A method of controlling the temperature of a wire

Abstract

The present application relates to the technical field of steel production, and specifically discloses a kind of bar line temperature control method, billet heating: the billet is sent into heating furnace and heated, so that it reaches the set rolling temperature;Billet head tail temperature difference control: install closed loop control water tank system in rolling line, and set temperature detection device;Rolling piece temperature accurate control: develop rolling line temperature control model;Steel surface red rust control: design performance prediction model;Temperature monitoring and adjustment: in the whole production process, establish rolling line PLC management and control platform;Finished product output: the rolling piece that has passed temperature control is transported to cooling bed, and the steel temperature on cooling bed is controlled at 875 DEG C, and the upper and lower fluctuation is less than 5 DEG C;The present application effectively reduces the energy consumption in the production process, and the rolling piece temperature control realizes closed loop automatic regulation, can realize unmanned intervention, improves production efficiency and automation level, realizes product performance stability, finished product surface is free of red rust, improves the quality and appearance of steel.

Description

Technical Field

[0001] This invention relates to the field of steel production technology, and specifically to a method for controlling the temperature of bar mill lines. Background Technology

[0002] Traditional strong and weak water piercing processes have problems in terms of rolling line temperature control, such as poor water tank control accuracy, lack of linkage between water flow and motor frequency control and workpiece temperature, and lack of effective control methods. These problems result in large fluctuations in workpiece temperature, large temperature difference in the bar, increased gas consumption, increased power consumption of water pump motors, and the easy formation of red rust on the product surface, which affects sales.

[0003] Therefore, it is necessary to design a bar mill temperature control method to solve the problems of large temperature difference and easy red rust formation on the surface in the existing steel rolling water tank control. Summary of the Invention

[0004] To address the problems existing in the prior art, the purpose of this invention is to provide a method for controlling the temperature of bar wire.

[0005] The technical solution adopted by this invention to solve its technical problem is: a method for controlling the temperature of a bar wire, comprising the following steps:

[0006] S1. Steel billet heating: The steel billet is sent into a heating furnace for heating until it reaches the set rolling temperature;

[0007] S2. Steel billet head and tail temperature difference control: Install a closed-loop control water tank system on the rolling line and set up a temperature detection device to monitor the steel billet temperature at the No. 2 flying shear in real time.

[0008] S3. Precise temperature control of rolled products: Develop a rolling line temperature control model, which works based on temperature detection data and preset control algorithms;

[0009] S4. Control of red rust on steel surface: Design a performance prediction model and establish the correlation between product performance, rolling temperature and rolling line water tank control;

[0010] S5. Temperature monitoring and adjustment: Throughout the production process, a rolling line PLC control platform is established to centrally and intelligently control the heating furnace, closed-loop control water tank system, and rolling line PLC system, continuously monitor the temperature of billets and rolled pieces, and adjust the flow rate and pressure of the water tank in a timely manner according to the actual temperature conditions.

[0011] S6. Finished Product Output: The temperature-controlled rolled product is transported to the cooling bed, where the steel temperature is controlled at 875℃ with fluctuations of less than 5℃.

[0012] Specifically, in step S2, the closed-loop control water tank system automatically adjusts the flow rate and pressure of the backup water tank based on the billet temperature fed back by the temperature detection device, so as to uniformly control the billet temperature.

[0013] Specifically, in step S3, during the rolling process, the temperature detection device monitors the temperature of the rolled piece in real time and feeds the data back to the rolling line temperature control model. The rolling line temperature control model calculates the adjustment values ​​of the water tank flow rate and pressure based on the temperature data and sends them to the closed-loop control water tank system. The closed-loop control water tank system accurately controls the water tank flow rate and pressure in each area of ​​the rolling line based on the adjustment values, so as to achieve closed-loop temperature control during the rolling process, ensuring high-precision control of the rolled piece temperature and the non-cooled section, and keeping the rolled piece temperature fluctuation within ±5℃.

