A method for rapid detection of belt breakage based on roller motor load in continuous unwinding unit

Abstract

The present invention discloses a method for quickly detecting belt breakage of a continuous unwinding unit based on the motor load of a roller group, which comprises the following steps: (1) collecting the motor loads M1, M2, ..., M of each roller group at time t; i ,……,M n and motor speed V1, V2, ..., V i ,……,V n , and collect the motor loads M1′, M2′, ..., M of each roller group at time t+Δt i ′, ..., M n ' and motor speed V1', V2', ..., V i ′, ..., V n ′. (2) Calculate the change rate of the motor load increment of each roller group and the change rate of the motor speed increment of each roller group within the Δt time. (3) Let #imgabs0# determine whether the K value is greater than ε=K1×T×V. If it is "yes", it is determined that the strip is broken; if it is "no", it is determined that the strip is not broken. The strip break rapid detection method described in the present invention can quickly detect the strip and determine whether the strip is broken.

Description

Technical Field

[0001] The invention relates to a rapid detection method, in particular to a belt break rapid detection method. Background Art

[0002] With the increase in steel demand and the improvement of technology, the operating speed of high-speed thin strip cold rolling continuous annealing units has been gradually increased. Among them, some continuous annealing units have an operating speed of up to 800 meters per minute. On this basis, if an accident occurs in the unit, it is very easy to cause significant losses due to the high operating speed of the strip.

[0003] In the cleaning section of the continuous annealing production line, the cleaning section is located after welding and before the furnace area, which includes an alkali washing tank, a scrubber, an electrolytic tank, a scrubber and a hot flushing tank. Since the production process of the cleaning section requires that it be closed, when a strip breaks in this section, the only way to detect whether a strip breaks is through the detection grating at the end of the cleaning section. This detection method has a huge disadvantage: if a strip breaks in the cleaning section, the unit cannot detect the strip break in time, and it has to wait until the strip break position escapes to the detection grating before it can be detected and then stopped and decelerated. Since the strip runs at a high speed and cannot be stopped and decelerated in time, the subsequent strip will easily escape into the continuous annealing furnace, causing a more serious production stoppage accident.

[0004] Therefore, when the strip breaks in the cleaning section, a rapid detection method is needed to quickly detect the break and locate the broken strip, so that the unit can be shut down in time and the strip speed can be reduced to prevent the strip from escaping into the continuous annealing furnace and causing the accident to expand.

[0005] The Chinese patent document with publication number CN108754116B and publication date of February 21, 2020, and titled "Method and device for preventing strip steel from being drawn into the furnace after the strip of the continuous annealing unit breaks", determines whether the strip of the continuous annealing unit is broken by detecting the tension value of the middle section of the continuous annealing unit. When the tension value drops below 2KN and remains for more than 0.5s, the continuous annealing unit is determined to be broken; when the strip of the continuous annealing unit breaks, the furnace speed is limited to 115-125m / min. If the strip breaks in the cleaning section, there may be a delay in reducing the tension value of the middle section of the unit.

[0006] The Chinese patent document with publication number CN202610289U and publication date of December 19, 2012, and titled "Annealing furnace strip steel break detection alarm", connects the break detector with the alarm box and sets the break detector at the annealing furnace strip steel break position to detect the break. However, it should be noted that the cleaning section of the continuous annealing production line is closed, and this method is not suitable for the cleaning section.

[0007] The Chinese patent document with publication number CN1036726C and publication date December 17, 1997, and titled “Strip Broken Detector”, detects whether the strip is broken by setting a strip broken detector inside the continuous annealing furnace, but this method is not suitable for the cleaning section.

[0008] Based on this, it is expected to obtain a method for quickly detecting strip breakage in a continuous annealing unit based on the motor load of the roller group, which can quickly detect whether the strip is broken in the cleaning section. Summary of the invention

[0009] One of the purposes of the present invention is to provide a method for quickly detecting strip breakage based on the motor load of a roller group of a continuous annealing unit. The method for quickly detecting strip breakage described in the present invention can be used to quickly detect the strip and determine whether a strip breakage accident occurs.

