Oxygen-free copper casting blank production regulation and control method and system

Abstract

The invention provides an oxygen-free copper casting blank production regulation and control method and system, is applied to the technical field of continuous casting, and aims to solve the problem of defects caused by the difference between the casting blank state and the normal production state when production is recovered after non-planned shutdown. According to the method, by predicting the casting blank state, generating the target curve set, monitoring the temperature deviation in real time and dynamically correcting the target curve set, accurate control over the technological parameters in the recovery stage is achieved, and the method has the advantages that casting blank defects generated in the recovery stage can be reduced, and smooth transition of production is guaranteed.

Description

Technical Field

[0001] This application relates to the technical field of continuous casting, and particularly to a method and system for regulating and controlling the production of oxygen-free copper billets. Background Art

[0002] The production of oxygen-free copper billets widely uses the continuous casting process. In this process flow, high-purity molten copper liquid is first injected into the tundish, and then enters a vertical or curved mold through a submerged nozzle at the bottom of the tundish. In the mold, the copper liquid undergoes primary solidification through forced cooling (usually water cooling) to form a solidified shell with a certain thickness. The solidified shell wraps the copper liquid that has not been fully solidified inside, forming a preliminarily shaped billet. Subsequently, a withdrawal device (such as pinch rolls) continuously and stably pulls out the billet with the solidified shell from the bottom or outlet of the mold. The billet pulled out of the mold enters the secondary cooling zone. The secondary cooling zone usually consists of multiple sections of spray devices or water tanks. By spraying cooling water on the surface of the billet or submerging it for cooling, the internal heat of the billet is further removed, promoting the continuous solidification of the internal liquid-phase metal and reducing the overall temperature of the billet, ultimately forming a finished billet with the required cross-sectional shape and internal structure. The entire production process is a complex system, involving the coordinated control of many process parameters such as casting temperature, tundish liquid level, billet withdrawal speed, cooling water flow rate and temperature in the mold, water flow rate and spray pattern in each section of the secondary cooling. The precise matching and stable control of these parameters are crucial for ensuring the compactness of the internal structure of the billet, the smooth surface quality without cracks, and the dimensional accuracy.

[0003] During the continuous and efficient production process of oxygen-free copper billets, the production line will inevitably encounter various unplanned emergencies, such as temporary fluctuations in the power supply system, short-term failures of upstream melting or heat preservation equipment, forced shutdowns to deal with emergency safety incidents, or unplanned maintenance interruptions due to the sudden discovery of equipment abnormalities that need to be dealt with immediately. These emergencies may cause the continuous casting production line to be forced to experience unplanned stops or short-term interruptions.

[0004] When the production line resumes normal production from an unplanned stop state, the withdrawal device needs to be restarted, and the withdrawal speed is gradually increased from zero to the withdrawal speed required for normal and stable production. At this time, the core challenge is that the actual state of the stationary billet in the mold and the secondary cooling zone during the stop period (including temperature distribution, solidified shell thickness, solidification front position, etc.) has a significant difference from the ideal or target state under normal and stable production conditions, and this difference is non-uniformly distributed. If the stable production parameters before the stop or the preset fixed start curve are simply used to resume the withdrawal speed and cooling control, it is very likely that the process parameters during the recovery process do not match the actual state of the billet.

[0005] Therefore, after an unplanned stop in the oxygen-free copper continuous casting production line, which results in a static and non-uniform temperature distribution and solidification state change of the billet along the length direction in the mold and the secondary cooling zone, how to dynamically predict and real-time sense the actual state of the billet during the process of resuming production and ramping up the drawing speed from zero to the normal speed, and based on this, coordinately and dynamically adjust the primary and secondary cooling parameters to minimize the billet defects generated during the recovery stage and ensure a smooth transition of production. For the above problems, the existing technologies urgently need to be improved. Summary of the Invention

[0006] In view of the deficiencies of the above-mentioned existing technologies, the present application provides a method and system for regulating the production of oxygen-free copper billets, which has the advantages of being able to reduce the billet defects generated during the recovery stage and ensuring a smooth transition of production.

[0007] In a first aspect, a method for regulating the production of oxygen-free copper billets is used to resume production after an unplanned stop. The method includes the steps of: S1: Obtain the duration of the unplanned stop and the cooling conditions during the stop; S2: Based on the duration of the unplanned stop and the cooling conditions, predict the temperature distribution and solidification state of the billet in the mold and the secondary cooling zone at the end of the stop to obtain billet state prediction information; S3: According to the billet state prediction information, generate target curves for the drawing speed, the cooling intensity of the mold, and the water flow rate of each section of the secondary cooling during the recovery stage, respectively, to form a set of target curves; S4: During the process of gradually increasing the drawing speed, collect the surface temperature of the billet downstream of the secondary cooling zone to obtain billet surface temperature measurement data; S5: Compare the billet surface temperature measurement data with the theoretical surface temperature of the billet at the current position calculated based on the target curve of the drawing speed to obtain a temperature deviation; S6: Based on the temperature deviation, correct the target curves for the drawing speed, the cooling intensity of the mold, and the water flow rate of each section of the secondary cooling to obtain a corrected set of target curves, and use the corrected set of target curves for production.

[0008] The method for regulating the production of oxygen-free copper billets provided by the present application aims to solve the defect problems caused by the difference in the billet state from the normal production state when resuming production after an unplanned stop. This method realizes the precise control of the process parameters during the recovery stage by predicting the billet state, generating a set of target curves, real-time monitoring the temperature deviation, and dynamically correcting the set of target curves, and has the advantages of being able to reduce the billet defects generated during the recovery stage and ensuring a smooth transition of production.

[0009] Further, step S1 includes: S11: Determine the unplanned parking duration. If the parking duration is less than the preset duration threshold, it is determined as short-term parking; if the parking duration is greater than or equal to the preset duration threshold, it is determined as long-term parking. S12: When it is determined as short-term parking, obtain the crystallizer cooling water flow rate, the cooling water flow rates of each section of secondary cooling, and the cooling water temperature, and record them as the cooling conditions for short-term parking. S13: When it is determined as long-term parking, determine whether to start the emergency cooling mode; if it is started, obtain the crystallizer emergency cooling water flow rate, the emergency cooling water flow rates of each section of secondary cooling, and the cooling water temperature, and record them as the cooling conditions for long-term parking; if it is not started, determine the cooling condition as natural cooling and record the ambient temperature.

[0010] An anaerobic copper billet production regulation method provided by the present application aims to solve the influence of the unplanned parking duration and cooling conditions on the billet state. By distinguishing the parking duration and cooling methods, parking information can be obtained more accurately, thereby providing more accurate basic data for subsequent temperature prediction and control.

[0011] Further, step S2 includes: S21: Construct a billet heat conduction and solidification model. S22: Use the billet heat conduction and solidification model to simulate the change of the temperature field inside the billet during parking until the simulation duration reaches the unplanned parking duration, and obtain the temperature distribution of the billet in the crystallizer and the secondary cooling zone at the end of parking. S23: Based on the temperature distribution, determine the solidification state of each position of the billet. S24: Integrate the temperature distribution and the solidification state to generate billet state prediction information, and the billet state prediction information includes the temperature values, solidified shell thickness, and liquidus position of each position of the billet.

