Bar wire temperature control method

Abstract

The invention relates to the technical field of steel production, and particularly discloses a bar line temperature control method which comprises the following steps: heating a steel billet: feeding the steel billet into a heating furnace for heating to reach a set rolling starting temperature; steel billet head and tail temperature difference control: installing a closed-loop control water tank system on a rolling line, and arranging a temperature detection device; precisely controlling the temperature of a rolled piece; developing a rolling line temperature control model; controlling red rust on the surface of the steel; designing a performance prediction model; temperature monitoring and adjustment: in the whole production process, establishing a rolling line PLC management and control platform; the rolled piece subjected to temperature control is conveyed to a cooling bed, the steel feeding temperature of the cooling bed is controlled to be 875 DEG C, and the up-down fluctuation is smaller than 5 DEG C; energy consumption in the production process is effectively reduced, closed-loop automatic adjustment of rolled piece temperature control is achieved, unmanned intervention can be achieved, the production efficiency and the automation level are improved, stable product performance is achieved, the surface of a finished product is free of red rust, and the quality and appearance of steel are improved.

Description

Technical Field

[0001] The invention relates to the technical field of steel production, and in particular to a bar wire temperature control method. Background Art

[0003] The traditional strong water penetration process and weak water penetration process have problems in the temperature control of the rolling line, such as poor water tank control accuracy, water flow and motor frequency control not linked with the temperature of the rolled piece, and lack of effective control means. These problems lead to large temperature fluctuations of the rolled piece, large temperature differences of the wire rods, increased gas consumption, increased power consumption of the water pump motor, and red rust easily forming on the product surface, affecting sales.

[0004] Therefore, it is necessary to design a bar line temperature control method to solve the problems of large temperature difference and easy red rust on the surface in the existing steel rolling water tank control. Summary of the invention

[0005] In view of the problems existing in the prior art, an object of the present invention is to provide a bar wire temperature control method.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a bar wire temperature control method, comprising the following steps:

[0007] S1. Billet heating: The billet is sent into a heating furnace for heating to reach the set rolling temperature;

[0008] S2. Temperature difference control between the head and tail of the billet: a closed-loop control water tank system is installed on the rolling line, and a temperature detection device is set to monitor the billet temperature at the No. 2 flying shear in real time;

[0009] S3. Precise control of rolled piece temperature: Develop a rolling line temperature control model, which works based on temperature detection data and a preset control algorithm;

[0010] S4. Control of red rust on steel surface: Design performance prediction model to establish the correlation between product performance, rolling temperature and rolling line water tank control;

[0011] S5. Temperature monitoring and adjustment: During the entire 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 the billet and rolled product, and adjust the flow and pressure of the water tank in time according to the actual temperature conditions;

[0012] S6. Finished product output: The temperature-controlled rolled pieces are transported to the cooling bed. The steel temperature on the cooling bed is controlled at 875°C, with fluctuations of less than 5°C.

[0013] Specifically, the closed-loop control water tank system in step S2 automatically adjusts the flow rate and pressure of the standby water tank according to the billet temperature fed back by the temperature detection device to make the billet temperature uniform.

[0014] Specifically, during the rolling process, the temperature detection device of the rolling line temperature control model in step S3 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 and pressure according to 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 and pressure in each area of ​​the rolling line according to the adjustment values, so that the temperature of the rolling process is closed-loop controlled, ensuring high-precision control of the rolled piece temperature and the non-cold section, and making the rolled piece temperature fluctuate within ±5°C.

[0015] Specifically, the temperature detection device used for the start 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, and promptly discovers factors that may cause red rust on the surface of the steel. When a possible problem is predicted, the performance prediction model sends an intervention and correction signal to guide the closed-loop control water tank system to adjust the rolling line temperature control to obtain good organizational performance and product appearance, ensuring that there is no red rust on the surface of the finished product.

[0016] 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 furnace composition, the average rolling sequence temperature of each section of the heating furnace, the average rolling sequence of the rolling line temperature control point, and the average rolling sequence of the rolling line water tank control feedback value.

[0017] Specifically, the rolling line PLC management and control platform in step S5 adopts industrial Ethernet ring network control to connect the high-wire rolling line PLC and the high-bar rolling line PLC, the high-wire rolling line PLC connects the high-wire closed-loop control water tank system and the 2# small-bar rolling line PLC, and the high-bar rolling line PLC connects the high-bar closed-loop control water tank system and the 1# small-bar rolling line PLC.