[0014] Specifically, the temperature detection device used for the initial rolling temperature in step S4 transmits real-time data to the performance prediction model. The performance prediction model analyzes and predicts based on the data, promptly identifying factors that may cause red rust on the steel surface. When a potential problem is predicted, the performance prediction model issues intervention and correction signals to guide the closed-loop control water tank system to adjust the rolling line temperature control in order to obtain good microstructure and product appearance, ensuring that the finished product surface is free of red rust.

[0015] Specifically, the performance prediction model is constructed using rolling sequence performance test values. The establishment of rolling sequence performance test values ​​requires the collection of the composition of the corresponding furnace, the average rolling sequence temperature of each section of the heating furnace, the average rolling sequence temperature of the rolling line temperature control point, and the average rolling sequence water tank control feedback value.

[0016] Specifically, in step S5, the rolling line PLC control platform uses an industrial Ethernet ring network to connect the high-speed wire rod rolling line PLC and the high-speed bar rolling line PLC. The high-speed wire rod rolling line PLC is connected to the high-speed wire rod closed-loop control water tank system and the No. 2 small bar rolling line PLC. The high-speed bar rolling line PLC is connected to the high-speed bar closed-loop control water tank system and the No. 1 small bar rolling line PLC.

[0017] The present invention has the following beneficial effects:

[0018] The bar mill temperature control method designed in this invention incorporates industrial Ethernet ring network control technology and establishes a rolling mill PLC management platform to achieve centralized and intelligent control of the heating furnace, water system, and rolling mill PLC system, laying the foundation for precise control of the rolling mill water tank.

[0019] The present invention designs a bar mill temperature control method and develops billet head-to-tail temperature difference control technology. By installing a closed-loop control water tank system on the rolling mill, the flow rate and pressure of the backup water tank are automatically adjusted according to the billet temperature to uniformly control the billet temperature. Furthermore, by precisely controlling the head and tail non-cooling sections, excessive head-to-tail temperature differences are avoided.

[0020] The present invention designs a bar wire temperature control method and develops a precise temperature control process for rolled products. By developing a temperature control model for the rolling line, it realizes closed-loop temperature control during the rolling process, ensuring high-precision control of the rolled product temperature and the non-cooled section, and precisely controlling the temperature fluctuation of each area of ​​the rolling line within ±5℃.

[0021] The bar mill temperature control method designed in this invention includes a performance prediction model, timely intervention and correction of the mill temperature control, to obtain good microstructure and product appearance under high-speed and fast-paced production mode, achieve stable product performance, and ensure that the finished product surface is free of red rust. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the process connection principle of the rolling mill PLC control platform.

[0023] Figure 2 This is the control flow diagram of the rolling mill temperature control model.

[0024] Figure 3 This is a statistical chart showing the relationship between cold rolling temperature and yield strength within the PLC control platform of the rolling line.

[0025] Figure 4 This is a comparison chart of statistical temperature and yield strength within the rolling mill PLC control platform.

[0026] Figure 5 This is a dataset framework diagram for the performance prediction model.

[0027] Figure 6 This is a mechanical performance diagram monitored and alerted by the PLC control platform for the rolling mill line.

[0028] Figure 7 This is a temperature acquisition graph monitored and alerted by the rolling mill PLC control platform. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0030] like Figures 1-7 As shown, a method for controlling the temperature of a bar wire includes the following steps:

[0031] 1. Steel billet heating: The steel billet is sent into a heating furnace for heating until it reaches the set rolling temperature.

[0032] 2. Billet Head-to-Tail Temperature Difference Control: A closed-loop control water tank system is installed on the rolling line, along with a temperature detection device to monitor the billet temperature at the No. 2 flying shear in real time. Based on the billet temperature feedback from the temperature detection device, the closed-loop control water tank system automatically adjusts the flow rate and pressure of the backup water tank to uniformly control the billet temperature. By precisely controlling the uncooled sections at both ends, excessive temperature differences between the billet's head and tail are avoided.

