Effect of parameters on thermal and fluid-flow behavior of battery thermal management system

In modern electric vehicles the thermal stability problems associated with Lithium-ion battery system is of major concern. Proper battery thermal management systems is required to ensure safety and efficient performance of battery cells. A realistic conjugate heat transfer and fluid-flow analysis of Lithium-ion prismatic battery cell is performed. The flow of air as coolant, is laminar, flowing between the heat generating battery cells. The effect of few important working parameters like volumetric heat generation, S̅q, conduction-convection parameter, ζcc, Reynolds number, aspect ratio, Ar, and spacing between the cells, W̅f, is investigated in this work. For the wide range of parameters considered, the temperature variations in battery cell and coolant is carried out. Focusing mainly on effect of Reynolds number and W̅f, behavior of local Nusselt number, local friction coefficient, Cf,x, average Nusselt number, average friction coefficient, Cf,avg, maximum temperature, mean fluid temperature, heat removed from the lateral surface of cell are discussed. Average Nusselt number increased with increase in Reynolds number but decreased with increase in W̅f, whereas Cf,avg decreased with increase in Reynolds number and W̅f. It is also found that their exists an upper and lower limit on Reynolds number and W̅f above and below which the change in Cf, avg and average Nusselt number is negligible. Maximum temperature is significantly influenced at low Reynolds number and for all W̅f. From the lateral surface of battery over which the coolant flows, more than 96% of heat generated in cell is removed