[0012] An anaerobic copper billet production regulation method provided by the present application aims to more comprehensively predict the state of the billet after unplanned parking and provide a more accurate basis for subsequent resumption of production.

[0013] Further, step S21 includes: S211: Measure the cooling water flow rate, water temperature, and spray density data along the length direction of the billet, establish a mapping relationship between the cooling intensity and the position, and obtain the cooling intensity distribution in the crystallizer and the secondary cooling zone. S212: Obtain the thermal conductivity, specific heat capacity, and density of the billet according to the material of the billet, and establish the thermophysical function relationship between the thermal conductivity, specific heat capacity, and density and the temperature change of the billet. S213: Determine the latent heat release parameter of solidification of the billet according to the specific heat capacity of the billet. S214: Construct the heat conduction and solidification model of the billet based on the cooling intensity distribution of the mold and secondary cooling zone, the thermophysical function relationship, and the latent heat release parameter of solidification.

[0014] An anaerobic copper billet production regulation method provided by this application aims to provide a more accurate method for constructing the heat conduction and solidification model of the billet, thereby improving the accuracy of predicting the billet state after an unscheduled shutdown.

[0015] Further, step S3 includes: S31: Determine the solidified shell thickness at the mold outlet, the temperature distribution in the central liquid phase zone, and the surface temperature distribution of each section in the secondary cooling zone according to the billet state prediction information; S32: Calculate the target curve of the withdrawal speed based on the solidified shell thickness; S33: Determine the target curve of the mold cooling intensity according to the temperature distribution in the central liquid phase zone; S34: Calculate the required water flow for each section in the secondary cooling based on the surface temperature distribution of each section in the secondary cooling zone and the target curve of the withdrawal speed, and generate the target curve of the water flow for each section in the secondary cooling according to the preset flow distribution strategy; The target curve group includes the target curve of the withdrawal speed, the target curve of the mold cooling intensity, and the target curve of the water flow for each section in the secondary cooling.

[0016] Further, step S34 includes: S341: Divide the billet into multiple nodes along the thickness direction and establish the heat conduction equation between the nodes; S342: Construct the boundary conditions of the heat conduction equation between the nodes according to the surface temperature distribution of each section in the secondary cooling zone and the target curve of the withdrawal speed in the recovery stage, and the boundary conditions are used to solve the heat conduction equation between the nodes; S343: Use an iterative algorithm to adjust the required water flow for each section in the secondary cooling zone, solve the heat conduction equation until the deviation between the calculated billet surface temperature and the surface temperature distribution of each section in the secondary cooling zone is less than the preset threshold; S344: According to the adjusted required water flow for each section in the secondary cooling zone, combine the preset flow distribution strategy, allocate the total water flow to each cooling section, and generate the target curve of the water flow for each section in the secondary cooling.

[0017] Further, step S5 includes: S51: Obtain the measurement time when collecting the billet surface temperature measurement data, and calculate the current position of the billet downstream in the secondary cooling zone under the billet surface temperature measurement data according to the target curve of the withdrawal speed and the measurement time; S52: Calculate the theoretical surface temperature of the slab at the current position according to the target curve group. S53: Subtract the theoretical surface temperature of the slab from the measured slab surface temperature data to obtain the temperature deviation.

[0018] Further, step S52 includes: S521: Extract the mold cooling intensity target curve and the water flow target curves for each section of secondary cooling from the target curve group. S522: Calculate the surface temperature of the slab at the mold outlet according to the mold cooling intensity target curve and the current position of the slab. S523: Calculate the temperature change of the slab in the secondary cooling zone section by section according to the surface temperature of the slab at the mold outlet and the water flow target curves for each section of secondary cooling, and obtain the theoretical surface temperature of the slab at the current position.

[0019] Further, step S6 includes: S61: Determine the correction strategies for the resumed casting speed, mold cooling intensity, and water flow for each section of secondary cooling. S62: Based on the correction strategies, calculate the correction amounts for the drawing speed, mold cooling intensity, and water flow for each section of secondary cooling during the recovery stage according to the temperature deviation. S63: Superimpose the correction amounts for the drawing speed, mold cooling intensity, and water flow for each section of secondary cooling onto the target curves for the drawing speed, mold cooling intensity, and water flow for each section of secondary cooling respectively, to obtain the corrected target curve group, and use the corrected target curve group for production.

[0020] In a second aspect, an oxygen-free copper slab production control system is applied to the steps of any one of the above methods, and the system includes: Unplanned shutdown information acquisition module: Acquire the duration of unplanned shutdown and the cooling conditions during shutdown. Slab state prediction module: Based on the duration of unplanned shutdown and the cooling conditions, predict the temperature distribution and solidification state of the slab in the mold and the secondary cooling zone at the end of shutdown, and obtain slab state prediction information. Target curve generation module: Generate target curves for the drawing speed, mold cooling intensity, and water flow for each section of secondary cooling during the recovery stage according to the slab state prediction information. Temperature data acquisition module: During the process of gradually increasing the drawing speed, acquire the surface temperature of the slab downstream of the secondary cooling zone to obtain the measured slab surface temperature data and form a target curve group. Temperature deviation calculation module: Compare the measured slab surface temperature data with the theoretical slab surface temperature at the current position calculated based on the target curve of the drawing speed to obtain the temperature deviation; Parameter correction control module: Based on the temperature deviation, correct the target curves of the drawing speed, mold cooling intensity, and water flow rate in each section of secondary cooling to obtain a corrected set of target curves, and use the corrected set of target curves for production.

[0021] Beneficial effects: An anaerobic copper slab production regulation method and system proposed in this application aims to solve the defect problems caused by the difference in slab state from the normal production state when resuming production after an unplanned shutdown. This method realizes precise control of process parameters in the recovery stage by predicting the slab state, generating a set of target curves, real-time monitoring the temperature deviation, and dynamically correcting the set of target curves, and has the advantages of being able to reduce the slab defects generated in the recovery stage and ensuring a smooth transition of production. Description of the Drawings

[0022] Figure 1 It is a flowchart of an anaerobic copper slab production regulation method proposed in this application.

[0023] Figure 2 It is a structural diagram of an anaerobic copper slab production regulation system proposed in this application.

[0024] Label description: 201, Parking information acquisition module; 202, Slab state prediction module; 203, Target curve generation module; 204, Temperature data acquisition module; 205, Temperature deviation calculation module; 206, Parameter correction control module. Specific Embodiments

[0025] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and marked in the drawings here can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the present application provided in the drawings below is not intended to limit the scope of the present application to be protected, but only represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0026] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Meanwhile, in the description of this application, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be construed as indicating or implying relative importance.

