Numerical Simulation And Structure Optimization Of Casting Roller For Lithium Battery Film

The casting roller is a key component of the lithium battery film production line.Its function is to draw the hot polymer melt extruded from the die and cast it for cooling and shaping,so that the cooled film can obtain good mechanical properties and higher surface quality of the casting roller.The surface quality of the film is closely related to the cooling process,and the selection of the structural parameters of the casting roller directly affects the cooling effect of the film.At this stage,the research on the temperature field of casting film has problems such as weak system,lack of organic combination of calculation and experiment.Aiming at the above shortcomings,this paper aims to design the optimal combination of casting roller structure parameters,and based on orthogonal design,response surface optimization design and related experimental demonstration methods,this paper conducts numerical simulation research and structural optimization design on lithium battery membranes and casting rollers,so as to ensure the cooling quality of thin film products.The main tasks completed in this paper are as follows:(1)Establish casting roller models with parallel runners and spiral runners.Use Fluent software to carry out the numerical simulation and comparative analysis of the cooling process of the diaphragm under the conditions of parallel and spiral flow channel casting rollers and cooling water single and two-way flow modes.The results show that after the film is cooled on the casting roller,the temperature at the outlet presents a distribution pattern of high and low ends in the middle,and the spiral flow channel casting roller with bidirectional cooling water has a better cooling effect.(2)Changing the cooling water flow rate,conduct field test of the diaphragm cooling process,and measure the temperature value at the outlet after the diaphragm is cooled.Compare it with the simulation results of four different turbulence models(Standard k-?,SST k-?,Standard k-?,RNG k-?).The simulation value is in good agreement with the test data,which verifies the correctness of the simulation model.Among them,the SST k-? model is the closest to the test data and has a better prediction effect.(3)The four structural parameters of casting roller diameter,runner size,runner pitch and wall thickness are selected for single factor numerical simulation study,and the influence trend of different casting roller structure parameters on the surface temperature and temperature uniformity of the casting film after cooling is obtained.And selected the casting roller diameter,runner size and pitch as the subsequent optimization parameters.(4)Taking the average temperature and temperature range at the exit of the film after cooling on the casting roller as the optimization target,using the orthogonal design method,numerical simulation of different combinations of the three variables of diameter,runner size and pitch is carried out.Response surface model analysis and multi-objective optimization methods are used to create objective optimization functions.After Pareto global optimization,the optimal structure parameters are obtained as diameter 839 mm,runner size 55×20.5mm,and thread pitch 956 mm.The optimized model is established and compared with the initial model.The optimized average temperature decreased by 0.498K and the temperature range decreased by 0.577K compared with the initial structure.The research methods used in this paper and the related laws and conclusions obtained provide a theoretical basis for improving the surface quality of the casting film and the arrangement of the structure parameters of the casting roller.It has certain guiding significance for the structural design and optimization research of components in the battery film production line and other similar products.