In this paper, the numerical simulation of the flow field of the lithium battery coating machine pole piece drying box is carried out, the structure modeling of the drying box is carried out by using Solidworks software , the numerical simulation is carried out by CFD finite element simulation software, and finally the flow field visualization method is used for experiments. The following conclusions were obtained:
(1) Numerical simulation was carried out for the situation of the upper and lower air chambers of the drying box with or without deflectors, and the flow field distribution near the upper and lower air chambers of the drying box and the surface of the pole piece was obtained , and the flow field of the drying box under different deflector structures was compared According to the distribution law , the size and uniformity of the surface velocity of the pole piece are quantitatively analyzed by using the method of mathematical statistics, and finally it is concluded that the
The A -form deflector structure (the length of the corner connection is the shortest) has a better drying effect. At this time, the wind speed in the air chamber evenly distributed, the number of vortices is small, and the airflow speed near the surface of the pole piece is evenly distributed.
(2) Numerical simulations were carried out on Drying Ovens with different air knife structures, and the flow field distribution . Through the analysis of the resistance loss of Drying Ovens in different air knife forms, it is determined
Form A air knife and form B air knife are the first air knife, followed by C form air knife; also for different forms of air knife, use mathematical statistics to quantitatively analyze the size and uniformity of the surface velocity of the pole piece, and determine the B form The air knife or the C- form air knife is used as the first air knife of the drying box. Considering the resistance loss of the drying box and the wind speed distribution on the surface of the pole piece, it is recommended to use the air knife structure of type B or C.
(3) In view of the fact that the speed distribution near the surface of the pole piece shows a trend of high speed at both ends and low speed in the middle, fine-tuning the distance between the air knife liner and the shell is used to change the size of the air outlet gap, change the position of the air inlet and Three methods are used to optimize the flow field on the surface of the pole piece by reducing the size of the air exhaust port and the air return port. After analyzing the characteristics of the flow field near the surface of the pole piece under different conditions, it is concluded that the first method can make the highest surface of the pole piece. The speed is reduced, and the speed in the middle part is increased, which can get a better drying effect.
(4) Use plexiglass to establish a physical model of the drying box, obtain the flow characteristics of the fluid in the drying box through digital camera observation and PIV test system, compare with the numerical simulation results and carry out relevant analysis, the experimental results and numerical simulation results reflect The flow field conditions are basically the same, and the numerical simulation can describe the fluid flow in the flow field very well.
The main innovations of this article:
(1) For the first time, the method of computational fluid dynamics is used to simulate and analyze the flow field of the entire drying box for the pole piece drying box of the lithium battery coating machine;
(2) Quantitative analysis of the size and uniformity of the surface velocity of the pole piece using the method of mathematical statistics for the first time;
Although this paper has achieved the above research results, there are still the following work to be further improved:
(1) In the simulation process, the influence of temperature on the flow field is ignored, which can be taken into consideration in further research ;
(2) The method adopted for quantitative analysis of the magnitude and uniformity of the surface velocity of the pole piece is relatively simple, and a variety of mathematical statistics methods can be considered in the follow-up research ;
(3) When conducting the experiment of the flow field of the drying box, due to the limitation of the experimental conditions, the model of the drying box used in the experiment is relatively simple and cannot truly reflect the flow field of the actual drying box. If the experimental conditions permit, the structure of the experimental model should be as far as possible Close to the original drying box structure.
