Research On The Flow Field Characters Of Lithium Battery Pole Piece Drying Cabinets

Lithium batteries are widely used. Pole pieces are important components of lithiumbatteries. The drying process after coating is the key technology of the pole pieceproduction. Drying cabinets are the core equipments used in pole piece drying process. Indrying cabinets, the flow field characteristics, especially the uniformity, have a huge effecton drying effectiveness. In addition, the resistance characteristics and heat transfercharacteristics of drying cabinets are the main factors in drying energy consumption. Thispaper aims to research deeply the internal flow field characteristics of drying cabinets bymeans of theoretical analysis, numerical simulation and experimental verification methodsand improve the drying cabinet structure, increase the work efficiency, reduce the dryingdefects.Under the intensive analysis of the large parameter field uniformity indexes and theircalculation methods, the unified index of parameter field uniformity for drying cabinets isproposed. The parameter field in drying cabinets is classified according to the distributioncharacteristics of parameters in the space field. According to the classes of the parameterfield the additional indexes of parameter field uniformity are proposed. These indexes areaccurate, definite in meaning, strong practicality and can be used to properly describe theparameter distribution characteristics at the key positions in drying cabinets.Numerical simulation models of three kinds of air nozzles are built using thecommercial software (SolidWorks2007), and the steady state flow fields are obtained bynumerical computation with finite volume method. Comparative analysis of the threekinds of air nozzle’s resistance characteristics is developed. Use the parameter fielduniformity index and additional indexes as the evaluation criteria, the comparativeanalysis of three kinds of air nozzle’s uniform flow effect is developed. The air nozzlewith lower resistance and height uniform flow capability is chosen for the study ofcabinets.The relationship between resistance and flow equalization effect of the air nozzles isanalysed. The design principles of air nozzles are put forward. The requirements on the channel cross section characteristics, flow equalization links characteristics, flowequalization links number and the transition of the flow equalization links in the designprocess are proposed.Using numerical simulation method, basis on the parameter field uniformity indexand some additional index, structural problems of the typical drying cabinet are found andthe integral structure of drying cabinet is improved. New drying cabinet has higher flowcharacteristics and low resistance. This type drying cabinet is called upper and lower airexhaust drying cabinet.The height and space length of the upper and lower air exhaust drying cabinet aredetermined. The comprehensive analysis on drying energy consumption, resistance energyconsumption and the synergism of flowing and temperature field of the drying cabinet aredeveloped. Then, a method for the selection of the proper inlet flow is put forward.Based on the similarity principle, the experimental models of air nozzles and dryingcabinet are made of organic glass and the boundary conditions of experimental facility aredetermined. The experimental studies of air nozzles and drying cabinet are carried out andthe correctness and rationality of numerical simulation and theoretical study are furthervalidation of verified.