[0033] 3. Precise Temperature Control of Rolled Workpieces: A rolling line temperature control model is developed. This model operates based on temperature detection data and a preset control algorithm. During the rolling process, the temperature detection device monitors the temperature of the rolled workpiece in real time and feeds the data back to the rolling line temperature control model. The model calculates the adjustment values ​​for water tank flow and pressure based on the temperature data and sends them to the closed-loop control water tank system. The closed-loop control water tank system precisely controls the water tank flow and pressure in each area of ​​the rolling line based on the adjustment values, enabling closed-loop temperature control during the rolling process. This ensures high-precision control of the rolled workpiece temperature and the non-cooled section, keeping the temperature fluctuation of the rolled workpiece within ±5℃.

[0034] 4. Control of red rust on steel surface: Design a performance prediction model to establish the correlation between product performance, initial rolling temperature, and rolling line water tank control; the temperature detection device used for initial rolling temperature transmits real-time data to the performance prediction model, which analyzes and predicts based on the data, promptly identifying factors that may cause red rust on the steel surface. When a potential problem is predicted, the performance prediction model issues intervention and correction signals to guide the closed-loop control water tank system to adjust the rolling line temperature control to obtain good microstructure and product appearance, ensuring that the finished product surface is free of red rust.

[0035] The performance prediction model is constructed using rolling sequence performance test values. The establishment of rolling sequence performance test values ​​requires the collection of the composition of the corresponding heat, the average rolling sequence temperature of each section of the heating furnace, the average rolling sequence temperature of the rolling line temperature control point, and the average rolling sequence water tank control feedback value.

[0036] 5. Temperature Monitoring and Adjustment: Throughout the production process, a rolling line PLC control platform is established to centrally and intelligently control the heating furnace, closed-loop control water tank system, and rolling line PLC system. The temperature of the billet and rolled product is continuously monitored, and the flow rate and pressure of the water tank are adjusted in a timely manner according to the actual temperature conditions to ensure the stability and accuracy of temperature control.

[0037] The rolling line PLC control platform uses an industrial Ethernet ring network to connect the high-speed wire rod rolling line PLC and the high-speed bar rolling line PLC. The high-speed wire rod rolling line PLC is connected to the high-speed wire rod closed-loop control water tank system and the No. 2 small bar rolling line PLC. The high-speed bar rolling line PLC is connected to the high-speed bar closed-loop control water tank system and the No. 1 small bar rolling line PLC.

[0038] 6. Finished product output: The temperature-controlled rolled parts are transported to the cooling bed, where the steel temperature is controlled at 875℃ with fluctuations of less than 5℃.

[0039] Example: The specific operation and working method for establishing a rolling mill PLC control platform are as follows:

[0040] 1. Level 1 Automation Underlying Design.

[0041] (1) Establish network communication between the rolling mill PLC and the water system PLC to realize network communication between the production system, water system, and scheduling system, and achieve remote centralized control of the water system. For example... Figure 1 As shown.

[0042] (2) The upper computer is designed with centralized monitoring function. The upper computer uses Siemens WINCC software to process various signals collected by PLC through logic operations, so as to realize remote operation and status monitoring of equipment. More than 90% of the on-site inspections are transferred to remote inspections. The number of inspectors per shift is reduced from 2 to 1.

[0043] The remote host computer has the following functions:

[0044] Real-time monitoring: Monitor the status of each signal point;

[0045] Signal acquisition: The frequency, current, and vibration of the motor are acquired by the frequency converter via Ethernet communication;

[0046] Automatic adjustment: Automatic start and stop of the integrated valve;

[0047] Remote start / stop: Remote start / stop of all pump station motors, electric valves, and cooling tower fans; motor frequency adjustment.

[0048] Historical curves: Displaying historical curves for motor current, frequency, water supply pressure, temperature, flow rate, water tank level, etc.

[0049] Automatic alarm: Based on process requirements, parameters are set to control the upper and lower limits, and an automatic alarm is triggered.

