Thermodynamic performance analysis of upper-and-lower cascaded latent heat thermal energy storage device under unsteady inlet temperature conditions

IF 8.9 2区 工程技术 Q1 ENERGY & FUELS
Zhongbin Zhang, Tianqi Zhu, Lihua Cao
{"title":"Thermodynamic performance analysis of upper-and-lower cascaded latent heat thermal energy storage device under unsteady inlet temperature conditions","authors":"Zhongbin Zhang,&nbsp;Tianqi Zhu,&nbsp;Lihua Cao","doi":"10.1016/j.est.2025.118712","DOIUrl":null,"url":null,"abstract":"<div><div>Latent heat thermal energy storage (LHTES) is critical for solar thermal utilization due to its high energy density, yet the impact of unsteady heat transfer fluid (HTF) inlet temperatures on cascaded LHTES units remains underexplored. This study numerically compares four unsteady inlet temperature profiles (<em>T</em><sub>A</sub>, <em>T</em><sub>B</sub>, <em>T</em><sub>C</sub>, <em>T</em><sub>D</sub>) with their steady counterparts (<em>T</em><sub>a</sub>, <em>T</em><sub>b</sub>, <em>T</em><sub>c</sub>, <em>T</em><sub>d</sub>) by assessing phase change material (PCM) liquid fraction, temperature distribution, melting uniformity, and heat/exergy storage capacity. Results demonstrate enhanced melting uniformity under all unsteady conditions. Specifically, the peak value of liquid fraction increased by 12.06 % (<em>T</em><sub>A</sub>), 22.01 % (<em>T</em><sub>B</sub>), 15.16 % (<em>T</em><sub>C</sub>) and 41.95 % (<em>T</em><sub>D</sub>), respectively, heat storage capacity increased by 2.12 % (<em>T</em><sub>A</sub>), 16.89 % (<em>T</em><sub>B</sub>), and 12.14 % (<em>T</em><sub>D</sub>) but decreased by 5.93 % (<em>T</em><sub>C</sub>); concurrently, exergy storage rose by 0.883 % (<em>T</em><sub>A</sub>), 20.388 % (<em>T</em><sub>B</sub>), and 13.993 % (<em>T</em><sub>D</sub>) yet declined by 7.862 % (<em>T</em><sub>C</sub>). A novel cut-off time determination method is proposed to optimize thermodynamic performance of cascaded LHTES under both steady and unsteady operations, providing critical theoretical guidance for real-world system efficiency.</div></div>","PeriodicalId":15942,"journal":{"name":"Journal of energy storage","volume":"138 ","pages":"Article 118712"},"PeriodicalIF":8.9000,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of energy storage","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2352152X25034255","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENERGY & FUELS","Score":null,"Total":0}
引用次数: 0

Abstract

Latent heat thermal energy storage (LHTES) is critical for solar thermal utilization due to its high energy density, yet the impact of unsteady heat transfer fluid (HTF) inlet temperatures on cascaded LHTES units remains underexplored. This study numerically compares four unsteady inlet temperature profiles (TA, TB, TC, TD) with their steady counterparts (Ta, Tb, Tc, Td) by assessing phase change material (PCM) liquid fraction, temperature distribution, melting uniformity, and heat/exergy storage capacity. Results demonstrate enhanced melting uniformity under all unsteady conditions. Specifically, the peak value of liquid fraction increased by 12.06 % (TA), 22.01 % (TB), 15.16 % (TC) and 41.95 % (TD), respectively, heat storage capacity increased by 2.12 % (TA), 16.89 % (TB), and 12.14 % (TD) but decreased by 5.93 % (TC); concurrently, exergy storage rose by 0.883 % (TA), 20.388 % (TB), and 13.993 % (TD) yet declined by 7.862 % (TC). A novel cut-off time determination method is proposed to optimize thermodynamic performance of cascaded LHTES under both steady and unsteady operations, providing critical theoretical guidance for real-world system efficiency.
进气温度不稳定条件下上下级联潜热蓄热装置热力性能分析
潜热储能(LHTES)由于其高能量密度而对太阳能热利用至关重要,但非定常传热流体(HTF)入口温度对级联LHTES装置的影响仍未得到充分研究。本研究通过评估相变材料(PCM)液相分数、温度分布、熔化均匀性和蓄热能力,对四种非定常进口温度分布(TA、TB、TC、TD)与稳定进口温度分布(TA、TB、TC、TD)进行了数值比较。结果表明,在所有非稳态条件下,熔化均匀性都有所提高。其中,液分峰值分别增加了12.06% (TA)、22.01% (TB)、15.16% (TC)和41.95% (TD),蓄热容量分别增加了2.12% (TA)、16.89% (TB)和12.14% (TD),但减少了5.93% (TC);同时,火用蓄能分别增长0.883% (TA)、20.388% (TB)和13.993% (TD),而下降7.862% (TC)。提出了一种新的确定截止时间的方法来优化级联LHTES在稳态和非稳态工况下的热力学性能,为实际系统效率提供了重要的理论指导。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
Journal of energy storage
Journal of energy storage Energy-Renewable Energy, Sustainability and the Environment
CiteScore
11.80
自引率
24.50%
发文量
2262
审稿时长
69 days
期刊介绍: Journal of energy storage focusses on all aspects of energy storage, in particular systems integration, electric grid integration, modelling and analysis, novel energy storage technologies, sizing and management strategies, business models for operation of storage systems and energy storage developments worldwide.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:604180095
Book学术官方微信