Air cooling control method for improving poor performance of disc screw head, middle tail and storage medium

Abstract

The invention discloses an air cooling control method for improving the poor performance of the head, the middle and the tail of a disc screw and a storage medium, and the method comprises the following steps: setting the total frequency raising time t of a frequency conversion fan from starting to the highest frequency, 60 s < = t < 100 s, and a steel signal of a pinch roll connected to a rolling line control program; and after the steel existence signal of the pinch roll is received, the frequency conversion fan performs automatic frequency increasing operation according to a set program through set time delay, and the frequency is reduced to the normal frequency after the set strong blowing duration is reached. The forced cooling device can realize forced cooling of the high-temperature section of the head in the production process of the coiled snail, thereby reducing the temperature difference of the head and the tail, enabling the head to fully complete phase change, finally reducing the performance difference of the head and the tail, realizing forced cooling through automatic air regulation of the frequency conversion fan, and eliminating the steel heaping accident caused by overlarge forced cooling resistance to the head of the coiled snail through water tank regulation.

Description

Technical Field

[0001] The present invention relates to the technical field of spiral ribbed bar production, in particular to an air-cooling control method and a storage medium for improving the poor performance of the head and tail of spiral ribbed bars. Background Art

[0002] In the field of high-speed wire rod production, spiral ribbed bars, as a common steel product, generally have a basic finished product speed of over 50 m / s. And due to the ribbed surface characteristics of spiral ribbed bars themselves, if the head passes through water, the resistance is too large and steel piling may occur. Therefore, when producing basic spiral ribbed bars (especially small specifications), the head needs to be clamped by pinch rolls to form tension before the water can be turned on to quickly reach the phase change range. Limited by the equipment installation conditions, the finished product stand is generally about 40 meters away from the pinch rolls, which results in the temperature of the head of the spiral ribbed bar finished product being generally dozens of degrees higher than that of the middle and tail parts for dozens of meters. Due to the temperature difference seriously affecting the phase change of the spiral ribbed bar finished product, the performance deviation between the head and tail of the spiral ribbed bar is relatively large. At present, the market's quality requirements for steel products are getting higher and higher, resulting in more and more quality objections for spiral ribbed bars due to abnormal performance.

[0003] Many problems have emerged in the use of traditional air-cooling fans: First, the time required for the fan to start up to the maximum power is relatively long, usually 120 s, which makes it impossible to provide sufficient cooling air volume in time when the head of the spiral ribbed bar enters the air-cooling area, affecting the cooling effect of the high-temperature section of the head; Second, the fan is always in a single working condition during operation and cannot adjust the air volume according to the different cooling requirements of the head, middle and tail parts of the spiral ribbed bar, making it difficult to achieve precise control of the overall cooling of the spiral ribbed bar; Third, there is a lack of effective connection between the air-cooling line control and the rolling line control system, and it is impossible to obtain the operation status information of the spiral ribbed bar in time, resulting in insufficient timeliness and accuracy of air-cooling control. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide an air-cooling control method and a storage medium for improving the poor performance of the head and tail of spiral ribbed bars, strengthen the frequency conversion control program of the fan for cooling the head of the spiral ribbed bar finished product, and ensure that while improving the performance of the head, the risk of steel piling is avoided.

[0005] The technical solution adopted by the present invention to solve its technical problems is: an air-cooling control method for improving the poor performance of the head and tail of spiral ribbed bars, including the following steps:

[0006] Set the total frequency increase time t for the frequency conversion fan from startup to the maximum frequency, 60 s ≤ t < 100 s, and access the signal of the pinch roll with steel in the rolling line control program;

[0007] After a set delay after receiving the signal of the pinch roll with steel, the frequency conversion fan performs an automatic frequency increase operation according to the set program, and drops back to the normal frequency after reaching the set strong blowing duration.

