Automatic control method for preventing accidents caused by plate shape change of roughing mill

Abstract

The invention relates to an automatic control method for preventing an accident caused by plate shape change of a roughing mill, which comprises the following steps of: detecting and tracking the actual position of strip steel by virtue of a rolling force signal of the roughing mill, an HMD hot metal detector and a tracking logic algorithm, and respectively arranging width gauges with a center line deviation detection function at an outlet R1 and an outlet R2 of the roughing mill, the actual position and position deviation of a steel billet are calculated through detection of center line deviation, when the center line deviation delta w is larger than or equal to 100 mm, a heat preservation cover is automatically lifted, a roller bed below the heat preservation cover automatically stops, when delta w is larger than or equal to 50 mm, a rolling mill gives an alarm and adjusts a roller gap, and when delta w is larger than or equal to 80 mm, a finish rolling F1 side guide plate is automatically opened by 18-22 mm on the original opening degree; according to the method, the change of the plate shape is tracked, and the occurrence of steel blockage and equipment accidents caused by the change of the rough rolling plate shape is effectively prevented and completely eradicated through the linkage relationship between the plate shape curve and the HMD and other photoelectric detection equipment, so that the aim of protecting the equipment is fulfilled.

Description

Technical Field

[0001] The invention relates to the technical field of hot-rolled strip steel shape control in the metallurgical industry, and in particular to an automatic control method for preventing accidents caused by changes in the shape of a roughing mill. Background Art

[0002] Hot-rolled strip steel mills are mainly divided into roughing mills and finishing mills. When the slab is processed into thin strip steel, the roughing mill generally has to bear a reduction rate of more than 80%. The general slab thickness is 210-250 mm, and the outlet thickness of the roughing mill is 28-40 mm. Therefore, the plate shape control of the roughing mill is particularly important during the rolling process. In the rolling mills of major steel companies across the country, due to the changes in the plate shape of the slab during the rolling process, such as buckling, sickle bending, etc., the lighter is the steel jamming accident, and the serious one will damage the equipment and cause a major accident. In addition, because the rough-rolled slab is thick and high-temperature, the accident will cause a long shutdown, and even damage the hydraulic pipeline to cause fire and other malicious incidents.

[0003] A Chinese patent with publication number CN116673342A discloses a method for rough rolling R2 slippage identification and automatic anti-slip control, in which the standard deviation of the slab shape centerline deviation during the rolling process is statistically summarized by a computer system, and whether slippage occurs is determined based on the size of the standard deviation. If slippage occurs, the speed reduction and load reduction are automatically controlled, and the speed reduction is to reduce the rolling speed of the rolling mill, and the load reduction is to reduce the pressing load of the rolling mill. Automatic anti-slip control is achieved by reducing the speed and load, thereby achieving the effect of reducing manual intervention, alleviating the operating labor load, and improving the stability of rough rolling. However, this method is aimed at slab slippage identification, and cannot solve the problem of accidents caused by plate deformation in the present application. Summary of the invention

[0004] The present invention provides an automatic control method for preventing accidents caused by changes in the plate shape of a rough rolling mill. The changes in the plate shape are tracked, and through the interlocking relationship between the plate shape curve and photoelectric detection equipment such as HMD, the occurrence of steel jams and equipment accidents caused by changes in the rough rolling plate shape can be effectively prevented and eliminated, thereby achieving the purpose of equipment protection.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] An automatic control method for preventing accidents caused by plate shape changes in a roughing mill comprises the following steps:

[0007] S1. During the rolling process of hot-rolled steel strip, the actual position of the steel strip is detected and tracked by the rolling force signal of the rolling mill, the HMD hot metal detector, and the tracking logic algorithm;

[0008] S2. Width gauges with centerline deviation detection function are respectively installed at the exits R1, R2 and R3 of the roughing mill;

[0009] S3. Through the detection of center line deviation, the width measuring instrument detects the actual width, width deviation and center line deviation curve of the strip, and calculates the actual position and position deviation of the billet through the curve;

[0010] S4. When the actual position deviation of the strip reaches the critical value or threshold, the rolling mill control system controls the roller table to automatically stop, the insulation cover to automatically lift, and the rolling mill side guide to automatically interlock;

[0011] S5. When the center line deviation Δw ≥ 100 mm, the insulation cover is automatically lifted and the roller below the insulation cover stops automatically. When Δw ≥ 50 mm, the rolling mill issues an alarm and adjusts the roll gap. When Δw ≥ 80 mm, the finishing rolling F1 side guide automatically opens 18 to 22 mm on the original opening.

[0012] Furthermore, the step S1 specifically includes: the billet runs on the roller table, the actual position of the strip is detected by the HMD hot metal detector, a rolling force is generated when the billet bites into the rolling mill, a bite signal is established by the change of the rolling force, which is used to determine the accuracy of the billet tracking, and the accurate position of the billet is calculated by multiplying the roller table speed and the rolling mill speed by time.

