Design And Simulation Of Gas Heat Dissipation Structure Of Lithium-ion Battery For Hybrid Electric Vehicle

Nowadays among the many types of batteries,lithium-ion batteries as one of the representatives of batteries have the advantages of smaller size,higher energy density,longer using life,lower self-discharge rate and without memory effect,that are widely used.But lithium-ion batteries always generate more heat.If the battery temperature continues rising,the battery pack easily forms heat accumulation,so that it will lead to breakage of each battery unit life,and even its thermal which caused the unsafe situation will out of control.Therefore,the battery pack heat dissipation structure exploit and effectively design related to the safety and reliability of hybrid electric vehicles during use.This paper mainly establishes the battery mathematical model,by studied battery heat generation mechanism and Heat transferring,the ANSYS FLUENT software supported to simulate battery working at the different temperature,different fluid types,different magnifications and different structures performed characteristics of heat dissipation.Structure was optimized the design,that improved the heat dissipation performance of the battery heat dissipation structure.The main contents of this article are as follows:From the perspective in battery heat dissipation,battery safety,and battery working life.The different materials batteries are compared one by one,and the cylindrical lithium iron phosphate battery is used as the research object of this paper.The reaction principle and heat generation mechanism of the battery are briefly described,the battery at fluid environment and thermal characteristics were analyzed.Through Heat transfer,we would establish a battery mathematical model.According to the finite element analysis method,ANSYS FLUENT software was used to analyze and simulate the temperature field distribution of the battery cells in natural convection with different magnifications and different temperatures.Obtained the battery cell the heating law.Based on the single cell thermal model,we established the battery pack model in the heat dissipation structure,simulated the flow field and temperature field characteristics in the forced air cooling heat dissipation and designed the discharge simulation under the conditions of 1 C,5 C,and 10 C magnifications,so we made the conclusion.In this paper,air-cooled heat dissipation structure not only combined the advantages of parallel air ducts such as made the battery temperature field more uniform,but also combined the advantages of serial air duct such as a small space.After adding two groups of auxiliary heat dissipation holes,the maximum temperature is reduced to 6.3 K.After adding the gas drainage plate,the uniformity of the flow field is improved,and the maximum temperature difference is reduced to 5.9 K.Under 10 C magnification,the maximum temperature difference of the cells in the battery pack can be controlled within 9.8 K.As the discharge magnification is growing,the convection heat transfer coefficient gradually decreased,and the battery temperature also gradually increased.By using of ANSYS FLUENT,this paper simplified the problem that complex fluid-solid coupling heat conduction phenomenon.After that we calculated and solved it.The battery thermal effect model was analyzed to provide some reference for solving the battery heat dissipation problem and establishing battery heat dissipation structure.