[0008] As a further improvement of the present invention: it further includes:

[0009] Obtain the normal frequency of the nth variable-frequency fan, and calculate the frequency increase time t required for the nth variable-frequency fan to increase from the normal frequency to the highest frequency n0 ;

[0010] Obtain the time t required for the coil head to reach the nth variable-frequency fan n ,

[0011] When t n > t n0 , determine the set delay t corresponding to the nth variable-frequency fan 延时 = t n -t n0 +t 补偿 , 0 ≤ t 补偿 ≤ 2;

[0012] When t n ≤ t n0 , determine that the set delay corresponding to the nth variable-frequency fan is t 延时 = 0.

[0013] As a further improvement of the present invention: it further includes:

[0014] Set the normal frequency of the first variable-frequency fan to be not less than x% of the highest frequency;

[0015] Calculate the frequency increase time t required for the first variable-frequency fan to increase to the highest frequency 10 ;

[0016] The time t1 required for the coil head to reach the first variable-frequency fan from the position where the pinch roll has steel signal;

[0017] When t1 ≤ t 10 , the first variable-frequency fan advances t1 - t 10 +t 补偿 and increases the frequency to the highest frequency according to the set program, enters the strong blowing mode, or the first variable-frequency fan operates without change;

[0018] When t1 > t 10 , the set delay t corresponding to the first variable-frequency fan 延时 = t1 - t 10 +t 补偿 , 0 ≤ t 补偿 ≤ 2.

[0019] As a further improvement of the present invention: it further includes:

[0020] Obtain the distance L that the coil head runs from the starting position to the inlet of the nth variable-frequency fan;

[0021] Also obtain the air-cooled roller table speed v;

[0022] According to the formula t n = L / v, calculate the time t required for the head of the coiled bar to run to the inlet of the nth variable-frequency fan n .

[0023] As a further improvement of the present invention: it further includes:

[0024] Obtain the spacing L0 between adjacent variable-frequency fans and the corresponding air-cooled roller table speed v0;

[0025] According to the formula t 间 = L0 / v0, calculate the interval time t between adjacent variable-frequency fans 间 ;

[0026] Set the strong blowing duration range to be t 间 ±t 修正 .

[0027] As a further improvement of the present invention: the set strong blowing duration of the variable-frequency fan is 5000 - 6000 milliseconds.

[0028] As a further improvement of the present invention: it further includes:

[0029] The normal frequency of the variable-frequency fan is preset by the program or is the currently monitored working frequency;

[0030] According to the equal division of the highest frequency of the variable-frequency fan, set the total number of frequency band levels m, and the unit frequency band frequency increase time is the total frequency increase time t / m;

[0031] Determine the frequency band level to which the normal frequency of the variable-frequency fan belongs;

[0032] Calculate the frequency increase time t n0 to be (m - the frequency band level to which it belongs) × t / m.

[0033] As a further improvement of the present invention: set the total frequency increase time t to be 60s, the highest frequency of the variable-frequency fan to be 50Hz, and the normal frequency of the variable-frequency fan to be 40HZ.

[0034] The present invention also provides a computer storage medium for storing a computer program, and the computer program is set to execute an air-cooling control method for improving the poor performance of the middle and tail of the wire rod head as described above when running.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] By optimizing the air-cooling control program, the present invention realizes effective cooling of the high-temperature section of the wire rod head, enables the head to fully complete the phase transformation, thereby improving the overall performance consistency of the wire rod. At the same time, it avoids the steel piling accident caused by relying on the water tank to adjust the cooling of the head, and improves the stability and safety of the production process. Brief Description of the Drawings

[0037] Figure 1 This is a schematic flow chart of an air-cooling control method for improving the poor performance of the middle and tail of the coiled bar in the present invention. Detailed Embodiments

[0038] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] To solve the technical problems in the prior art, the present invention will be further described below in conjunction with the description of the drawings and embodiments:

[0040] As Figure 1 shown, an embodiment of the present invention discloses an air-cooling control method for improving the poor performance of the middle and tail of the coiled bar, including the following steps:

[0041] Set the total frequency increase time t of the variable-frequency fan from startup to the highest frequency, 60s ≤ t < 100s, and connect the signal of the pinch roll with steel in the rolling line control program; preferably, t is 60s;

[0042] After a set delay after receiving the signal of the pinch roll with steel, the variable-frequency fan performs an automatic frequency increase operation according to the set program, and drops back to the normal frequency after reaching the set strong blowing duration.

