Optimization study of a Z-type airflow cooling system of a lithium-ion battery pack

Abstract: The present study aims to optimize the structural design of a Z-type flow lithium-ion battery pack with a forced air-cooling system (FACS) known as BTMS (Battery Thermal Management System). The main goal is to minimize Tmax (maximum temperature) and \delta Tmax (maximum temperature difference) while ensuring an even airflow distribution within the battery module. The present study thoroughly investigates critical factors such as the inlet air velocity, tapered inlet manifold, and the number of secondary outlets to evaluate their impact on thermal performance and airflow uniformity within the battery module. Increasing the inlet air velocity from 3 to 4.5 m/s significantly improves the thermal cooling performance of the BTMS, resulting in a decrease of 4.57 {\deg}C (10.05%) in Tmax and 0.29 {\deg}C (9.79%) in \delta Tmax compared to the original 3 m/s velocity. Further, the study assesses the significance of a tapered inlet manifold as a critical factor, revealing its substantial impact on cooling performance and temperature reductions in battery cells 3-9. It also facilitates a more uniform airflow distribution, decreasing the velocity difference between channel 9 and channel 1 from 3.32 m/s to 2.50 m/s. Incorporating 7 secondary outlets significantly improves the heat dissipation ability of the BTMS, resulting in a decrease of 0.894 {\deg}C (2.18%) in Tmax and 2.23 {\deg}C (72.84%) in \delta Tmax compared to the configuration with 0 secondary outlets. By optimizing these parameters, the aim is to enhance BTMS's capabilities, improving LIB packs' performance and reliability.