Thermal Management of Battery Cooling System 2021-26-0161

Lithium-ion batteries has emerged as the most suitable option to lead the next wave of automotive revolution. Power density, high energy and packing efficiency are main factors for the currently available alternates. Battery and cell types face issues which need to be worked upon. Battery thermal management is the main factor affecting the working of the battery due to dynamic operation and range of environments under which they operate. The design as well as the three-dimensional computational fluid dynamics (CFD) simulations are carried out for battery system with and without cooling management at pack level. Initially battery system of 66 kWh/400V was designed with 296 Lithium ion pouch cells (37 modules), weight of 400 kg with overall dimensions of 1550 x 1190 x 270mm without any coolant system. The analysis resultant temperature distribution is above the optimal performance battery temperature range (25-55°C) with local heat spots. Considering dissipation of surplus heat generated and uniform heat distribution across battery, thermal cooling system is designed in the system. Coolant with 40% ethylene glycol water solution is used to remove heat from the battery pack. Operational constant power input (heat loss) for the battery system is calculated from five pack chambers as 1868(W) which results in temperature distribution to be cooled. The coolant mass flow rate at the inlet connector is 352kg/h with temperature of 24°C. From the digital simulation results, coolant temperature was found to be below 46°C and battery solid temperatures below 50°C. The pressure drop for the coolant fluid was analyzed and verified for smooth flow paths. The details of the battery cooling system and temperature comparisons for various configurations are detailed.