Numerical simulation of air outlet spacing change in thermal management lithium-ion battery pack with triangular arrangement for use in electric vehicles

In this paper, a battery pack (BP) consisting of a number of cylindrical lithium-ion batteries is simulated. The battery cells are arranged in a triangle with a sharp point in front of the input and a base on the output side of the BP. The BP includes one inlet and two outlets for airflow to cool the battery. By changing the outlet distance from each other, for 6 different distances in the range of air velocity changes from 0.01 to 0.02, pressure drop (PDR) values, heat transfer coefficient (HTRC) from batteries to air, battery temperature, air temperature (T-Air) in each outlet have been studied. This simulation is performed in COMSOL software. The results of this study showed that increasing the air velocity increases the HTRC from the batteries to the air and also increases the PDR in the BP. However, increasing the air velocity has reduced the maximum values of the battery cell temperature and the T-Air in both outlets. Increasing the distance of the outlets from the wall of the BP increases the PDR in the BP but decreases a small amount of the maximum. Also, bringing the outlets closer together increases the amount of HTRC from the battery cells to the air and reduces the T-Air in both outlets. The lowest exhaust T-Air occurs in the outlets attached to each other in the middle of the BP.