Structure Design Of Liquid-cooling Thermal Management For Power Batteries In Pure Electric Passenger Vehicles

Energy crisis and environmental pollution are two major problems that the world are facing today.In this background,the electric vehicle with the advantages of energy saving and emission reduction has developed rapidly in recent years.As the core component supplying energy of the electric vehicle,the performance of the power battery pack determines whether the electric vehicle can work normally and stably.However,too high or too low working environment temperature will seriously affect the performance of the battery pack,therefore,a set of effective battery thermal management system is very necessary to ensure the normal operation of electric vehicles.Taking 18650 lithium-ion battery in a kind of domestic pure electric vehicle as example,the influence of temperature on the performance and service life of batteries are analyzed.With the general design process of the battery thermal management system introduced,a set of liquid cooling thermal management scheme is presented.The model is built and simulation is made.Finally,the experiment is carried out to verify the simulation results.The main contents are as follows.Firstly,with a review of related literature,the research progress of battery thermal management system,the structure of single battery,performance parameters,heat and transfer mechanism are learned in order to determine the design goal of thermal management system.Secondly,according to the size of the battery box,18650 lithium-ion batteries are arranged in pack.A set of liquid cooling thermal management scheme is put forward,including the structure design of related components.Serpentine pipes will be used to control the temperature of batteries.Finally,simulation models of power batteries and liquid cooling system will be built and reasonably simplified.The physical parameters of the key parts are determined,and then the boundary conditions will be obtained according to the existent research data.The FLUENT will be used to take flow field simulation of the whole liquid cooling system and thermal simulation of single serpentine pipe and adjacent batteries.According to the result of flow field,the liquid cooling scheme will be optimized and the position of total inlet and outlet will be adjusted to the middle of main pipe.In the thermal simulation results,the temperature difference of high-temp condition at 1800 s is within 3? in battery pack and the temperature difference of low-temp condition at 1800 s is within 11? in battery pack.Then,according to the simulation conditions,the experimental scheme will be designed and the difference between experiment results and simulation results is within 2.1?.The difference is normal,which proves feasibility and rationality of the thermal management scheme.