Water cooling system and control method for horizontal continuous casting of internally threaded copper tubes

Abstract

The present invention relates to the technical field of intelligent production of copper tubes, and in particular to a water cooling system and control method for horizontal continuous casting of internally threaded copper tubes, comprising: a region division module for functionally partitioning the water cooling system and generating multiple cooling zones; a temperature monitoring configuration module for setting multiple temperature monitoring points according to the multiple cooling zones; a data acquisition module for real-time acquisition of the copper tube drawing speed and the real-time temperatures of multiple temperature monitoring points; a fluctuation analysis module for performing comprehensive fluctuation analysis on multiple real-time temperatures to obtain temperature fluctuation characteristics; the system can adapt to changes in drawing speed, dynamically integrate process constraints, and accurately control by zone.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent production of copper tubes, and in particular to a water cooling system and a control method for horizontal continuous casting of internally threaded copper tubes. Background Art

[0002] As a key component in refrigeration, heat exchange and other fields, the manufacturing quality of internally threaded copper tubes directly depends on the stability of the horizontal continuous casting process. During the continuous casting process, the cooling control of the copper tubes from liquid metal solidification is particularly critical - it is necessary to ensure that the surface solidifies rapidly to form a uniform shell, while avoiding internal grain coarsening or cracking.

[0003] Existing water cooling systems often lack a detailed concept of regional division and generally control the entire water cooling process as a whole. They are unable to implement precise regulation based on the unique needs of different functional areas. As a result, during the continuous casting process, it is difficult to effectively deal with the complex conditions caused by the different temperature change characteristics of the copper tubes in different areas. As a result, the temperature distribution of the copper tubes is uneven during the cooling process, which in turn affects the internal structure and surface quality of the copper tubes, making them prone to defects such as cracks and deformation.

[0004] At the same time, when faced with the dynamic adjustment of the copper tube pulling speed, the existing water cooling system fails to fully consider the impact of the pulling speed change on the temperature control of each cooling area, lacks an effective mechanism for coordinated control based on the real-time pulling speed and temperature fluctuations of the copper tube, and does not fully utilize the various condition constraints in the production process requirements to optimize the control objectives of the water cooling system. As a result, it is difficult for the water cooling system to achieve the best control effect during operation, which not only wastes energy but also fails to meet the increasingly high production quality standards.

[0005] Therefore, there is an urgent need for a water cooling system that can adapt to changes in drawing speed, dynamically integrate process constraints, and precisely control different areas to improve the forming quality and production efficiency of internally threaded copper tubes. Summary of the Invention

[0006] The present invention provides a water cooling system and control method for horizontal continuous casting of internally threaded copper tubes that can adapt to changes in casting speed, dynamically integrate process constraints, and accurately control regions, which can effectively solve the problems in the background technology.

[0007] In order to achieve the above objectives, in a first aspect, the present invention provides a water cooling system for horizontal continuous casting of an internally threaded copper tube, comprising:

[0008] The zone division module is used to divide the water cooling system into functional zones and generate multiple cooling zones;

[0009] A temperature monitoring configuration module, configured to set a plurality of temperature monitoring points according to the plurality of cooling zones;

[0010] A data acquisition module is used to obtain the copper tube drawing speed and the real-time temperature of the plurality of temperature monitoring points in real time;

[0011] A fluctuation analysis module, configured to perform comprehensive fluctuation analysis on the multiple real-time temperatures to obtain temperature fluctuation characteristics;

[0012] A constraint triggering module is configured to obtain the conditional constraints required by the production process and the real-time operation vector of each cooling zone when it is detected that the real-time pulling speed of the copper tube exceeds a preset pulling speed range and / or the temperature fluctuation characteristic exceeds a preset fluctuation threshold;

[0013] A function optimization module, configured to convert the conditional constraints into constraint vectors, and integrate the constraint vectors into the control objective function corresponding to each cooling zone to perform function update;

[0014] The control decision module is used to input the real-time operation vector into the corresponding updated control objective function, obtain the water cooling control instruction corresponding to the cooling area, and independently adjust the water cooling actuator parameters of the cooling area.

[0015] In combination with the first aspect, in one possible design, the multiple cooling zones include a crystallizer cooling zone, a primary cooling zone, and a secondary cooling zone.

[0016] In a second aspect, the present invention further provides a water cooling control method for horizontal continuous casting of an internally threaded copper tube, comprising:

[0017] Dividing the water cooling system into zones to obtain multiple cooling zones, including at least a crystallizer cooling zone, a primary cooling zone, and a secondary cooling zone;

[0018] According to the plurality of cooling areas, a plurality of temperature monitoring points are set;

[0019] Obtaining the real-time pulling speed of the copper tube and the real-time temperatures of the plurality of temperature monitoring points;

[0020] Performing comprehensive fluctuation analysis on the multiple real-time temperatures to obtain temperature fluctuation characteristics;

[0021] In response to the copper tube real-time pulling speed not being within a preset pulling speed range, and / or the temperature fluctuation characteristic exceeding a preset fluctuation threshold, obtaining condition constraints required by the production process and a real-time operation vector of each cooling zone;

[0022] Converting the conditional constraints into constraint vectors, and integrating the constraint vectors into the control objective function corresponding to each cooling zone to perform function update;

[0023] Each of the real-time operation vectors is input into the corresponding updated control objective function to obtain the water cooling control instruction of the cooling area, and the water cooling actuator parameters of the cooling area are independently adjusted accordingly.

[0024] In conjunction with the second aspect, in one possible design, the real-time operation vector includes at least one of the following parameters:

[0025] The real-time water flow, real-time water pressure, real-time water temperature and cooling nozzle opening status of each cooling area.

[0026] In conjunction with the second aspect, in a possible design, the real-time operation vector further includes: a cooling efficiency coefficient calculated according to the real-time pulling speed of the copper tube, and the cooling efficiency coefficient calculation formula is:

[0027] η=( v⋅T target ) / ( P water ⋅Q);

[0028] Where η is the cooling efficiency coefficient, v is the real-time pulling speed, T target is the target temperature of the cooling area, P water is the real-time water pressure, and Q is the real-time water flow.

