Method for optimizing rolling performance of vertical roll in thick plate production

Abstract

According to the method for optimizing the rolling performance of the vertical roll in the thick plate production, aiming at the working condition that the vertical roll and the horizontal roll are non-continuous rolling, whether the vertical roll is in a rolling time period or a non-rolling time period is firstly distinguished, and then constant-speed rolling control is established aiming at the rolling time period. According to the method for optimizing the rolling performance of the vertical roll in thick plate production, release of the rolling force range is achieved while the problem of power tripping of the vertical roll is solved, and the working capacity range of a unit is enlarged while the working efficiency of the vertical roll is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of heavy plate production, and particularly relates to a method for optimizing the rolling performance of vertical rolls in heavy plate production. Background Art

[0002] In the prior art, some medium and heavy plate production lines are equipped with vertical roll mills. The vertical roll mills adopt a close arrangement method very close to the horizontal roll mill. Some are arranged in front of the main rolling mill, and some are arranged behind the main rolling mill. As Figure 1 , 2 shown, Figure 1 shows the schematic relationship of the close-type vertical roll mill arranged in front of the main rolling mill; Figure 2 shows the close-type vertical roll mill arranged behind the main rolling mill. The vertical roll mill is mainly used for controlling the plane shape of the steel plate, correcting the uneven spread that is prone to occur in the forming and spreading stages, performing vertical roll edging on the length direction after forming and the width direction after spreading, reducing the unevenly deformed parts in the length and width directions of the steel plate, and reducing the shearing amount of the rolled steel plate.

[0003] The existing general speed control method for the close-type vertical roll mill and the horizontal roll mill is as Figure 3 shown. The adopted speed control strategy is still mainly based on the horizontal rolls, that is, first accelerating, then continuing to accelerate to the maximum rolling speed after biting the steel, and then decelerating to eject the steel. In this process, the vertical rolls complete the rolling operation in the acceleration section. However, it is found in actual use that the vertical rolls often trip easily. To solve this problem, the adopted measures are all to optimize the control of the rolling force, which leads to the serious obstruction of the working range of the rolling force on the one hand, and on the other hand, in order to meet the process quality requirements of the products, it is necessary to perform complex re-distribution of the rolling on the entire production line.

[0004] The invention application with the application number: CN2012101049196 discloses "a vertical roll control method and device for a medium and heavy plate vertical roll mill". During the electric adjustment of the roll gap, according to the actual position information and the target position information of the vertical rolls, the working state of the medium and heavy plate vertical roll mill is determined. According to the different working states of the vertical rolls of the medium and heavy plate vertical roll mill, the balance force of the pull-back hydraulic cylinder is adjusted to different balance force setting values. Specifically, when performing electric roll gap adjustment, a smaller balance force setting value is used; when not performing electric roll gap adjustment, a larger balance force setting value is used. This variable balance force control method not only achieves the purpose of making the vertical roll bearing seat in close contact with the lead screw of the electric roll gap control system, but also reduces the motor load, realizes energy conservation and consumption reduction, and at the same time reduces the wear of mechanical equipment.

[0005] The invention application with the application number: CN2017103739381 discloses an "optimized setting method for vertical roll speed during the forward pass rolling process in hot continuous rough rolling", including: (1) collecting actual data; (2) calculating the average rolling force and average rolling torque of the vertical roll before and after the horizontal roll bites the steel; (3) calculating the comprehensive torque of the vertical roll before and after the horizontal roll bites the steel; (4) calculating the correction amount of the back slip coefficient of the horizontal roll; (5) optimizing and learning the correction amount of the back slip coefficient; (6) calculating the correction amount of the back slip coefficient of the horizontal roll for the next slab and using it for the initial speed setting of the next slab. Summary of the Invention

[0006] The object of the present invention is to solve the problem of vertical roll power failure and at the same time release the working range of the rolling force.

[0007] To achieve the above technical objectives, the present invention provides a method for optimizing the rolling performance of vertical rolls in heavy plate production, and its technical solution is specifically as follows:

[0008] A method for optimizing the rolling performance of vertical rolls in heavy plate production,

[0009] The method is aimed at the working condition where the vertical roll and the horizontal roll are not continuously rolled. By first distinguishing whether the vertical roll is in the rolling period or the non-rolling period,

[0010] and then establishing a constant speed rolling control for the rolling period to complete.

[0011] Furthermore,

[0012] The determination of whether the vertical roll is in the rolling period or the non-rolling period is completed according to the bite steel signal and the rolling force signal. Specifically: taking the moment when the bite steel signal is formed as the start moment when the vertical roll enters the rolling period, and taking the moment when the rolling force suddenly becomes zero as the end moment of the vertical roll rolling;

[0013] Based on this, the establishment of a constant speed rolling control for the rolling period is specifically as follows:

[0014] First, control the vertical roll speed to reach the constant speed vertical roll rolling speed at the moment when the bite steel signal is formed;

[0015] Then, control the vertical roll to complete the rolling operation at a constant rolling speed and switch to the rolling line speed at the moment when the rolling force suddenly becomes zero.