[0018] The present invention has the following beneficial effects:

[0019] The bar line temperature control method designed by the present invention designs industrial Ethernet ring network control technology, establishes a rolling line PLC management and control platform, realizes centralized and intelligent control of the heating furnace, water system, and rolling line PLC system, and lays the foundation for precise control of the rolling line water tank.

[0020] The bar line temperature control method designed by the present invention develops a temperature difference control technology for the head and tail of the steel billet. A closed-loop control water tank system is installed on the rolling line to automatically adjust the flow and pressure of the standby water tank according to the temperature of the steel billet to make the temperature of the steel billet uniform. The temperature of the steel billet is also avoided from being too large by accurately controlling the head and tail non-cooling sections.

[0021] The bar line temperature control method designed by the present invention develops a precise temperature control process for the rolled piece. By developing a rolling line temperature control model, closed-loop temperature control of the rolling process is achieved, ensuring high-precision control of the rolled piece temperature and the non-cold section, and precisely controlling the temperature fluctuation of each area of ​​the rolling line within ±5°C.

[0022] The bar line temperature control method designed by the present invention designs a performance prediction model, timely intervenes and corrects the rolling line temperature control, obtains good organizational performance and product appearance under high-speed and fast-paced production mode, realizes stable product performance, and has no red rust on the surface of the finished product. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is the process connection schematic diagram of the rolling line PLC control platform.

[0024] Figure 2 It is the control flow chart of the rolling line temperature control model.

[0025] Figure 3 It is a statistical chart of cold rolling temperature and yield strength in the rolling line PLC control platform.

[0026] Figure 4 It is a comparison chart of statistical temperature and yield strength in the rolling line PLC control platform.

[0027] Figure 5 It is a dataset framework diagram of the performance prediction model.

[0028] Figure 6 It is the mechanical performance diagram of the rolling line PLC control platform monitoring and early warning.

[0029] Figure 7 It is the temperature collection chart of the rolling line PLC control platform monitoring and early warning. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely further describe the technical solutions in the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] like Figure 1-Figure 7 As shown, a bar wire temperature control method comprises the following steps:

[0032] 1. Billet heating: The billet is sent into the heating furnace for heating to reach the set rolling temperature.

[0033] 2. Control of temperature difference between the head and tail of the billet: A closed-loop control water tank system is installed on the rolling line, and a temperature detection device is set to monitor the temperature of the billet at the No. 2 flying shear in real time. According to the billet temperature feedback from the temperature detection device, the closed-loop control water tank system automatically adjusts the flow and pressure of the standby water tank to even out the billet temperature. By accurately controlling the head and tail non-cooling section, the temperature difference between the head and tail of the billet can be avoided.

[0034] 3. Precise control of rolled piece temperature: Develop a rolling line temperature control model, which works according to temperature detection data and preset control algorithms. 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 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 and pressure in each area of ​​the rolling line according to the adjustment values, so that the temperature of the rolling process is closed-loop controlled, ensuring high-precision control of the rolled piece temperature and the non-cold section, and keeping the rolled piece temperature fluctuation within ±5°C.

[0035] 4. Control of red rust on steel surface: Design a performance prediction model to establish the correlation between product performance, rolling temperature, and rolling line water tank control; the temperature detection device used for the rolling temperature transmits real-time data to the performance prediction model, and the performance prediction model analyzes and predicts based on the data to promptly identify factors that may cause red rust on the steel surface. When a possible problem is predicted, the performance prediction model sends an intervention and correction signal to guide the closed-loop control water tank system to adjust the rolling line temperature control to obtain good organizational performance and product appearance, ensuring that there is no red rust on the surface of the finished product.

[0036] The performance prediction model is constructed using the rolling sequence performance test value. The establishment of the rolling sequence performance test value requires the collection of the furnace composition, the average rolling sequence temperature of each section of the heating furnace, the rolling sequence average of the rolling line temperature control point and the rolling sequence average of the rolling line water tank control feedback value.

[0037] 5. Temperature monitoring and adjustment: During the entire production process, a rolling line PLC management and 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 the steel billet and rolled products, and adjust the flow and pressure of the water tank in time according to the actual temperature conditions to ensure the stability and accuracy of temperature control.