[0029] In conjunction with the second aspect, in one possible design, the setting of the temperature monitoring points includes:

[0030] A first temperature sensor and a second temperature sensor are respectively provided at the inlet and outlet of the crystallizer cooling zone to monitor the temperature difference of the solidified shell on the surface of the copper tube;

[0031] An annular array of infrared thermometers is arranged at equidistant axial positions in the primary cooling zone to capture radial temperature gradient distribution data of the copper tube;

[0032] Distributed temperature sensor arrays are provided at multiple cross sections of the secondary cooling zone to obtain axial temperature gradient distribution data of the copper tube.

[0033] In conjunction with the second aspect, in one possible design, the comprehensive fluctuation analysis includes:

[0034] Comprehensively calculating the real-time temperature standard deviation of the plurality of cooling areas as a first fluctuation feature;

[0035] Frequency domain analysis is performed on the temperature sequences of the plurality of temperature monitoring points in the same cooling area, and the proportion of fluctuation energy above a preset characteristic frequency is extracted as a second fluctuation feature.

[0036] In conjunction with the second aspect, in one possible design, the preset characteristic frequency is dynamically adjusted according to the real-time pulling speed of the copper tube and satisfies the following relationship:

[0037] f c =k⋅v;

[0038] Among them, f c is the preset characteristic frequency, v is the real-time casting speed, and k is the process correlation coefficient.

[0039] In conjunction with the second aspect, in one possible design, the temperature fluctuation characteristic exceeds a preset fluctuation threshold, including:

[0040] The first fluctuation feature and / or the second fluctuation feature exceeds the corresponding preset fluctuation threshold.

[0041] In conjunction with the second aspect, in one possible design, updating the control objective function includes:

[0042] A differentiated objective function is defined for each of the cooling zones:

[0043] The objective function of the mold cooling zone prioritizes maximizing the solidification rate of the copper tube surface;

[0044] The objective function of the primary cooling zone prioritizes heat flux stability;

[0045] The objective function of the secondary cooling zone prioritizes minimizing the axial temperature gradient;

[0046] The constraint vector is embedded into the objective function in the form of Lagrange multipliers to generate the control objective function with constraint optimization.

[0047] The technical solution of the present invention can achieve the following technical effects:

[0048] Through the regional division module and the temperature monitoring configuration module, the cooling process is divided into multiple cooling areas, and temperature monitoring points are independently configured to realize regional temperature field perception. Differential regulation is performed on the cooling characteristics of different areas to avoid the imbalance of surface and internal cooling caused by traditional overall control, and significantly reduce cracks and deformation defects; the data acquisition module obtains the drawing speed data in real time, the fluctuation analysis module combines the drawing speed and temperature fluctuation characteristics, and triggers the constraint trigger module to dynamically adjust the control strategy. When the drawing speed changes, the system automatically predicts the trend of heat load changes and coordinates to adjust the water cooling intensity of each area to prevent grain coarsening or overcooling defects caused by drawing speed fluctuations; the function optimization module The block converts the production process constraints into mathematical constraint vectors, embeds the regionalized control objective function, and simultaneously optimizes energy consumption and water cooling efficiency while meeting the core process requirements of surface quality and internal organization, taking into account both quality and energy efficiency; the control decision module generates instructions based on the updated objective function, and the execution control module independently adjusts the water cooling parameters of each area. Local temperature anomalies can be quickly isolated and processed through independent regulation to avoid global system downtime and ensure continuous production stability; the energy efficiency balance coefficient is dynamically calculated through real-time operation vectors to constrain control instruction generation; within the range allowed by the process, the water pressure set value in high-energy consumption areas is preferentially reduced to reduce ineffective cooling and reduce overall energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0050] Figure 1 This is a structural block diagram of the water cooling system for horizontal continuous casting of internally threaded copper tubes;

[0051] Figure 2 The following is a logic flow chart of the water cooling control method for horizontal continuous casting of internally threaded copper tubes. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0053] The present application is described below in conjunction with the accompanying drawings.

[0054] like Figure 1As shown, a water cooling system for horizontal continuous casting of internally threaded copper tubes of the present invention specifically includes: a region division module, a temperature monitoring configuration module, a data acquisition module, a fluctuation analysis module, a constraint triggering module, a function optimization module, and a control decision module;

[0055] The area division module functionally partitions the water cooling system to generate multiple cooling areas; the multiple cooling areas include a crystallizer cooling area, a primary cooling area, and a secondary cooling area; the temperature monitoring configuration module sets multiple temperature monitoring points according to the multiple cooling areas; the data acquisition module obtains the real-time temperature of the copper tube drawing speed and multiple temperature monitoring points in real time; the fluctuation analysis module performs a comprehensive fluctuation analysis on multiple real-time temperatures to obtain temperature fluctuation characteristics; when the constraint triggering module detects that the real-time drawing speed of the copper tube exceeds the preset drawing speed range, and / or the temperature fluctuation characteristics exceed the preset fluctuation threshold, it obtains the conditional constraints required by the production process and the real-time operation vector of each cooling area; the function optimization module converts the conditional constraints into constraint vectors, and integrates them into the control objective function corresponding to each cooling area to update the function; the control decision module inputs the real-time operation vector into the corresponding updated control objective function to obtain the water cooling control instruction corresponding to the cooling area, and thereby independently adjusts the water cooling actuator parameters of the cooling area.