[0027] Please refer to Figure 1 , a method for regulating the production of oxygen-free copper billets, which is used to resume production after an unplanned shutdown. The method includes the steps: S1: Obtain the duration of the unplanned shutdown and the cooling conditions during the shutdown; S2: Based on the duration of the unplanned shutdown and the cooling conditions, predict the temperature distribution and solidification state of the billet in the mold and the secondary cooling zone at the end of the shutdown to obtain billet state prediction information; S3: According to the billet state prediction information, generate target curves for the drawing speed, mold cooling intensity, and water flow rates in each section of the secondary cooling during the recovery stage respectively, to form a group of target curves; S4: During the process of gradually increasing the drawing speed, collect the surface temperature of the billet downstream of the secondary cooling zone to obtain billet surface temperature measurement data; S5: Compare the billet surface temperature measurement data with the theoretical surface temperature of the billet at the current position calculated based on the target curve of the drawing speed to obtain a temperature deviation; S6: Based on the temperature deviation, correct the target curves for the drawing speed, mold cooling intensity, and water flow rates in each section of the secondary cooling to obtain a corrected group of target curves, and use the corrected group of target curves for production.

[0028] After the oxygen-free copper continuous casting production line experiences an unplanned shutdown, the billet shows a static and non-uniform temperature distribution and solidification state change along the length direction in the mold and the secondary cooling zone. How to dynamically predict and real-time sense the actual state of the billet according to the shutdown duration and the cooling conditions during the shutdown during the process of resuming production and increasing the drawing speed from zero to the normal speed, and based on this, coordinately and dynamically adjust the primary and secondary cooling parameters to minimize the billet defects generated during the recovery stage and ensure a smooth transition of production is the problem to be solved by this technical solution.

[0029] Among them, the duration of the unplanned shutdown refers to the time interval from the normal operation state of the production line to the restart due to sudden reasons, which can be achieved by using a timer to record or reading from the system log.

[0030] The cooling conditions during the shutdown refer to the cooling method and intensity acting on the billet during the shutdown, which can be obtained by monitoring parameters such as cooling water flow rate, water temperature, whether emergency cooling is started, or ambient temperature.

[0031] Predicting the temperature distribution and solidification state of the slab in the mold and secondary cooling zone at the end of the stop means determining the temperature values at each point inside the slab and the solid-liquid phase distribution at the end of the stop through calculation or simulation methods. A numerical simulation method based on a heat transfer and solidification model can be used to achieve this.

[0032] The slab state prediction information refers to the data set describing the predicted temperature distribution and solidification state of the slab, which can include the temperature values of the slab along the length and thickness directions, the solidification shell thickness, and the liquidus position.

[0033] The target curves of the withdrawal speed, mold cooling intensity, and water flow rates in each section of secondary cooling during the recovery stage refer to the sequence of expected control parameter values that change with time or the position of the slab during the resumption of production.

[0034] The surface temperature of the slab downstream of the secondary cooling zone refers to the outer surface temperature of the slab measured in a non-contact manner at the end or subsequent positions of the secondary cooling area, and an infrared thermometer device can be used to collect it.

[0035] The measured data of the slab surface temperature refers to the numerical values of the slab surface temperature collected in real time.

[0036] The theoretical surface temperature of the slab refers to the surface temperature that the slab should have at the measurement position deduced by a calculation model based on the current applied withdrawal speed, mold cooling intensity, and target curves of water flow rates in each section of secondary cooling. A forward calculation method based on the heat conduction equation can be used to achieve this.

[0037] The temperature deviation refers to the difference between the measured data of the slab surface temperature and the theoretical surface temperature of the slab.

[0038] The corrected target curves refer to adjusting the original target curves of the withdrawal speed, mold cooling intensity, and water flow rates in each section of secondary cooling according to the temperature deviation. A proportional-integral-derivative (PID) control, fuzzy control, or rule-based adjustment strategy can be used to achieve this, mainly to make the actual production process closer to the ideal state and compensate for prediction errors and external disturbances.

[0039] As a preferred embodiment, the solution of the present application is specifically implemented as follows: The unplanned stop duration and cooling conditions are obtained through sensors and databases connected to the production control system. The slab state prediction module uses a two-dimensional transient heat transfer and solidification model based on the finite difference method, inputs parameters such as the stop duration, mold cooling water flow rate, water temperature, water flow rates in each section of secondary cooling, water temperature, and ambient temperature, and calculates the temperature field and solidification shell thickness distribution of the slab along the length direction at the end of the stop.

[0040] The target curve generation module determines the initial resumed casting speed based on the predicted solidified shell thickness at the mold outlet, combines the predicted temperature distribution in the secondary cooling zone, and determines the required cooling intensity and water flow rate during the recovery stage through inverse calculation to generate a piecewise linear target curve that varies with the recovery time.

[0041] An infrared thermometer is installed at the end of the secondary cooling zone to collect the surface temperature data of the billet in real time. The temperature deviation calculation module calculates the theoretical surface temperature at the temperature measurement position using the forward heat transfer model based on the current casting speed and the target curve, and subtracts the measured temperature to obtain the deviation. The parameter correction control module uses a rule-based expert system to find the preset correction rule table according to the magnitude and change trend of the temperature deviation, determines the correction amounts of the drawing speed, the cooling intensity of the mold, and the water flow rate of each section of the secondary cooling, and sends the correction amounts to the actuator to adjust the actual control parameters.

[0042] Through the above solution, the present application can accurately predict the actual state of the billet after an unplanned stop, and generate a reasonable recovery production control strategy based on this. At the same time, through real-time monitoring and feedback correction, it can cope with prediction errors and uncertainties in the production process, dynamically match the actual control parameters with the billet state, effectively avoid defects such as surface cracks and internal porosity of the billet caused by insufficient or excessive cooling, improve the success rate of recovery production and the quality of the billet, and ensure the smooth transition and efficient operation of the production line.

[0043] Further, step S1 includes: S11: Determine the duration of the unplanned stop. If the stop duration is less than the preset duration threshold, it is determined as a short-term stop; if the stop duration is greater than or equal to the preset duration threshold, it is determined as a long-term stop. S12: When it is determined as a short-term stop, obtain the mold cooling water flow rate, the cooling water flow rate of each section of the secondary cooling, and the cooling water temperature, and record them as the short-term stop cooling conditions. S13: When it is determined as a long-term stop, determine whether to start the emergency cooling mode; if it is started, obtain the emergency cooling water flow rate of the mold, the emergency cooling water flow rate of each section of the secondary cooling, and the cooling water temperature, and record them as the long-term stop cooling conditions; if it is not started, determine that the cooling condition is natural cooling and record the ambient temperature.

[0044] Among them, the preset duration threshold refers to the time limit for distinguishing short-term stops and long-term stops, which can be set according to empirical data, simulation calculations, or process requirements.

[0045] Among them, the short-term stop cooling conditions refer to a set of parameters used to describe the cooling effect on the billet during a short stop duration, which can include the cooling water flow rate and temperature of the mold and the secondary cooling zone.

