随着电动汽车的普及和发展，电池作为储能器件广泛应用。然而，高能量密度和高功率密度要求导致电池发热问题突出。若处理不当，电池会过热甚至起火爆炸，对安全、可靠性和寿命有极大影响。因此，设计一个合适且有效的热管理系统来保证电池的性能和安全意义重大。本文选取商用磷酸铁锂电池模组为研究主体，通过数值分析、理论研究与实验验证结合的方式，分析了锂电池的热特性并设计出了一套合适且有效的电池液体热管理方案，使电池能够稳定维持在正常的工作温度范围内，最终实现锂电池散热的目的。其主要研究内容及结论如下：

（1）首先，总结了当前锂电池热管理冷却技术的研究进展，对锂离子电池的基本结构和工作原理进行了分析，同时在分析锂电池产热和传热机理的基础上，给出了锂电池各热物性参数的计算方法，对锂电池进行了不同放电倍率和环境温度下的温升试验。

（2）其次，针对方形磷酸铁锂电池设计了三种热管理系统模型，并对该热管理装置进行分析。通过三种液冷板结构方案的对比，选择了一套散热效果最佳的电池液冷散热系统，建立了液冷系统的热仿真模型，对该系统进行稳态温度场仿真分析，分析了不同入口流速、流道深度以及流道角度对电池组液体热管理系统换热特性的影响，结果表明，在环境温度为25℃，入口流速0.1m/s，流道深度为5mm，流道角度为30°的情况下，电池组在2C放电倍率下的最高温度为28.17℃，最大温差为2.26℃。

（3）最后，对电池液体热管理模型进行了正交优化试验。以环境温度、冷却液温度及冷却液流向为三因素，每个因素对应四水平，通过极差和方差分析法对电池组的最高温度和最大温差进行评价确定了最优散热方案。试验结果表明，相比于冷却液流向，冷却液初始温度对电池组的最高温度和最大温差影响较为显著；且当环境温度为15℃、冷却液初始为25℃、冷却液流向为方案四时，电池组的散热效果及温度均匀性最好。

With the popularity and development of electric vehicles, batteries are widely used as energy storage devices. However, high energy density and high power density requirements lead to prominent battery heating problems. If not properly handled, the battery will overheat or even explode, which has a great impact on safety, reliability and life. Therefore, it is of great significance to design a suitable and effective thermal management system to ensure the performance and safety of the battery. This article selects the commercial lithium iron phosphate battery module as the research subject, Through the combination of numerical simulation, theoretical analysis and experimental verification, the thermal characteristics of lithium batteries are analyzed and a set of appropriate and effective liquid thermal management scheme for batteries is designed, so that the batteries can be stably maintained within the normal operating temperature range, and the purpose of heat dissipation of lithium batteries is finally realized. The main research contents and conclusions are as follows:

(1) Summarized the research status of lithium battery thermal management cooling technology, The basic structure and working principle of lithium-ion battery are analyzed. At the same time, based on the analysis of the heat production and heat transfer mechanism of lithium battery, the calculation method of each thermal physical property parameter of lithium battery is given, the temperature rise test of lithium battery at different discharge rate and ambient temperature was carried out.

(2) Three thermal management system models were designed for square lithium iron phosphate batteries, and the thermal management device was analyzed. Through the comparison of three kinds of liquid cooling plate structure schemes, a set of battery liquid cooling system with the best cooling effect was selected, and the thermal simulation model of the liquid cooling system was established to simulate and analyze the steady-state temperature field of the system, the influence of different inlet flow rate, channel depth and channel Angle on the heat transfer characteristics of the battery pack liquid thermal management system was analyzed. The results showed that the maximum temperature of the battery pack at 2C discharge rate was 28.17℃ when the ambient temperature was 25℃, the inlet flow rate was 0.1m/s, the channel depth was 5mm, and the channel Angle was 30°. The maximum temperature difference is 2.26℃.

(3) The orthogonal optimization test of the battery liquid thermal management model was carried out. With ambient temperature, coolant temperature and coolant flow direction as three factors, each factor corresponds to four levels, the maximum temperature and maximum temperature difference of the battery pack were evaluated by range and variance analysis to determine the optimal heat dissipation scheme. The test results show that the initial temperature of the coolant has a significant effect on the maximum temperature and maximum temperature difference of the battery pack compared with the flow direction of the coolant. When the ambient temperature is 15℃, the initial coolant is 25℃, and the coolant flow direction is Case4, the heat dissipation effect and temperature uniformity of the battery pack are the best.