[0056] In this embodiment, the cooling process is divided into multiple cooling areas, such as the crystallizer, primary and secondary cooling areas, through the area division module and the temperature monitoring configuration module, and temperature monitoring points are independently configured to realize regional temperature field perception and perform differentiated regulation on the cooling characteristics of different areas. For example, the crystallization area needs to solidify quickly and the secondary area needs gradient control, so as to avoid the imbalance of surface and internal cooling caused by traditional overall control and significantly reduce cracks and deformation defects. The data acquisition module obtains the pulling speed data in real time, and the fluctuation analysis module combines the pulling speed and temperature fluctuation characteristics, such as the frequency domain energy distribution, to trigger the constraint trigger module to dynamically adjust the control strategy. When the pulling speed changes, such as acceleration leading to a shortened cooling time, the system automatically predicts the trend of heat load changes and coordinates the water cooling intensity of each area to prevent grain coarsening or overcooling defects caused by pulling speed fluctuations. The function optimization module converts the production process into Process constraints, such as temperature gradient limits and energy consumption thresholds, are converted into mathematical constraint vectors and embedded in regional control objective functions. For example, solidification rate is prioritized in the crystallization zone, and gradient minimization is the goal in the secondary zone. While meeting the core process requirements of surface quality and internal organization, energy consumption and water cooling efficiency are optimized simultaneously, taking both quality and energy efficiency into consideration. The control decision module generates instructions based on the updated objective function, and the execution control module independently adjusts the water cooling parameters of each zone. Local temperature anomalies, such as nozzle blockage in a certain area, can be quickly isolated and processed through independent regulation to avoid global system downtime and ensure continuous production stability. Through real-time operation vectors, such as cumulative energy consumption and cooling efficiency coefficient, the energy efficiency balance coefficient is dynamically calculated, and constraint control instructions are generated. Within the allowable range of the process, the water pressure set value of high-energy consumption areas, such as the secondary cooling zone, is prioritized to be reduced to reduce ineffective cooling and reduce comprehensive energy consumption.

[0057] like Figure 2 As shown, the present invention also provides a water cooling control method for horizontal continuous casting of internally threaded copper tubes, which specifically includes the following steps:

[0058] Step S1, dividing the water cooling system into regions to obtain multiple cooling regions;

[0059] Step S2: setting a plurality of temperature monitoring points according to the plurality of cooling zones; the temperature monitoring points are used to monitor the temperature of the copper tube during the continuous casting process, and each cooling zone includes at least one temperature monitoring point;

[0060] Step S3, obtaining the real-time pulling speed of the copper tube and the real-time temperatures of the plurality of temperature monitoring points;

[0061] Step S4: performing comprehensive fluctuation analysis on the multiple real-time temperatures to obtain temperature fluctuation characteristics;

[0062] Step S5: in response to the copper tube real-time pulling speed not being within a preset pulling speed range, and / or the temperature fluctuation characteristic exceeding a preset fluctuation threshold, obtaining the conditional constraints required by the production process and the real-time operation vector of each cooling zone;

[0063] Step S6: converting the conditional constraints into constraint vectors, and integrating them into the control objective function corresponding to each cooling zone to perform function update;

[0064] Step S7: input each of the real-time operation vectors into the corresponding updated control objective function to obtain the water cooling control instruction of the cooling area, and independently adjust the water cooling actuator parameters of the cooling area based on this instruction.

[0065] In this embodiment, through fine zoning control of the water cooling system, precise regulation is implemented according to the functional requirements of different cooling areas, the uniformity of temperature distribution of the copper tube is improved, the internal structure and surface quality are enhanced, and defects such as cracks and deformation are reduced; through dynamic analysis of real-time drawing speed and temperature fluctuation characteristics, a coordinated mechanism of drawing speed change and cooling control is established, and process parameter fluctuations are quickly responded to ensure the stability of the cooling process; the conditional constraints required by the production process are integrated into the control objective function, the operating objectives of the water cooling system are optimized, and the process constraint information is fully utilized to improve production efficiency and product quality; through the input of real-time operation vectors and the update of objective functions, independent and intelligent control of each cooling area is achieved, and the adaptability and control accuracy are improved; this method improves the forming quality of the copper tube while optimizing energy utilization efficiency, reducing production costs, and meeting the increasingly high production quality standards and energy-saving requirements.

[0066] In some embodiments of the present invention, the divided cooling zones include a crystallizer cooling zone, a primary cooling zone, and a secondary cooling zone. Specifically;

[0067] The mold cooling zone is located at the mold outlet (0~0.5m), responsible for the rapid solidification of the copper liquid to form a uniform surface solidification shell. High-pressure atomizing nozzles (pressure 1.5~3.0MPa) are used to achieve high-density cooling.

[0068] The primary cooling zone is located downstream of the crystallizer (0.5~2.0m) and is used to control the grain refinement inside the copper tube. It is equipped with a wide-angle fan-shaped nozzle (pressure 0.8~1.5MPa) to achieve uniform circumferential heat dissipation.

[0069] The secondary cooling zone is located in the middle and rear section of the copper tube (2.0-5.0m) and is divided into three sub-zones (2.0-3.0m, 3.0-4.0m, and 4.0-5.0m). An adjustable angle nozzle (angle 15°-60°) is used to control the axial temperature gradient.

[0070] Each cooling area is independently equipped with a closed-loop water system, including a water pump, regulating valve, pressure sensor and flow meter, to ensure control isolation between areas. Insulation baffles are set at the area boundaries to reduce thermal interference.

[0071] In some embodiments of the present invention, the parameter information included in the real-time operation vector is specifically as follows:

[0072] Real-time water flow rate: This indicates the volume of water flowing through the cooling zone per unit time. It is measured and collected by electromagnetic flowmeters or turbine flowmeters installed in the water inlet pipes of each cooling zone. It directly determines the cooling intensity. For example, the crystallizer cooling zone requires a high flow rate (120-150 L / min) to achieve rapid solidification, while the flow rate in the secondary cooling zone can be dynamically adjusted (80-120 L / min) to match the changes in casting speed.

[0073] Real-time water pressure: This indicates the pressure of cooling water at the nozzle and is measured and collected by pressure sensors installed at the outlet of the water pump in each area. It directly affects the cooling water spray speed and coverage area. For example, high-pressure atomization in the crystallizer (2.0-2.5 MPa) can refine the water droplet size and enhance heat exchange efficiency; low pressure in the secondary cooling zone (0.5-1.0 MPa) prevents cracks caused by overcooling.