[0013] Furthermore, the step S3 calculates the actual position and position deviation of the steel billet, specifically including: the width measuring instrument curve detects three curves of the actual width of the strip, the width deviation of the strip, and the center line deviation of the strip, and obtains the center line deviation of the current block of steel being rolled, the center line deviation Δw=w1-w0, wherein w1 is the center line of the strip detected by the width measuring instrument, and w0 is the center line of the equipment calibrated when the width measuring instrument is installed.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1) The actual position and position deviation of the billet are accurately measured and calculated by the width gauge at the R1 exit, R2 exit or R3 exit of the rough rolling mill, thereby providing a data basis for the deformation of the plate shape;

[0016] 2) Through center line detection, position deviation and critical value comparison, and position sensor, timely alarm is issued, and automatic interlocking control is performed on the roll gap, insulation cover, roller table, and rolling mill;

[0017] 3) Effectively prevent and eliminate more than 90% of steel jams and equipment accidents caused by changes in plate shape during rough rolling. Through automatic detection and control of electrical process control, the development of hot rolling intelligent manufacturing is realized, creating tangible benefits of millions of yuan per year, and can promote the intangible benefits of the development of intelligent equipment. DETAILED DESCRIPTION

[0018] The specific embodiments of the present invention are further described below:

[0019] The present invention provides an automatic control method for preventing accidents caused by plate shape changes of a rough rolling mill, comprising the following steps:

[0020] S1. Detect and track the actual position of the steel strip by relying on the rolling force signal of the rolling mill, the HMD hot metal detector and the tracking logic algorithm. Specifically, the steel billet runs on the roller, and the actual position of the steel strip is detected by the HMD hot metal detector. When the steel billet bites into the rolling mill, a rolling force is generated. The bite signal is established through the change of the rolling force to determine the accuracy of the steel billet tracking. The accurate position of the steel billet is calculated by multiplying the roller speed and the rolling mill speed by time.

[0021] S2. Width gauges with centerline deviation detection function are respectively installed at the exits R1, R2 and R3 of the roughing mill.

[0022] S3. Through the detection of centerline deviation, the width measuring instrument detects the actual width, width deviation and centerline deviation curve of the strip, and these curves will be sent to the primary control system. The actual position and position deviation of the steel billet can be calculated through the primary PLC. The actual position and position deviation of the steel billet can be calculated through the curve. When the centerline data exceeds the actual physical position of the equipment, it will be judged that the steel block has defects such as lateral bending and poor plate shape, providing a basis for the next step of equipment control;

[0023] The actual position and position deviation of the steel billet are calculated specifically including: the width measuring instrument curve detects the actual width of the strip, the strip width deviation, and the center line deviation of the strip, and the center line deviation of the current piece of steel being rolled is obtained. After the real-time data of the center line deviation is plotted as a curve, the degree of sickle or side bending of the current piece of steel can be determined. The center line deviation Δw=w1-w0, where w1 is the center line of the strip detected by the width measuring instrument, and w0 is the center line of the equipment calibrated when the width measuring instrument is installed.

[0024] S4. When the actual position deviation of the strip reaches the critical value or threshold, the rolling mill control system controls the roller table to stop automatically, the insulation cover to lift automatically, and the side guide of the rolling mill to automatically interlock.

[0025] S5. The most effective way to solve the abnormal plate shape is to adjust the roll gap deviation. There are two main bases for the operator to adjust the plate shape: one is to visually observe the change of the plate shape; the other is to adjust it after the center line deviation is too large; in order to prevent the operator from being distracted and causing adjustment delays, when the width gauges at the R1 exit and R3 exit detect that the center line deviation of the billet head position is Δw ≥ 50㎜, an alarm will be given on the HMI operation screen, indicating that the plate shape needs to be adjusted, or the mill roll gap, or the roll gap deviation needs to be adjusted; when Δw ≥ 80㎜, the finishing rolling F1 side guide will automatically open 20㎜ on the original opening degree, and when the billet position deviation Δw ≥ 100㎜ is detected, the insulation cover will be lifted and the roller stop will be triggered to prevent the insulation cover from being damaged or waste caused by excessive billet offset.

[0026] The above embodiments are implemented based on the technical solution of the present invention, and detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to the above embodiments. The methods used in the above embodiments are conventional methods unless otherwise specified.

Claims

1. An automatic control method for preventing accidents caused by changes in plate shape of a roughing mill, It is characterized in that The steps include: S1. During the rolling process of hot-rolled steel strip, the actual position of the steel strip is detected and tracked by the rolling force signal of the rolling mill, the HMD hot metal detector, and the tracking logic algorithm; S2. Width gauges with centerline deviation detection function are respectively installed at the exits R1, R2 and R3 of the roughing mill; S3. Through the detection of center line deviation, the width measuring instrument detects the actual width, width deviation and center line deviation curve of the strip, and calculates the actual position and position deviation of the billet through the curve; S4. When the actual position deviation of the strip reaches the critical value or threshold, the rolling mill control system controls the roller table to automatically stop, the insulation cover to automatically lift, and the rolling mill side guide to automatically interlock; S5. When the center line deviation Δw ≥ 100 mm, the insulation cover is automatically lifted and the roller below the insulation cover stops automatically. When Δw ≥ 50 mm, the rolling mill issues an alarm and adjusts the roll gap. When Δw ≥ 80 mm, the finishing rolling F1 side guide automatically opens 18 to 22 mm on the original opening.

2. An automatic control method for preventing accidents caused by changes in plate shape of a roughing mill according to claim 1, It is characterized in that The step S1 specifically includes: the steel billet runs on the roller table, the actual position of the steel strip is detected by the HMD hot metal detector, a rolling force is generated when the steel billet bites into the rolling mill, a steel biting signal is established through the change of the rolling force, which is used to determine the accuracy of the steel billet tracking, and the accurate position of the steel billet is calculated by multiplying the roller table speed and the rolling mill speed by time.

3. An automatic control method for preventing accidents caused by plate shape changes in a roughing mill according to claim 1, It is characterized in that The step S3 calculates the actual position and position deviation of the steel billet, specifically including: the width measuring instrument curve detects three curves of the actual width of the strip, the width deviation of the strip, and the center line deviation of the strip, and obtains the center line deviation of the current piece of steel being rolled, the center line deviation Δw=w1-w0, wherein w1 is the center line of the strip detected by the width measuring instrument, and w0 is the center line of the equipment calibrated when the width measuring instrument is installed.