Brief Introduction of Mathematical Model of Packaging Steel Strip Thickness Setting

Brief Introduction of Mathematical Model of Packaging Steel Strip Thickness Setting
　　Tandem cold rolling setting calculation includes two major parts, namely the setting calculation related to thickness and the setting calculation related to strip shape. The following mainly describes the thickness setting model. For the plate shape setting model, see Chapter 7.
　　The thickness setting calculation is also called the basic setting, because it needs to calculate the thickness-related parameters such as roll gap, speed, tension, etc., but also provides all other parameter settings except for the shape-related parameters value.
　　Thickness setting is actually a realization of load distribution or thickness distribution. When the thickness distribution is fixed, the thickness distribution (the thickness of each rack outlet) is used as the basis to determine each rack through the forward sliding model and the flow equation Considering that the speed of tandem cold rolling is determined by the combination of the master speed and the relative speed, the speed setting is the determination of the master speed and the relative speed of each stand. The thickness distribution (the thickness of each stand exit) is also used as the basis to determine the roll gap of each stand through the rolling force model (calculation) and the bounce equation. The calculation accuracy of the roll gap setting value of each stand depends on the rolling force. The prediction accuracy of the model, therefore, how to determine the hardness of the material (resistance of plastic deformation) and the friction coefficient between the rolls of the rolling material are the two key points. In order to make full use of the measured data to improve the calculation accuracy of the forward slip and rolling force models, the model is widely used. Adaptation and model self-learning.
　　Tandem cold rolling thickness setting calculation can be divided into:
　　 (1) Pre-set calculation, mainly used to set and calculate the roll gap and other parameters of the rolling mill before threading.
　　(2) The post-setting calculation is mainly the corrective calculation performed after multiple model adaptations during the rolling process of this block of steel.
　　(3) The setting calculation of dynamic specification change is mainly used for dynamic setting when the specification is changed in full continuous cold rolling or pickling-tandem mill combined unit.
　　 But the setting model used in the above-mentioned setting calculations is the same. In addition, the setting model is also used for recalculation during rolling force adaptation (see model adaptation for details). After all data records and the load distribution (or thickness distribution) are determined according to the rolling strategy, each rack can perform each model according to the data record and the exit thickness of the previous rack (that is, the thickness of the population of the rack) and the exit thickness of the rack. Calculate to finally obtain the following setting values:
　　 (1) The relative speed value of each frame and the master speed value (the master speed is used for synchronous acceleration and deceleration of each frame) and the maximum speed when threading.
　　 (2) Roll gap value of each frame when threading.
　　 (3) Rolling force of each stand during tape threading.
　　 (4) The tension setting value between the racks and the front and back winding when threading and the additional value of tension at low speed.
　　(5) The front sliding of each frame when the belt is worn.
　　 (6) Calculation of coolant dose.
　　 (7) Roll gap correction of each stand during steady-speed rolling.
　　 (8) The rolling force of each stand during steady-speed rolling.
　　(9) The critical rolling force of the last stand.
　　(10) The forward slip of each stand during steady-speed rolling.
　　 (11) Tension setting during steady-speed rolling.
　　(12) is used for the frame elastic stiffness coefficient of AGC.
　　(13) is used for the plastic stiffness coefficient of AGC.
　　(14) The length of the wedge section when the specification is dynamically changed.
　　(15) The master speed factor when dynamically changing specifications.
　　(16) Rolling torque and rolling power, etc.
　　 Some of them are used for equipment control (roll gap, speed, tension, etc.), and some are used for coefficients for other control functions (such as AGC).
　　 In the setting calculation, the speed setting is the priority, that is, after the thickness distribution (load distribution) has been set, how to make the steady speed rolling as high as possible without exceeding the limits of the electromechanical equipment capacity and process conditions.