[0074] Real-time water temperature: This indicates the inlet temperature of the cooling water and is measured and collected using a PT100 thermal resistor or infrared thermometer installed in the cooling water circulation pipeline. Water temperature determines the driving force of heat conduction. For example, if the water temperature is too high (>35°C), auxiliary refrigeration equipment must be activated to prevent a decrease in cooling capacity. Low-temperature water (15-25°C) can increase the solidification rate.

[0075] Cooling nozzle opening status: indicates the percentage of nozzle valve opening, used to control the water flow cross-sectional area; data is collected through the feedback signal of the electric control valve; by adjusting the cooling nozzle opening status, the cooling coverage and uniformity are adjusted; for example, a nozzle opening of more than 80% in the primary cooling zone ensures full circumferential coverage; differential adjustment of the nozzle opening in the secondary cooling zone sub-zones (such as a combination of 45° and 60° openings) can optimize the axial temperature gradient.

[0076] Specifically, the real-time operation vector can be controlled by either a single parameter or a multi-parameter joint control; single parameter control, for example, only uses water pressure as input, which is suitable for simple process scenarios, such as constant flow control under steady-state pulling speed; multi-parameter joint control, for example, simultaneously monitors water pressure, flow, and water temperature, and is used for complex dynamic working conditions, such as when the pulling speed suddenly changes and the flow and pressure need to be adjusted synchronously; multi-dimensional parameter monitoring covers the key physical quantities of the cooling process, avoiding the blind spots of control caused by single signal control; through parameter correlation analysis, high-efficiency parameters are adjusted preferentially while meeting process requirements.

[0077] In this embodiment, by introducing multi-dimensional operating parameters and calculating the cooling efficiency coefficient, the operating status of the water cooling system is comprehensively described, providing rich data support for precise control; the introduction of the cooling efficiency coefficient enables the system to dynamically adjust the cooling parameters according to the real-time pulling speed, adapt to the cooling requirements under different production conditions, and improve the flexibility and control accuracy of the system; by clarifying the specific parameters of the real-time operating vector and its calculation method, clear guidance is provided for the implementation of the water cooling control system, which is convenient for engineering application; the definition of the real-time operating vector not only supports the current control needs, but also provides basic data for subsequent algorithm optimization, enhancing the scalability and intelligence level of the system.

[0078] More specifically, the real-time operation vector can also use a cooling efficiency coefficient to quantify the matching efficiency between the pulling speed and the target temperature under unit cooling resources. The calculation formula is:

[0079] η=( v⋅T target ) / ( P water ⋅Q);

[0080] Where η is the cooling efficiency coefficient, v is the real-time pulling speed, T target is the target temperature of the cooling area, P water is the real-time water pressure, Q is the real-time water flow; v⋅T target Reflects the production process requirements. The higher the drawing speed or the higher the target temperature, the greater the demand for cooling intensity. water ⋅Q represents cooling resource consumption, and the product of water pressure and flow rate is approximately proportional to the pump power. The higher the cooling efficiency coefficient, the more efficient the matching of target casting speed and temperature is with unit cooling resource input, which means a better energy efficiency ratio. By introducing the cooling efficiency coefficient, process requirements and resource consumption are dynamically linked, solving the pain point of traditional energy efficiency optimization methods lacking quantitative indicators, and significantly improving the economy and reliability of the water cooling system.

[0081] To achieve accurate temperature monitoring and cooling control, the specific deployment of temperature monitoring points in different cooling areas and the selection of sensors include the following:

[0082] Crystallizer cooling zone: A first temperature sensor and a second temperature sensor are installed at the entrance and exit of the crystallizer cooling zone, respectively. The first temperature sensor is installed at the inlet of the copper liquid in the crystallizer, in direct contact with the copper liquid, and measures the initial temperature. A K-type thermocouple is used to monitor the initial thermal state of the copper liquid entering the crystallizer. The second temperature sensor is located at the crystallizer outlet, a certain distance away from the surface of the copper tube, and measures the surface temperature of the solidified shell. A wear-resistant armored thermocouple is used to prevent damage to the copper tube due to movement and friction. The crystallizer cooling zone is the initial stage of copper tube solidification. The temperature difference of the surface solidified shell directly affects the surface quality of the copper tube. By arranging sensors at the inlet and outlet, the temperature changes of the copper tube in the early stage of solidification can be captured in real time, ensuring that a uniform shell is quickly formed on the surface and avoiding cracks or surface defects caused by excessive temperature differences.

[0083] Primary cooling zone: Annular array infrared thermometers are installed at equidistant axial positions in the primary cooling zone to capture radial temperature gradient distribution data of the copper tube. The primary cooling zone is the main stage of copper tube solidification, and the uniformity of the radial temperature gradient is crucial to the internal structure of the copper tube. The annular array infrared thermometer can cover the entire circumference of the copper tube and monitor the radial temperature distribution in real time to ensure cooling uniformity and avoid grain coarsening or deformation defects caused by excessive radial temperature differences.

[0084] Secondary cooling zone: Distributed temperature sensor arrays are set up at multiple cross-sections in the secondary cooling zone to obtain axial temperature gradient distribution data of the copper tube. The secondary cooling zone is the later stage of copper tube solidification. The control of the axial temperature gradient directly affects the dimensional stability and internal quality of the copper tube. The distributed temperature sensor array can monitor temperature changes at multiple points along the axial direction of the copper tube, capture the axial temperature gradient distribution, ensure the stability of the cooling process, and avoid thermal stress concentration or dimensional deviation caused by excessive axial temperature difference.

[0085] In this embodiment, appropriate temperature monitoring point layout schemes are designed according to the functional requirements of different cooling areas. Multiple sensors and multiple layout methods are used to realize multi-dimensional monitoring of the temperature distribution of the copper tube, covering multiple key parameters such as radial, axial and surface. Through multi-point and multi-mode temperature monitoring, the temperature distribution data of the copper tube in different cooling areas is obtained in real time, which provides accurate data support for subsequent fluctuation analysis, control objective function update and water cooling control instruction generation, thereby improving the accuracy and reliability of cooling control.