[0043] Through the optimization of the frequency increase time of the variable-frequency fan and the improvement of the control program, strong cooling of the high-temperature section of the head of the coiled bar is achieved, effectively reducing the temperature difference between the head and the tail. This enables the head of the coiled bar to fully complete the phase transformation, reduces the poor performance between the head and the tail, improves the overall quality of the coiled bar, and meets the market demand for high-quality steel products. Relying on the automatic air volume adjustment of the variable-frequency fan to achieve strong cooling avoids the steel piling accident caused by excessive resistance when the head of the coiled bar is strongly cooled by relying on the water tank adjustment. This improves the stability and safety of the production process, reduces the downtime and economic losses caused by production accidents, and ensures the continuity of production.

[0044] Compared with the traditional method of cutting off the non-cooled section at the head in the finishing process, without increasing equipment investment, through precise air-cooling control, the cooling process of the head of the coiled bar is effectively controlled, reducing metal waste caused by head performance problems, improving the metal yield, and reducing production costs.

[0045] The original fan control system only considered general operating conditions and failed to account for the impact of the uncooled section caused by the head not being able to penetrate water during coil production. Furthermore, most industries practice shearing off the uncooled section during the finishing process, which severely impacts metal yield. Completely shearing off the uncooled section of the finished product would also severely impact metal yield.

[0046] To this end, the frequency increase gradient (0 to 50Hz) of the variable frequency fan was optimized from 120s to 60s. By optimizing the connection between the air cooling line control program and the rolling line control program (the steel signal of the pinch rollers of the rolling line is connected to the air cooling control system), the fan will automatically increase the frequency through the newly developed program after receiving the finished steel signal after a delay (for example: the fan normally operates at 40Hz, and rises to 50Hz after receiving the signal. Different fan systems will calculate different delays), and then return to normal frequency after the strong blowing time written by the program. The variable frequency fan repeats this control operation to achieve forced cooling of the single head non-cooling section, thereby reducing the temperature difference between the head, middle and tail of the finished product, and ultimately achieving a higher yield while stabilizing performance.

[0047] In practical applications, the total frequency ramp-up time for current variable-frequency fans has been optimized from 120s to 60s. This means that it takes 60s from fan startup to a maximum of 50Hz (100%), broken down into 12s for each 10Hz (20%) frequency ramp-up. If this time is less than 60s, an overvoltage fault will occur.

[0048] In some embodiments, the present invention further comprises:

[0049] Get the normal frequency of variable frequency fan No. n and calculate the frequency increase time t required for variable frequency fan No. n to increase from normal frequency to maximum frequency n0 ;

[0050] Get the time t required for the coil head to reach the variable frequency fan No. n n ,

[0051] When t n >t n0 When the delay time t corresponding to the variable frequency fan No. n is determined, 延时 =t n -t n0 +t 补偿 , 0≤t 补偿 ≤2;

[0052] When t n ≤t n0 When the delay time corresponding to the variable frequency fan No. n is determined to be t 延时 =0.

[0053] In actual application, when the speed of the air-cooled roller table is 0.6 m / s, the head of the coil runs to the inlet of the 2# fan in about 11 seconds and to the inlet of the 3# fan in about 17 seconds. Therefore, the standard parameters to ensure strong blowing at the head are as follows:

[0054] Spinning delay: The set delay of the 2# fan is 0, and the set delay of the 3# fan is 6000 milliseconds.

[0055] Automatic adjustment duration of the fan, that is, the set strong blowing duration: Currently, both the 2# and 3# fans are in the range of 5000 - 6000 milliseconds.

