关键词: 动力电池包；热管理；液冷系统；温度一致性；仿真分析

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