A monitoring method for monitoring the detection of anomalies by a hot metal detector of a rolling mill

Abstract

The application discloses a kind of for monitoring the monitoring method of the abnormality of hot metal detector of rolling mill, it is related to rolling mill control technology, the current transient value of rolling mill, torque transient value, and the current feedback value of rolling mill, torque feedback value of rolling mill are collected;The current transient value is differentially operated with the current feedback value of rolling mill, to obtain current difference value;The torque transient value is differentially operated with the torque feedback value of rolling mill, to obtain torque difference value;According to the size relation between current difference value and the standard current value set, the current heat source detected by hot metal detector is judged, and according to the size relation between torque difference value and the standard torque value set, the current heat source detected by hot metal detector is judged;If the current heat source is determined as high temperature scale, then execute abnormal alarm mechanism.The application ensures rolling stability, improves rolling performance, meets production rhythm, guarantees yield, avoids the security risk of rolling mill and motor equipment in varying degrees.

Description

Technical Field

[0001] This invention relates to rolling mill control technology, and more specifically, to a monitoring method for detecting anomalies using a hot metal detector in a rolling mill. Background Technology

[0002] In the double-high-speed wire rod rolling operation, the intermediate rolling mill has 8 sets of mills, and two sets of hot metal detectors are designed at the mill entrance to detect red-hot steel signals. The original design ensured smooth rolling under normal conditions. These two sets of hot metal detectors at the mill entrance served as signal relays for the upstream steel distribution system of the intermediate rolling mill, and also for tracking the presence of steel signals in the intermediate rolling mill and the No. 1 looper in the double-high-speed zone. However, in the current design, during normal rolling, the high-temperature iron oxide scale on the surface of the red-hot steel in the mill entrance stand continuously falls directly below the two sets of hot metal detectors, causing false triggering of the red-hot steel signal. This ultimately results in the upstream steel distribution system of the intermediate rolling mill failing to properly distribute steel, and the tracking of the presence of steel signals in the intermediate rolling mill and the No. 1 looper in the double-high-speed zone failing to generate normal signals. Furthermore, abnormal fluctuations in the mill's current or torque cannot be properly monitored, and abnormal conditions on the roll surface cannot be promptly reported. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a monitoring method for detecting abnormalities in the hot metal detector of the rolling mill, which addresses the shortcomings of the prior art. This method ensures the normal steel distribution of the upstream steel distribution system of the intermediate rolling mill and the normal feedback of the tracking steel signal of the intermediate rolling mill and the No. 1 looper of the double-line high-speed zone. It can effectively judge the rolling mill condition of the entrance stand of the intermediate rolling mill and accurately detect the hot metal signal, thus ensuring rolling stability.

[0004] This invention discloses a monitoring method for detecting abnormalities in a hot metal detector used in a rolling mill. The method involves collecting transient current and torque values ​​from the rolling mill, as well as current and torque feedback values. The transient current values ​​are then compared with the current feedback values ​​to obtain a current difference. Similarly, the transient torque values ​​are compared with the torque feedback values ​​to obtain a torque difference. The current heat source detected by the hot metal detector is determined based on the relationship between the current difference and a set standard current value. Simultaneously, the current heat source is determined based on the relationship between the torque difference and a set standard torque value. If the current heat source is determined to be high-temperature iron oxide scale, an abnormality alarm mechanism is activated.

[0005] As a further improvement, the specific method for determining the current heat source detected by the hot metal detector based on the relationship between the current difference and the set standard current value is as follows:

[0006] If the current difference is greater than or equal to the set current percentage value of the standard current value, the first delay is started. If after the first delay, the ratio of the current difference to the standard current value is still greater than or equal to the set current percentage value, then the current heat source is determined to be high-temperature iron oxide scale.

[0007] If the current difference is less than the set current percentage of the standard current value, then the current heat source is determined to be a red-hot steel rolled piece.

[0008] Furthermore, the set current percentage value is 25%-35%.

[0009] Furthermore, the first delay is 600 milliseconds.

