Method for detecting the temperature of the head of a steel billet based on direct rolling

Abstract

The application discloses a billet head temperature detection method based on direct rolling, and particularly relates to the following steps: measuring the temperature of the billet, reading the real-time temperature, high-frequency scanning the real-time temperature of the billet, continuously updating, transmitting the last updated real-time highest temperature to the final highest temperature, and displaying the final highest temperature on the WINCC system main screen; comparing the calculated final highest temperature with the set lowest rolling temperature to determine whether to discard the billet, and resetting the last updated real-time highest temperature of the PLC control system to 0 when all the billets pass through the pyrometer or the discarding of the billet is completed; and performing the above steps until the temperature measurement of all the billets is completed. Since the highest temperature is calculated by the high-frequency scanning and continuous comparison method, the accuracy is higher than that of the fixed-point measurement, and the highest temperature of the head 1.5 m can represent the real temperature condition of the billet, so that the low-temperature billet caused by human factors is avoided from entering the rolling mill, and the production efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of rolling technology, specifically relating to a method for detecting the head temperature of steel billets based on direct rolling. Background Technology

[0002] Direct rolling, lacking a heating furnace, results in the continuously cast billet being transported from the steelmaking plant at a lower head temperature than the entire billet due to process variations. Since steel rolling requires specific billet temperatures, it cannot proceed if these requirements are not met. Therefore, only the billet head temperature needs to be measured to determine if it meets rolling requirements. Current technology involves a hot metal detector signaling the incoming steel, followed by a delay in billet movement until a pyrometer illuminates a point 1.5 meters above the billet head, at which point the pyrometer reading is taken. However, because this measurement is essentially a fixed-point temperature reading, it is inaccurate and prone to significant discrepancies. Summary of the Invention

[0003] The purpose of this invention is to provide a method for detecting the head temperature of steel billets based on direct rolling, which improves the accuracy of steel billet head temperature detection.

[0004] The technical solution adopted in this invention is a method for detecting the head temperature of directly rolled steel billets, specifically implemented according to the following steps:

[0005] Step 1, Temperature Measurement: A pyrometer is installed at the roller table in front of the first stand of the rolling mill for temperature detection. The PLC control system reads the real-time temperature T from the pyrometer. 实时 And set the minimum rolling temperature T. 设定 ;

[0006] Step 2, Temperature Reading: When no billet passes through the first stand of the rolling mill, the PLC control system reads the real-time temperature as 0, i.e., T. 实时 <500℃, and let the initial real-time highest temperature T max =0; When the billet is conveyed through the high-temperature timer, the PLC control system reads the real-time temperature T. 实时 That is, T 实时 When the temperature reaches ≥500℃, temperature scanning begins, and timers T1 and T2 start counting from zero.

[0007] Step 3, Temperature Scan: The PLC control system monitors the real-time temperature T of the steel billet. 实时 Perform high-frequency scanning to obtain the real-time highest temperature T. max ;

[0008] Step 4, Temperature Calculation: The billet continues to move, and the real-time highest temperature T... max The PLC control system continues to update until timer T1 reaches t1 from 0, at which point it stops scanning and displays the last updated real-time maximum temperature T. max Transmitted to the final highest temperature T最终 T 最终 This refers to the highest temperature at the top 1.5 meters of the billet;

[0009] Step 5, Temperature Display: The PLC control system communicates with the WINCC system via TCP / IP to display the final maximum temperature T of the head. 最终 Displayed on the main screen of the WinCC system;

[0010] Step 6, Temperature Comparison: Compare the calculated final maximum temperature T 最终 With the set minimum rolling temperature T 设定 Compare the results to determine whether to discard the defective product.

[0011] Step 7, Temperature Reset: After all the steel billets have passed through the pyrometer or the scrap removal is completed, the PLC control system will reset the real-time maximum temperature T last updated in Step 4. max Reset to 0, and simultaneously reset timers T1 and T2 to zero; when the next billet passes by, continue to execute steps 2-7 until the temperature measurement of all billets is completed.

[0012] The invention is further characterized in that,

[0013] In step 3, if the real-time temperature T of each scan... 实时 >Current real-time highest temperature T max At that time, the real-time temperature T 实时 Transmitted to the real-time highest temperature T max If the real-time temperature T in each scan 实时 ≤Current real-time highest temperature T max T max It remains unchanged.

