Thermal investigation and forced air-cooling strategy of battery thermal management system considering temperature non-uniformity of battery pack

[Display omitted] •Novel BTMS and its control strategy based on controllable valves are propose.•The optimal cases for three BTMS structures are explored.•The obtained Tmax and ΔTmax are 4.63 K and 7.68 K, respectively. To alleviate the temperature inconsistency within the battery pack, air-based battery thermal management systems (BTMS) are frequently utilized. However, the current model struggles to address the heat dissipation issue brought out by the heterogeneity of batteries. In this study, a control strategy was theoretically investigated and numerically modelled to balance the temperature distribution of the whole pack. Firstly, three modified BTMS configurations with controllable valves were proposed based on the typical Z-type model. In this study, the airflow inside the pack can be adjusted by two valves to balance the temperature distribution. Then, the optimal valve opening of the three structures were explored, and the modification decreased the maximum temperature by 4.0 K and decreased the maximum temperature difference by 5.93 K. Finally, the appropriate strategies of valve opening were determined for each original type of BTMS considering the temperature uniformity. Optimized models with valve control strategies reduced the maximum temperature and maximum temperature difference by 4.63 K and 7.68 K, respectively. The outcomes showed that the technique successfully alleviated the battery pack's thermal imbalance issue, and provided a novel route for the improvement and optimization of the BTMS.