[0016] Furthermore,

[0017] In a heavy plate production system, there is a first motor group for controlling the transmission of conveying rollers, a second motor group for controlling the transmission of vertical rollers, a third motor group for controlling the transmission of horizontal rollers, a signal receiving and output unit, and a basic automation control machine. Through the collaborative operation of the above settings, the output of the synchronous constant-speed rolling speed of the first motor group, the second motor group, and the third motor group during the working period of the vertical rollers is formed. The specific process is as follows:

[0018] S1: Taking the arrival of the first rolled piece at the mill entrance as a trigger signal, the basic automation control machine is triggered to send drive signals to the first motor group, the second motor group, and the third motor group;

[0019] S2: The first motor group, the second motor group, and the third motor group receiving the drive signals reach the set vertical roll constant-speed rolling speed at the moment when the rolled piece arrives at the vertical roll and generates a signal of steel biting according to the set acceleration control;

[0020] S3: When the signal receiving and output unit receives that the vertical roll rolling force signal is zero, it notifies the basic automation control machine to send the rolling line speed to the first motor group, the second motor group, and the third motor group.

[0021] A method for optimizing the vertical roll rolling performance in heavy plate production according to the present invention separates the acceleration period and the load working period of the vertical roll for control, achieving the effect of releasing the rolling force range while solving the problem of vertical roll power failure, and increasing the production line working capacity of the unit while ensuring the working efficiency of the vertical roll. Description of the Drawings

[0022] Figure 1 、 2 is a layout schematic diagram of the vertical roll mill and the main mill in the background technology of the present invention;

[0023] Among them,

[0024] Figure 1 is a layout schematic diagram of the close-type vertical roll mill arranged in front of the main mill;

[0025] Figure 2 is a layout schematic diagram of the close-type vertical roll mill arranged behind the main mill;

[0026] Figure 3 is a speed control schematic diagram of the prior art in the present invention;

[0027] Figure 4 is a speed control schematic diagram after optimization in the present invention. Detailed Embodiment

[0028] Next, a method for optimizing the vertical roll rolling performance in heavy plate production according to the present invention will be further specifically described according to the drawings in the specification and the detailed embodiments.

[0029] As Figure 4 shown in the optimized speed control scheme, the technical setting idea and process are as follows:

[0030] Regarding the problem that the vertical rolls often trip in the existing control strategy, the existing solutions and ideas all point to the optimization of the rolling force, and the problem is solved at the cost of reducing the rolling force; however, due to the constraints of the final process quality requirements of the rolled piece, it brings complexity when following this solution idea, because the reduction of the rolling force must be accompanied by changes in other process parameters to meet the response to the final process quality requirements. This technical solution breaks out of this conventional way of solving problems, starts from the essence of the jump, forms a solution to the problem, and at the same time does not bring additional optimization settings during the solution process, greatly reducing the complexity of optimization due to problem-solving, and has the value of general promotion.

[0031] The core setting of this technical solution to solve the above problems is: separate control of the acceleration period and the load period. The final determination of the entire setting scheme is based on the completion of speed control. However, this setting process does not mean the solution and implementation of all problems, because the positions of the vertical rolls and the horizontal rolls are fixed, and the speed control still needs to meet that when the rolled piece reaches the biting position of the horizontal rolls, the corresponding speed still needs to meet the set speed of the horizontal rolls. This means that the speed corresponding to the moment of the horizontal roll biting signal is a non-variable benchmark. And the entire optimized speed scheme also starts from this benchmark. Specifically: First, starting from this benchmark, according to the distance between the vertical rolls and the horizontal rolls, combined with the minimum time required for the motor to accelerate, the minimum rolling speed during vertical roll rolling is determined; then, since the distance from the vertical rolls to the mill entrance is also fixed, two problems will arise here: 1. Whether the distance from the mill entrance to the vertical rolls can support the motor to accelerate from startup to the constant speed during vertical roll rolling, so this constraint factor needs to be considered during specific optimization. 2. How to accurately establish control so that when the rolled piece reaches the vertical rolls, the motor also exactly accelerates to the output power corresponding to the target rolling constant speed of the vertical rolls. The solution to this problem is achieved by combining the utilization of the vertical roll biting signal. Specifically: During the setting process, taking the biting signal as the trigger signal, triggering the detection of the current speed, and adjusting the distance from the mill entrance to the vertical rolls in the model control according to the detection result until the moment of accelerating to the target vertical roll constant speed corresponds to the moment of vertical roll biting. After the technical solution completes the above settings, there is still a problem that has not been solved, that is, the problem of determining the end moment of vertical roll rolling. In this technical solution, a control strategy combining the rolling force is adopted, and the sudden change of the rolling force to zero is used to represent the end moment of vertical roll rolling.

