Method for correcting sampling points of finish rolling setting

Abstract

The application discloses a kind of methods for revising finishing setting sampling point, including according to the water beam mode of heating furnace, size and interval, slab size, calculate the first water beam and the last water beam position contacted with the slab, according to default finishing setting sampling point position and finished strip thickness, calculate the slab position of sampling point, determine the relationship between the default finishing setting sampling point corresponding the slab end position and the water beam in slab end position, according to the relationship, revise the finishing setting sampling point position, and send the adjusted setting sampling point position to artificial operation picture alarm.The beneficial effect is that: it makes up the vacancy that traditional method does not consider the influence of water beam printing on head setting in heating furnace, breaks through the limitation of traditional same proportion control, provides a more flexible solution for the preset model of hot continuous rolling finishing mill under complex working conditions, has significant engineering application value and industry popularization significance.

Description

Technical Field

[0001] This invention relates to the field of metallurgical automation control technology, and in particular to a method for correcting the setting sampling points of finishing mills. Background Technology

[0002] In the field of hot strip rolling, the setting of sampling points after the finishing mill is a core aspect of the self-learning process of the finishing mill setting model. The location of the sampling points directly determines the accuracy of the finishing mill pre-setting, the stability of the rolling process, and the overall quality control effect of the strip. Field production practice shows that using a fixed pattern of sampling points for self-learning on slabs of different lengths will produce completely opposite control effects due to differences in the location of abnormal temperature and thickness zones at the head, seriously affecting rolling stability and product quality consistency.

[0003] During the heating furnace, the slab is cooled by water-cooled beams, resulting in a distinct low-temperature zone and thickness deviation zone at the head of the slab. The length and location of this abnormal zone vary significantly with the slab length, the layout of the walking beams, and its position in the furnace. If a uniform sampling point strategy is used, the abnormal measured data caused by the water beam marks can easily be introduced into the self-learning process, amplifying the deviations in the model settings for finishing rolling force, roll gap, and temperature. This can lead to problems such as head threading instability, thickness deviations, and poor slab shape. Therefore, adaptively modifying the sampling points for finishing rolling based on the impact of the head water beams on the sampling points during the heating process for slabs of different lengths is of great significance for rolling stability and quality control.

[0004] Currently, there is no existing technology that can automatically correct the setting of the sampling point for finishing rolling based on the position of the water beam at the head of the slab in the heating furnace, so as to solve the problems of rolling instability and strip quality caused by the large setting deviation due to the presence of water beam marks at the head of the strip.

[0005] Therefore, an adaptive correction method for the sampling points of the finishing mill based on the linkage between the slab length and the water beam mark position is needed. By combining the slab length and calculating the influence range of the water beam mark at the head of the strip, abnormal data segments can be avoided and the head sampling point position can be corrected and optimized. Summary of the Invention

[0006] The purpose of this invention is to provide a method for correcting the setting sampling points of finishing mills in order to solve the above-mentioned problems.

[0007] The present invention achieves the above objectives through the following technical solutions: A method for correcting the sampling points set in a finishing mill includes the following steps: S1. Based on the steel arrangement, size and spacing of the water beams in the heating furnace, and the size of the slab, calculate the positions of the first and last water beams in contact with the slab. S2. Calculate the sampling point position on the slab based on the default fine rolling setting sampling point position and finished strip thickness; S3. Determine the relationship between the default fine rolling setting sampling point and the position of the water beam at the end of the slab; S4. Correct the location of the sampling points set for the finishing mill according to the positional relationship; S5. Send the adjusted sampling point location to the manual operation screen alarm to remind the operator to follow up according to the on-site production situation.

[0008] Furthermore, the steel placement method of the heating furnace in step S1 includes placing steel in the center and placing steel at both ends.