[0038] The rolling line PLC management and control platform adopts industrial Ethernet ring network control to connect the high-wire rolling line PLC and the high-bar rolling line PLC. The high-wire rolling line PLC is connected to the high-wire closed-loop control water tank system and the 2# small-bar rolling line PLC. The high-bar rolling line PLC is connected to the high-bar closed-loop control water tank system and the 1# small-bar rolling line PLC.

[0039] 6. Finished product output: The temperature-controlled rolled pieces are transported to the cooling bed. The steel temperature on the cooling bed is controlled at 875°C, with fluctuations of less than 5°C.

[0040] Example: The specific operation and working method of establishing the rolling line PLC control platform are as follows:

[0041] 1. First-level automation underlying design.

[0042] (1) Establish network communication between the rolling line PLC and the water system PLC, realize network communication among the production system, water system, and dispatching system, and realize remote centralized control of the water system. Figure 1 shown.

[0043] (2) Design the centralized monitoring function of the upper computer. The upper computer uses Siemens WINCC software to perform logical operations on various signals collected by the PLC to achieve remote operation and status monitoring of the equipment. More than 90% of the post inspections are transferred from on-site to remote. The number of inspection personnel per shift is optimized from 2 to 1.

[0044] The remote host computer has the following functions:

[0045] Real-time monitoring: monitor the status of each signal point;

[0046] Signal acquisition: The frequency, current and vibration of the motor are collected by the inverter through Ethernet communication;

[0047] Automatic adjustment: automatic start and stop of integrated valve;

[0048] Remote start and stop: remote start and stop of all pump station motors, electric valves, cooling tower fans, and motor frequency adjustment;

[0049] Historical curves: motor current, frequency, water supply pressure, temperature, flow, pool liquid level and other historical curves display;

[0050] Automatic alarm: According to process requirements, set the upper and lower limits of parameter control and automatically alarm.

[0051] (3) Add remote control function for water pump

[0052] System design: According to the variable frequency pump operation characteristic curve, calculate the relationship between flow, pressure and frequency. F1 is the highest frequency performance curve of the variable frequency drive, and F2 and F3 are low frequency performance curves. H is the actual head.

[0053] Remote control: The centralized control center can remotely start and stop the pump station motor and monitor the motor operating status through the upper computer screen configuration and parameter setting.

[0054] Rolling line frequency setting: Through PLC hardware configuration and programming, bilateral communication between the water system and the rolling line PLC is established. The rolling line position can adjust the frequency according to the temperature and flow, which improves the work efficiency

[0055] 2. Rolling line temperature control and rolling control system.

[0056] (1) Design ideas

[0057] After the first-level automation has the functions of remote automatic adjustment of water pumps and valve opening adjustment, the rolling line temperature control model is designed. Figure 2 shown.

[0058] (2) Experimental process

[0059] The target temperature was 875°C, and was controlled within ±5°C of the target value.

[0060] like Figure 3 As shown, during the trial operation, the rolling specification was φ22×2, 2# water tank was not used, 45# water tank was opened, the water inlet 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 upper cooling bed temperature was initially set to 880℃, and the frequency was automatically set to 75 after the system was running. 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 within the standard range.

[0061] After the system is running normally, the average temperature of 1# shear, water pump frequency, water temperature, upper cooling bed temperature, and yield strength curve are as follows: Figure 4 shown.

[0062] Based on the industrial Internet platform and the centralized control system for rolling steel, a temperature control model is 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, achieve real-time adjustment of water supply frequency, pressure, and flow, ensuring high-precision control of the temperature of the rolled piece and the non-cooling section. The average temperature of the upper cooling bed is controlled within the range of 875±5℃, the yield strength of the steel meets the requirements, the Si content fluctuates slightly around 0.23, and the N content fluctuates between 130 and 140.

[0063] 3. Performance prediction model.

[0064] (1) Model learning dataset construction Figure 5 shown.

[0065] (2) Model Learning

[0066] Identification of key performance influencing factors, data model training, and the performance prediction capabilities of the main learning components of the rolling sequence granularity model; the influence of heating furnaces and rolling lines is easily limited by data granularity.

