| If the working temperature of lithium iron phosphate batteries used in electric vehicles is not controlled,problems such as overheating,performance degradation and even spontaneous combustion may occur.In order to control the working temperature of lithium iron phosphate battery,domestic and foreign scholars have designed a large number of thermal management devices based on different heat dissipation modes.According to the temperature of the lithium iron phosphate battery management problem,this paper puts forward a water-cooled heat dissipation of the lithium iron phosphate battery thermal management devices,has set up a water cooling for the application of parallel channel cooling plate test bench,water-cooled radiator cooling performance for the experimental research,and using numerical simulation method of cooling plate structure is optimized.A water-cooled cooling device for lithium iron phosphate battery was set up,and the surface temperature of lithium iron phosphate battery under different working conditions was studied through experiments.By setting different ambient temperature and discharge rate for the battery pack,the influence of different working conditions on the curve of battery pack surface temperature changing with time was recorded.The experimental device of battery heat dissipation with circulating cooling water is designed,and the surface temperature of lithium iron phosphate battery is controlled by means of water cooling heat dissipation,so that the battery surface can maintain the most suitable working temperature even under high temperature environment.Aiming at the lithium iron phosphate battery pack and its heat dissipation plate used in the experiment,the three-dimensional model of the water-cooled heat dissipation device of the battery pack was established by FLUENT.The heat generation equation of lithium iron phosphate battery was established and the transient heat dissipation model of lithium iron phosphate battery coupled by multiple physical fields was established.The change of battery pack surface temperature with time is simulated under the condition set in the experiment,and the accuracy of the model is verified by comparing with the experimental data.Aiming at the cylindrical parallel channel heat dissipation plate structure used in the experiment,an optimization scheme for improving its heat dissipation performance is proposed.Three new types of water-cooled heat dissipating plates for lithium iron phosphate battery are designed: square parallel channel plate,snake-shaped channel plate and column pin channel plate.An orthogonal experiment was designed to determine the optimal dimension parameters of the parallel channel cooling plate structure.Through numerical simulation and post-treatment analysis of the flow distribution uniformity and ideal power loss of three heat dissipation panels in parallel channel structure,snagging channel structure and column pin channel structure,the optimal size parameters of heat dissipation panel structure are determined.After the above research,three new heat dissipation plate structures were applied to the lithium iron phosphate battery,and the surface temperature variation of the battery was simulated numerically.By analyzing the temperature curve with time and the cloud map of the temperature distribution on the battery pack surface,the heat dissipation effects of three new heat dissipation plate structures,square parallel channel plate,snake-shaped channel plate and column pin channel plate,were studied.Compared with the simulation results under the same working conditions,the results show that the new heat dissipation plate structure optimizes the heat dissipation performance of the water cooling unit of lithium iron phosphate battery. |
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