[0009] Furthermore, in the steel arrangement method, the positions of the first and last water beams in contact with the slab are calculated based on whether the starting position of the slab head is above the water beams. When the starting position of the slab head is not above the water beam, the calculation formula for the starting and ending positions of the first water beam in contact with the slab is as follows: , , Wherein, x1 is the starting position of the first water beam in the slab within the heating furnace, in meters; L is the length of the slab within the heating furnace, in meters; n is the number of water beams below the slab; s is the distance between the center lines of two water beams, in meters; d is the diameter of the water beam, in meters; and x1' is the ending position of the first water beam in the slab within the heating furnace, in meters.

[0010] The formula for calculating the starting and ending positions of the last water beam in contact with the slab is as follows: , , Where, x n The last water beam is located at the starting position of the slab inside the heating furnace, in meters. When the starting position of the slab head is above the water beam, x1 is 0m, x n Let Lm be the value of the first water beam's termination position and the last water beam's starting position. The formulas are as follows: , .

[0011] Further, in step S2, the formula for calculating the sampling point at the position of the slab is: , Among them, L F The sampling point position for finishing rolling corresponds to the position of the slab, in meters (m); LFS is the length of the sampling point for finishing mill setup, in m; h F is the target thickness at the exit of the finishing mill, in m; h J is the thickness of the slab in the heating furnace, in m. Further, step S3 specifically includes: determining the positions of the head and tail of the slab and the first water beam according to whether a hot coil box is used in the strip rolling process; defining the dead zone distance from the water beam and denoting it as L Fd , with a value range of [0.05, 0.2] and the unit of m; clarifying the positional relationship by combining the slab position corresponding to the finishing mill setup sampling point, the position of the first water beam on the slab, and the dead zone distance from the water beam, when x1-L Fd <L F <x1, the slab position corresponding to the finishing mill setup sampling point and the position of the first water beam on the slab are defined as the first relationship; when x1'-L Fd <L F <x1', the slab position corresponding to the finishing mill setup sampling point and the position of the first water beam on the slab are defined as the second relationship; when L F <x1-L Fd , the slab position corresponding to the finishing mill setup sampling point and the position of the first water beam on the slab are defined as the third relationship.

[0012] Further, step S4 specifically includes: In the case of the first relationship or the second relationship, the slab position L corresponding to the finishing mill setup sampling point F is increased by the dead zone distance L from the water beam Fd , that is, the corrected calculation formula for the position of the finishing mill setup sampling point is: , where L Fs1 is the corrected length of the finishing mill setup sampling point in the case of the first relationship or the second relationship, in m; In the case of the third relationship, no correction is made to the position of the finishing mill setup sampling point.

[0013] The beneficial effects are as follows: The method for correcting the finishing mill setup sampling point according to the present invention calculates each relevant position of the slab, combines the characteristics of the rolling process, adopts a mode of avoiding the critical positions that affect the finishing mill setup, re-corrects the setup sampling point, fills the gap that the traditional method does not consider the influence of the water beam mark in the heating furnace on the head setup, provides a more flexible solution for the preset model of the hot strip finishing mill under complex working conditions, and has remarkable engineering application value and industry promotion significance. Brief Description of the Drawings

[0014] Figure 1 This is an execution flowchart of a method for correcting the setting sampling points in finishing mills according to the present invention; Figure 2 This is a schematic diagram of the slab being placed in a heating furnace according to the present invention; Figure 3 This is a schematic diagram showing the relationship between the sampling point corresponding to the slab position and the position of the first water beam provided by the present invention.

[0015] The attached figures are labeled as follows: 1. Slab; 2. Water beam. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] The following combination Figures 1-3 To further illustrate the embodiments of the invention, a method for correcting the sampling points set in a finishing mill specifically includes the following steps: S1. Based on the steel arrangement of the heating furnace water beam 2, the size and spacing of the heating furnace water beam 2, and the size of the slab 1, calculate the positions of the first water beam 2 and the last water beam 2 that are in contact with the slab 1.

[0018] The steel placement method of the heating furnace can be mainly divided into central steel placement and end steel placement. In this embodiment, the central steel placement method of the heating furnace is taken as an example. There are 9 water beams 2 in the heating furnace. The slab 1 is centrally arranged above the 9 water beams 2. The positions of the first water beam 2 and the last water beam 2 that are in contact with the slab 1 are calculated.