[0010] Furthermore, after the first delay ends, the signal output by the hot metal detector is collected; if the hot metal detector does not output a red steel signal at this time, it is determined that the hot metal detector is falsely triggered and the abnormal alarm mechanism is not executed; if the hot metal detector still outputs a red steel signal, the abnormal alarm mechanism is executed.

[0011] As a further improvement, the specific method for determining the current heat source detected by the hot metal detector based on the relationship between the torque difference and the set standard torque value is as follows:

[0012] If the torque difference is greater than or equal to the set torque percentage value of the standard torque value, the second delay is initiated. If, after the second delay ends, the ratio of the torque difference to the standard torque value remains greater than or equal to the set torque percentage value, then the current heat source is determined to be high-temperature iron oxide scale.

[0013] If the torque difference is less than the set torque percentage of the standard torque value, then the current heat source is determined to be a red-hot steel rolled piece.

[0014] Furthermore, the set torque percentage value is 15%-25%.

[0015] Furthermore, the second delay is 600 milliseconds.

[0016] Furthermore, after the second delay ends, the signal output by the hot metal detector is collected; if the hot metal detector does not output a red steel signal at this time, it is determined that the hot metal detector is falsely triggered and the abnormal alarm mechanism is not executed; if the hot metal detector still outputs a red steel signal, the abnormal alarm mechanism is executed.

[0017] To further improve the method, a 300-millisecond time pulse is set as the current acquisition trigger signal for acquiring transient current values; and a 250-millisecond time pulse is set as the torque acquisition trigger signal for acquiring transient torque values.

[0018] Beneficial effects

[0019] The advantages of this invention are as follows: After the red steel enters the intermediate mill, the difference between the transient values ​​of current and torque collected based on time pulse signals and the feedback values ​​of current and torque, combined with the standard values ​​of current and torque, is used to determine the type of heat source detected by the hot metal detector during the rolling process. This allows for the determination of whether the mill is in normal operating condition, ensuring the normal steel distribution of the upstream steel distribution system of the intermediate mill and the normal feedback of the tracking signal of the steel-bearing system of the intermediate mill and the No. 1 looper in the high-speed section of the double-line mill. Simultaneously, by combining the monitoring of mill current and torque anomalies and false alarms from the hot metal detector, the operating conditions of the mill at the entrance stand of the intermediate mill can be effectively judged, and the red steel signal can be accurately detected, ensuring stable rolling. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the monitoring method of the present invention. Detailed Implementation

[0021] The present invention will be further described below with reference to embodiments, but this does not constitute any limitation on the present invention. Any limited modifications made by any person within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0022] See Figure 1 The present invention provides a monitoring method for detecting abnormalities using a hot metal detector in a rolling mill, the method comprising the following steps.

[0023] Step 1: Establish two sets of time pulse functions at the millisecond level.

[0024] A time pulse program system is established in the PLC control system of the double-high-speed rolling mill. Specifically, based on the timer S_ODT in the PLC, a time pulse of 300 milliseconds is used as the current acquisition trigger signal for acquiring the current signal variable of the rolling mill current; and a time pulse of 250 milliseconds is used as the torque acquisition trigger signal for acquiring the torque signal variable of the rolling mill torque.

[0025] Step 2: Collect the current signal of the inlet stand of the intermediate rolling mill.

[0026] Based on the double-high wire rod rolling condition and the aforementioned current acquisition trigger signal, the current of the mill at the entrance stand of the intermediate rolling mill is assigned as a percentage to an intermediate variable, which is the current signal variable. This enables dynamic acquisition of the mill current and real-time monitoring of current changes in all mills at the entrance stand of the intermediate rolling mill. The changes in mill current are determined by the load during rolling and controlled within a standard range, reflecting the real-time operating condition of the mill. Based on favorable rolling conditions, stable operation of the mill and motors is ensured.

[0027] Step 3: Collect the torque signal of the inlet stand of the intermediate rolling mill.

