| For the heat dissipation of pure electric vehicle battery pack,liquid immersion cooling technology can not only ensure that the battery is in a suitable temperature range,but also maintain good temperature uniformity in the battery pack,taking into account high energy density and safety,which may be the development direction in the future.In recent years,some scholars have proved by simulation and experiment that the liquid immersion cooling battery pack has certain advantages in lowering the maximum temperature in the battery pack and improving the temperature uniformity in the battery pack compared with the traditional air-cooled and indirect liquid-cooled battery packs.However,at present,there is little research on the heat dissipation performance and influencing factors of temperature uniformity of the liquid immersion cooling battery pack composed of multiple batteries at home and abroad,and there are few studies on the over-temperature problem of some batteries in the battery pack.In order to solve these problems,the main contents and conclusions of this paper are as follows:1)By consulting relevant literatures,with the help of the experience of largescale application of liquid immersion cooling technology in data centers,and selecting suitable batteries and cooling liquid,a theoretical model of liquid immersion cooling battery pack containing 60 batteries with 18650 batteries and D-1 electronic fluoride liquid as cooling liquid was established.According to the requirements of vehicle thermal management system at present,the flow range of coolant,different battery arrangements and the research conditions of over-temperature batteries in different locations are determined.2)Based on the establishment of theoretical model,through numerical simulation,the effects of different coolant flow,different battery arrangement and different over-temperature batteries on the heat dissipation performance and temperature field uniformity of battery pack was studied.The simulation re-sults show that when the coolant flow is greater than 0.5 L/min,the temperature inhomogeneity in the battery pack is less than 5 K;Three different battery arrangements have little influence on the temperature distribution in the battery pack.In addition,under different coolant flow rates,the temperature field fluctuation in the battery pack caused by battery over-temperature at different positions is less than 0.6 K.3)According to the theoretical research conditions,combined with the compatibility of D-1 electronic fluorinated liquid and related materials,a set of experimental devices for heat dissipation performance of liquid immersion cooling battery pack was developed,and the experimental test of heat dissipation performance of battery pack with different coolant flow rates was carried out.The experimental results show that the distribution law of temperature field in battery case obtained by numerical simulation is consistent with that obtained by experiment.In addition,under different coolant flow rates,the temperature difference between inlet and outlet of coolant obtained by numerical simulation is in good agreement with the experimental results,with the relative deviation less than 4%.These results prove the correctness of theoretical model and numerical simulation results. |
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