动力电池组热管冷却系统传热特性分析
发布时间：2019-06-24 22:15
【摘要】：电池热管理系统对于新能源汽车动力性能有着至关重要的影响,有效的冷却能够改善动力电池工作环境和工作性能,从而保证电动汽车的行车安全性和可靠性。国内外研究者在动力电池冷却技术及电池热管理方面开展了大量研究,主要针对空冷、水冷、相变材料冷却和热管冷却这几种冷却技术进行研究和改善,目前工程实际普遍使用的是空冷和水冷系统,但由于相变冷却对于提升电池组温度一致性具有很大优势,电池组相变材料冷却和热管冷却有望发展为新一代电池组热管理技术。本文依托国家自然基金项目(项目号:51375202),采用理论研究、仿真分析和试验验证相结合的研究方法,建立了车用锂离子电池的电化学-热耦合模型,对热管冷却系统的基础传热问题进行了研究,并通过仿真和试验研究了热管冷却系统冷却特性和温度场均匀性问题,通过研究基础共性技术,为热管冷却系统应用于新能源汽车动力电池热管理系统奠定基础。本文主要研究内容如下:(1)建立了锂离子电池的电化学-热耦合模型,搭建了数学模型控制方程,研究了电池的基本特性,包括电池容量、电池充放电曲线、不同倍率下的放电曲线及单体电池的温度特性。(2)主要针对热管冷却系统涉及到的基础传热问题进行了研究,包括热管相变传热、流体横掠管束的外部强迫对流传热系数和多层固体热传导中的接触热阻。介绍了热管冷却系统的结构与机理,将复杂的热管内伴随相变传热的两相流动问题进行了简化,得到了热管相变传热的等效传导模型;通过试验关联式求解了流体横掠管束的外部强迫对流传热系数;利用功率谱法确定了粗糙接触表面的分形参数,并通过Monte Carlo随机数模拟方法描述了粗糙接触表面形貌,最终基于建立的粗糙表面形貌确定了接触热导。(3)基于COMSOL仿真软件,建立了以12块动力电池为基础的热管冷却系统仿真模型,研究了单体电池的温升特性,并着重研究了电池模组的温度场均匀性以及温度均匀性的影响因素,此外,对比研究了热管冷却系统相对于自然对流的温升特性、高温冷却特性和低温加热特性。(4)搭建了动力电池组热管冷却试验系统,通过对自然对流冷却和热管-强制空气冷却的对比试验研究,分析动力电池组在不同冷却方式、不同放电倍率下的冷却效果和温度场均匀性,针对仿真与试验结果对热管冷却系统进行了对比分析,为热管冷却系统应用于新能源汽车动力电池热管理系统奠定了一定的基础。
[Abstract]:Battery thermal management system plays an important role in the power performance of new energy vehicles. Effective cooling can improve the working environment and performance of power batteries, so as to ensure the safety and reliability of electric vehicles. Researchers at home and abroad have carried out a lot of research on power battery cooling technology and battery thermal management, mainly on air cooling, water cooling, phase change material cooling and heat pipe cooling. At present, air cooling and water cooling systems are widely used in engineering practice, but phase change cooling has great advantages in improving the temperature consistency of battery pack. Battery pack phase change material cooling and heat pipe cooling are expected to develop into a new generation of battery thermal management technology. In this paper, based on the National Nature Fund project (project number: 51375202), the electrochemical-thermal coupling model of lithium-ion battery for vehicle is established by using the research method of theoretical research, simulation analysis and experimental verification. The basic heat transfer problem of the heat pipe cooling system is studied, and the cooling characteristics and temperature field uniformity of the heat pipe cooling system are studied through simulation and experiment, and the basic common technology is studied. It lays a foundation for the application of heat pipe cooling system in the thermal management system of power battery of new energy vehicle. The main contents of this paper are as follows: (1) the electrochemical-thermal coupling model of lithium-ion battery is established, the mathematical model control equation is set up, and the basic characteristics of the battery are studied, including battery capacity, battery charge-discharge curve, discharge curve under different rate and temperature characteristics of single cell. (2) the basic heat transfer problems involved in heat pipe cooling system are studied, including phase change heat transfer of heat pipe. The external forced convective heat transfer coefficient of the fluid traversing the tube bundles and the contact thermal resistance in the multi-layer solid heat conduction. The structure and mechanism of the cooling system of the heat pipe are introduced, the complex two-phase flow problem accompanied by the phase change heat transfer in the heat pipe is simplified, and the equivalent conduction model of the phase change heat transfer of the heat pipe is obtained, and the external forced convective heat transfer coefficient of the fluid traversing the tube bundles is solved by the experimental correlation. The fractal parameters of rough contact surface are determined by power spectrum method, and the rough contact surface morphology is described by Monte Carlo random number simulation method. Finally, the contact thermal conductivity is determined based on the established rough surface morphology. (3) based on COMSOL simulation software, the simulation model of heat pipe cooling system based on 12 power batteries is established, and the temperature rise characteristics of single cell are studied. The temperature field uniformity and the influencing factors of the temperature uniformity of the battery module are studied emphatically. in addition, the temperature rise characteristics, high temperature cooling characteristics and low temperature heating characteristics of the heat pipe cooling system relative to the natural convection are compared and studied. (4) the heat pipe cooling test system of the power battery pack is built, and the natural convective cooling and the heat pipe forced air cooling are compared and studied. The cooling effect and temperature field uniformity of power battery pack under different cooling modes and different discharge rates are analyzed. According to the simulation and test results, the cooling system of heat pipe is compared and analyzed, which lays a certain foundation for the application of heat pipe cooling system in the thermal management system of power battery of new energy vehicle.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U469.72