[0028] Based on the double-high wire rod rolling condition, and using the aforementioned torque acquisition trigger signal, the torque of the mill at the entrance stand of the intermediate rolling mill is assigned as a percentage to another intermediate variable. This intermediate variable is the torque signal variable, enabling dynamic acquisition of the mill torque and real-time monitoring of torque changes across all mills at the entrance stand of the intermediate rolling mill. The changes in mill torque are also determined by the load during rolling and controlled within standard ranges.

[0029] Step 4: Calculate the current difference and torque difference of the inlet stand of the intermediate rolling mill.

[0030] The transient current value is obtained based on the current signal variable obtained in step two above, which is achieved by multiplying the current signal variable by the standard current value. The transient current value is then compared with the current feedback value from the rolling mill to obtain the current difference, which serves as a subsequent judgment condition. Similarly, the transient torque value is obtained based on the torque signal variable obtained in step three above. The transient torque value is then compared with the torque feedback value from the rolling mill to obtain the torque difference, which serves as another subsequent judgment condition. The current / torque feedback value is a static value reflecting the rolling mill's operating condition. After filtering and averaging, it remains within the set error range of the standard current / torque value during normal rolling mill operation. If it exceeds the corresponding error range, the system alarms, reflecting whether the overall operating condition of the rolling mill is normal. For the transient current / torque value, this embodiment also uses screen configuration software to generate and display the real-time waveform of the transient value's trend analysis, facilitating on-site monitoring by operators.

[0031] Step 5: Establish a red steel detection system based on a dual-thermal metal detector.

[0032] This system primarily adopts the traditional red-hot metal detection system structure of the entrance stand of the intermediate rolling mill. Specifically, two hot metal detectors are installed before the mill to detect red-hot metal signals. These detectors also serve as signal relays for the upstream steel distribution system of the intermediate rolling mill, and for tracking the presence of steel signals in the intermediate rolling mill and the No. 1 looper in the high-speed double-line section. This ensures the normal steel distribution of the upstream steel distribution system and the normal feedback of the presence of steel signals from the intermediate rolling mill and the No. 1 looper in the high-speed double-line section. Therefore, during actual installation, it is necessary to ensure the stability and reliability of the dual hot metal detectors' detection performance and avoid false signals and external signal interference.

[0033] Step 6: Establish a rolling mill current alarm system.

[0034] Using the signal from the hot metal detectors as a reference, if both detectors detect a red-hot steel signal, the current difference is compared with the set standard current value. If the current difference is greater than or equal to 30% of the standard current value, and after a 600-millisecond delay, the ratio of the current difference to the standard current value remains greater than or equal to 30%, it indicates abnormal fluctuations in the rolling current at the entrance stand of the intermediate rolling mill. The hot metal detectors are detecting a red-hot steel signal of high-temperature iron oxide scale, indicating a potential risk of roll surface burn-out. Simultaneously, the HMI (Hardware Management Interface) displays a corresponding alarm signal for abnormal current drop to promptly alert process operators to stop rolling and inspect the mill's physical condition and operating status. If the current difference is less than 30% of the standard current value, it indicates normal rolling operation, and the hot metal detectors are detecting a red-hot steel signal on the rolled piece.

[0035] Step 7: Establish a rolling mill torque alarm system.

[0036] Using the hot metal detector signal as a reference, if both hot metal detectors detect a red-hot steel signal, the torque difference is compared with the set standard torque value. If the torque difference is greater than or equal to 20% of the standard torque value, and after a 600-millisecond delay, if the ratio of the torque difference to the standard torque value remains greater than or equal to 20%, it indicates abnormal rolling torque fluctuation at the entrance stand of the intermediate rolling mill. The hot metal detectors are detecting a red-hot steel signal of high-temperature iron oxide scale, indicating a potential risk of roll surface burn-out. Simultaneously, the HMI (Hill Management Interface) provides a corresponding mill torque abnormality alarm signal to promptly remind process operators to stop rolling and inspect the mill's physical condition and operating status. If the torque difference is less than 20% of the standard torque value, it indicates normal rolling operation, and the hot metal detectors are detecting a red-hot steel signal on the rolled piece.