[0086] In some preferred embodiments, temperature fluctuation characteristics are extracted by analyzing temperature monitoring data to determine the operating status of the cooling system and trigger corresponding control mechanisms; the temperature fluctuation characteristics include a first fluctuation characteristic and a second fluctuation characteristic; wherein the method for extracting the first fluctuation characteristic includes:

[0087] The real-time temperature standard deviation of multiple real-time temperature data in each cooling area is calculated, and the real-time temperature standard deviations corresponding to multiple cooling areas are weighted to obtain the first fluctuation feature; the standard deviation is an indicator to measure the degree of data dispersion, reflecting the temperature change amplitude between multiple temperature monitoring points. By calculating the real-time temperature standard deviation, the temperature uniformity on the surface or inside of the copper tube can be quickly evaluated. If the standard deviation is too large, it means that the temperature distribution is uneven, and there may be problems such as insufficient cooling intensity or local overcooling, and the control mechanism needs to be triggered for adjustment.

[0088] More specifically, the calculation formula for the first fluctuation characteristic is:

[0089]

[0090] in, represents the real-time temperature standard deviation of the i-th cooling zone, represents the first wave feature, Indicates the real-time temperature of the jth temperature monitoring point in the i-th cooling area; is the average temperature of the i-th cooling area; is the number of temperature monitoring points in the i-th cooling area; Represents the weight coefficient corresponding to the i-th cooling area; the weight reflects the difference in contribution of different cooling areas to the overall fluctuation; the larger the first fluctuation eigenvalue, the more uneven the temperature distribution, and the high-weight area needs to be regulated first.

[0091] In addition, the method for extracting the second fluctuation feature includes:

[0092] Frequency domain analysis is performed on the temperature series of multiple temperature monitoring points in the same cooling area, and the proportion of fluctuation energy above the preset characteristic frequency is extracted as the second fluctuation feature; frequency domain analysis can reveal the frequency characteristics of temperature fluctuations and help identify rapid thermal shocks or periodic temperature changes; by extracting the proportion of high-frequency fluctuation energy, rapid temperature fluctuations caused by changes in drawing speed or unstable nozzle operation during the cooling process of the copper tube can be captured; if the proportion of high-frequency fluctuation energy is too high, it means that the cooling system may be subject to external interference, such as drawing speed fluctuations or nozzle blockage, and the control parameters need to be adjusted in time to maintain cooling stability.

[0093] Specifically, the preset characteristic frequency is dynamically adjusted according to the real-time pulling speed of the copper tube. When the pulling speed increases, the time the copper tube spends in the cooling area is shortened. It is necessary to monitor temperature fluctuations in a higher frequency band to capture rapid thermal shock. The preset characteristic frequency satisfies the following relationship:

[0094] f c =k⋅v;

[0095] Among them, f cis the preset characteristic frequency, v is the real-time drawing speed, and k is the process correlation coefficient. Changes in the drawing speed directly affect the time it takes for the copper tube to pass through the cooling area, thereby changing the frequency characteristics of the temperature fluctuation. When the drawing speed increases, the time it takes for the copper tube to pass through the cooling area is shortened, and it is necessary to monitor temperature fluctuations in a higher frequency band to capture rapid thermal shock. When the drawing speed decreases, the monitoring frequency band can be appropriately lowered. By dynamically adjusting the preset characteristic frequency, it is ensured that the frequency domain analysis can adapt to the temperature fluctuation characteristics under different drawing speed conditions, thereby improving the applicability and accuracy of the fluctuation analysis.

[0096] In some embodiments of the present invention, there are two triggering conditions for step S5. As long as one of the conditions is met, the subsequent operation will be performed. Specifically:

[0097] The real-time drawing speed of the copper tube is not within the preset drawing speed range: the preset drawing speed range is a reasonable drawing speed interval set in advance based on the production process requirements of the copper tube and factors such as the performance of the equipment; when the monitored real-time drawing speed of the copper tube exceeds this preset range, it means that the current drawing speed state may affect the cooling effect and forming quality of the copper tube; for example, too fast a drawing speed may cause the copper tube to stay in the cooling area for too short a time and cannot be fully cooled; too slow a drawing speed may cause the copper tube to be overcooled, resulting in internal stress and other problems; at this time, the conditional constraints required by the production process (such as the maximum cooling capacity of the equipment, the temperature and cooling time requirements of the quality standards, etc.) and the real-time operation vector of each cooling zone (crystallizer cooling zone, primary cooling zone and secondary cooling zone) will be obtained (including parameters such as real-time water flow, real-time water pressure, real-time water temperature, cooling nozzle opening status, and the cooling efficiency coefficient calculated based on the real-time drawing speed of the copper tube).

[0098] Temperature fluctuation characteristics exceed the preset fluctuation threshold: The temperature fluctuation characteristics are obtained by performing a comprehensive fluctuation analysis on the data of the temperature monitoring points, including the first fluctuation characteristics and the second fluctuation characteristics. When either or both of these fluctuation characteristics exceed their corresponding preset fluctuation thresholds, it indicates that the temperature distribution of the copper tube during the continuous casting process has abnormal fluctuations, which may affect the quality of the copper tube. At this time, the conditional constraints required by the production process and the real-time operation vector of each cooling zone are also obtained.

[0099] In this embodiment, by monitoring the real-time drawing speed and temperature fluctuation characteristics of the copper tube, once an abnormality is found, the conditional constraints required by the production process and the real-time operation vector of the cooling area are obtained in time, which can provide an accurate basis for the subsequent adjustment of the water cooling control, help to ensure the quality of the copper tube during the continuous casting process, and avoid copper tube defects caused by improper drawing speed or excessive temperature fluctuations, such as surface cracks, uneven internal structure, etc.; obtaining the real-time operation vector can understand the working status of each cooling area in real time, combined with the conditional constraints required by the production process, so that the system can respond quickly according to the actual production situation, improve the adaptability of the water cooling control system to different production conditions and changes, and ensure that the system can operate stably under various working conditions.