[0050] (3) Add remote control function for water pumps

[0051] System Design: Based on the variable frequency pump's operating characteristic curves, the relationship between flow rate, pressure, and frequency is calculated. F1 is the performance curve of the variable frequency drive at its highest operating frequency, and F2 and F3 are the performance curves at lower operating frequencies. H represents the actual head.

[0052] Remote control: The central control center can remotely start and stop the pump station motors and monitor the motor operating status through the upper computer screen configuration and parameter setting.

[0053] Rolling line frequency setting: Through PLC hardware configuration and programming, two-way communication is established between the water system and the rolling line PLC. The rolling line operators adjust the frequency based on temperature and flow rate, improving work efficiency.

[0054] 2. Rolling line temperature and rolling control system.

[0055] (1) Design concept

[0056] After achieving Level 1 automation with functions such as remote automatic adjustment of water pumps and valve opening adjustment, a rolling mill temperature control model is designed. For example... Figure 2 As shown.

[0057] (2) Experimental procedure

[0058] The target temperature is 875℃, and all temperatures are controlled within ±5℃ of the target value.

[0059] like Figure 3 As shown, during the trial operation, the rolling specification was φ22×2. Water tank #2 was not used, and water tank #45 was used. The inlet water pressure was 7.5 kg for the south line and 9 kg for the north line. The opening degree was 40 for the south line and 75 for the north line. The initial setting of the upper cooling bed temperature was 880℃. After the system started running, the frequency was automatically set to 75. After running for a period of time, the target temperature was changed to 875℃ and then maintained. During the trial operation, the average temperature of the upper cooling bed was within ±5℃ of the target value. The yield strength and other test results of each furnace in the unmanned control were all within the standard range.

[0060] After the system is running normally, the temperature uniformity of the No. 1 shear, the water pump frequency, the water temperature, the temperature of the upper cooling bed, and the yield strength curves are as follows: Figure 4 As shown.

[0061] Based on an industrial internet platform and a centralized control system for molten steel rolling, a temperature control model was designed to achieve closed-loop temperature control during the rolling process. The performance prediction model of the industrial internet platform and the rolling line temperature control model, through the centralized control network system, enable real-time adjustment of water supply frequency, pressure, and flow rate. This ensures high-precision control of the rolled piece temperature and the non-cooled section, with the average temperature of the upper cooling bed controlled within the range of 875±5℃. The steel yield strength meets requirements, with Si content fluctuating slightly around 0.23% and N content fluctuating between 130 and 140%.

[0062] 3. Performance prediction model.

[0063] (1) Model learning dataset construction, such as Figure 5 As shown.

[0064] (2) Model Learning

[0065] Key performance influencing factors identification, data model training, and the rolling sequence granularity model mainly learn the performance prediction ability of the component influence; the influence of heating furnace and rolling line is easily limited by data granularity.

[0066] (3) Monitoring and early warning, such as Figures 6-7 As shown.

[0067] Ultimately, this forms a system that integrates composition early warning, temperature early warning, pre-rolling prediction, post-rolling prediction, and prediction with a closed-loop mechanism.

[0068] In practical applications, this invention can achieve the following:

[0069] 1. Reduced energy consumption: Through automatic temperature control technology, the water system can reduce electricity consumption by 8% and save 5 cubic meters of gas per ton of steel. 3 This effectively reduces energy consumption during the production process.

[0070] 2. Achieve unmanned operation: The temperature control of the rolled piece achieves closed-loop automatic adjustment, which can realize unmanned intervention, improving production efficiency and automation level.

[0071] 3. Improve product quality: The temperature of the rolled parts in the upper steel zone is controlled within ±5℃, and through the design of a performance prediction model, stable product performance is achieved, and the finished product surface is free of red rust, thus improving the quality and appearance of the steel.

