Research And Optimization Of The Strip Shape Control System For A 1420mm Cold Rolling Mill

In recent years,with the development of science and technology,the strip shape control technology developed quickly as well.It had promoted the cold-rolling strip equipment progress and industrial upgrading.Strip shape control system played a very important role in the production of cold-rolling coil.As the customer's requirement of strip shape increased everyday,how to enhance the quality of strip shape has become the key research object in iron-works.Therefore,the research of strip shape control model is much further.According to learn the strip shape control system of a 1420mm cold-rolling mill,This thesis obtained certain achievement on aiming at the control system model and the factors which affecting the strip shape system simulation and industrial practice.The main contents and research results of this thesis are as following:(1)This thesis introduced the basic concept and the mechanism of plate shape,by analyzing the roll's elastic deformation theory and flatness control theory,it studied the technology of flatness control,and it introduced the development of the flatness control theory and the latest flatness control technology of other country in recent years,at last it established the this thesis' background and content.(2)Take a 1420mm mill as an example,this thesis analyzed the strip shape control system of the control model,and it introduced the plate shape expression equation,though that we got the understanding of the work roll-bending roll,intermediate roll bending,rolling mill level adjustment,segmented cooling and other methods in strip shape adjustment.we understanded the set up and adjust way for target plate shape through the in-depth analysis of the mechanism for the strip shape control.(3)In order to analyze the strip shape control function of rolling mill,the three-dimensional finite element model is established under the ideal rolling condition.This thesis analyzed all the shape rules and flatness control factors on the influence law of strip shape,and studied the relation ship between them.It got the control characteristic of the work roll bending and intermediate roll bending for the secondary and four times plate shape.(4)This thesis simulated the frame shape closed loop control system,and deeply analyzed the distribution algorithm of the two roll bending force allocation mechanism.It has proved that the rationality of XO and proportional distribution method,and showed two improved methods of how to control the bending roll in allusion to the shortcomings of the original flatness feedback control model.The simulation results show that the new models is better that the original ones.(5)After we used the new XO point method in the actual production,the standard deviation of the strip's secondary and four times plate shape declined.And the field application had achieved the desired effect.Also,the practice proved that the new strip shape closed-loop control algorithm is effective to the flatness improvement.