[0100] Furthermore, how to determine whether the operating state of the cooling system is abnormal based on the first fluctuation feature and the second fluctuation feature is specifically implemented as follows:

[0101] When the first fluctuation feature and / or the second fluctuation feature exceeds its corresponding preset fluctuation threshold, the temperature fluctuation feature is determined to be abnormal; specifically, if the first fluctuation feature exceeds the preset threshold, it means that the temperature difference between the temperature monitoring points is too large, which may cause uneven temperature distribution on the surface or inside of the copper tube, and the control mechanism needs to be triggered for adjustment; if the second fluctuation feature exceeds the preset threshold, it means that the high-frequency component of the temperature fluctuation is too large, which may be caused by rapid thermal shock or instability of the cooling system, and the cooling parameters need to be adjusted in time to maintain system stability; if both exceed the preset threshold at the same time, it means that there may be major problems with the operating status of the cooling system, which needs to be handled as a priority.

[0102] Among them, the preset fluctuation threshold is the upper limit value set for the first fluctuation feature and the second fluctuation feature respectively, which is used to determine whether the temperature fluctuation exceeds the normal range; the preset fluctuation threshold is determined based on process requirements and historical data analysis, and can reflect the normal fluctuation range of the cooling system under different working conditions; for example, for a certain cooling area, the preset threshold of the first fluctuation feature is set to 0.5°C, and the preset threshold of the second fluctuation feature is set to a fluctuation energy ratio not exceeding 10%.

[0103] In this embodiment, through quantitative analysis of the first fluctuation characteristic and the second fluctuation characteristic, combined with the judgment condition of the preset fluctuation threshold, real-time monitoring and anomaly detection of the temperature fluctuation characteristic are realized to ensure that the operating status of the cooling system is always within the controllable range; when the temperature fluctuation characteristic exceeds the preset threshold, the constraint trigger module can be triggered to obtain the conditional constraints required by the production process and adjust the control objective function, thereby optimizing the cooling control strategy to avoid copper tube quality problems caused by excessive temperature fluctuations; by setting the preset fluctuation thresholds of the first fluctuation characteristic and the second fluctuation characteristic, quantitative judgment of the temperature fluctuation characteristic is realized, providing a reliable basis for anomaly detection and dynamic control of the cooling system; combined with the analysis results of the time domain (first fluctuation characteristic) and the frequency domain (second fluctuation characteristic), the temperature fluctuation characteristics are comprehensively evaluated to ensure accurate judgment of the operating status of the cooling system.

[0104] In some embodiments of the present invention, the conditional constraints required by the production process are converted into a constraint vector and integrated into the control objective function corresponding to each cooling zone for function update; wherein the conditional constraints required by the production process include:

[0105] Equipment cooling capacity limitations: For example, the maximum flow rate and maximum pressure of the water pump in the water cooling system have upper limits. Assuming that the maximum flow rate of a certain model of water pump is 200L / min, in the crystallizer cooling zone, a high flow rate is required to achieve rapid solidification of the copper liquid to form a uniform surface solidification shell. For example, the normal operating flow rate range is 120-150L / min. When considering the condition constraint of the equipment cooling capacity, if an abnormal situation occurs during system operation and the flow rate needs to be further increased, the maximum flow rate of the water pump of 200L / min cannot be exceeded. Similarly, for the cooling nozzle, the maximum pressure it can withstand is also limited. Taking the high-pressure atomizing nozzle in the crystallizer cooling zone as an example, if its rated maximum working pressure is 3.0MPa, when setting the control target, the water pressure cannot exceed this value, otherwise the nozzle may be damaged, affecting the cooling effect and production continuity.

[0106] The quality standard requirements for temperature and cooling time: In the primary cooling zone, in order to control the grain refinement inside the copper tube, the quality standard requires that the temperature of the copper tube at a specific position in this area must be stable in a certain temperature range within a certain period of time, such as 800-850℃ for 30-40 seconds; this means that in the control objective function, it is necessary to ensure that by adjusting the water cooling parameters, such as water flow, water pressure, etc., the copper tube can meet the quality standard requirements of this temperature and time in the primary cooling zone; in the secondary cooling zone, there are strict regulations on the axial temperature gradient of the copper tube to ensure the dimensional stability and internal quality of the copper tube; assuming that the quality standard requires that in the 3.0-4.0m sub-zone of the secondary cooling zone, the axial temperature gradient of the copper tube cannot exceed 5℃ / m, this becomes a constraint that must be considered in the control objective function, and this requirement is met by adjusting parameters such as the angle of the cooling nozzle in this area and the water flow rate.

[0107] Constraints related to the copper tube drawing speed: The real-time drawing speed of the copper tube is closely related to the cooling process; the preset drawing speed range is determined according to the production process and equipment performance. For example, for a certain specification of internally threaded copper tube, the preset drawing speed range is 0.8-1.2m / min; when the drawing speed exceeds this range, it will affect the cooling effect and forming quality of the copper tube; if the drawing speed is too fast, such as reaching 1.5m / min, the copper tube stays in the cooling area for too short a time and may not be fully cooled, resulting in the internal structure not meeting the quality standards; if the drawing speed is too slow, such as 0.5m / min, the copper tube may be over-cooled, resulting in internal stress and other problems; therefore, the drawing speed range becomes an important conditional constraint, and corresponding adjustments should be made in the control objective function based on the relationship between the real-time drawing speed and the preset drawing speed range.

[0108] The constraints of the above-mentioned production process requirements are quantified and mathematically expressed, and converted into vector form. For example, the maximum flow rate and maximum pressure of the water pump in the equipment cooling capacity limit, the temperature and cooling time requirements of the quality standard, and the copper tube drawing speed range are given corresponding dimensions in the vector respectively. Suppose a three-dimensional constraint vector is constructed. , where C1 represents the pump flow-related constraint value, such as the normalized value of the maximum flow; C2 represents the temperature-related constraint value, such as the normalized representation of a specific temperature range in a certain area; C3 represents the casting speed-related constraint value, such as the relationship between the real-time casting speed and the preset casting speed range. In this way, complex conditional constraints are concisely and clearly expressed in the form of mathematical vectors, which is convenient for subsequent application in the control objective function.