[0072] 4. Cost savings: The water system can save 6 people in operation, saving about 900,000 yuan per year; the temperature in the steelmaking area is controlled within ±5 degrees Celsius, silicon and manganese alloys decrease by 0.1, and the price per ton of steel decreases by about 7 yuan, saving about 10.5 million yuan per year, thus reducing production costs.

[0073] 5. Green and low-carbon: This technology helps to inhibit the formation of surface red rust, reduces the impact on the environment, achieves clean production, and meets the requirements of green and low-carbon development.

[0074] This invention is not limited to the above-described embodiments. Anyone should know that any structural changes made under the guidance of this invention, and any technical solutions that are the same as or similar to this invention, fall within the protection scope of this invention.

[0075] The technologies, shapes, and structures not described in detail in this invention are all known technologies.

Claims

1. A method for controlling the temperature of a bar wire rod, characterized in that, Includes the following steps: S1. Steel billet heating: The steel billet is sent into a heating furnace for heating until it reaches the set rolling temperature; S2. Steel billet head and tail temperature difference control: Install a closed-loop control water tank system on the rolling line and set up a temperature detection device to monitor the steel billet temperature at the No. 2 flying shear in real time. S3. Precise Temperature Control of Rolled Workpiece: A rolling line temperature control model is developed. The rolling line temperature control model operates based on temperature detection data and a preset control algorithm. During the rolling process, the temperature detection device monitors the temperature of the rolled workpiece in real time and feeds the data back to the rolling line temperature control model. The rolling line temperature control model calculates the adjustment values ​​of water tank flow rate and pressure based on the temperature data and sends them to the closed-loop control water tank system. The closed-loop control water tank system precisely controls the water tank flow rate and pressure in each area of ​​the rolling line based on the adjustment values, enabling closed-loop temperature control during the rolling process. This ensures high-precision control of the rolled workpiece temperature and the non-cooled section, keeping the rolled workpiece temperature fluctuation within ±5℃. S4. Control of red rust on steel surface: Design a performance prediction model to establish the correlation between product performance, initial rolling temperature, and rolling line water tank control; The temperature detection device used for initial rolling temperature transmits real-time data to the performance prediction model, which analyzes and predicts based on the data, promptly identifying factors that cause red rust on the steel surface. When a problem is predicted, the performance prediction model issues intervention and correction signals to guide the closed-loop control water tank system to adjust the rolling line temperature control in order to obtain good microstructure and product appearance, ensuring that the finished product surface is free of red rust; S5. Temperature monitoring and adjustment: Throughout the production process, a rolling line PLC control platform is established to centrally and intelligently control the heating furnace, closed-loop control water tank system, and rolling line PLC system, continuously monitor the temperature of billets and rolled pieces, and adjust the flow rate and pressure of the water tank in a timely manner according to the actual temperature conditions. S6. Finished product output: The temperature-controlled rolled parts are transported to the cooling bed, where the steel temperature is controlled at 875℃, with fluctuations within 5℃.

2. The bar wire temperature control method according to claim 1, characterized in that, In step S2, the closed-loop control water tank system automatically adjusts the flow rate and pressure of the backup water tank based on the billet temperature fed back by the temperature detection device to uniformly control the billet temperature.

3. The bar wire temperature control method according to claim 1, characterized in that, The performance prediction model is constructed using rolling sequence performance test values. The establishment of rolling sequence performance test values ​​requires the collection of the composition of the corresponding furnace, the average rolling sequence temperature of each section of the heating furnace, the average rolling sequence temperature of the rolling line temperature control point, and the average rolling sequence water tank control feedback value.

4. The bar wire temperature control method according to claim 1, characterized in that, In step S5, the rolling line PLC control platform uses an industrial Ethernet ring network to connect the high-speed wire rod rolling line PLC and the high-speed bar rolling line PLC. The high-speed wire rod rolling line PLC is connected to the high-speed wire rod closed-loop control water tank system and the No. 2 small bar rolling line PLC. The high-speed bar rolling line PLC is connected to the high-speed bar closed-loop control water tank system and the No. 1 small bar rolling line PLC.

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