[0019] In the method of centered steel placement in the heating furnace, there are two cases depending on whether the starting position of the head of slab 1 is above the water beam; The first method involves calculating the starting and ending positions of the first water beam in contact with slab 1 when the head of slab 1 is not above water beam 2. , , Where x1 is the starting position of the first water beam 2 in the slab inside the heating furnace, in meters; L is the length of the slab 1 inside the heating furnace, in meters; n is the number of water beams 2 below the slab 1; s is the distance between the center lines of the two water beams 2, in meters; d is the diameter of the water beam 2, in meters; and x1' is the ending position of the first water beam 2 in the slab 1 inside the heating furnace, in meters.

[0020] The formula for calculating the starting and ending positions of the last water beam 2 in contact with the slab is as follows: , , Where, x n The last water beam 2 is located at the starting position of the slab 1 inside the heating furnace, in meters (m); L is the length of the slab 1 inside the heating furnace, in meters (m); n is the number of water beams below the slab 1; s is the distance between the center lines of two water beams 2, in meters (m); d is the diameter of the water beam 2, in meters (m); x n 'This refers to the last water beam 2 at the end position of the slab inside the heating furnace, in meters.'

[0021] The second scenario involves the slab 1 head starting above the water beam 2. Since the starting position of the slab 1 head is above the water beam 2, the starting position where the first water beam 2 contacts the slab 1 inside the heating furnace is the slab 1 head position, denoted as 0m. The ending position of the last water beam 2 inside the heating furnace is Lm. Therefore, it is only necessary to calculate the ending position of the first water beam 2 in contact with the slab 1 and the starting position of the last water beam 2. The formula is: , .

[0022] like Figure 2 As shown, in this embodiment, the starting position of the head of the slab 1 is not above the water beam 2, and the length of the slab 1 is 10.4m, the number of water beams in contact with the slab 1 is 9, the diameter of the water beams is 0.3m, and the distance between adjacent water beams is 1.2m.

[0023] Applying the first scenario above, substituting the data into the calculation formula for when the starting position of the slab head is not above the water beam, we obtain the data shown in Table 1, as follows: Table 1 S2. Based on the default sampling point location and finished strip thickness set in the finishing rolling process, calculate the sampling point at position 1 of the slab using the following formula: , Among them, L F The sampling point position for finishing rolling is set at position 1 of the slab, in meters (m); L FS The sampling point length is set for the finishing mill, in meters (m); h F The target thickness for the finishing mill exit is in meters (m); h J The thickness of the slab 1 inside the heating furnace is in meters (m). In this embodiment, L is set. FS For 10m, h F It is 0.003 meters, h Jis 0.2 meters, and L is calculated by the formula of the sampling point at the slab position F is 0.15 meters.

[0024] S3. Determining the positional relationship between the end of the slab corresponding to the default finishing mill setup sampling point and the position of the heating water beam 2 at the end of the slab 1 according to whether a hot coil box is used in the strip rolling process; Herein, the purpose of clarifying whether a hot coil box is used in the strip rolling process is that after the hot coil box is used, the head and tail of the slab 1 will be exchanged before entering the finishing rolling, that is, the tail of the slab 1 in the heating furnace becomes the head of the finished rolled strip.

[0025] The position L corresponding to the position of the finishing mill setup sampling point on the slab 1 is calculated F , and compared with the start and end positions of the first water beam 2 on the slab 1 in the heating furnace after the rolling process with or without the hot coil box is determined, so as to clarify the positional relationship between the slab position corresponding to the finishing mill setup sampling point position and the position of the first water beam 2 on the slab.

