Evaluation of Indirect Liquid Cooling for Electric Vehicle Battery Thermal Management System

Abstract

Green-powered electric vehicles are reliable substitutes to lessen greenhouse gas emissions and reliance on fossil fuels. Electric vehicles are now extensively used worldwide, and this will be high in the future. The battery pack is the key feature of an electric vehicle. The battery pack's performance and life are incredibly temperature-sensitive, a problem related to battery thermal management. So, it is mandatory to keep the optimal temperature range for smooth performance and safety. This study evaluates the coolant cooling system for the thermal management of 45kWh and 64 kWh battery packs, respectively. A chiller and radiator are employed to cool the operating fluid, combining water and ethylene glycol with the 50:50 ratio. A thermal-fluid simulation executed using a standard commercial tool known as GT Suite, and the battery pack temperature experiment using a vehicle was conducted to validate the simulation results. The results reveal that the proposed systems'performance typically improved by mproving the flow rate and the chiller power. It depicts that the cooling rate is maximum at 40 °C initial attery temperature and an ambient temperature of 25 °C with 3 kW chiller capacity and flow rate of 20 liters per minute (LPM) in the chiller cycle mode. While in the radiator cycle, the highest cooling rate is at an ambient temperature of 25 °C, an initial battery temperature of 40 °C with an airflow rate of 3600 cubic meters per hour (CMH), and a 30 LPM of coolant flow rate in both systems, respectively. Besides, a thermal management system of a 45 kWh battery pack was found better than a 64 kWh battery pack system in terms of cooling performance. In the future, the proposed BTMS could be a realistic solution and help develop the electric vehicles' thermal system.