[0046] Among them, the long-time parking cooling condition refers to a set of parameters used to describe the cooling effect on the continuous casting billet during parking when the parking time is relatively long, which may include the cooling water flow rate and temperature during emergency cooling, or the ambient temperature during natural cooling.

[0047] Among them, the emergency cooling mode refers to an enhanced cooling measure taken to quickly reduce the temperature of the continuous casting billet or control the solidification state during long-time parking, which may involve increasing the cooling water flow rate, changing the spraying method, or using other cooling media.

[0048] Among them, natural cooling refers to the cooling process that occurs when the continuous casting billet only exchanges heat with the surrounding environment during long-time parking and the emergency cooling mode is not started, and its cooling rate is usually slow.

[0049] As a preferred embodiment, the solution of the present application is specifically implemented as follows: On the oxygen-free copper continuous casting production line, when an unplanned stop occurs, the system automatically records the start time of the stop. After the stop ends, the parking duration is calculated. For example, the preset duration threshold can be set to 10 minutes. If the parking duration is less than 10 minutes, it is determined as a short-time parking. At this time, the system automatically reads the data of the mold cooling water flow sensor, the cooling water flow sensors of each section of secondary cooling, and the cooling water temperature sensor during parking, and records these data, marked as short-time parking cooling conditions. If the parking duration is greater than or equal to 10 minutes, it is determined as a long-time parking. The system checks the operating status of the emergency cooling system. If the emergency cooling system has been started manually or automatically, the system reads the data of the mold emergency cooling water flow, the emergency cooling water flow of each section of secondary cooling, and the cooling water temperature sensor during emergency cooling, and records it as long-time parking cooling conditions. If the emergency cooling system has not been started, the system reads the data of the workshop ambient temperature sensor and records it as natural cooling conditions. These obtained parking durations and corresponding cooling condition data are then input into the continuous casting billet state prediction model to calculate the temperature distribution and solidification state of the continuous casting billet at the end of the stop.

[0050] Further, step S2 includes: S21: Construct a continuous casting billet heat conduction and solidification model; S22: Utilize the continuous casting billet heat conduction and solidification model to simulate the change of the temperature field inside the continuous casting billet during parking until the simulation duration reaches the unplanned parking duration, and obtain the temperature distribution of the continuous casting billet in the mold and the secondary cooling zone at the end of the stop; S23: Based on the temperature distribution, judge the solidification state of each position of the continuous casting billet; S24: Integrate the temperature distribution and the solidification state to generate continuous casting billet state prediction information, and the continuous casting billet state prediction information includes the temperature value, solidified shell thickness, and liquidus position of each position of the continuous casting billet.

[0051] Among them, constructing a slab heat conduction and solidification model means establishing a mathematical and physical model that can describe the temperature distribution and phase change process of the slab during the cooling process.

[0052] Simulating the temperature field change inside the slab during the parking period means using the slab heat conduction and solidification model, inputting the cooling conditions and parking duration during the parking period, and calculating and predicting the temperature distribution inside the slab that changes with time.

[0053] Judging the solidification state of each position of the slab means, based on the temperature distribution obtained from the simulation and combined with the solidification characteristics of the material (such as liquidus temperature, solidus temperature), determining whether different positions inside the slab are in a liquid state, a solid state, or a coexistence state of solid and liquid phases. Specifically, when there is at least one position inside the slab where the temperature is less than the melting point of the slab, it is judged that this position is in a solid state; when there is at least one position inside the slab where the temperature is greater than or equal to the melting point of the slab and less than the melting temperature of the slab, it is judged that this position is in a solid-liquid coexistence state; when there is at least one position inside the slab where the temperature is greater than or equal to the melting temperature of the slab, it is judged that this position is in a liquid state.

[0054] Integrating the temperature distribution and solidification state means correlating and organizing the temperature values obtained from the simulation and information such as the thickness of the solidified shell and the position of the liquidus line judged, to form a structured data set, which can be achieved by means such as data structure definition, database storage, or output in a specific file format.

[0055] The slab state prediction information refers to the integrated data set, which contains information describing the key state parameters of the slab at the end of parking, and can include the temperature values of each position of the slab, the thickness of the solidified shell, and the position of the liquidus line.

[0056] Furthermore, step S21 includes: S211: Measuring the cooling water flow rate, water temperature, and spray density data along the length direction of the slab, establishing the mapping relationship between the cooling intensity and the position, and obtaining the cooling intensity distribution of the mold and the secondary cooling zone; S212: Obtaining the thermal conductivity, specific heat capacity, and density of the slab according to the material of the slab, and establishing the thermophysical function relationship of the thermal conductivity, specific heat capacity, and density changing with the temperature of the slab; S213: Determining the latent heat release parameter of solidification of the slab according to the specific heat capacity of the slab; S214: Constructing a slab heat conduction and solidification model according to the cooling intensity distribution of the mold and the secondary cooling zone, the thermophysical function relationship, and the latent heat release parameter of solidification.

[0057] Among them, the cooling intensity refers to the ability of the cooling medium (such as cooling water) to take away heat from the surface of the continuous casting billet. Its magnitude is affected by various factors such as the cooling water flow rate, water temperature, spraying method (spray density, nozzle type, injection pressure, etc.), and the surface state of the continuous casting billet. It can be characterized by the heat transfer coefficient per unit area; the thermophysical function relationship refers to the mathematical expressions or data tables of physical quantities such as the thermal conductivity, specific heat capacity, and density of the material changing with temperature. These parameters are the basis for heat conduction calculations and reflect the heat conduction and heat storage characteristics of the material at different temperatures; the solidification latent heat release parameter refers to the heat released per unit mass of metal when changing from the liquid state to the solid state during the solidification process of the continuous casting billet, as well as the release method or distribution law of this heat within the solidification temperature range. This parameter is the key to simulating the solidification process.

[0058] Specifically, the steps to construct the heat conduction and solidification model of the continuous casting billet are as follows: Obtain the cooling intensity distribution: The mapping relationship between the cooling intensity q and the position x can be described by the convective heat transfer coefficient h(x). The heat transfer coefficient , where is the cooling water flow rate, is the cooling water temperature, is the spray density of the cooling water.

[0059] Cooling intensity distribution: , where is the surface temperature of the continuous casting billet at the position .

[0060] According to the cooling intensity distribution, the boundary conditions of the surface of the continuous casting billet in the mold and the secondary cooling zone can be obtained: , this boundary condition is used to ensure that the heat conduction and solidification model of the continuous casting billet can reflect the heat exchange behavior between the continuous casting billet and the cooling medium (such as cooling water) during the actual production process. Among them, is the normal temperature gradient of the surface of the continuous casting billet, is the thermal conductivity of the continuous casting billet, and n is the normal direction of the surface of the continuous casting billet.

[0061] The variation relationships of the thermophysical properties (thermal conductivity, specific heat capacity, density) with temperature can be expressed as: ; ; .