[0014] In step 4, t1 = 1.5 / n, where n is the linear velocity of the roller conveyor in m / s.

[0015] In step 6, when T 最终 <T 设定 When timer T2 reaches t2 from 0, the PLC control system automatically stops the roller conveyor and simultaneously sends a scrap removal command to the scrap removal system to remove the steel billet; when T... 最终 ≥T 设定 The PLC system does not send rejection commands, and the roller conveyor runs automatically.

[0016] t2 = L / 2 / n, where L is the fixed length of the billet in meters and n is the linear speed of the roller conveyor in meters per second.

[0017] The beneficial effects of this invention are as follows: A pyrometer is used to measure the real-time temperature of the steel billet. The PLC control system performs high-frequency temperature scanning. Each scan compares the real-time temperature with the stored highest temperature, updating the highest temperature until the steel billet reaches a position 1.5m above the pyrometer, at which point the highest temperature is measured. Simultaneously, based on the measured highest temperature, it is determined whether the temperature meets the rolling temperature requirements, and temperatures that do not meet the requirements are automatically rejected. Because the highest temperature is calculated using high-frequency scanning and continuous comparison, the accuracy is higher than fixed-point measurement, and selecting the highest temperature at the head of the billet (1.5m) is sufficient to represent the true temperature condition of the billet (the head of the entire billet has a lower temperature). Furthermore, the automatic rejection function reduces the labor intensity of personnel, prevents low-temperature steel from entering the rolling mill due to human error, lowers equipment failure rates, and improves production efficiency. Detailed Implementation

[0018] The present invention will now be described in detail with reference to specific embodiments.

[0019] Example 1

[0020] This invention is based on a method for detecting the head temperature of directly rolled steel billets, and is implemented using a steel billet head temperature detection system. The detection system includes a temperature measurement module, a temperature reading module, a temperature scanning module, a temperature calculation module, a temperature display module, a temperature reset module, an automatic scrap rejection module, and a PLC control system.

[0021] The temperature measurement module uses a pyrometer to measure the real-time temperature of the steel billet;

[0022] The temperature reading module uses the measured temperature to determine that the billet has reached the pyrometer and begins to read the temperature.

[0023] The temperature scanning module scans and updates the real-time temperature of the steel billet.

[0024] The temperature calculation module uses the linear velocity of the billet to calculate the time it takes for the billet head to travel 1.5m, and the highest temperature received by the PLC system within that time.

[0025] The temperature display module will display the final maximum temperature on the WINCC screen;

[0026] The automatic rejection module automatically rejects steel billets that have not reached the required rolling temperature.

[0027] The temperature reset module is used to reset the final maximum temperature of the steel after it is removed from the pyrometer, so that it can wait for the temperature detection of the next steel billet.

[0028] Specifically, the process involves measuring and reading the real-time temperature of the billet. The PLC control system then performs high-frequency scanning of the billet's real-time temperature and continuously updates the maximum real-time temperature. The latest updated maximum real-time temperature is transmitted to the final maximum temperature, which is the highest temperature at the top 1.5 meters of the billet. This final maximum temperature is then displayed on the main screen of the WINCC system. The calculated final maximum temperature is then compared with the set minimum rolling temperature to determine whether to reject the billet. Once all billets have passed through the pyrometer or the rejection process is complete, the last updated maximum real-time temperature of the PLC control system is reset to 0. This process continues as the next billet passes through, until the temperature measurement of all billets is completed.

[0029] Example 2

[0030] This invention is based on a method for detecting the head temperature of directly rolled steel billets, and is implemented according to the following steps:

[0031] Step 1, Temperature Measurement: Install a pyrometer at the roller table in front of the first stand of the rolling mill for temperature detection. Position the detection port directly opposite the center of the steel billet on the roller table. Connect the pyrometer's analog 4-20mA signal to the PLC control system. Through A / D conversion, the PLC control system reads the real-time temperature T from the pyrometer. 实时 And set the minimum rolling temperature T. 设定 The data is transmitted to the PLC control system.

[0032] Step 2, Temperature Reading: When no billet passes through the first stand of the rolling mill, the PLC control system reads the real-time temperature as 0, i.e., T. 实时 <500℃, and let the initial real-time highest temperature T max =0; When the billet is conveyed through the high-temperature timer, the PLC control system reads the real-time temperature T. 实时 That is, T 实时 When the temperature reaches ≥500℃, temperature scanning begins, and timers T1 (for head 1.5m calculation) and T2 (for automatic rejection calculation) start counting from zero.