[0010] In order to achieve the above object, the present invention provides a method for quickly detecting belt breakage of a continuous unwinding unit based on the motor load of a roller group, which comprises the following steps:

[0011] (1) Collect the motor loads M1, M2, ..., M of each roller group at time t i ,……,M n and motor speed V1, V2, ..., V i ,……,V n , and collect the motor loads M1′, M2′, ..., M of each roller group at time t+Δt i ′, ..., M n ' and motor speed V1', V2', ..., V i ′, ..., V n ′;

[0012] (2) Calculate the rate of change of the motor load increment of each roller group within the Δt time: And the rate of change of the motor speed increment of each roller group:

[0013] (3) Order where λ i is the weighted coefficient of contribution of each roller group to the belt breakage, and Determine whether the K value is greater than ε=K1×T×V. If it is "yes", it is determined that the strip is broken; if it is "no", it is determined that the strip is not broken; wherein T represents the strip thickness, and its unit parameter is mm; V represents the strip running speed, and its unit parameter is m / min; K1 represents the coefficient related to the strip running speed V and the strip thickness T, and its value range is 1.6-2.5.

[0014] In the technical scheme described in the present invention, the present invention comprehensively considers the equipment and process characteristics of the entrance section of the continuous annealing unit, combines the influence of the strip on the motor load, and analyzes the change law of the motor load when the strip breaks through a large amount of sample data. It is found that after the strip breaks, the motor load and speed of the roller group will suddenly change after the strip breaks, so as to quickly detect the strip breaking accident.

[0015] By adopting the method for rapid strip breakage detection described in the present invention, strip breakage in the cleaning section can be detected more quickly in production practice, thereby preventing the strip from escaping into the furnace or causing strip breakage in the furnace, as well as unnecessary opening of the cover to handle the strip and purging, reducing fault handling time and reducing the economic losses caused thereby.

[0016] Furthermore, in the method for rapid detection of broken strips described in the present invention, there is also a step (0) before step (1): collecting the strip running speed V, and determining whether the strip running speed V is greater than a speed threshold. If it is greater than the speed threshold, the surface unit is already in a stable operating state, and enters step (1).

[0017] Furthermore, in the belt breakage rapid detection method described in the present invention, the speed threshold is 50 m / min.

[0018] Furthermore, in the method for rapid belt breakage detection of the present invention, in step (3), if the answer is "No", the method further includes the following steps: setting t=t+Δt, and returning to execute step (0) or step (1).

[0019] Furthermore, in the method for rapid detection of broken belts of the present invention, the method further comprises step (4): selecting r1 to r n The value of the sudden change in is extracted, and the value of i is extracted, and it is determined that the position where the strip breaks is between the i-th roller group and the i+1-th roller group.

[0020] In the above technical scheme of the present invention, the method for rapid detection of broken strips described in the present invention can accurately locate the location where the broken strip occurs. The positioning function provided by the method can effectively shorten the time for finding and processing the broken strip, and can reduce the economic losses caused by the broken strip.

[0021] Furthermore, in the method for rapid detection of broken belts of the present invention, the value of the mutation is r i Greater than the mutation threshold r0.

[0022] Furthermore, in the method for rapid belt breakage detection of the present invention, the mutation threshold r0=50.

[0023] Furthermore, the method for rapid belt breakage detection of the present invention further includes the step of: after the judgment is "yes", issuing a belt breakage alarm.

[0024] Furthermore, the method for rapid belt breakage detection of the present invention further includes the step of: after the judgment is "yes", issuing a control signal to stop and reduce the speed of the unit.

[0025] In the above technical scheme, in the method for rapid strip break detection described in the present invention, when a strip break occurs, a control signal can be issued to shut down and slow down the unit, thereby achieving timely shutdown and speed reduction to prevent the strip from escaping into the continuous annealing furnace, thereby aggravating the accident.

[0026] The belt breakage rapid detection method based on the motor load of the roller group of the continuous unwinding unit of the present invention has the following advantages and beneficial effects compared with the prior art:

[0027] In the present invention, the equipment and process characteristics of the entrance section of the continuous annealing unit are comprehensively considered, and combined with the influence of the strip on the motor load, a large amount of sample data is analyzed to find the changing law of the motor load when the strip breaks. It is found that the motor load and speed of the roller group will suddenly change after the strip breaks, so as to quickly detect the strip break accident.

[0028] By adopting the method for rapid strip breakage detection based on the roller group motor load of the continuous annealing unit described in the present invention, strip breakage in the cleaning section can be detected more quickly in production practice, and the strip can be prevented from escaping into the furnace or causing strip breakage in the furnace, as well as unnecessary opening of the cover to handle the strip and purge, thereby reducing fault handling time and reducing the economic losses caused thereby.