[0062] Among them, T is the theoretical temperature; is the constant term, representing the basic value of the thermal conductivity at low temperatures; is the first-order coefficient, representing the rate of linear change of the thermal conductivity with temperature; is the second-order coefficient, representing the non-linear change of the thermal conductivity with temperature; is a constant term, representing the base value of the specific heat capacity at low temperatures; is the coefficient of the first-order term, representing the rate of linear change of the specific heat capacity with temperature; is the coefficient of the second-order term, representing the non-linear change of the specific heat capacity with temperature; is a constant term, representing the base value of the density at low temperatures; is the coefficient of the first-order term, representing the rate of linear change of the density with temperature; is the coefficient of the second-order term, representing the non-linear change of the density with temperature. K(T) represents the relationship of the thermal conductivity coefficient changing with temperature, and ρ(T) represents the relationship of the density changing with temperature.

[0063] The latent heat of solidification L is the heat released when the material changes from the liquid state to the solid state, that is, the latent heat of solidification release parameter: , where is the liquidus temperature, is the solidus temperature, is the relationship of the specific heat capacity changing with temperature.

[0064] The heat conduction equation is: , where, is the temperature gradient, is the latent heat of solidification release term, which can be expressed as: , where is the solid fraction, which can be expressed as: .

[0065] In summary, the complete billet heat conduction and solidification model includes: Heat conduction equation: , Boundary conditions: , Thermophysical function relationship: ; ; .

[0066] Cooling intensity distribution: .

[0067] In practical applications, the billet heat conduction and solidification model is usually solved by numerical methods (such as the finite element method or the finite difference method), which can accurately simulate the cooling process of the billet in the mold and the secondary cooling zone, predict the temperature field and solidification state, so as to optimize the production process and improve the quality of the billet.

[0068] Furthermore, step S3 includes: S31: According to the billet state prediction information, determine the solidified shell thickness at the mold exit, the temperature distribution in the central liquid phase zone of the billet, and the surface temperature distribution of each section in the secondary cooling zone; S32: Calculate the target curve of the drawing speed based on the solidified shell thickness; S33: Determine the target curve of the mold cooling intensity based on the temperature distribution in the central liquid phase region; S34: Calculate the required water flow rate for each section of secondary cooling based on the surface temperature distribution of each section in the secondary cooling zone and the target curve of the drawing speed, and generate the target curve of the water flow rate for each section of secondary cooling according to the preset flow distribution strategy; The target curve group includes the target curve of the drawing speed, the target curve of the mold cooling intensity, and the target curve of the water flow rate for each section of secondary cooling.

[0069] Among them, the prediction information of the slab state refers to the estimated data of the temperature distribution and solidification state of the slab in the mold and the secondary cooling zone at the end of the unplanned shutdown, which can be realized by using the numerical simulation method based on the heat conduction and solidification model.

[0070] The solidified shell thickness refers to the thickness of the solid shell formed by the solidification of the slab at a specific position (such as the mold outlet), which can be determined by the method of judging the solidification front position based on the temperature distribution.

[0071] The temperature distribution in the central liquid phase region refers to the temperature change of the liquid metal that has not solidified in the central region of the slab along the length direction, which can be determined by the method of extracting the center line temperature based on the temperature distribution data.

[0072] The surface temperature distribution of each section in the secondary cooling zone refers to the temperature change of the surface of the slab in different cooling sections along the length direction in the secondary cooling zone, which can be determined by the method of extracting the surface temperature based on the temperature distribution data.

[0073] The target curve of the drawing speed refers to the preset trajectory of the speed of the drawing device pulling the slab changing with time or the position of the slab during the resumption of production.

[0074] The target curve of the mold cooling intensity refers to the preset trajectory of the cooling intensity of the mold on the slab changing with time or the position of the slab during the resumption of production.

[0075] The target curve of the water flow rate for each section of secondary cooling refers to the preset trajectory of the cooling water flow rate sprayed or immersed by each section in the secondary cooling zone on the slab changing with time or the position of the slab during the resumption of production.

[0076] The preset flow distribution strategy refers to the rule or algorithm for distributing the total required water flow rate of secondary cooling calculated to each cooling section in the secondary cooling zone, and the flow rate ratio of each section can be determined by the method based on the length ratio of each section, based on the target temperature gradient of each section, or based on the optimization algorithm.

[0077] Further, step S34 includes: S341: Divide the continuous casting billet into multiple nodes along the thickness direction and establish the heat conduction equation between the nodes; S342: According to the surface temperature distribution of each section in the secondary cooling zone and the target curve of the drawing speed during the recovery stage, construct the boundary conditions of the heat conduction equation between the nodes, and the boundary conditions are used to solve the heat conduction equation between the nodes; S343: Adopt an iterative algorithm to adjust the water flow required for each section in the secondary cooling zone, solve the heat conduction equation between the nodes until the deviation between the calculated surface temperature of the continuous casting billet and the surface temperature distribution of each section in the secondary cooling zone is less than the preset threshold; S344: According to the water flow required for each section in the secondary cooling zone obtained after adjustment, combined with the preset flow distribution strategy, distribute the total water flow to each cooling section to generate the target curve of the water flow for each section in the secondary cooling.

[0078] Among them, assuming that the continuous casting billet is divided into N nodes along the thickness direction, and the distance between adjacent nodes is equal, the heat conduction equation between the nodes can be expressed as: , where, is the theoretical temperature of the i-th node, is the square of the node spacing, represents the next theoretical temperature adjacent to the i-th node, represents the previous theoretical temperature adjacent to the i-th node; is the solidification latent heat release of the i-th node.

[0079] Among them, the surface temperature distribution of each section in the secondary cooling zone is: ; is the heat transfer coefficient of the heat conduction equation between the nodes, .

[0080] Among them is the drawing speed at time t, and the target curve of the drawing speed during the recovery stage can be expressed as: , where, , , ... are coefficients determined according to process requirements and billet characteristics, and t is time.

[0081] Since the drawing speed will affect the residence time of the continuous casting billet in each section of the secondary cooling zone, thus affecting the surface temperature of the continuous casting billet, therefore, the drawing speed can be taken into account when constructing the heat transfer coefficient of the heat conduction equation.

[0082] Therefore, by combining the surface temperature distribution of each section in the secondary cooling zone and the target curve of the drawing speed during the recovery stage, the boundary conditions of the heat conduction equation between nodes are obtained as follows: .

[0083] The formula for adjusting the water flow required for each section in the secondary cooling zone using an iterative algorithm is as follows: , where is the water flow of the m-th section during the n-th iteration; is the water flow of the m-th section during the n-th iteration; is the adjustment coefficient, which plays a role in adjusting the cooling intensity according to the deviation between the surface temperature of the billet and the target surface temperature of the billet. It can be set according to the experience of technicians and gradually debugged in actual applications; is the surface temperature of the billet calculated during the n-th iteration; is the target surface temperature of the billet, that is, the temperature desired to be achieved during the production process.

