Study on a liquid cooled battery thermal management system pertaining to the transient regime

Abstract The research on battery thermal management systems in a transient and ultimate perspective is important to maintain the battery temperature within a reasonable range and save energy. In the present study, the transient and ultimate behaviors in a battery module consisting of 48 cells cooled by liquid are considered as the main focus. A lumped mass model with cold plate cooling design is developed to simulate battery module cooling performance. The results suggest that there is a cooling cap upper limit for a cold plate cooling system. When the inlet mass flow rate of the cold plate reaches a certain range, the cooling effect will not be improved obviously any more. The optimal Reynolds number for the designed cold plate and module is 475. In addition, there is a cooling hysteresis time for the indirect cooling structure. When the inlet flow rate increases suddenly, the surface temperature of the cells does not immediately decrease. For example, even with the discharge rate is 1C, the delay time is up to 66.37 s. Therefore, when considering precise control strategies of a battery thermal management system, the dynamic empirical correlations proposed by this study can offer some useful guidance.