A feed-forward optimization control method for coating thickness in galvanizing production line

Abstract

The invention discloses a method for plating thickness feedforward optimal control of a galvanization production line. A plating thickness set value presetting module is adopted to smoothly carry out switching without producing off-grade goods rejects; an air knife height feedforward setting module is adopted to avoid the accident of galvanizing zinc splashing and ensure the transverse uniformity of strip steel; a plating thickness neural network prediction module is adopted to accurately predict the plating thickness so as to provide basis for adjusting control variable; a control variable multi-target optimizing module is adopted for carrying out iterative search on the optimal air knife distance and air knife pressure setting in current working conditions; a distance distribution module is adopted to overcome the defect of inconsistent plating thickness of upper and lower surfaces of the strip steel caused by errors of a center line of the strip belt and abrasion of a stabilizing roll and a tower top roll. The method provided by the invention solves the control difficulties that plating thickness deviation is over large and plating thickness detection is hysteretic due to product specification switching and strip steel speed change, and can realize automatic presetting control on the plating thickness and effectively reduce plating quality fluctuation.

Description

technical field [0001] The invention belongs to the technical field of industrial process optimization control, in particular to the feedforward optimization automatic control technology of air knife distance and air knife pressure in the continuous galvanizing process of cold rolling. Background technique [0002] Galvanizing: here refers to hot-dip galvanizing, also called hot-dip galvanizing and hot-dip galvanizing, which is an effective metal anti-corrosion method and is mainly used in metal structure facilities in various industries. Hot-dip galvanizing is to immerse the rust-removed and annealed steel parts in the molten zinc solution, so that the surface of the steel components is attached with a zinc layer, so as to achieve the purpose of anti-corrosion. [0003] "Small air knife, small air pressure" principle: In the production process of hot-dip galvanizing, if the distance of the air knife is too large, it is easy to cause serious scattering of the gas ejected by ...

AI Technical Summary

Problems solved by technology

Due to the lack of effective control techniques to overcome the above-mentioned difficulties, the control of coating thickness and coating uniformity has always been a problem that plagues the improvement of product quality in galvanized production when the specification of the coating changes or the speed of the strip steel changes greatly. Relying on the operator's experience, manual operation combined with the underlying loop PID is used for control, which has low control accuracy, long transition time for product specification changes, large zinc consumption, large quality fluctuations, and even cannot guarantee the coating thickness and coating surface uniformity meet the requirements of product quality indicators, often there will be substandard products

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