| Hybrid electric vehicles have tremendous advantages in energy conservation and reducingemissions, so they have became hot spots of study currently. While Battery pack performancedirectly affects the fuel economy, driving range as the vehicle is in EV Mode state, power foracceleration and safety of the vehicle.During the application of the Li-ion batteries, it generates a lot of heat. Without theeffective thermal management, the battery temperature will rise and lead to non-uniformtemperature distribution between the modules, and eventually that will affect usability, cyclelife, safety of batteries. In this paper, we designed indirect liquid cooling system and simulateand analyze the temperature field and flow characteristics of the radiator for battery pack byusing COMSOL. The simulation results show that the liquid cooling can effectively reducethe battery temperature and provide better temperature uniformity between the differentbatteries in order to meet the batteries working under the optimal operating condition.This work is supported by the985project of Hunan University and the Open Fund Projectof Jiangsu provincial key laboratory (QK09003). It studies on the cooling performance of theLithium-ion battery pack by using liquid cooling system. The main work and innovations ofthe thesis are as follows:(1)Based on the heat transfer theory, a three-dimensional thermal model is presented, andthe paper used a mathematical model which coupled electronic and thermal, to analyze thethermal characteristics when the battery discharged at different rate and different environment.As the battery was at1C,3C and5C discharge rate, the total generated heat was10000W/m~3,53000W/m~3and115000W/m~3respectively.(2) The fluid field and temperature field of the radiator for HEV Lithium battery packusing liquid cooling system wad simulated by COMSOL software, and the influence of themaximum temperature and temperature difference of the battery module with various flowchannel design were studied. The simulations reveal that the cold plate structure with twochannels had batter heat dissipation, and the maximum temperature and temperaturedifference was32.08℃and3.83℃when the single battery was at3C discharge rate.(3) The cooling performance of the changes of fluid temperature and mass flow wadsimulated when the battery pack was discharged at1C,3C,5C rate. The simulation resultsshow that the liquid cooling can effectively reduce the battery temperature and temperaturedifferences between the battery was less than1℃, but the difference between inside andoutside temperatures of the single cell was large during high-rate discharge and the temperature difference was7.22℃as thecoolant flow was lower. However, the change of mass flow and optimal design can deducethe temperature difference to4.15℃and make the battery work in the reasonable range. |
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