Circulating oil-immersed battery thermal management system for cylindrical lithium-ion battery module

Abstract

Since the lifetime of lithium-ion battery (LIB) is directly related to the operating temperature, it is important to investigate efficient and safe thermal management strategies. This paper mainly studies the effects of pipe position and coolant flow rate on oil-immersed battery thermal management system (BTMS) during circulating cooling. In addition, the theoretical analysis of heat transfer in the 1C, 1.5C and 2C discharge processes is carried out on the oil circulation cooling system. The study found that the temperature of the battery module submerged in the transformer oil dropped by about 34% compared to natural air cooling. In the 9 sets of pipe positions, the inlet and outlet pipeline positions are diagonally distributed, that is, the design of C 4, C 5 and C 6 pipeline positions shows good cooling performance as a whole. Under the condition of high rate discharge, changing the flow rate has a significant impact on the cooling performance of the battery module. The theoretical analysis shows that the influence of forced convection can be ignored in the oil-immersed cooling system at lowRe, and with the increasing increase of Re, forced convection dominates the heat transfer of the system. This study provides a new supplement for the process safety of LIB and BTMS applications.