[0109] According to the functional requirements of different cooling zones, a differentiated objective function is defined for each cooling zone to describe the cooling control target of the cooling zone;

[0110] Mold cooling zone: The objective function for this zone prioritizes maximizing the solidification rate on the copper tube surface. Located at the mold outlet, the mold cooling zone is responsible for rapidly solidifying the copper liquid to form a uniform surface solidification shell. Rapid and uniform surface solidification is crucial to the subsequent forming quality of the copper tube. Therefore, when constructing the objective function for this zone, the design focuses on maximizing the solidification rate on the copper tube surface by adjusting the water cooling parameters.

[0111] Primary cooling zone: The objective function for this zone prioritizes heat flux stability. Located downstream of the mold, the primary cooling zone is used to control grain refinement within the copper tube. Stable heat flux helps achieve uniform cooling, thereby ensuring grain refinement and uniform microstructure within the copper tube. Therefore, the objective function considers how to maintain heat flux stability through measures such as configuring wide-angle fan nozzles to achieve circumferentially uniform heat dissipation.

[0112] Secondary cooling zone: Its objective function prioritizes minimizing the axial temperature gradient. The secondary cooling zone is located in the middle and rear sections of the copper tube. Control of the axial temperature gradient directly affects the dimensional stability and internal quality of the copper tube. Therefore, when designing the objective function, emphasis is placed on how to use the adjustable angle nozzle to control the axial temperature gradient to minimize the axial temperature gradient.

[0113] After defining differentiated objective functions for each cooling zone, the constraint vector obtained above is embedded into the corresponding objective function in the form of Lagrange multipliers. The Lagrange multiplier method is a commonly used method for solving constrained optimization problems. By introducing Lagrange multipliers, the constraints are combined with the objective function to form a new control objective function with constrained optimization. For example, for the objective function of the crystallizer cooling zone, assuming that there are constraints, such as the maximum flow limit of the water pump, after introducing the Lagrange multiplier, the new control objective function will contain the original objective function terms and terms related to the constraints. In this way, the updated control objective function can more accurately calculate the water cooling control instructions for each cooling zone according to the specific goals of each cooling zone under the constraints of meeting the production process requirements, thereby achieving precise adjustment of the water cooling actuator parameters of each cooling zone, improving the control effect of the water cooling system, and ensuring the production quality of the internal threaded copper tube.

[0114] In this embodiment, by defining differentiated objective functions for each cooling zone and embedding process constraints into the objective function in the form of Lagrange multipliers, a control objective function with constrained optimization is generated, thereby achieving refined and intelligent control of the cooling system. This not only improves the forming quality of the copper tube, but also enhances the adaptability and energy utilization efficiency of the system, providing important guarantees for high-quality continuous casting of internally threaded copper tubes.

[0115] Furthermore, the updated control objective function is a constrained optimization function constructed based on the conditional constraints of process requirements and the real-time operation vector; the control objective function of each cooling zone reflects the priority goal of the cooling control in that zone; the updated control objective function uses the real-time operation vector as the input variable to calculate the optimal water cooling control instruction; the output is the water cooling control instruction for the cooling zone, which is used to adjust the parameters of the water cooling actuator.

[0116] The control objective function of each cooling zone is optimized independently, so the water cooling control instructions are also generated independently for that zone. By independently adjusting the parameters of the water cooling actuator, precise control of each cooling zone can be achieved. For example:

[0117] Crystallizer cooling zone: adjust the water flow and water pressure of the high-pressure atomizing nozzle to ensure that the copper liquid solidifies quickly to form a uniform surface solidification shell;

[0118] Primary cooling zone: adjust the water flow and water pressure of the wide-angle fan-shaped nozzle to ensure the grain refinement inside the copper tube;

[0119] Secondary cooling zone: Adjust the water flow, water pressure and angle of the adjustable angle nozzle to ensure that the axial temperature gradient of the copper tube is minimized.

[0120] More specifically, the water-cooled actuator includes a water pump, a regulating valve, a nozzle and other equipment, and its adjustment methods include:

[0121] Water pump: The speed of the water pump is adjusted by the frequency converter to control the water flow;

[0122] Regulating valve: Control water pressure and flow through the opening of the electric regulating valve;

[0123] Nozzles: Optimize cooling coverage and uniformity by adjusting the angle or opening of the nozzles.

[0124] In this embodiment, by inputting the real-time operation vector into the updated control objective function, specific water cooling control instructions are calculated, and the water cooling actuator parameters of each cooling area are independently adjusted to ensure that the cooling system can dynamically adjust the operating parameters of each cooling area according to the latest process conditions and real-time monitoring data, thereby achieving precise control of the temperature distribution during the continuous casting process of the internal threaded copper tube and improving product quality and production efficiency.

[0125] In some schemes, multiple embodiments of the present application can be combined and the combined scheme can be implemented. Optionally, some operations in the process of each method embodiment are optionally combined, and / or the order of some operations is optionally changed. In addition, the execution order between the steps of each process is only exemplary and does not constitute a limitation on the execution order between the steps. There can also be other execution orders between the steps. It is not intended to indicate that the execution order is the only order in which these operations can be performed. Ordinary technicians in this field will think of many ways to reorder the operations described herein. In addition, it should be noted that the process details involved in a certain embodiment of this article are also applicable to other embodiments in a similar manner, or different embodiments can be used in combination.

[0126] Furthermore, some steps in the method embodiments may be equivalently replaced with other possible steps. Alternatively, some steps in the method embodiments may be optional and may be deleted in certain usage scenarios. Alternatively, other possible steps may be added to the method embodiments. Furthermore, the various method embodiments may be implemented separately or in combination.

