Thermal Management Of Lithium Ion Battery Pack Based On Liquid Cooling And Phase Change Material

At present,under the broad prospects for development in new energy cars,lithium-ion battery as a power new energy vehicles of the main chemical power got great development in the lithium ion battery has a huge advantage,also has certain problem can produce a lot of heat on the job,resulting in storage capacity and battery life decreases,serious will cause security problems such as thermal runaway fire,therefore,to solve the problem of thermal dissipation of the battery work to appear,guarantee the normal work of the battery,need a good battery thermal management system Among several commonly used battery thermal management syst ems,applying PCMS to the system is the most promising way of heat dissipation at present.PCMS can maintain their constant temperature when absorbing heat and absorb enough heat to make the battery work.The main research contents of this paper can be summarized as follows:Mainly expounds the thermogenesis mechanism of power battery and battery thermal model,and studied the thermal management system of battery pack common reference to the different types of power battery,finally determine the type 18650lithium-ion battery as the research target,and determine the best temperature range and temperature requirements and the internal structure of the type of battery principle of electrochemical reaction mechanism of heat and heat transfer characteristics.This article uses the battery thermal management system of the cooling medium is the phase change materials and phase change materials in the process of cooling,heat dissipation of battery thermal management system will be affected by phase change materials endothermic melting occurs after the effect of natural convection,under different discharge rate in lithium ion batteries(1 c,2 c,3 c)in the use of Fluent software simulation module for the battery thermal management system for simulation.Results show that the thermal management system meet the lithium ion battery under low discharge rate(1 c,2 c)to the requirement of temperature,but there are shortcomings,and can’t meet the lithium ion batteries at high discharge rate(3 c)requirements for temperature.Aiming at the existing deficiency and high discharge rate can’t meet the requirements of battery to temperature,therefore,the preparation of a kind of high coefficient of thermal conductivity of composite phase change material(CPCM),in the lithium ion battery and 3 c discharge rate,the composite phase change material(CPCM)as cooling medium power battery module in the central regions of the different sizes of heat transfer enhancement local characteristic has carried on the comparative study.At the same time,the different proportions of PCM in the composite PCM were analyzed and compared.Phase change materials in a charge and discharge cycle,the absorption of heat in a timely manner,but in more than one charge and discharge cycle,phase change materials absorb heat is not able to get timely discharge,resulting in phase change materials thermal management system in order to solve the multiple phase change materials after the charge and discharge cycle thermal management system of thi s problem,this article USES the liquid-cooled and phase change materials,the cooling system of the combination of heat transfer enhancement by 9 batteries local and cools the hybrid thermal management system of combining the numerical simulation method was adopted for the combination of active and passive cooling zone cooling effect for the battery thermal management system.