储能科学与技术 ›› 2021, Vol. 10 ›› Issue (6): 2252-2259.doi: 10.19799/j.cnki.2095-4239.2021.0185

• 储能系统与工程 • 上一篇    下一篇

基于临界换热系数与干预时间的车用锂电池热设计及运行策略

许国良1(), 张玉洁1, 黄晓明1, 何锐2   

  1. 1.华中科技大学能源与动力工程学院,湖北 武汉 430074
    2.中广核工程有限公司,广东 深圳 518000
  • 收稿日期:2021-04-27 修回日期:2021-06-05 出版日期:2021-11-05 发布日期:2021-11-03
  • 通讯作者: 许国良 E-mail:scoee@hust.edu.cn
  • 作者简介:许国良(1967—),男,博士,教授,主要研究方向为新能源技术和电厂劣质煤稳定燃烧技术,E-mail:scoee@hust.edu.cn

Thermal design and operation strategy of automotive lithium battery based on critical heat transfer coefficient and intervention time

Guoliang XU1(), Yujie ZHANG1, Xiaoming HUANG1, Rui HE2   

  1. 1.School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
    2.China Guangdong Nuclear Power Engineering Co, Ltd, Shenzhen 518000, Guangdong, China
  • Received:2021-04-27 Revised:2021-06-05 Online:2021-11-05 Published:2021-11-03
  • Contact: Guoliang XU E-mail:scoee@hust.edu.cn

摘要:

针对车用锂电池在高倍率放电情况下的热管理问题开展研究。基于电池生热量和散热量匹配的热管理理念,创新性地提出了确保电池热安全运行的临界换热系数hcr,并基于单电池的热电耦合模型发展了一种确定临界换热系数的数值分析方法。对极端工况下的18650锂电池进行临界换热系数的数值研究发现放电倍率和换热环境温度是其主要影响因素。换热环境温度和放电倍率增加,临界换热系数会急剧增加。为了进一步提高电池的热安全运行能力,针对h<hcr的工作状况,提出了基于干预时间τintv的热管理运行策略,并详细讨论了干预时间τintv的数值确定方法和影响因素。数值结果显示,在干预时间内对锂电池实现降倍率运行等措施,可以有效地将电池温度控制在安全范围内。进一步研究还发现,给定h的锂电池干预时间受放电倍率、环境温度等因素的影响较大。本文的工作对车用锂电池热管理系统的设计以及运行管理有着良好的理论指导意义。

关键词: 锂离子电池, 热管理, 临界等效换热系数, 干预时间

Abstract:

The thermal management of automotive lithium batteries during high-rate discharge is being investigated. Based on the thermal management concept of matching the heat generation and heat dissipation of the battery, the critical heat transfer coefficient hcr is innovatively proposed to ensure the battery's safe operation, and a set of numerical solution methods for determining hcr is developed. For numerical calculation, a thermoelectric coupling model of a single cell is established. The findings indicate that the critical heat transfer coefficient of a given lithium battery is related to the discharge rate and the temperature of the heat exchange environment, and is less affected by the battery's initial temperature. The critical heat transfer coefficient increases sharply once the ambient temperature exceeds 293.15 K. A thermal management operation strategy based on the intervention time τintv is proposed for the working condition of h<hcr to further improve the battery's thermal safety operation capability. Furthermore, the numerical determination method, influencing factors, and intervention effect of intervention time are thoroughly examined. The results show that the intervention time of the lithium battery for a given h is greatly affected by the discharge rate, and the reduced rate operation of the lithium battery during the intervention time can effectively control the battery temperature within a safe range This work has important theoretical implications for the design and operation management of the vehicle lithium battery thermal management system.

Key words: lithium-ion battery, thermal management, critical equivalent heat transfer coefficient, intervention time

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