[0033] Step 3, Temperature Scan: The PLC control system monitors the real-time temperature T of the steel billet. 实时 Perform high-frequency scanning;

[0034] Specifically: if the real-time temperature T for each scan... 实时 >Current real-time highest temperature T max (initial value T) max When =0), the real-time temperature T is... 实时 Transmitted to the real-time highest temperature T max If the real-time temperature T in each scan 实时 ≤Current real-time highest temperature T max T maxRemain unchanged;

[0035] In other words, when the steel billet undergoes high-temperature timing, due to the real-time highest temperature T... max The initial value is 0, and the real-time temperature T is the first temperature detected by the PLC control system. 实时 =890℃, greater than the initial temperature. max Therefore, after the first scan is completed, the real-time temperature T will be recorded. 实时 Transmitted to the real-time highest temperature T max Real-time highest temperature T max =890℃; The PLC control system begins the second scan, real-time temperature T 实时 =910℃, greater than the highest temperature T in the first update. max 890℃, so after the second scan, the real-time temperature T will be recorded. 实时 Transmitted to the real-time highest temperature T max Real-time highest temperature T max =910℃; The PLC control system begins its third scan, with real-time temperature T 实时 =860℃, less than the highest temperature T in the second update. max 910℃, so the highest real-time temperature T after the third scan was completed. max The temperature remains unchanged at 910℃. As the billet moves forward, the PLC control system continuously scans.

[0036] Step 4, Temperature Calculation: The billet continues to move, and the real-time highest temperature T... max The PLC control system continues to update until timer T1 reaches t1 from 0, at which point it stops scanning and displays the last updated real-time maximum temperature T. max Transmitted to the final highest temperature T 最终 T 最终 This refers to the highest temperature at the top 1.5 meters of the billet;

[0037] Where t1=1.5 / n, 1.5 is the 1.5m of the billet head, and n is the linear speed of the roller conveyor in m / s, indicating that the temperature measurement point of the high temperature gauge is exactly located 1.5m from the billet head;

[0038] Step 5, Temperature Display: The PLC control system communicates with the WINCC system via TCP / IP to display the final maximum temperature T of the head. 最终 Displayed on the main screen of the WinCC system;

[0039] Step 6, Temperature Comparison: Compare the calculated final maximum temperature T 最终 With the set minimum rolling temperature T 设定 Compare;

[0040] When T 最终 <T 设定When timer T2 reaches t2 from 0, the PLC control system automatically stops the roller conveyor and sends a scrap removal command to the scrap removal system. After receiving the scrap removal command from the PLC system, the hydraulic rod of the scrap removal system automatically lifts to remove the steel billet. After a 10-second delay, once the steel billet has completely detached from the hydraulic rod, the scrap removal is complete, and the hydraulic rod automatically retracts.

[0041] Where t2=L / 2 / n, L is the fixed length of the billet, and n is the linear speed of the roller conveyor in m / s, indicating that the measuring point of the pyrometer is in the middle of the billet. Since the pyrometer is installed at the head of the scrap rejection system, the billet is located in the middle of the scrap rejection system.

[0042] When T 最终 ≥T 设定 The PLC system does not send rejection commands, and the roller conveyor runs automatically.

[0043] Step 7, Temperature Reset: After all the steel billets have passed through the pyrometer or the scrap removal is completed, the PLC control system will reset the real-time maximum temperature T last updated in Step 4. max Reset to 0, and simultaneously reset timers T1 and T2 to zero; when the next billet passes by, continue to execute steps 2-7 until the temperature measurement of all billets is completed.

[0044] Example 3

[0045] First, in the WINCC system, the billet rolling temperature is set to no less than 890℃. The real-time temperature is the current temperature of the billet, the real-time maximum temperature is the highest temperature among all the currently scanned temperatures, and the final maximum temperature is the highest temperature of the billet within 1.5m of the billet head that is saved.

[0046] When the billet reaches the pyrometer position, the PLC system scans the first temperature value, 810℃. Since this temperature is greater than 500℃, billet temperature measurement begins, and the timer starts counting down, with the initial real-time maximum temperature value being 0. Because the first temperature value is greater than 0℃, the real-time maximum temperature is updated to 810℃. The billet continues to move. When the second billet temperature scanned is 800℃, which is lower than the updated real-time maximum temperature of 810℃, the real-time maximum temperature value remains unchanged at 810℃. When the third billet temperature scanned is 880℃, which is higher than the updated real-time maximum temperature of 810℃, the real-time maximum temperature is updated to 880℃. This process continues for the Nth scan.