[0084] Using the finite difference method to solve the heat conduction equation, the temperature distribution T(x, t) inside the billet is obtained, specifically as follows: , where is the temperature of the i-th node during the n-th iteration, is the temperature of the i-th node during the (n + 1)-th iteration; is the temperature of the (i + 1)-th node during the n-th iteration; is the temperature of the (i - 1)-th node during the n-th iteration; ρ is the density of the billet, is the relationship between the specific heat capacity of the billet and temperature change, is the time step. The iteration stops until the deviation between the calculated surface temperature of the billet and the surface temperature distribution of each section in the secondary cooling zone is less than the preset threshold; otherwise, continue to adjust the water flow and re-solve the heat conduction equation between nodes.

[0085] Combining the preset flow distribution strategy means that after determining the total water flow required for each section, the total flow is distributed to each independent control section in the secondary cooling zone according to the preset rules or ratios. It can be combined using a proportional distribution strategy based on the length ratio of each section, a fixed ratio set based on experience, or a dynamic ratio distribution strategy based on specific cooling curve requirements.

[0086] Distributing the total water flow to each cooling section means determining the specific water supply flow for each independent control unit in the secondary cooling zone according to the distribution strategy. It can be achieved by controlling the output of valves or pumps and setting the calculated flow values into the cooling water control systems of each cooling section.

[0087] Further, step S5 includes: S51: Obtain the measurement time when collecting the measured data of the slab surface temperature, and calculate the current position of the slab downstream of the secondary cooling zone under the measured data of the slab surface temperature according to the target curve of the drawing speed and the measurement time; S52: Calculate the theoretical surface temperature of the slab at the current position according to the target curve group; S53: Subtract the theoretical surface temperature of the slab from the measured data of the slab surface temperature to obtain a temperature deviation.

[0088] Specifically, first, according to the target curve of the drawing speed in the recovery stage and the measurement time when collecting the measured data of the slab surface temperature, calculate the actual position of the slab corresponding to the measured data downstream of the secondary cooling zone.

[0089] In the actual continuous casting production application, the position sensor is easily affected by high temperature, and it is difficult to meet the process requirements in terms of measurement accuracy. Among the existing high-temperature resistant position sensors, such as eddy current position sensors, magnetostrictive position sensors, etc., the cost is relatively high, which is not conducive to industrial promotion. Further, even if a high-temperature resistant position sensor is adopted, on the continuous casting production line, due to environmental factors such as cooling water impact and vibration, the measurement accuracy of the position sensor will be distorted.

[0090] The reason why this application chooses to adopt the indirect calculation method is, on the one hand, to save costs, and on the other hand, to ensure the accuracy of obtaining the current position. In addition, the calculation method is stored in the software, and there is no need to consider the problem of mechanical wear, which provides convenience for later maintenance.

[0091] This application realizes the acquisition of the current position by integrating the speed of the drawing speed target curve before the measurement time point, so as to determine the distance that the slab moves from the starting position (such as the mold outlet) to the measurement point. The actually measured temperature data and the theoretically calculated temperature data are corresponding to the same position of the slab to ensure the accuracy of the comparison.

[0092] Secondly, according to the overall target curve group in the recovery stage, calculate the theoretical surface temperature of the slab at the above-determined current position. This usually requires using a slab heat conduction model, which takes parameters such as the mold cooling intensity and the water flow rate of each section of secondary cooling included in the above target curve group as inputs to simulate the temperature change of the slab along the length direction during the process of resuming the drawing speed. Through this model, the theoretical surface temperature that the slab should reach when operating according to the target curve can be calculated at the current position.

[0093] Finally, subtract the measured slab surface temperature data actually collected from the theoretical slab surface temperature calculated at this position to obtain the temperature deviation. This temperature deviation reflects the difference between the slab temperature during actual production and the theoretical temperature when operating according to the plan (target curve group).

[0094] This method determines the actual position of the slab by combining the casting speed target curve and the measurement time, and calculates the theoretical surface temperature at this position based on the target curve, so as to achieve a more accurate evaluation of the temperature deviation.

[0095] Furthermore, step S52 includes: S521: Extract the mold cooling intensity target curve and the water flow target curve for each section of secondary cooling in the target curve group; S522: Calculate the slab surface temperature at the mold outlet according to the mold cooling intensity target curve and the current position of the slab; S523: Calculate the temperature change of the slab in the secondary cooling zone section by section according to the slab surface temperature at the mold outlet and the water flow target curve for each section of secondary cooling, and obtain the theoretical slab surface temperature at the current position.

[0096] Specifically, this solution aims to provide a more accurate method for calculating the theoretical surface temperature of the slab, thereby improving the accuracy of temperature deviation calculation and ultimately enhancing the production quality of oxygen-free copper slabs.

[0097] First, extract the mold cooling intensity target curve and the water flow target curve for each section of secondary cooling in the target curve group, which are the basic data for calculating the theoretical surface temperature of the slab. These target curves are generated based on the predicted state of the slab after unscheduled shutdown and represent the cooling strategy planned to be adopted during the resumption of production.

[0098] The mold cooling intensity and the secondary cooling water flow directly affect the cooling rate and temperature distribution of the slab. Therefore, accurately extracting these data is the key to subsequent calculations. Then, calculate the slab surface temperature at the mold outlet according to the mold cooling intensity target curve and the current position of the slab. The mold outlet temperature is the initial temperature of the slab entering the secondary cooling zone and has an important impact on subsequent temperature changes. By combining the distribution of the mold cooling intensity along the length direction and the movement of the slab in the mold, the mold outlet temperature can be estimated more accurately.

[0099] Finally, according to the surface temperature of the slab at the mold outlet and the target curve of the water flow rate in each section of the secondary cooling, the temperature change of the slab in the secondary cooling zone is calculated section by section, and the theoretical surface temperature of the slab at the current position is obtained. This method of calculating section by section takes into account the differences in the cooling intensity of each section in the secondary cooling zone, can more accurately simulate the temperature change process of the slab in the secondary cooling zone, and thus obtain a more accurate theoretical surface temperature of the slab.

[0100] Further, step S6 includes: S61: Determine the correction strategies for the resumed drawing speed, the mold cooling intensity, and the water flow rate in each section of the secondary cooling; S62: Based on the correction strategies, calculate the correction amounts for the drawing speed, the mold cooling intensity, and the water flow rate in each section of the secondary cooling during the recovery stage according to the temperature deviation; S63: Add the correction amounts for the drawing speed, the mold cooling intensity, and the water flow rate in each section of the secondary cooling to the target curve groups of the drawing speed, the mold cooling intensity, and the water flow rate in each section of the secondary cooling respectively, to obtain the corrected target curve groups, and use the corrected target curves for production.

[0101] Among them, the correction strategy refers to the rules or algorithms for determining how to calculate the correction amounts for the drawing speed, the mold cooling intensity, and the water flow rate in each section of the secondary cooling according to the magnitude, direction, and change trend of the temperature deviation. It can be implemented by proportional control, proportional integral derivative (PID) control, fuzzy control, model-based control, or look-up table method, etc.

[0102] Specifically, in this solution, during the process of resuming production, the deviation between the real-time measured surface temperature of the slab and the theoretical temperature is used as a feedback signal to dynamically adjust the target curves of the drawing speed, the mold cooling intensity, and the water flow rate in each section of the secondary cooling.