[0056] Taking the 2# fan as an example, when the head of the coil runs to the inlet of the 2# fan in about 11 seconds, in the case of frequency increase from 30HZ to 50HZ, since the frequency increase takes 24s, which is greater than 11 seconds, theoretically, the frequency should be increased immediately (the delay is negative, and actually 0 is taken, that is, no additional delay is required); when the frequency increases from 40HZ to 50HZ, the frequency increase takes 12s, which is also greater than 11 seconds, and the frequency also needs to be increased immediately. For the 3# fan, when the head of the coil runs to the inlet of the 3# fan in about 17 seconds, it takes 24s to increase the frequency from 30HZ to 50HZ and 12s to increase the frequency from 40HZ to 50HZ. In both cases, the theoretical delay is negative, and actually, the frequency also needs to be increased immediately, but fine-tuning may be required. This indicates that when the frequency increase time is greater than the arrival time of the coil head, the fan needs to start increasing the frequency as early as possible, and even may not need to wait for additional delay; if the frequency increase time is less than the arrival time of the coil head, the delay can be reasonably set according to the difference between the two to ensure that the fan reaches the highest frequency when the coil head arrives.

[0057] The spinning delay and automatic adjustment duration settings of the fan are determined based on the time when the head of the wire rod coil reaches each fan. The spinning delay of the 2# fan is set to 0. After receiving the signal of the finished product incoming steel, the 2# fan does not need to wait for additional delay and immediately starts the automatic frequency increase operation according to the new program, increasing from the normal operating 40Hz to the highest frequency 50Hz, preparing to perform strong blowing when the head of the coil arrives, so as to ensure that the head obtains high-intensity cooling in a timely manner.

[0058] The spinning delay of the 3# fan is set to 6000 milliseconds. This is because it takes about 17 seconds for the head of the wire rod coil to enter the air-cooled area and reach the inlet of the 3# fan. After receiving the signal of the finished product incoming steel, the 3# fan first waits for a 6-second delay and then starts the automatic frequency increase operation, increasing from 40Hz to 50Hz. After the 6-second delay and subsequent frequency increase process, the head of the coil just arrives at the position of the 3# fan. At this time, the 3# fan is already at the highest frequency and can immediately perform strong blowing on the head of the coil, ensuring that the head is accurately and efficiently cooled at the appropriate time point, meeting the process requirements for strong blowing at the head in the production of wire rod coils and improving the performance difference between the head, middle, and tail of the wire rod coils.

[0059] The automatic adjustment duration of the fan is 5000 - 6000 milliseconds, which is related to the residence time of the head of the coiled bar in the action areas of each fan. When the head of the coiled bar is in the action areas of Fan 2 and Fan 3, it needs to be strongly blown and cooled for a certain period of time to achieve good performance improvement effects. The adjustment duration of 5000 - 6000 milliseconds can ensure that when the head of the coiled bar passes through the action area of the fan, the fan continuously provides sufficient cooling air volume to complete the effective cooling of the head and ensure the improvement of the performance difference between the head, middle, and tail of the coiled bar. If the adjustment duration is too short, the head may not be fully cooled; if it is too long, it may cause overcooling and affect the performance of the coiled bar.

[0060] Further, it also includes:

[0061] Obtain the spacing L0 between adjacent variable-frequency fans and the corresponding air-cooled roller table speed v0;

[0062] According to the formula t 间 = L0 / v0 to calculate the interval time t between adjacent variable-frequency fans 间 ;

[0063] Set the strong blowing duration range as t 间 ±t 修正 .

[0064] In addition, when the speed of the air-cooled roller table is constantly 0.6 m / s, it takes about 11 seconds for the head of the coiled bar to run to the inlet of Fan 2 and about 17 seconds to run to the inlet of Fan 3. The wire spitting delay of Fan 2 is set to 0, and that of Fan 3 is set to 6000 milliseconds. This indicates that the delay setting of Fan 3 is based on the time required for the head of the coiled bar to run from the starting position to this fan, and there is a time difference relative to Fan 2. This time difference is related to the time for the coiled bar to run from the position of Fan 2 to the position of Fan 3 on the roller table, that is, the delay of Fan 3 minus the delay of Fan 2 is approximately equal to the time required for the head of the coiled bar to run from Fan 2 to Fan 3 (17 - 11 = 6 seconds), ensuring that different fans are accurately started for cooling in sequence when the head of the coiled bar reaches their respective action areas.

[0065] Before the head variable-frequency control program was put into use, the temperature of the rolled piece at the outlet of Fan 3 was between 630 - 650 °C, the performance of the head of the coiled bar was relatively low, and the performance difference between the head and tail was obvious, resulting in unstable product quality and many customer complaints.