[0047] Assume the speed of the roller conveyor is 1 m / s, the travel speed of the billet is 1 m / s, and the delay of the timer at the 1.5 m position of the billet head is t = 1.5 / 1 = 1.5 s;

[0048] If the real-time maximum temperature is updated to 900℃, the maximum temperature at the billet head is 900℃, and the PLC control system continues to operate the roller conveyor. If the real-time maximum temperature is updated to 880℃, the final maximum temperature at the billet head is 880℃, which is lower than the set 890℃. The PLC control system sends an alarm signal to the WINCC system via communication. Then, it controls the roller conveyor to transport the steel to the middle position of the scrap removal system and sends a scrap removal command to the scrap removal system. After receiving the scrap removal command, the hydraulic rod of the scrap removal system automatically lifts to scrap the billet. After a 10-second delay, once the billet has completely detached from the hydraulic rod, the scrap removal is complete, and the hydraulic rod automatically retracts. Then, the PLC control system resets the real-time maximum temperature and the timer to zero, preparing for the temperature measurement of the next billet. At the same time, the final maximum temperature is displayed on the main screen of the WINCC system, and the billet head temperature measurement is completed.

Claims

1. A method for detecting the head temperature of steel billets produced by direct rolling, characterized in that, The specific steps are as follows: Step 1, Temperature Measurement: A pyrometer is installed at the roller table in front of the first stand of the rolling mill for temperature detection. The PLC control system reads the real-time temperature T from the pyrometer. 实时 And set the minimum rolling temperature T. 设定 ; Step 2, Temperature Reading: When no billet passes through the first stand of the rolling mill, the PLC control system reads the real-time temperature as 0, i.e., T. 实时 <500℃, and let the initial real-time highest temperature T max= 0; When the steel billet is conveyed through the high-temperature timer, the PLC control system reads the real-time temperature T. 实时 That is, T 实时 When the temperature reaches ≥500℃, temperature scanning begins, and timers T1 and T2 start counting from zero. Step 3, Temperature Scan: The PLC control system monitors the real-time temperature T of the steel billet. 实时 Perform high-frequency scanning to obtain the real-time highest temperature T. max ; If the real-time temperature T for each scan 实时 >Current real-time highest temperature T max At that time, the real-time temperature T 实时 Transmitted to the real-time highest temperature T max If the real-time temperature T in each scan 实时 ≤Current real-time highest temperature T max T max Remain unchanged; Step 4, Temperature Calculation: The billet continues to move, and the real-time highest temperature T... max The PLC control system continues to update until timer T1 reaches t1 from 0, at which point it stops scanning and displays the last updated real-time maximum temperature T. max Transmitted to the final highest temperature T 最终 T 最终 This refers to the highest temperature at the top 1.5 meters of the billet; Step 5, Temperature Display: The PLC control system communicates with the WINCC system via TCP / IP to display the final maximum temperature T of the head. 最终 Displayed on the main screen of the WinCC system; Step 6, Temperature Comparison: Compare the calculated final maximum temperature T 最终 With the set minimum rolling temperature T 设定 Compare the results to determine whether to discard the defective product. When T 最终 <T 设定 When timer T2 reaches t2 from 0, the PLC control system automatically stops the roller conveyor and simultaneously sends a scrap removal command to the scrap removal system to remove the steel billet; when T... 最终 ≥T 设定 The PLC system does not send rejection commands, and the roller conveyor runs automatically. Step 7, Temperature Reset: After all the steel billets have passed through the pyrometer or the scrap removal is completed, the PLC control system will reset the real-time maximum temperature T last updated in Step 4. max Reset to 0, and simultaneously reset timers T1 and T2 to zero; when the next billet passes by, continue to execute steps 2-7 until the temperature measurement of all billets is completed.

2. The method for detecting the head temperature of a billet based on direct rolling according to claim 1, characterized in that, In step 4, t1 = 1.5 / n, where n is the linear velocity of the roller conveyor, in m / s.

3. The method for detecting the head temperature of a billet based on direct rolling according to claim 1, characterized in that, t2=L / 2n, where L is the fixed length of the billet in meters and n is the linear speed of the roller conveyor in meters per second.