[0032] Based on the technical solution formed by the above settings, the specific process is as follows:

[0033] Based on the first motor group that controls the conveying roll drive, the second motor group that controls the vertical roll drive, the third motor group that controls the horizontal roll drive, the signal receiving and output unit, and the basic automation control machine in the heavy plate production system, through the collaborative operation of these settings, the output of the synchronous constant-speed rolling speed of the first motor group, the second motor group, and the third motor group during the vertical roll working period is formed; the specific process is as follows:

[0034] S1: Taking the arrival of the first rolled piece at the mill inlet as the trigger signal, the basic automation control machine is triggered to send drive signals to the first motor group, the second motor group, and the third motor group;

[0035] S2: The first motor group, the second motor group, and the third motor group that receive the drive signal reach the set vertical roll constant-speed rolling speed at the moment when the rolled piece arrives at the vertical roll and generates a signal of biting the steel according to the set acceleration control;

[0036] S3: When the signal receiving and output unit receives that the vertical roll rolling force signal is zero, it notifies the basic automation control machine to send the rolling line speed to the first motor group, the second motor group, and the third motor group.

[0037] Embodiment

[0038] Suppose a vertical roll mill in a heavy plate plant is in front of the horizontal mill, and the equipment parameters of the vertical roll rolling are as follows:

[0039] Vertical roll diameter: 800mm;

[0040] Drive motor: 1250kW * 2.

[0041] Reduction ratio: 3.47

[0042] Rated speed: 2.53m / s

[0043] Maximum vertical roll rolling force: 5000kN.

[0044] The unoptimized vertical roll speed and pass capacity are as follows:

[0045] Horizontal mill biting speed: 2.0m / s,

[0046] Roller table acceleration: 2.2m / s 2

[0047] Mill acceleration: 1.8m / s 2

[0048] Maximum horizontal mill speed: 4m / s.

[0049] Under the above speed regime, power failure will occur when the vertical roll rolling force reaches 280kN.

[0050] After using this technical solution:

[0051] Vertical roll steel biting speed and rolling speed: 1.5 m / s,

[0052] Acceleration of roller table: 2.2 m / s 2

[0053] Acceleration of rolling mill: 1.8 m / s 2

[0054] Maximum speed of horizontal rolling mill: 4 m / s.

[0055] The vertical rolling mill can roll normally at 450 kN without tripping problems.

Claims

1. A method for optimizing the rolling performance of vertical rolls in heavy plate production, characterized in that: the method is for the working condition where the vertical roll and the horizontal roll are not continuously rolled. First, it distinguishes whether the vertical roll is in the rolling period or the non-rolling period, and then establishes a constant-speed rolling control for the rolling period to complete.

2. The method for optimizing the rolling performance of vertical rolls in heavy plate production according to claim 1, characterized in that: the determination of whether the vertical roll is in the rolling period or the non-rolling period is completed according to the biting signal and the rolling force signal. Specifically: the moment when the biting signal is formed is used as the start moment when the vertical roll enters the rolling period, and the moment when the rolling force suddenly becomes zero is used as the end moment of the vertical roll rolling; Based on this, the establishment of the constant-speed rolling control for the rolling period is specifically as follows: First, control the vertical roll speed to reach the constant vertical roll rolling speed at the moment when the biting signal is formed; Then, control the vertical roll to complete the rolling operation at a constant rolling speed and switch to the rolling line speed at the moment when the rolling force suddenly becomes zero.

3. The method for optimizing the rolling performance of vertical rolls in heavy plate production according to claim 1, characterized in that: in the heavy plate production system, there is a first motor group for controlling the transmission of the conveying rolls, a second motor group for controlling the transmission of the vertical rolls, a third motor group for controlling the transmission of the horizontal rolls, a signal receiving and output unit, and a basic automation control machine. Through the collaborative operation of the above settings, the output of the synchronous constant-speed rolling speeds of the first motor group, the second motor group, and the third motor group during the working period of the vertical roll is formed. The specific process is as follows: S1: Using the arrival of the first rolled piece at the mill entrance as a trigger signal, trigger the basic automation control machine to send drive signals to the first motor group, the second motor group, and the third motor group; S2: The first motor group, the second motor group, and the third motor group that receive the drive signals reach the set vertical roll constant-speed rolling speed at the moment when the rolled piece reaches the vertical roll and a biting signal is generated according to the set acceleration control; S3: When the signal receiving and output unit receives that the vertical roll rolling force signal is zero, notify the basic automation control machine to send the rolling line speed to the first motor group, the second motor group, and the third motor group.

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