Abstract
The successful application of oil-immersed transformers inspires the thought about the feasibility of the transformer oil on developing an oil-immersed battery thermal management system. This paper tentatively designs a model-scale transformer oil-immersed battery thermal management system to investigate the feasibility of the cyclic transformer oil fluid on cooling the battery. It is found that at 2C discharge rate, the battery immersed in the stationary transformer oil fluid exhibits a maximum temperature of 37.35 degrees C and a maximum temperature inhomogeneity of 2.64 degrees C, much lower than that exposed to the open air. To further improve the heat dissipation performance of the oil-immersed cooling system, different oil volumetric flow rates ranging from 3 to 50 mL/min are tested to examine the cooling effectiveness. As the oil fluid circulates, the maximum battery temperature can maintain below 35 degrees C. The increasing TO volumetric flow rate can continuously lower the battery temperature, while this effect gradually wanes as the flow rate exceeds 15 mL/min. The theoretical analysis indicates that as the heat transfer mode is dominated by natural convection, the increasing TO flow rate will significantly improve the cooling effectiveness of the system. In other cases, the increasing flow rate improves the cooling performance to a small extent, and concurrently intensifies the consumption of pumping power. The TO fluid with a flow rate of 15 mL/min (Reynolds number = 0.59) is suggested as the optimal choice for the current TO-immersed BTMS. The current oil-immersed battery cooling system validates the concept of direct-contact cooling method through model-scale experiments and theoretical considerations, which provides novel insights into the development of more efficient oil-immersed battery thermal management systems utilizing the dielectric oils.
NSTL
Elsevier