Investigation of the Thermal Performance of a Wavy Channel Liquid Cooling System for Electric Vehicle Batteries using Computational Fluid Dynamics

Abstract

Given the looming threat of climate change, to which the carbon emissions of the transport sector are a major contributor, electric vehicles have risen as a low-emission, high-performance alternative to traditional vehicles. However, electric vehicles suffer from low market penetration, largely due to short battery life and thus high battery replacement expenditure. High battery temperatures due to heat generation during use are a leading cause of their short lifespan. Battery cooling systems are therefore critical components of electric vehicles. This study investigates a wavy channel liquid cooling system using computational fluid dynamics. Its thermal performance is determined at different discharging rates, and the effects of the number of batteries per module and coolant inlet temperature are determined. The internal temperature gradient of the battery is also investigated. The study finds that an increase in discharge rate leads to an increase both in temperature and maximum temperature difference. Increasing the number of batteries per module is not found to have any significant effect. The coolant temperature is found to affect the battery temperatures, but not the maximum temperature difference. However, in spite of the satisfactory average temperatures attained in some cases, the internal temperature gradient and maximum temperature of the battery is found to be excessively high. Therefore, modifications to the geometry and the exploration of supplementary cooling media are recommended.