Research On Structure Optimization Of Plenum Chamber In Lithium Battery Film Production Line

In the process of producing the film of the lithium battery,the plenum chambers that are longitudinally symmetrical in the insulated room will provide a stable velocity field and a temperature field for preheating,stretching and thermoforming the film casting.However,the orifice plate configuration of the plenum chamber not only affects the distribution of the hot air flow in the insulated room,but also influences the intensity,uniformity,and efficiency of the heat transfer in the film to a different degree.In the past,the method of designing the orifice plate configuration was mainly based on experience.Therefore,there are many disadvantages such as lacking regular cognition of the influence on the effect of the heat transfer,failing to guarantee the stretching quality of the film because of the poor uniformity.Also,the traditional plenum chamber group will cause greater energy loss as a result of the air supply method of full-hole arrangement structure.So based on this issue,this article carried out the simulation and experimental research on the characteristics of the flow field.The rapid development of CFD,a method of computational fluid dynamics,provides possibility for the optimization design of the plenum chamber,because this method can be used to observe the three-dimensional flow field in a thermal insulated room and can simultaneously perform quantitative analysis of the heat transfer effect on film.Therefore,this paper relies on the plenum chamber in the actual project to establish a numerical simulation model.Then,through the test system of the plenum chamber against the jet impact heat transfer on the target surface,it is verified that the numerical simulation method and model are correct.Next,use parametric design to optimize the orifice plate configuration of the plenum chamber and based on the optimization results a new arrangement method of the plenum chamber group is designed.Specific content includes:(1)A numerical simulation model was established based on the prototype of a plenum chamber in the insulated room in the production line of the lithium battery film.In order to explore the influence of staggered angle and hole opening ratio on the heat transfer effect of the target surface,the author compared and analyzed the orifice plate configurations with 3,4,and 5 rows of spanning holes used in the project.And then the overall performance of configurations under different topological structures were evaluated.(2)A 5:1 plenum chamber based on the equivalent Froude number criterion was made.And it formed a test system with a hot air heating system,a speed measuring device,and a heat flux sensor.Then the velocity of the jet at the orifice plate and the surface heat transfer coefficient at the target surface were measured,which compared with the results of the numerical simulation so as to verify the correctness of the numerical simulation study.(3)Based on the optimized scheme of orifice plate configuration,parametric modeling,DOE experiment design,and response surface analysis of the plenum chamber model in the insulated room were conducted.Then,the nonlinear regression analysis and optimization of multi-objective functions were performed on the relationships between structural parameters of orifice plate configuration and the heat transfer intensity and between it and heat transfer uniformity of the film.As a result,a nonlinear relationship and Pareto optimal solution for engineering applications were obtained.(4)After selecting the optimized orifice plate configuration scheme,an arrangement method of a plenum chamber group with a gradually expanding orifice plate configuration was designed.This method can increase the number of hot air circulation in the insulated room,greatly reduce the amount of air supply and compensation and achieve the goal of energy saving and emission reduction.In this paper,the author hopes that these rules and conclusions drawn could provide certain theoretical basis and solutions for the design of plenum chamber and the arrangement of plenum chamber groups in the production line of the lithium battery film.