[0127] The various variations and specific embodiments of the water cooling control method for horizontal continuous casting of an internally threaded copper tube in the aforementioned embodiment are also applicable to the water cooling system for horizontal continuous casting of an internally threaded copper tube in this embodiment. Through the aforementioned detailed description of the water cooling control method for horizontal continuous casting of an internally threaded copper tube, those skilled in the art can clearly know the implementation method of the water cooling system for horizontal continuous casting of an internally threaded copper tube in this embodiment, so for the sake of brevity of the specification, it will not be described in detail here.

[0128] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A water cooling system for horizontal continuous casting of internally threaded copper tubes, characterized in that: include: The zone division module is used to divide the water cooling system into functional zones and generate multiple cooling zones; A temperature monitoring configuration module, configured to set a plurality of temperature monitoring points according to the plurality of cooling zones; A data acquisition module is used to obtain the copper tube drawing speed and the real-time temperature of the plurality of temperature monitoring points in real time; A fluctuation analysis module, configured to perform comprehensive fluctuation analysis on the multiple real-time temperatures to obtain temperature fluctuation characteristics; A constraint triggering module is configured to obtain the conditional constraints required by the production process and the real-time operation vector of each cooling zone when it is detected that the real-time pulling speed of the copper tube exceeds a preset pulling speed range and / or the temperature fluctuation characteristic exceeds a preset fluctuation threshold; A function optimization module, configured to convert the conditional constraints into constraint vectors, and integrate the constraint vectors into the control objective function corresponding to each cooling zone to perform function update; The control decision module is used to input the real-time operation vector into the corresponding updated control objective function, obtain the water cooling control instruction corresponding to the cooling area, and independently adjust the water cooling actuator parameters of the cooling area.

2. The water cooling system for horizontal continuous casting of internally threaded copper tubes according to claim 1 is characterized in that: The plurality of cooling zones include a crystallizer cooling zone, a primary cooling zone, and a secondary cooling zone.

3. A water cooling control method for horizontal continuous casting of internally threaded copper tubes, characterized in that: include: Dividing the water cooling system into zones to obtain multiple cooling zones, including at least a crystallizer cooling zone, a primary cooling zone, and a secondary cooling zone; According to the plurality of cooling areas, a plurality of temperature monitoring points are set; Obtaining the real-time pulling speed of the copper tube and the real-time temperatures of the plurality of temperature monitoring points; Performing comprehensive fluctuation analysis on the multiple real-time temperatures to obtain temperature fluctuation characteristics; In response to the copper tube real-time pulling speed not being within a preset pulling speed range, and / or the temperature fluctuation characteristic exceeding a preset fluctuation threshold, obtaining condition constraints required by the production process and a real-time operation vector of each cooling zone; Converting the conditional constraints into constraint vectors, and integrating the constraint vectors into the control objective function corresponding to each cooling zone to perform function update; Each of the real-time operation vectors is input into the corresponding updated control objective function to obtain the water cooling control instruction of the cooling area, and the water cooling actuator parameters of the cooling area are independently adjusted accordingly.

4. The water cooling control method for horizontal continuous casting of internally threaded copper tubes according to claim 3, characterized in that: The real-time operation vector includes at least one of the following parameters: The real-time water flow, real-time water pressure, real-time water temperature and cooling nozzle opening status of each cooling area.

5. The water cooling control method for horizontal continuous casting of internally threaded copper tubes according to claim 3, characterized in that: The real-time operation vector also includes: a cooling efficiency coefficient calculated according to the real-time pulling speed of the copper tube, and the cooling efficiency coefficient calculation formula is: η=( v·T target ) / ( P water ·Q); Where η is the cooling efficiency coefficient, v is the real-time pulling speed, T target is the target temperature of the cooling area, P water is the real-time water pressure, and Q is the real-time water flow.

6. The water cooling control method for horizontal continuous casting of internally threaded copper tubes according to claim 3, characterized in that: The setting of the temperature monitoring points includes: A first temperature sensor and a second temperature sensor are respectively provided at the inlet and outlet of the crystallizer cooling zone to monitor the temperature difference of the solidified shell on the surface of the copper tube; An annular array of infrared thermometers is arranged at equidistant axial positions in the primary cooling zone to capture radial temperature gradient distribution data of the copper tube; Distributed temperature sensor arrays are provided at multiple cross sections of the secondary cooling zone to obtain axial temperature gradient distribution data of the copper tube.

7. The water cooling control method for horizontal continuous casting of internally threaded copper tubes according to claim 6, characterized in that: The comprehensive volatility analysis includes: Comprehensively calculating the real-time temperature standard deviation of the plurality of cooling areas as a first fluctuation feature; Frequency domain analysis is performed on the temperature sequences of the plurality of temperature monitoring points in the same cooling area, and the proportion of fluctuation energy above a preset characteristic frequency is extracted as a second fluctuation feature.

8. The water cooling control method for horizontal continuous casting of internally threaded copper tubes according to claim 7, characterized in that: The preset characteristic frequency is dynamically adjusted according to the real-time drawing speed of the copper tube and satisfies the following relationship: f c =k·v; Among them, f c is the preset characteristic frequency, v is the real-time casting speed, and k is the process correlation coefficient.

9. The water cooling control method for horizontal continuous casting of internally threaded copper tubes according to claim 8, characterized in that: The temperature fluctuation characteristic exceeds a preset fluctuation threshold, including: The first fluctuation feature and / or the second fluctuation feature exceeds the corresponding preset fluctuation threshold.

10. The water cooling control method for horizontal continuous casting of internally threaded copper tubes according to any one of claims 3 to 9, characterized in that: The updating of the control objective function includes: A differentiated objective function is defined for each of the cooling zones: The objective function of the mold cooling zone prioritizes maximizing the solidification rate of the copper tube surface; The objective function of the primary cooling zone prioritizes heat flux stability; The objective function of the secondary cooling zone prioritizes minimizing the axial temperature gradient; The constraint vector is embedded into the objective function in the form of Lagrange multipliers to generate the control objective function with constraint optimization.

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