CFD Analysis of the Battery Thermal Management System for a Heavy-Duty Truck

Li-ion batteries (LIBs) optimum performance and lifetime depend on temperature, with the commonly suggested operating temperature being in the range of 25 to 40 °C. It's also crucial to keep the temperature difference between battery cells below 5°C. Operation at different temperature ranges can adversely affect or degrade the performance and lifetime of LIBs. A battery thermal management system (BTMS) is essential for keeping the battery temperature within the optimum range. This paper aims to develop and analyze the BTMS for an electric heavy-duty truck. To achieve this aim, battery cells and modules are modelled in ANSYS Fluent software. Validation with experimental results and mesh sensitivity studies are also performed to increase confidence in simulation data. The model is then analyzed for a specific cooling systems to investigate its effect on battery thermal performance during the operation. From the simulation results, the proposed efficient cooling system geometry is developed. Simulations based on discharge rates from a mathematical model of the truck are run with the optimum geometry design to identify optimal coolant mass flow rates and inlet temperatures at various ambient temperatures. It was found that the mass flow rate of 18 Lpm (36 Lpm pack flow rate) is optimal and the optimum inlet temperature is about 305.2K (32.2°C) for the ambient temperature of 313K (40°C).