Multi-Perspective Behavioural Investigations on Coolant of Battery Thermal Management Systems in Electrical Vehicles Using Computational Fluid Dynamics

Battery thermal management system (BTMS) is a very important field that is currently being focused on by the thermal and energy departments all around the world. This work primarily emphasizes channel design for BTMS and the utilization of modern computational fluid dynamics (CFD) investigations in BTMS. Enhancing the fluid-battery heat transfer interaction is the aim of the proposed channel design. A reliable CFD study and better wall treatment confirmed the thermal performance of the identical channel design. Secondly, this study focuses on finding a suitable velocity at which a coolant can perform its best efficiently, that is, by absorbing most of the heat present in the battery system. Six coolant fluids were chosen to achieve the goal of finding the best velocity at three different heat generation rates (HGR). These HGRs include 5318, 19,452 and 42,400 W/m³ describing the C Ratings 1C, 2C and 3C, respectively. Six coolants were Ethylene Glycol, Propylene Glycol, Glycerine, Ethyl Alcohol, Water liquid and Water Glycol. It is concerning that even after choosing the required coolant for heat absorption, it becomes necessary that the velocity at which it can be allowed to flow through the battery system determines the effectiveness of the coolants. It was concluded that the coolant fluids better perform at 1 m/s. This lets us know that, when the flow of the coolant is at its lowest velocity, it can efficiently absorb the heat while it stays at that particular instant. The coolant's temperature was measured to be higher at the outlet (after it has flowed through the entire battery system) compared to the intake temperature. This indicates that the coolant has absorbed heat through molecular interaction. The input temperature was recorded at 29.85°C. It was also noted that Ethyl Alcohol and Propylene Glycol work the best at the HGR of 5318 W/m³, and the other coolants work the best at 19,452 W/m³ at 1 m/s. Using low-velocity fluids in liquid BTMS has been found to enhance thermal management by improving heat transfer efficiency, ensuring structural integrity, extending the duration of heat exchange, enhancing temperature uniformity and reducing energy consumption. These factors collectively contribute to making lithium-ion batteries safer and more effective for a range of applications.