[0029] In some preferred embodiments, the method for rapid strip breakage detection described in the present invention can not only quickly detect whether a strip breakage accident has occurred, but also accurately locate the location where the strip breakage has occurred. The positioning function provided by the method can shorten the time for finding and processing the strip breakage, and effectively reduce the economic losses caused by the strip breakage.

[0030] Accordingly, in certain embodiments, the method for rapid strip break detection described in the present invention can issue a control signal to shut down and slow down the unit when a strip break accident is detected, thereby causing the continuous annealing unit to shut down and slow down in time to prevent the strip from escaping into the continuous annealing furnace and causing the accident to escalate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The present invention is a flowchart of the steps of a method for rapid detection of belt breakage based on the motor load of a roller group of a continuous unwinding unit in one embodiment of the present invention. DETAILED DESCRIPTION

[0032] The method for rapid detection of broken belts based on the motor load of the roller group of the continuous unwinding unit of the present invention will be further explained and illustrated below in conjunction with specific embodiments. However, such explanation and illustration do not constitute an improper limitation on the technical solution of the present invention.

[0033] Figure 1 The present invention is a flowchart of the steps of a method for rapid detection of belt breakage based on the motor load of a roller group of a continuous unwinding unit in one embodiment of the present invention.

[0034] In the method for rapid detection of belt breakage of the continuous unwinding unit based on the motor load of the roller group described in the present invention, in this embodiment, it includes the steps of:

[0035] (A) The motors of each roller group in the cleaning section are numbered i in sequence in the direction of strip running. The number i can be 1, 2, 3...n.

[0036] (B) Collect the running speed V of the strip steel and determine whether V is greater than 50 m / min. If V is greater than 50, it indicates that the unit is in a stable running state and further proceeds to step (C).

[0037] (C) Collect the motor loads M1, M2, ..., M of each roller group at time t i ,……,M n and motor speed V1, V2, ..., V i ,……,V n , and collect the motor loads M1′, M2′, ..., M of each roller group at time t+Δt i ′, ..., M n ' and motor speed V1', V2', ..., V i ′, ..., V n ′.

[0038] (D) Calculate the rate of change of the motor load increment of each roller group within the Δt time: And the rate of change of the motor speed increment of each roller group:

[0039] (E) According to the sensitivity of each roller to load changes, λ i is the weighted coefficient of each roller's contribution to the belt breakage, and

[0040] (F) Determine whether the K value is greater than ε=K1×T×V. If it is "yes", it is determined that the strip is broken and the process goes to step (G); if it is "no", it is determined that the strip is not broken, and t=t+Δt is set, and the process goes back to step (B). Where T represents the strip thickness, and its unit parameter is mm; V represents the strip running speed, and its unit parameter is m / min; K1 represents the coefficient related to the strip running speed V and the strip thickness T, and its value range is controlled between 1.6-2.5.

[0041] It should be noted that if the answer is "No", when it is determined that the strip is not broken, let t = t + Δt. In some embodiments, it is also possible to directly return to step (C) without returning to step (B).

[0042] (G) Select r1~r n The value of the sudden change in the value, that is, the r value is greater than the sudden change threshold r0, the sudden change threshold r0 = 50, and the value of the roller group motor corresponding to the number i is extracted, then it is determined that the position where the strip breaks is between the i-th roller group and the i+1-th roller group.

[0043] (H) Determine whether there is operator intervention. When Q=1, it indicates that there is operator intervention, and the process goes to step (I); when Q=0, it indicates that there is no operator intervention, and the process goes to step (J). Q is a logic value set by the on-site operator.

[0044] (I) The software sounds an alarm and pops up a warning box stating "the unit has a belt break" and the location of the broken belt. The operator decides whether to shut down the unit.

[0045] (J) The software sounds an alarm and pops up a warning box stating "the unit has a belt break" and the location of the broken belt. At the same time, it issues a belt break command to stop the unit and reduce its speed.

[0046] Example 1-2

[0047] In order to better illustrate the specific application of the method for rapid belt breakage detection based on the motor load of the roller group of the continuous annealing unit of the present invention, the present invention is verified by two specific examples below.

