φ</em><sub>c</sub> increasing by 153.68%, and the wall-average Nusselt number Nu<sub>c</sub> in the charging process increasing by 45.47%. Furthermore, an optimal <em>γ</em> of 0.625 is identified for the discharging process, resulting in −29.61%, 38.27%, and 20.2% changes in <em>t</em><sub>d</sub>, the discharging power <em>Φ</em><sub>d</sub>, and the wall-average Nusselt number Nu<sub>d</sub> in the discharging process compared to <em>γ</em> of 0.55. Bifurcation angle <em>θ</em> significantly influences <em>t</em><sub>c</sub> and <em>t</em><sub>d</sub>. The optimal <em>θ</em> for the charging process is 60°, reducing <em>t</em><sub>c</sub> by 40.7% compared to that of 180°. For the discharging process, the optimal <em>θ</em> is 90°, reducing <em>t</em><sub>d</sub> by 8.81%. The number of branches <em>n</em> significantly impacts heat transfer by influencing heat conduction. For the charging process, increasing <em>n</em> from 4 to 14 results in −45.39%, 81.78%, and −39.67% changes in <em>t</em><sub>c</sub>, <em>Φ</em><sub>c</sub>, and Nu<sub>c</sub>, respectively, while during the discharging process, it leads to changes of −31.91%, 45.48%, and −25.91% in <em>t</em><sub>d</sub>, <em>Φ</em><sub>d</sub>, and Nu<sub>d</sub>, respectively.</div></div>","PeriodicalId":428,"journal":{"name":"Solar Energy","volume":"291 ","pages":"Article 113397"},"PeriodicalIF":6.0000,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Solar Energy","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0038092X25001604","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENERGY & FUELS","Score":null,"Total":0}
引用次数: 0
Abstract
For a latent heat thermal energy storage (LHTES) unit, its heat transfer performance can be significantly enhanced by increasing the fin surface. The LHTES unit with an annular heat source (AHS) is proposed for different shape fins and structural parameters. A corresponding numerical simulation has been conducted. The results show that pipe diameter ratio γ has the greatest influence on the heat transfer power Φ, followed by the outer and inner fin type in the charging and discharging processes. The increase of γ from 0.55 to 0.7 leads to tc decreasing by 62.65%, the charging power Φc increasing by 153.68%, and the wall-average Nusselt number Nuc in the charging process increasing by 45.47%. Furthermore, an optimal γ of 0.625 is identified for the discharging process, resulting in −29.61%, 38.27%, and 20.2% changes in td, the discharging power Φd, and the wall-average Nusselt number Nud in the discharging process compared to γ of 0.55. Bifurcation angle θ significantly influences tc and td. The optimal θ for the charging process is 60°, reducing tc by 40.7% compared to that of 180°. For the discharging process, the optimal θ is 90°, reducing td by 8.81%. The number of branches n significantly impacts heat transfer by influencing heat conduction. For the charging process, increasing n from 4 to 14 results in −45.39%, 81.78%, and −39.67% changes in tc, Φc, and Nuc, respectively, while during the discharging process, it leads to changes of −31.91%, 45.48%, and −25.91% in td, Φd, and Nud, respectively.
期刊介绍:
Solar Energy welcomes manuscripts presenting information not previously published in journals on any aspect of solar energy research, development, application, measurement or policy. The term "solar energy" in this context includes the indirect uses such as wind energy and biomass