The Research About Stepped Cooling In Board Tape Tandem Cold Rolling Mill Close-Loop Control

Shape and flatness is an important quality indicator of the cold rolled strip. In the present, controlling strip flatness in the process of production is still a significant issue in the world steel industry. Along with the improvement of products'accuracy required by the market, it is necessary to set up fast, high-precision flatness to control the models online, so as to accurately control flatness and improve the control ability of flatness. Flatness close-loop feedback control can make a continuous, dynamic, and real-time control to the strip flatness, so as to ensure the good flatness.Based on the stepped cooling device of 1420 mm cold-rolled units from a factory, this dissertation makes a further study on the principles of cooling system in the cold rolling close-loop feedback control and designs the water-jet beam structure with SolidWorks 3-d graphics software; in addition, it establishes the thermal deformation model of work rolls with finite element software in order to test the ability of cooling control on the flatness.Secondly, the disertation makes a respective study on the cooling control model under the traditional mathematical model as well as the fuzzy control theory; it analyzes the critical variables that may influence the performance of cooling control in these two models and guides the parameter setting in the production. This disertation also makes a contrast between these two control models in order to help to select an appropriate control model in the production. Meanwhile, these two models are documented into M file respectively, which provides a calculation model for the establishment of semi-physical simulation platform of stepped cooling.Finally, the present study builds a semi-physical simulation platform based on the personal computer. It establishes communication links among WinCC 6.0, Excel and Matlab under DDE technology, designs the monitoring interface of the cooling system using the Siemens WinCC configuration software and calculates the sampled flatness signals using Matlab with powerful calculation. Thus control model can be tested and debugged at last.