Abstract: To address the common industry challenges of poor temperature uniformity and insufficient low-temperature heating efficiency of platformized power battery packs for battery electric vehicles under wide-temperature-range operating conditions, this paper takes a 145.4 Ah ternary lithium battery pack as the research object, proposes a collaborative optimization method of inlet/outlet structure and flow channel topology, and systematically conducts forward design and full-process verification of the liquid cooling thermal management system. By optimizing the nozzle inner diameter and adding a buffer structure, the flow resistance of the liquid cooling plate at 20 L/min is reduced from 74.95 kPa to 44.97 kPa; by adopting the topology optimization of branch series connection and water blocking bend, the flow unevenness of parallel branches is controlled within 10%. The test results show that the maximum temperature difference of the battery cells during 2.4C fast charging at 25 ℃ is 6 ℃; the average temperature rise rate of the battery cells at -20℃ reaches 0.7 ℃/min, and the maximum heating temperature difference is ≤7 ℃. The platformized liquid cooling system development method formed in this study has a simulation and test error of less than 6%, which can provide a complete technical route and engineering reference for the mass production of similar products.

Key words: power battery pack; thermal management; liquid cooling system; temperature uniformity; simulation analysis

摘要： 针对纯电动汽车平台化动力电池包宽温域工况下温度一致性差、低温加热效率不足的 行业共性问题，文章以某 145.4 Ah 三元锂电池包为研究对象，提出进出水口结构+流道拓扑 协同优化方法，系统开展液冷热管理系统正向设计与全流程验证。通过优化水嘴内径并增设 缓冲结构，将 20 L/min 流量下液冷板流阻从 74.95 kPa 降至 44.97 kPa；采用支路串联+阻水弯 拓扑优化，将并联支路流量不均匀度控制在 10%以内。试验结果表明，常温 25 ℃下 2.4C 快 充过程电芯最大温差为 6 ℃，-20 ℃低温工况下电芯平均温升速率达 0.7 ℃/min，加热最大温 差≤7 ℃。该研究形成的平台化液冷系统开发方法，仿真与实测误差小于 6%，可为同类产品 量产提供完整技术路径与工程参考。

关键词: 动力电池包；热管理；液冷系统；温度一致性；仿真分析