【作者】 刘莹莹；

【导师】 巨星； 刘明义；

【作者基本信息】 华北电力大学(北京) ， 能源动力硕士（专业学位）， 2025， 硕士

【摘要】 随着全球能源结构加速向可再生能源转型,新型储能制造业作为现代化能源转型产业体系的关键环节,其重要性愈发凸显。随着市场对电池能量密度大、寿命长、安全性高等需求的快速增长。锂离子电池的热安全问题成为制约其性能与寿命的关键因素。浸没冷却技术因具有散热能力强、均温性好的特点而备受关注,但其多物理场耦合机制与浸没冷却系统优化设计方法仍需深入研究。本文以电化学-热耦合模型为基础,进行了电池浸没冷却系统的多物理场分布特性研究,在此基础上通过COMSOL/SIMULINK协同仿真平台提出了浸没冷却系统冷却液动态调控策略,旨在提升锂离子电池浸没冷却系统的热安全性与综合性能。首先,本文基于电化学与传热学理论,建立了包括电池产热及流动浸没的电化学-热及非等温流动耦合模型,通过仿真分析浸没冷却过程中电池组的温度场及流场分布规律,揭示冷却液物性参数对浸没冷却性能的影响。仿真结果表明,浸没冷却可显著降低电池组最高温度,降幅达35%。在低倍率工况下,可将电池间温差控制在3℃以内。进一步将模型扩展至电池包层级,研究多电池模块耦合下的热场非均匀性及流场特征,提出基于浸没冷却电池包流道优化的均温设计方法。其次,针对浸没冷却系统的动态控制需求,结合SIMULINK搭建了基于电化学-热耦合模型的流动浸没协同仿真平台,开发冷却液流量控制策略,实现冷却液流量实时动态优化。通过COMSOL与SIMULINK的联合仿真验证,优化后的电池组最高温度降低6%。最后基于多物理场协同分析结果,开发面向多工况场景的浸没式锂电池组冷却液动态调控设计框架,在设定场景下电池温升速率降低到1.27℃/min,有效控制温升的同时也为高能量密度电池系统的热管理设计与系统热安全优化提供了新思路。更多还原

【Abstract】 With the global energy landscape undergoing a rapid transformation towards renewable energy sources,the new energy storage manufacturing industry has emerged as an indispensable part of the modernized energy transition system,and its significance is becoming increasingly prominent.The market’s demand for batteries with high energy density,long service life,and enhanced safety is escalating at a remarkable pace.As a result,the thermal safety of lithium-ion batteries has emerged as a crucial determinant that significantly impacts their performance and service life.Immersion cooling technology has attracted extensive attention owing to its outstanding heat dissipation performance and ability to achieve uniform temperature management.Nevertheless,the underlying mechanisms of multiphysical field coupling and the optimal design approaches for immersion cooling systems still necessitate more in-depth research.In this paper,an investigation into the multi-physical field distribution characteristics of the battery immersion cooling system is carried out based on an electrochemical-thermal coupling model.On the basis of this research,a dynamic control strategy for the coolant within the immersion cooling system is proposed by leveraging the COMSOL/SIMULINK cosimulation platform.This strategy is specifically designed to improve the thermal safety and overall performance of lithium-ion battery immersion cooling systems.Firstly,an integrated electrochemical-thermal and non-isothermal flowcoupled model has been constructed.Rooted in electrochemical and heat transfer theories,this model takes into account both the heat generation within batteries and the dynamics of the coolant.Through numerical simulations,an in-depth analysis of the temperature and flow field distributions during the immersion cooling process is conducted,thereby emphasizing the impact of coolant properties on the efficiency of thermal management.The simulation results demonstrate that immersion cooling is capable of reducing the maximum temperature of battery modules by 35%,and under low-rate operating conditions,it can maintain the temperature differences between cells at less than 3℃.Subsequently,the model is further extended to analyze battery packs,uncovering the thermal inhomogeneity and flow interactions among multiple modules.In order to attain temperature uniformity,a channel optimization strategy has been put forward,which mainly focuses on the redesign of the coolant pathways.Second,To address the dynamic control requirements of the immersion cooling system,we developed a flow-immersion co-simulation platform using an electrochemical-thermal coupling model integrated with SIMULINK.This allowed us to create a coolant flow control strategy that enables real-time dynamic optimization of coolant flow.Joint simulations conducted with COMSOL and SIMULINK verified that the maximum temperature of the optimized battery pack was reduced by 6%.Additionally,based on the results of a multi-physical field collaborative analysis,we established a design framework for the dynamic regulation of coolant in immersion cooling lithium battery packs,tailored for various operating conditions.Under the defined scenarios,the temperature rise rate of the battery was reduced to 1.27℃/min.This approach not only effectively controls the temperature increase but also offers new insights to design thermal management systems for high-energy-density batteries and optimizing their thermal safety.更多还原