[0103] First, a correction strategy needs to be preset or determined online. This strategy defines how the temperature deviation is converted into the adjustment amounts for various process parameters. For example, when the measured temperature is higher than the theoretical temperature, it may be necessary to reduce the drawing speed and increase the cooling intensity; when the measured temperature is lower than the theoretical temperature, it may be necessary to increase the drawing speed and weaken the cooling intensity. Based on this determined correction strategy, the temperature deviation calculated in step S5 is input into the correction algorithm to calculate the amounts that need to be adjusted for the drawing speed, the mold cooling intensity, and the water flow rate in each section of the secondary cooling at the current moment, that is, the correction amounts.

[0104] These correction amounts reflect the differences between the actual state of the current slab and the predicted state based on the initial target curves, as well as the amplitude of the parameter adjustment required to eliminate this difference.

[0105] Finally, add the calculated correction amounts to the target curves of the original drawing speed, mold cooling intensity, and water flow rates in each section of secondary cooling generated in step S3, respectively, so as to obtain a new set of target curves that have been corrected in real time.

[0106] In the subsequent production process, the control system no longer executes completely according to the initial set of target curves, but uses this set of corrected target curves to control the drawing device and the cooling system. This process can be continuously carried out to form a closed-loop control, enabling the process parameters to be dynamically adjusted according to the actual temperature state of the billet, thereby more precisely guiding the billet to complete the solidification and cooling processes. In this way, this solution combines prediction (S1 - S3) with real-time feedback (S4 - S5), uses the temperature deviation to correct the initial plan online, and improves the adaptability and accuracy of process control in the resumed production stage. Please refer to Figure 2 , an oxygen-free copper billet production regulation and control system, which is applied to the steps of any of the above methods. The system includes: Unplanned stop information acquisition module 201: Acquire the duration of unplanned stop and the cooling conditions during the stop; Billet state prediction module 202: Based on the duration of unplanned stop and the cooling conditions, predict the temperature distribution and solidification state of the billet in the mold and the secondary cooling zone at the end of the stop, and obtain billet state prediction information; Target curve generation module 203: According to the billet state prediction information, generate the target curves of the drawing speed, mold cooling intensity, and water flow rates in each section of secondary cooling during the resumption stage, and form a set of target curves; Temperature data acquisition module 204: During the process of gradually increasing the drawing speed, acquire the surface temperature of the billet downstream of the secondary cooling zone to obtain billet surface temperature measurement data; Temperature deviation calculation module 205: Compare the billet surface temperature measurement data with the theoretical surface temperature of the billet at the current position calculated based on the target curve of the drawing speed to obtain the temperature deviation; Parameter correction control module 206: Based on the temperature deviation, correct the target curves of the drawing speed, mold cooling intensity, and water flow rates in each section of secondary cooling to obtain a set of corrected target curves, and use the set of corrected target curves for production.

[0107] Among them, the unplanned stop information acquisition module 201 refers to the unit used to collect the basic data related to unplanned stop events, which can be implemented by sensors, data interfaces, or manual input interfaces.

[0108] The billet state prediction module 202 refers to the unit used to simulate and calculate the change of the internal thermal state of the billet during the stop, which can be implemented by a simulation software module based on physical models (such as finite element, finite difference).

[0109] The target curve generation module 203 refers to a unit that calculates and outputs a preset trajectory of various key parameters during the resumption of production changing with time or position according to the predicted billet state, and it can be implemented by an algorithm program running on a computer or a controller.

[0110] The temperature data acquisition module 204 refers to a unit that is used to monitor the surface temperature of the billet in real time, and it can be implemented by non-contact or contact temperature sensors such as infrared thermometers and thermocouples.

[0111] The temperature deviation calculation module 205 refers to a unit that is used to compare the difference between the actually measured temperature and the theoretically calculated temperature, and it can be implemented by a data processing program running on a processing unit.

[0112] The parameter correction control module 206 refers to a unit that adjusts the target curve group according to the temperature deviation and outputs a control instruction, and it can be implemented by a closed-loop control algorithm module running on a controller.

[0113] Specifically, through the modular design, the system functionalizes each step function of the above method, thereby realizing the automatic execution of the entire regulation process.

[0114] First, the parking information acquisition module 201 acquires the duration of the unplanned parking and the cooling conditions during the parking, and these data are provided to the billet state prediction module 202. Based on these data, the billet state prediction module 202 predicts the temperature distribution and solidification state of the billet at the end of the parking, and obtains the billet state prediction information. This prediction information reflects the actual internal state of the billet after parking and provides a basis for subsequent parameter adjustment.

[0115] The target curve generation module 203 generates initial target curves for the drawing speed, mold cooling intensity, and water flow rates in each section of secondary cooling during the recovery stage according to the billet state prediction information, providing guidance for the resumption of production. During the gradual increase of the drawing speed, the temperature data acquisition module 204 acquires the surface temperature of the billet downstream of the secondary cooling zone in real time, obtaining the billet surface temperature measurement data.

[0116] The temperature deviation calculation module 205 compares the measured temperature with the theoretical surface temperature of the billet at the current position calculated based on the drawing speed target curve to obtain the temperature deviation.

[0117] The parameter correction control module 206 corrects the target curve group for the drawing speed, mold cooling intensity, and water flow rates in each section of secondary cooling based on the temperature deviation, and uses the corrected target curves for production. Through the closed loop formed by temperature data acquisition, deviation calculation, and parameter correction control, the system can perceive and respond to the changes in the billet state in real time and dynamically adjust the production parameters.

[0118] The system automates the complex calculation and judgment processes in the above method, enabling rapid and precise regulation. Thus, during the production resumption process, the drawing speed and cooling intensity can be dynamically adjusted according to the actual state of the continuous casting billet, avoiding defects caused by mismatches between parameters and the billet state.

[0119] In this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0120] The above description is only for the embodiments of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A method for regulating the production of oxygen-free copper billets, which is used to resume production after an unplanned shutdown, is characterized in that, The method includes the steps of: S1: Obtain the unplanned parking duration and the cooling conditions during parking; S2: Based on the unplanned parking duration and the cooling conditions, predict the temperature distribution and solidification state of the billet in the mold and the secondary cooling zone at the end of parking, and obtain billet state prediction information; S3: According to the billet state prediction information, generate target curves for the drawing speed, mold cooling intensity, and water flow rates in each section of the secondary cooling respectively during the recovery stage, and form a set of target curves; S4: During the process of gradually increasing the drawing speed, collect the surface temperature of the billet downstream of the secondary cooling zone to obtain billet surface temperature measurement data; S5: Compare the billet surface temperature measurement data with the theoretical surface temperature of the billet at the current position calculated based on the target curve of the drawing speed to obtain a temperature deviation; S6: Based on the temperature deviation, correct the target curves for the drawing speed, mold cooling intensity, and water flow rates in each section of the secondary cooling to obtain a corrected set of target curves, and use the corrected set of target curves for production.