[0067] (3) Monitoring and early warning Figure 6-Figure 7 shown.

[0068] Ultimately, component warning, temperature warning, pre-rolling prediction, post-rolling prediction, and the combination of prediction and closed loop are formed.

[0069] The present invention can achieve the following in practical application:

[0070] 1. Reduce energy consumption: Through automatic temperature control technology, the water system can reduce electricity consumption by 8%, and gas can save 5m3 per ton of steel. 3 , effectively reducing energy consumption in the production process.

[0071] 2. Realize unmanned operation: The temperature control of the rolled piece realizes closed-loop automatic adjustment, which can realize unmanned intervention and improve production efficiency and automation level.

[0072] 3. Improve product quality: The temperature of rolled pieces in the upper steel zone is controlled within ±5°C, and by designing a performance prediction model, stable product performance is achieved, and there is no red rust on the surface of the finished product, which improves the quality and appearance of the steel.

[0073] 4. Cost saving: 6 water system operators can be saved, saving about 900,000 yuan per year; the temperature of the upper steel zone is controlled within ±5 degrees Celsius, silicon and manganese alloys are reduced by 0.1, and the price of a ton of steel is reduced by about 7 yuan, saving about 10.5 million yuan per year and reducing production costs.

[0074] 5. Green and low-carbon: This technology helps to inhibit the formation of red rust on the surface, reduces the impact on the environment, realizes clean production, and meets the requirements of green and low-carbon development.

[0075] The present invention is not limited to the above-mentioned implementation modes, and anyone should be aware of the structural changes made under the enlightenment of the present invention, and all those having the same or similar technical solutions as the present invention fall within the protection scope of the present invention.

[0076] The techniques, shapes, and structural parts not described in detail in the present invention are all well-known techniques.

Claims

1. A bar wire temperature control method, characterized in that: The following steps are involved: S1. Billet heating: The billet is sent into a heating furnace for heating to reach the set rolling temperature; S2. Temperature difference control between the head and tail of the billet: a closed-loop control water tank system is installed on the rolling line, and a temperature detection device is set to monitor the billet temperature at the No. 2 flying shear in real time; S3. Precise control of rolled piece temperature: Develop a rolling line temperature control model, which works based on temperature detection data and a preset control algorithm; S4. Control of red rust on steel surface: Design performance prediction model to establish the correlation between product performance, rolling temperature and rolling line water tank control; S5. Temperature monitoring and adjustment: During the entire 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 the billet and rolled product, and adjust the flow and pressure of the water tank in time according to the actual temperature conditions; S6. Finished product output: The temperature-controlled rolled pieces are transported to the cooling bed. The steel temperature on the cooling bed is controlled at 875°C, with fluctuations of less than 5°C.

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

3. The bar wire temperature control method according to claim 1, characterized in that: In the rolling process of the rolling line temperature control model in step S3, 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 and pressure according to 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 and pressure in each area of ​​the rolling line according to the adjustment values, so that the temperature of the rolling process is closed-loop controlled, ensuring high-precision control of the rolled piece temperature and the non-cold section, and making the rolled piece temperature fluctuate within ±5°C.

4. The bar wire temperature control method according to claim 1, characterized in that: The temperature detection device used for the rolling start temperature in step S4 transmits real-time data to the performance prediction model. The performance prediction model analyzes and predicts based on the data, and promptly discovers factors that may cause red rust on the steel surface. When a possible problem is predicted, the performance prediction model sends out intervention and correction signals to guide the closed-loop control water tank system to adjust the rolling line temperature control to obtain good organizational performance and product appearance, ensuring that there is no red rust on the surface of the finished product.

5. The bar wire temperature control method according to claim 4, 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 furnace composition, the average rolling sequence temperature of each section of the heating furnace, the average rolling sequence of the rolling line temperature control point, and the average rolling sequence of the rolling line water tank control feedback value.

6. The bar wire temperature control method according to claim 1, characterized in that: The rolling line PLC management and control platform in step S5 adopts industrial Ethernet ring network control to connect the high-wire rolling line PLC and the high-bar rolling line PLC. The high-wire rolling line PLC connects the high-wire closed-loop control water tank system and the 2# small-bar rolling line PLC. The high-bar rolling line PLC connects the high-bar closed-loop control water tank system and the 1# small-bar rolling line PLC.

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