Simulation Study on Thermal Performance of an Indirect Boiling Cooling Cylindrical Battery System with Two‐Phase Coolant R141b

Abstract

In this study, a novel indirect boiling cooling battery thermal management system with two‐phase coolant R141b is proposed for the commercial cylindrical lithium‐ion battery pack. The heat conduction blocks are used to enlarge the heat transfer area between batteries and straight round tubes, and the R141b coolant flows and boils inside tubes to remove heat generated from batteries. Three‐dimensional simulation models are built and used to study the influence of partial structural parameters (height of heat conduction blocks, number and diameter of round tubes), the flow pattern layout, the coolant flow rate, and the battery discharge rate on the cooling performance of battery thermal management system (BTMS). The results show that the cross‐flow layout significantly improves the temperature uniformity of the batteries, with the maximum temperature difference reduced by 30% compared to the concurrent flow. Meanwhile, the appropriate geometrical parameters can further improve both cooling capacity of the BTMS and the temperature uniformity of the batteries. When the optimized structure with a coolant flow rate of 0.1 under the cross‐flow layout, the maximum temperature and maximum temperature difference of batteries discharged at 2 C reduced to 38.6 and 3.81 which are 97% and 64% of those in the concurrent flow, respectively.