[0066] After the new control program of the present invention was put into use and after a period of operation and debugging, the temperature of the rolled piece at the outlet of Fan 3 was stabilized between 600 - 620 °C, a decrease of more than 30 °C. At the same time, through the detection of the performance of the head of the coiled bar, it was found that the average performance of the head was improved by more than 10 Mpa, the performance difference between the head and tail of the coiled bar was significantly improved, the product quality was greatly improved, the quality objections were effectively reduced, and the economic benefits and market competitiveness of the enterprise were improved.

[0067] The following table shows the statistical results of the production performance test of spiral ribbed steel bars after the control method of the present invention is put into use.

[0068]

[0069] In some embodiments, it further includes:

[0070] Set the normal frequency of the No. 1 variable-frequency fan to be not less than x% of the maximum frequency;

[0071] Calculate the frequency increase time t required for the No. 1 variable-frequency fan to reach the maximum frequency 10 ;

[0072] The time t1 required for the head of the coil to reach the No. 1 variable-frequency fan from the position where the pinch roll has steel signal;

[0073] When t1 ≤ t 10 , the No. 1 variable-frequency fan increases its frequency to the maximum frequency in advance by t1 - t 10 +t 补偿 in accordance with the set program and enters the strong blowing mode, or the No. 1 variable-frequency fan operates without change;

[0074] When t1 > t 10 , the set delay time t corresponding to the No. 1 variable-frequency fan 延时 = t1 - t 10 +t 补偿 , 0 ≤ t 补偿 ≤ 2.

[0075] When t1 ≤ t 10 , since the difference between t1 and t 10 is too large, no operation is required for the No. 1 variable-frequency fan.

[0076] In some embodiments, it further includes:

[0077] Obtain the distance L from the starting position of the coil head to the inlet of the No. n variable-frequency fan;

[0078] Also obtain the speed v of the air-cooled roller table;

[0079] According to the formula t n = L / v, calculate the time t required for the coil head to reach the inlet of the No. n variable-frequency fan n .

[0080] In some embodiments, the set strong blowing duration of the variable-frequency fan is 5000 - 6000 milliseconds.

[0081] In terms of the automatic adjustment duration of the fan, the 2# and 3# fans are both in the range of 5000 - 6000 milliseconds. This is to ensure that the head of the spiral ribbed steel bar can obtain sufficient and appropriate cooling time when passing through the action area of each fan, so as to achieve uniform cooling.

[0082] In some embodiments, it further includes:

[0083] The normal frequency of the variable-frequency fan is preset by the program or is the working frequency monitored currently;

[0084] According to the equal division of the highest frequency of the variable-frequency fan, set the total number of frequency band levels m, and the frequency increase time per unit frequency band is the total frequency increase time t / m;

[0085] Determine the frequency band level to which the normal frequency of the variable-frequency fan belongs;

[0086] Calculate the frequency increase time t n0 It is (m - the frequency band level to which it belongs) × t / m.

[0087] Furthermore, set the total frequency increase time t to 60s, the highest frequency of the variable-frequency fan to 50Hz, and the normal frequency of the variable-frequency fan to 40HZ.

[0088] The present invention also provides a computer storage medium for storing a computer program, and the computer program is configured to execute, when running, an air-cooling control method for improving the poor performance of the middle and tail of the coil screw head as described above.

[0089] The main functions of the present invention: By optimizing the air-cooling control program, effectively cool the high-temperature section of the coil screw head, enable the head to fully complete the phase transformation, and thus improve the overall performance consistency of the coil screw. The strong cooling achieved by the automatic air volume adjustment of the variable-frequency fan can eliminate the steel piling accident caused by the excessive resistance of the strong cooling of the coil screw head by the water tank.

[0090] In summary, after those of ordinary skill in the art read the documents of the present invention, all other corresponding transformation schemes made without creative mental labor according to the technical solutions and technical concepts of the present invention fall within the scope protected by the present invention.