本文编号：2505408
[Abstract]:Battery thermal management system plays an important role in the power performance of new energy vehicles. Effective cooling can improve the working environment and performance of power batteries, so as to ensure the safety and reliability of electric vehicles. Researchers at home and abroad have carried out a lot of research on power battery cooling technology and battery thermal management, mainly on air cooling, water cooling, phase change material cooling and heat pipe cooling. At present, air cooling and water cooling systems are widely used in engineering practice, but phase change cooling has great advantages in improving the temperature consistency of battery pack. Battery pack phase change material cooling and heat pipe cooling are expected to develop into a new generation of battery thermal management technology. In this paper, based on the National Nature Fund project (project number: 51375202), the electrochemical-thermal coupling model of lithium-ion battery for vehicle is established by using the research method of theoretical research, simulation analysis and experimental verification. The basic heat transfer problem of the heat pipe cooling system is studied, and the cooling characteristics and temperature field uniformity of the heat pipe cooling system are studied through simulation and experiment, and the basic common technology is studied. It lays a foundation for the application of heat pipe cooling system in the thermal management system of power battery of new energy vehicle. The main contents of this paper are as follows: (1) the electrochemical-thermal coupling model of lithium-ion battery is established, the mathematical model control equation is set up, and the basic characteristics of the battery are studied, including battery capacity, battery charge-discharge curve, discharge curve under different rate and temperature characteristics of single cell. (2) the basic heat transfer problems involved in heat pipe cooling system are studied, including phase change heat transfer of heat pipe. The external forced convective heat transfer coefficient of the fluid traversing the tube bundles and the contact thermal resistance in the multi-layer solid heat conduction. The structure and mechanism of the cooling system of the heat pipe are introduced, the complex two-phase flow problem accompanied by the phase change heat transfer in the heat pipe is simplified, and the equivalent conduction model of the phase change heat transfer of the heat pipe is obtained, and the external forced convective heat transfer coefficient of the fluid traversing the tube bundles is solved by the experimental correlation. The fractal parameters of rough contact surface are determined by power spectrum method, and the rough contact surface morphology is described by Monte Carlo random number simulation method. Finally, the contact thermal conductivity is determined based on the established rough surface morphology. (3) based on COMSOL simulation software, the simulation model of heat pipe cooling system based on 12 power batteries is established, and the temperature rise characteristics of single cell are studied. The temperature field uniformity and the influencing factors of the temperature uniformity of the battery module are studied emphatically. in addition, the temperature rise characteristics, high temperature cooling characteristics and low temperature heating characteristics of the heat pipe cooling system relative to the natural convection are compared and studied. (4) the heat pipe cooling test system of the power battery pack is built, and the natural convective cooling and the heat pipe forced air cooling are compared and studied. The cooling effect and temperature field uniformity of power battery pack under different cooling modes and different discharge rates are analyzed. According to the simulation and test results, the cooling system of heat pipe is compared and analyzed, which lays a certain foundation for the application of heat pipe cooling system in the thermal management system of power battery of new energy vehicle.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U469.72
【引证文献】
相关硕士学位论文 前2条
1 张凯鹏;电池成组液流热控及其强化增效实验分析[D];吉林大学;2017年
2 刘玮;液冷式电池热管理系统换热特性与控制方法研究[D];吉林大学;2017年
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