Configuration optimization of battery pack in parallel air-cooled battery thermal management system using an optimization strategy

Battery thermal management system (BTMS) is essential for heat dissipation of the battery pack to guarantee the safety of electric vehicles. Among the various BTMSs, the parallel air-cooled system is one of the most commonly used solutions. In this paper, the configuration of the battery pack in parallel air-cooled BTMS is optimized through arranging the spacings among the battery cells for cooling performance improvement. The flow resistance network model is introduced to calculate the velocities of the cooling channels. The heat transfer model is used to calculate the battery cell temperature. Combining these two models, an optimization strategy is proposed to optimize the configuration of the battery pack under the constant cell heat generation rate. The numerical results of typical cases show that the optimization strategy can obtain the final solution in only several times of adjustments of cell spacings. The cooling performance of the BTMS is improved remarkably after optimization. The maximum temperature difference is reduced by 42% and the maximum temperature of the battery pack is reduced slightly after optimization, with no increment on the total pressure drop of the system. Furthermore, the optimized BTMS still performs much better than the original one for various inlet flow rates and for the situation of unsteady heat generation rate.