[0037] Step 8: Determine if the hot metal detector detects a false signal.

[0038] Based on steps six and seven above, after the delay ends, the signal output by the hot metal detector is collected again. If the hot metal detector does not output a red steel signal at this time, it is considered that the hot metal detector has been falsely triggered and no abnormal alarm is issued; if the hot metal detector still outputs a red steel signal, it means that the hot metal detector has not been falsely triggered and the abnormal alarm operation continues.

[0039] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention, and these will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A monitoring method for detecting anomalies using a hot metal detector in a rolling mill, characterized in that, Collect transient current and torque values ​​of the rolling mill, as well as current and torque feedback values ​​of the rolling mill; The difference between the transient current value and the current feedback value of the rolling mill is calculated to obtain the current difference. The torque transient value is calculated by subtracting the torque feedback value of the rolling mill to obtain the torque difference value; the current heat source detected by the hot metal detector is determined based on the relationship between the current difference value and the set standard current value, and the current heat source detected by the hot metal detector is determined based on the relationship between the torque difference value and the set standard torque value; if the current heat source is determined to be high-temperature iron oxide scale, an abnormal alarm mechanism is executed. The specific method for determining the current heat source detected by the hot metal detector based on the relationship between the current difference and the set standard current value is as follows: If the current difference is greater than or equal to the set current percentage value of the standard current value, the first delay is started. If after the first delay, the ratio of the current difference to the standard current value is still greater than or equal to the set current percentage value, then the current heat source is determined to be high-temperature iron oxide scale. If the current difference is less than the set current percentage of the standard current value, then the current heat source is determined to be a red-hot steel rolled piece; The specific method for determining the current heat source detected by the hot metal detector based on the relationship between the torque difference and the set standard torque value is as follows: If the torque difference is greater than or equal to the set torque percentage value of the standard torque value, the second delay is initiated. If, after the second delay ends, the ratio of the torque difference to the standard torque value remains greater than or equal to the set torque percentage value, then the current heat source is determined to be high-temperature iron oxide scale. If the torque difference is less than the set torque percentage of the standard torque value, then the current heat source is determined to be a red-hot steel rolled piece.

2. The monitoring method for detecting abnormalities using a hot metal detector in a rolling mill, as described in claim 1, is characterized in that... The set current percentage value is 25%-35%.

3. The monitoring method for detecting abnormalities using a hot metal detector in a rolling mill, as described in claim 1, is characterized in that... The first delay is 600 milliseconds.

4. A monitoring method for detecting abnormalities using a hot metal detector in a rolling mill, as described in claim 1, characterized in that, After the first delay ends, the signal output by the hot metal detector is collected; if the hot metal detector does not output a red steel signal at this time, it is determined that the hot metal detector is falsely triggered and the abnormal alarm mechanism is not executed; if the hot metal detector still outputs a red steel signal, the abnormal alarm mechanism is executed.

5. A monitoring method for detecting abnormalities using a hot metal detector in a rolling mill, as described in claim 1, characterized in that, The set torque percentage value is 15%-25%.

6. A monitoring method for detecting abnormalities using a hot metal detector in a rolling mill, as described in claim 1, characterized in that, The second delay is 600 milliseconds.

7. A monitoring method for detecting abnormalities using a hot metal detector in a rolling mill, as described in claim 1, characterized in that, After the second delay ends, the signal output by the hot metal detector is collected; if the hot metal detector does not output a red steel signal at this time, it is determined that the hot metal detector is falsely triggered and the abnormal alarm mechanism is not executed; if the hot metal detector still outputs a red steel signal, the abnormal alarm mechanism is executed.

8. A monitoring method for detecting abnormalities using a hot metal detector in a rolling mill, as described in claim 1, characterized in that, Set a 300-millisecond time pulse as the current acquisition trigger signal for acquiring transient current values; set a 250-millisecond time pulse as the torque acquisition trigger signal for acquiring transient torque values.

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