Study And Design Of Plate Roll Crown Control Based On Fuzzy Control

Flatness accuracy plate is one of the important indicators of quality. Excellent work roll cooling and thermal crown control are the effective measures for reducing work roll consumption, controlling plate shape and enhancing production yield. Work roll cooling and thermal crown control can improve roll cooling effect, prevent occurrence of severe thermal cracks on work roll, reduce roll wear and roll changing frequency and avoid bad plate profile. The article systematically analyses the roll water cooling system equipment of plate mill, reasonably arrange the equipment, properly regulate water pressure and control water flow in zones, which enables uniform cooling of the rolls, reduces thermal crown and uneven wear over the rolls, prolong roll campaign life and improve plate shape.The research background of this thesis is based on the plate mill crown automatic control system of the Tianjin Iron&Steel Group Co. Ltd. After exploring a great deal of references on plate shape, the development of the shape control technology applied in method of shape control study conducted in-depth. The thesis consists of the following aspects:(1) The control principle on plate shape is summarized. Factors effecting on plate shape and plate convexity are analyzed. The plate shape control technique and its development tendency are comprehensively introduced.(2) This article introduces the principle of subsection cooling of rolls. It also discusses the controlling method of roller thermal crown and meaning of the parameter controlling. Since the roller thermal crown is in close relationship with the roller cooling water, so we could, on the basis of fully understanding the change of the roller thermal crown at rolling process, timely master the working situation of the cooling water system and make the relevant, adjustment thus providing the requirements for profile and flatness control.(3) Stepped cooling control is a major method to improve plate shape quality. Fuzzy control theory is introduced to stepped cooling control for plate mill in Tianjin Iron&Steel Group Co. Ltd. and new models are established, which play an important role in improving plate shape, and good results are achieved(4) The project design of stepped cooling control system is accomplished. Achieved the roll stepped cooling of fuzzy control and applied in industrial site. The practical running results indicate that the proposed stepped cooling fuzzy controller has better performance.