[0048] Embodiment 1:

[0049] In Example 1, the strip thickness T = 0.5 mm, the unit running speed V 机 =580m / min. The motors of each roller group in the cleaning section are numbered in the direction of the strip running, 1, 2, 3...32.

[0050] The running speed of the steel strip V = 581 m / min, V is greater than 50 m / min. At the moment t = 54 minutes and 34 seconds, the motor loads of each roller group M1 = 7, ..., M 17 =290, M 18 =325, M 19 =252, ..., M 32 =120, motor speed V1 = 580m / min, V2 = 581m / min, ..., V 14 =580m / min, V 15 =582m / min, V 16 =581m / min, V 32=582m / min. In this embodiment, Δt=0.1s, t+0.5=54:34.100 collects the motor loads of each roller group M1′=43, ..., M 17 ′=219、M 18 ′=224、M 19 ′=198、……、M 32 ′=105, motor speed V1′=579m / min, V2′=580m / min, ..., V1′4=580m / min, V1′5=550m / min, V1′6=579m / min, ..., V3′2=581m / min.

[0051] Calculate the rate of change of the motor load increment of each roller group within Δt = 0s:

[0052] The rate of change of each roller group motor speed increment:

[0053] calculate There is λ i =[0.07, 0.05, 0.06, 0.06, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.07, 0.05, 0.06, 0.05, 0.06, 0.05, 0.06, 0.07, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.06, 0.05], and K = 624.

[0054] Correspondingly, the value range of K1 is between 1.6-2.5. In this embodiment, the value of K1 is 1.72, and ε=K1×T×V=498.8 is calculated. The K value calculated above is compared with the value of ε. If the K value is greater than ε, it is determined that the strip is broken.

[0055] Select r1~r n The value of the mutation in r 15 =64, that is, the r value is greater than r0=50, and the i value is 15, which means that the strip is broken between the 15th and 16th roller groups. To determine whether there is operator intervention, Q=0, no operator intervention, the software will sound an alarm and pop up a warning box of "the unit is broken" and the broken position, and at the same time issue a broken belt instruction to stop the unit and reduce speed.

[0056] It should be noted that, in the on-site production, the strip breaking accident in Example 1 was caused by the strip breaking behind the turning roller at the entrance of the electrolytic cell in the cleaning section, and the subsequent strip steel did not escape into the continuous annealing furnace. If the strip breaking rapid detection method described in the present invention is not used for detection, when the strip breaking detection is performed by the grating between the cleaning section and the entrance looper trolley in the original traditional method, the strip steel running speed is 581.6m / min when the strip breaks, and it takes about 4s for the strip breaking to run to the detection grating. There will be a 4s delay when the detection grating detects the strip breaking, and the subsequent strip steel is likely to escape into the continuous annealing furnace, causing the accident to expand and bring huge economic losses.

[0057] Embodiment 2:

[0058] In Example 2, the strip thickness T = 0.8 mm, the unit running speed V 机 =568m / min. The motors of each roller group in the cleaning section are numbered in the direction of the strip running, 1, 2, 3...32.

[0059] The running speed of the steel strip V = 568 m / min, V is greater than 50 m / min. At the moment t = 25 minutes and 46 seconds, the motor loads of each roller group M1 = 12, ..., M 15 =294, M 16 =327, M 17 =249, ..., M 32 =125, motor speed V1 = 566m / min, V2 = 566m / min, ..., V 14 =568m / min, V 15 =568m / min, V 16 =569m / min, ..., V 32 =569 m / min. In this embodiment, Δt=0.1s, t+0.5=25: At 46.500, the motor loads of each roller group M1′=46, ..., M 15 ′=223、M 16 ′=227、M 17 ′=202、……、M 32 ′=112, motor speed V1′=567m / min, V2′=566m / min, ..., V1′4=568m / min, V1′5=568 / min, V1′6=570m / min, ..., V3′2=570m / min.

[0060] Calculate the rate of change of the motor load increment of each roller group within Δt = 0s: The rate of change of each roller group motor speed increment:

[0061] calculate There is λ i =[0.07, 0.05, 0.06, 0.06, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.07, 0.05, 0.06, 0.05, 0.06, 0.05, 0.06, 0.07, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.06, 0.05], and K = 612.

[0062] Correspondingly, the value range of K1 is between 1.6-2.5. In this embodiment, the value of K1 is 1.72, and it is calculated that ε=K1×T×V=488.5. The K value calculated above is compared with the value of ε. If the K value is greater than ε, it is determined that the strip is broken.