[0026] Combining the position of the finishing mill setup sampling point corresponding to the slab 1, the position of the first water beam 2 on the slab 1, and the water beam dead zone distance, the following three corresponding relationships are obtained: Herein, the water beam dead zone distance is defined and denoted as L Fd , which is given by production technicians based on on-site production experience and verified repeatedly through multiple experiments. The optimal value range is within the interval [0.05, 0.2], with the unit being m; As shown in Figure 3 a, when x1-L Fd <L F <x1, the sampling point is adjacent to the front of the water beam mark, and the positional relationship between the slab position corresponding to the finishing mill setup sampling point position and the first water beam on the slab is defined as the first relationship; As shown in Figure 3 b, when x1'-L Fd <L F <x1', the positional relationship between the slab position corresponding to the finishing mill setup sampling point position and the first water beam on the slab is defined as the second relationship; As shown in Figure 3 c, when L F <x1-L Fd , the sampling point is located before the water beam mark and not within the water beam dead zone distance range, and the positional relationship between the slab position corresponding to the finishing mill setup sampling point position and the first water beam on the slab is defined as the third relationship.

[0027] With specific reference to Figure 2 , L FdThe sampling point is located a short distance from both sides of the water beam 2. This area is where the temperature is about to change significantly. If the sampling point is located in this area, it will either go from high temperature to low temperature (relationship 1) or from low temperature to high temperature (relationship 2). This means it will either be about to enter the water beam 2 or about to leave the water beam 2. Even if the sampling point causes the head to hit the target, the subsequent temperature change will prevent the mill's roll gap from responding quickly, resulting in a significant change in thickness.

[0028] In this embodiment, the strip rolling process does not use a hot coil box. Based on the finishing rolling, the sampling point position corresponds to 0.15m from the slab 1 position. The first water beam 2 is 0.25m from the starting position of the slab inside the heating furnace, and 0.55m from the ending position of slab 1 inside the heating furnace. The distance from the dead zone of the water beam is 0.15m. Figure 3 As shown in the diagram, the positional relationship can be determined as relationship one, i.e., x1-L. Fd <L F <x1。

[0029] S4. Correct the location of the sampling points set for the finishing mill according to the positional relationship; The correction method is as follows: When the relationship is one or two, the sampling point position of the finishing mill is set to correspond to the slab position L1. F Increase the distance to the dead zone of the water beam L Fd The calculation formula after correcting the sampling point position in the finishing mill is as follows: , Among them, L Fs1 The sampling point length is set for the corrected finishing mill in relation one or relation two, in meters; L F The default sampling point position for finishing rolling is set to position 1 on the slab, in meters (m); L Fd The distance to the dead zone of the water beam is in meters (m); h F The target thickness for the finishing mill exit is in meters (m); h J The thickness of the slab 1 inside the heating furnace is in meters (m).

[0030] In the case of relationship three, the sampling point position for the finishing mill is not corrected.

[0031] In summary, if the position of slab 1 corresponding to the sampling point set in the finishing mill is within the dead zone of the first water beam 2 at the position of slab 1, then the setting value of the sampling point should be corrected.

[0032] In this embodiment, the default relationship between the sampling point at the end of slab 1 and the position of the heating water beam at the end of slab 1 is considered to be relationship one. F For 0.15m, L Fd It is 0.15m, hF It is 0.003 meters, h J The value is 0.2 meters, and L can be calculated. Fs1 It is 20 meters.

[0033] S5. Send the above-mentioned adjustment of the sampling point position due to special location relationship to the manual operation screen alarm to remind the operator to follow up according to the on-site production situation.

[0034] Through the above application examples, it can be seen that the method of correcting the setting sampling point of the finishing mill of the present invention can automatically correct the setting sampling point of the finishing mill according to the position of the water beam in the heating furnace at the head of the slab in actual production. This can solve the problems of rolling instability and strip quality caused by the large setting deviation due to the presence of water beam marks at the head of the strip. It has positive significance for improving strip threading stability and strip quality.

[0035] The above method corrects the slab setting sampling point by comparing the slab position corresponding to the setting sampling point in the finishing mill with the start and end positions of the first water beam at the heating head of the slab in the heating furnace, and by combining the length of the dead zone of the water beam.

[0036] This method for correcting the sampling points for finishing mill settings involves calculating the relevant positions of the slab and, combined with the characteristics of the rolling process, avoiding critical positions that affect the finishing mill settings. This re-corrects the sampling points, filling the gap in traditional methods that do not consider the impact of water beam marks in the heating furnace on the head settings. It provides a more flexible solution for the pre-setting model of hot continuous rolling mills under complex operating conditions, demonstrating significant engineering application value and industry promotion potential.