Claims

1. An air-cooling control method for improving the poor performance of the middle and tail parts of a spiral bar head, characterized in that It includes the following steps: Set the total frequency increase time t for the variable-frequency fan from startup to the highest frequency, where 60s ≤ t < 100s, and connect the signal indicating the presence of steel in the pinch roll to the rolling line control program; After a set delay upon receiving the signal indicating the presence of steel in the pinch roll, the variable-frequency fan performs an automatic frequency increase operation according to the set program and returns to the normal frequency after reaching the set strong blowing duration.

2. The air-cooling control method for improving the poor performance of the middle and tail of the spiral bar head according to claim 1, characterized in that It also includes: Obtain the normal frequency of the nth variable-frequency fan, and calculate the frequency increase time t required for the nth variable-frequency fan to increase from the normal frequency to the highest frequency n0 ; Obtain the required time t for the coiled head to reach the nth variable-frequency fan n , When t n > t n0 When, determine the set delay time t corresponding to the nth variable-frequency fan 延时 = t n - t n0 + t 补偿 where 0 ≤ t 补偿 ≤ 2; When t n ≤ t n0 When it is, determine that the set delay corresponding to the nth variable-frequency fan is t 延时 = 0 3. The air-cooling control method for improving the poor performance of the middle and tail parts of the spiral bar head according to claim 2, characterized in that, It also includes: Set the normal frequency of the No. 1 variable-frequency fan to be not less than x% of the highest frequency; Calculate the frequency increase time t required for the No. 1 variable frequency fan to reach the highest frequency 10 ; The time t1 required for the head of the coil from the position where the signal indicating the presence of steel in the pinch roll is received to the No. 1 variable-frequency fan; When t1 ≤ t 10 the No. 1 variable-frequency fan increases its frequency to the highest frequency in advance by t1 - t 10 +t 补偿 according to the set program and enters the strong blowing mode, or the No. 1 variable-frequency fan runs without change; When t1 > t 10 the set delay time t corresponding to the No. 1 variable frequency fan 延时 = t1 - t 10 + t 补偿 where 0 ≤ t 补偿 ≤ 2 4. A forced air cooling control method for improving the poor performance of the middle and tail parts of a spiral bar head according to claim 2, characterized in that It also includes: Obtain the distance L from the starting position of the coil head to the inlet of the nth variable-frequency fan; Also obtain the speed v of the air-cooled roller table; According to the formula t n = L / v, calculate the time t required for the head of the coil to run to the inlet of the nth variable-frequency fan n .

5. An air-cooling control method for improving the poor performance of the middle and tail parts of the spiral bar head according to claim 2 or 3, characterized in that It also includes: Obtain the spacing L0 between adjacent variable-frequency fans and the corresponding speed v0 of the air-cooled roller table; According to the formula t 间 = L0 / v0 to calculate the interval time t between adjacent variable-frequency fans 间 ; Set the strong blowing duration range to t 间 ±t 修正 .

6. The air-cooling control method for improving the poor performance of the middle and tail parts of the spiral bar head according to claim 5, wherein, The set strong blowing duration of the variable-frequency fan is 5000 - 6000 milliseconds.

7. An air-cooling control method for improving the poor performance of the middle and tail parts of a spiral bar head according to claim 5, characterized in that, It also includes: The normal frequency of the variable-frequency fan is preset by the program or is the currently monitored operating frequency; Evenly divide according to the highest frequency of the variable-frequency fan, set the total number of frequency band levels m, and the frequency increase time per unit frequency band is t / m; Determine the frequency band level to which the normal frequency of the variable-frequency fan belongs; Calculate the up-conversion time t n0 It is (m - the number of frequency band levels) × t / m.

8. An air-cooling control method for improving the poor performance of the middle and tail of a coil bar head according to claim 6, characterized in that, Set the total frequency increase time t to 60s, the highest frequency of the variable-frequency fan to 50Hz, and the normal frequency of the variable-frequency fan to 40HZ.

9. A computer storage medium, characterized in that, For storing a computer program, the computer program is set to execute, when running, an air-cooling control method for improving the poor performance of the head and tail of the spiral bar as described in any one of claims 1 to 8.

Images