[0063] In r1~r n If there is no sudden change in the value, it is determined that the strip is broken before the entrance turning roller numbered 1. To determine whether there is operator intervention, Q = 1, if there is operator intervention, the software will sound an alarm and pop up a warning box of "the unit has broken strip" and the broken strip position, and the operator will decide whether to stop the machine.

[0064] It should be noted that, during on-site production, the belt breaking accident in Example 2 was caused by the belt breaking between the steering pinch roller and the welder before the alkali immersion tank in the cleaning section, and the subsequent strip steel did not escape into the continuous annealing furnace. If the belt breaking rapid detection method described in the present invention is not used for detection, when the belt breaking detection is performed by the grating between the cleaning section and the entrance looper trolley in the traditional method, the running speed of the strip steel is 568m / min when the belt breaks, and it takes about 8s for the broken belt to run to the detection grating. There will be an 8s delay when the detection grating detects the broken belt. In this way, the subsequent strip steel will still run at high speed for a long time without constraints, which will not only cause secondary belt breaking, but also cause greater damage to the equipment in the cleaning section, and the shutdown time for handling the accident will be longer, which will bring huge economic losses.

[0065] From the above, it can be seen that in the above embodiments 1-2, the method for rapid strip break detection of the present invention can realize rapid detection and strip break location when a strip break accident occurs, and it can timely control the shutdown and speed reduction of the continuous annealing unit to prevent the possibility of the accident expanding due to the escape of the strip into the continuous annealing furnace.

[0066] It should be noted that the combination of the various technical features in this case is not limited to the combination described in the claims of this case or the combination described in the specific embodiments. All technical features recorded in this case can be freely combined or combined in any way unless there is a contradiction between them.

[0067] It should also be noted that the above-listed embodiments are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and similar changes or modifications made therewith can be directly derived or easily associated with the contents disclosed by those skilled in the art from the present invention, and all should belong to the protection scope of the present invention.

Claims

1. A method for rapid detection of belt breakage of a continuous unwinding unit based on the motor load of a roller group, characterized in that: Includes steps: (1) Collect the motor loads M1, M2, ..., M of each roller group at time t i ,……,M n and motor speed V1, V2, ..., V i ,……,V n , and collect the motor loads M1′, M2′, ..., M of each roller group at time t+Δt i ′, ..., M n ' and motor speed V1', V2', ..., V i ′, ..., V n ′; (2) Calculate the rate of change of the motor load increment of each roller group within the Δt time: And the rate of change of the motor speed increment of each roller group: (3) Order where λ i is the weighted coefficient of contribution of each roller group to the belt breakage, and Determine whether the K value is greater than ε=K1×T×V. If it is "yes", it is determined that the strip is broken; if it is "no", it is determined that the strip is not broken; T represents the strip thickness, and its unit parameter is mm; V represents the strip running speed, and its unit parameter is m / min; K1 represents the coefficient related to the strip running speed V and the strip thickness T, and its value range is 1.6-2.5; (4) Select r1~r n The value of the sudden change in is extracted, and the value of i is extracted, and it is determined that the position where the strip breaks is between the i-th roller group and the i+1-th roller group.

2. The method for rapid detection of broken belts according to claim 1, characterized in that: Before step (1), there is also step (0): collecting the strip running speed V, and judging whether the strip running speed V is greater than the speed threshold. If it is greater than the speed threshold, the surface unit is already in a stable operating state, and enters step (1).

3. The method for rapid detection of broken belts according to claim 2, characterized in that: The speed threshold is 50 m / min.

4. The method for rapid belt breakage detection according to claim 1 or 2, characterized in that: In step (3), if the answer is "No", the method further includes the following steps: setting t=t+Δt, and returning to execute step (0) or step (1).

5. The method for rapid belt breakage detection according to claim 1, characterized in that: The value of the mutation is r i Greater than the mutation threshold r0.

6. The method for rapid belt breakage detection according to claim 5, characterized in that: The mutation threshold r0=50.

7. The method for rapid belt breakage detection according to claim 1, characterized in that: The method further comprises the steps of: after the judgment is "yes", issuing a belt break alarm.

8. The method for rapid belt breakage detection according to claim 1, characterized in that: The method also includes the steps of: after judging as "yes", sending a control signal to stop and slow down the unit.

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