[0037] Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A method for correcting the sampling points set in a finishing mill, characterized in that, Includes the following steps: S1. Based on the steel arrangement, size and spacing of the water beams in the heating furnace, and the size of the slab, calculate the positions of the first and last water beams in contact with the slab. S2. Calculate the sampling point position on the slab based on the default fine rolling setting sampling point position and finished strip thickness; S3. Determine the relationship between the default fine rolling setting sampling point and the position of the water beam at the end of the slab; S4. Correct the location of the sampling points set for the finishing mill according to the positional relationship; S5. Send the adjusted sampling point location to the manual operation screen alarm to remind the operator to follow up according to the on-site production situation.

2. The method for correcting the sampling points set in finishing rolling according to claim 1, characterized in that: The steel placement method for the heating furnace described in step S1 includes center placement of steel and placement of steel at both ends.

3. The method for correcting the sampling points set in finishing rolling according to claim 2, characterized in that: In the steel arrangement method, the positions of the first and last water beams in contact with the slab are calculated based on whether the starting position of the slab head is above the water beam. When the starting position of the slab head is not above the water beam, the calculation formula for the starting and ending positions of the first water beam in contact with the slab is as follows: ， ， Wherein, x1 is the starting position of the first water beam in the slab within the heating furnace, in meters; L is the length of the slab within the heating furnace, in meters; n is the number of water beams below the slab; s is the center-line distance between two water beams, in meters; d is the diameter of the water beam, in meters; and x1' is the ending position of the first water beam in the slab within the heating furnace, in meters. The formula for calculating the starting and ending positions of the last water beam in contact with the slab is as follows: ， ， Where, x n The last water beam is located at the starting position of the slab inside the heating furnace, in meters. When the starting position of the slab head is above the water beam, x1 is 0m, x n Let Lm be the value of the first water beam's termination position and the last water beam's starting position. The formulas are as follows: ， 。 4. The method for correcting the sampling points set in finishing rolling according to claim 3, characterized in that: In step S2, the formula for calculating the sampling point at the position of the slab is: ， Among them, L F The sampling point position for finishing rolling corresponds to the position of the slab, in meters (m); L FS The sampling point length is set for the finishing mill, in meters (m); h F The target thickness for the finishing mill exit is in meters (m); h J The thickness of the slab inside the heating furnace is expressed in meters (m).

5. The method for correcting the sampling points set in finishing rolling according to claim 4, characterized in that: Step S3 specifically includes: The position of the slab head and tail relative to the first water beam is determined based on whether a hot coil box is used in the strip rolling process. Define the dead zone of the water beam as L. Fd The value range is [0.05, 0.2], and the unit is m; In combination with the clear positional relationship between the slab position corresponding to the sampling point position for finishing mill setup, the position of the first water beam at the slab position, and the water beam dead zone distance, when x1-L Fd <L F <x1, the positional relationship between the slab position corresponding to the sampling point position for finishing mill setup and the position of the first water beam at the slab position is defined as the first relationship; when x1'-L Fd <L F <x1', the positional relationship between the slab position corresponding to the sampling point position for finishing mill setup and the position of the first water beam at the slab position is defined as the second relationship; when L F <x1-L Fd , the positional relationship between the slab position corresponding to the sampling point position for finishing mill setup and the position of the first water beam at the slab position is defined as the third relationship.

6. The method for correcting the sampling points set in finishing rolling according to claim 5, characterized in that: Step S4 specifically includes: When either Relationship 1 or Relationship 2 applies, the sampling point position of the finishing mill will correspond to the slab position L. F Increase the distance to the dead zone of the water beam L Fd The calculation formula after correcting the sampling point position in the finishing mill is as follows: ， Among them, L Fs1 The length of the sampling points for the corrected finishing mill is set for either relation one or relation two, in meters. In the case of relationship three, the sampling point position of the finishing mill is not corrected.

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