2. A method for regulating the production of oxygen-free copper billets according to claim 1, characterized in that, Step S1 includes: S11: Determine the unplanned parking duration. If the parking duration is less than the preset duration threshold, it is determined as short-term parking; if the parking duration is greater than or equal to the preset duration threshold, it is determined as long-term parking; S12: When it is determined as short-term parking, obtain the mold cooling water flow rate, the cooling water flow rates in each section of the secondary cooling, and the cooling water temperature, and record them as short-term parking cooling conditions; S13: When it is determined as long-term parking, judge whether to start the emergency cooling mode; if it is started, obtain the mold emergency cooling water flow rate, the emergency cooling water flow rates in each section of the secondary cooling, and the cooling water temperature, and record them as long-term parking cooling conditions; if it is not started, determine that the cooling condition is natural cooling and record the ambient temperature.

3. A method for regulating the production of oxygen-free copper billets according to claim 1, characterized in that, Step S2 includes: S21: Construct a billet heat conduction and solidification model; S22: Use the billet heat conduction and solidification model to simulate the temperature field change inside the billet during parking until the simulation duration reaches the unplanned parking duration, and obtain the temperature distribution of the billet in the mold and the secondary cooling zone at the end of parking; S23: Based on the temperature distribution, judge the solidification state of each position of the billet; S24: Integrate the temperature distribution and the solidification state to generate billet state prediction information, where the billet state prediction information includes the temperature values, solidified shell thickness, and liquidus position of each position of the billet.

4. A method for regulating the production of oxygen-free copper billets according to claim 3, characterized in that, Step S21 includes: S211: Measure the cooling water flow rate, water temperature, and spray density data along the length direction of the billet, establish a mapping relationship between the cooling intensity and the position, and obtain the cooling intensity distribution of the mold and the secondary cooling zone; S212: Obtain the thermal conductivity, specific heat capacity, and density of the billet according to the material of the billet, and establish a thermophysical functional relationship between the thermal conductivity, specific heat capacity, and density and the temperature change of the billet; S213: Determine the latent heat release parameter of solidification of the billet according to the specific heat capacity of the billet; S214: Construct the billet heat conduction and solidification model according to the cooling intensity distribution of the mold and the secondary cooling zone, the thermophysical functional relationship, and the latent heat release parameter of solidification.

5. A method for regulating the production of oxygen-free copper billets according to claim 1, characterized in that, Step S3 includes: S31: Determine the solidified shell thickness at the mold outlet, the temperature distribution in the central liquid zone, and the surface temperature distribution of each section in the secondary cooling zone based on the slab state prediction information; S32: Calculate the target curve of the drawing speed based on the solidified shell thickness; S33: Determine the target curve of the mold cooling intensity based on the temperature distribution in the central liquid zone; S34: Calculate the required water flow rate for each section in the secondary cooling based on the surface temperature distribution of each section in the secondary cooling zone and the target curve of the drawing speed, and generate the target curve of the water flow rate for each section in the secondary cooling according to the preset flow distribution strategy; The target curve group includes the target curve of the drawing speed, the target curve of the mold cooling intensity, and the target curve of the water flow rate for each section in the secondary cooling.

6. A method for regulating the production of oxygen-free copper billets according to claim 5, characterized in that, Step S34 includes: S341: Divide the slab into multiple nodes along the thickness direction and establish the heat conduction equation between the nodes; S342: Construct the boundary conditions of the heat conduction equation between the nodes based on the surface temperature distribution of each section in the secondary cooling zone and the target curve of the drawing speed in the recovery stage, and the boundary conditions are used to solve the heat conduction equation between the nodes; S343: Use the iterative algorithm to adjust the required water flow rate for each section in the secondary cooling zone, solve the heat conduction equation until the deviation between the calculated slab surface temperature and the surface temperature distribution of each section in the secondary cooling zone is less than the preset threshold; S344: According to the adjusted required water flow rate for each section in the secondary cooling zone, combine the preset flow distribution strategy, allocate the total water flow rate to each cooling section, and generate the target curve of the water flow rate for each section in the secondary cooling.

7. A method for regulating the production of oxygen-free copper billets according to claim 1, characterized in that, Step S5 includes: S51: Obtain the measurement time when the slab surface temperature measurement data is collected, and calculate the current position of the slab downstream in the secondary cooling zone under the slab surface temperature measurement data according to the target curve of the drawing speed and the measurement time; S52: Calculate the theoretical surface temperature of the slab at the current position according to the target curve group; S53: Subtract the theoretical surface temperature of the slab from the slab surface temperature measurement data to obtain the temperature deviation.

8. A method for regulating the production of oxygen-free copper billets according to claim 7, characterized in that Step S52 includes: S521: Extract the mold cooling intensity target curve and the water flow rate target curve for each section in the secondary cooling from the target curve group; S522: Calculate the surface temperature of the slab at the mold outlet according to the mold cooling intensity target curve and the current position of the slab; S523: According to the surface temperature of the slab at the mold outlet and the water flow rate target curve for each section in the secondary cooling, calculate the temperature change of the slab in the secondary cooling zone section by section to obtain the theoretical surface temperature of the slab at the current position.

9. A method for regulating the production of oxygen-free copper billets according to claim 1, characterized in that, Step S6 includes: S61: Determine the correction strategies for the recovery speed, the mold cooling intensity, and the water flow rate for each section in the secondary cooling; S62: Based on the correction strategies, calculate the correction amount of the drawing speed, the correction amount of the mold cooling intensity, and the correction amount of the water flow rate for each section in the secondary cooling according to the temperature deviation; S63: Superimpose the withdrawal speed correction amount, mold cooling intensity correction amount, and water flow correction amounts for each section of secondary cooling onto the target curves of the withdrawal speed, mold cooling intensity, and water flow for each section of secondary cooling respectively, to obtain the corrected target curve group, and use the corrected target curve group for production.

10. An oxygen-free copper billet production control system, characterized in that, Applied to the steps of the method according to any one of claims 1-9 above, the system includes: A stop information acquisition module: acquire the unplanned stop duration and the cooling conditions during the stop; A billet state prediction module: based on the unplanned stop duration and the cooling conditions, predict the temperature distribution and solidification state of the billet in the mold and the secondary cooling zone at the end of the stop, to obtain billet state prediction information; A target curve generation module: generate target curves for the withdrawal speed, mold cooling intensity, and water flow for each section of secondary cooling in the recovery stage respectively according to the billet state prediction information; A temperature data acquisition module: during the process of gradually increasing the withdrawal speed, acquire the surface temperature of the billet downstream of the secondary cooling zone, to obtain billet surface temperature measurement data and form a target curve group; A temperature deviation calculation module: compare the billet surface temperature measurement data with the theoretical surface temperature of the billet at the current position calculated based on the target curve of the withdrawal speed, to obtain a temperature deviation; A parameter correction control module: based on the temperature deviation, correct the target curves of the withdrawal speed, mold cooling intensity, and water flow for each section of secondary cooling, to obtain a corrected target curve group, and use the corrected target curve group for production.

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