Water cooling system for horizontal continuous casting of internal thread copper pipe and control method

Abstract

The invention relates to the technical field of intelligent production of copper pipes, in particular to a water cooling system for horizontal continuous casting of an internal-thread copper pipe and a control method, and the water cooling system comprises an area division module which is used for carrying out function division on the water cooling system to generate a plurality of cooling areas; the temperature monitoring configuration module is used for setting a plurality of temperature monitoring point positions according to the plurality of cooling areas; the data acquisition module is used for acquiring the pulling speed of the copper pipe and the real-time temperature of a plurality of temperature monitoring points in real time; the fluctuation analysis module is used for carrying out comprehensive fluctuation analysis on the plurality of real-time temperatures to obtain temperature fluctuation characteristics; the method can adapt to the pulling speed change, process constraints are dynamically fused, and regional accurate regulation and control are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent production of copper tubes, and particularly 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 fields such as refrigeration and heat exchange, 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 tube from liquid metal solidification is particularly crucial - it is necessary to ensure rapid surface solidification to form a uniform shell while avoiding internal grain coarsening or crack generation.

[0003] Existing water cooling systems often lack the concept of fine regional division, treating the entire water cooling process as a whole for general control, and unable to implement precise regulation according to the unique requirements of different functional areas, resulting in difficulties in effectively coping with the complex situations caused by different temperature change characteristics of each area during continuous casting, uneven temperature distribution of the copper tube during the cooling process, and thus affecting the internal organizational structure and surface quality of the copper tube, and prone to defects such as cracks and deformations.

[0004] At the same time, in the face of the dynamic adjustment of the copper tube drawing speed, the existing water cooling systems fail to fully consider the impact of the drawing speed change on the temperature control of each cooling area, lack an effective mechanism for coordinated control according to the real-time drawing speed and temperature fluctuations of the copper tube, and also do not make full use of various condition constraints in the production process requirements to optimize the control objectives of the water cooling system, resulting in difficulties in achieving the best control effect during the operation of the water cooling system, not only wasting energy but also unable to meet the increasingly high production quality standards.

[0005] Therefore, there is an urgent need for a water cooling system that can adapt to the change of drawing speed, dynamically integrate process constraints, and precisely regulate in different regions 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 a control method for horizontal continuous casting of internally threaded copper tubes that can adapt to the change of drawing speed, dynamically integrate process constraints, and precisely regulate in different regions, which can effectively solve the problems in the background art.

[0007] To achieve the above object, in the first aspect, the present invention provides a water cooling system for horizontal continuous casting of internally threaded copper tubes, including:

[0008] A regional division module for functionally partitioning the water cooling system to generate multiple cooling regions;

[0009] A temperature monitoring and configuration module for setting multiple temperature monitoring points according to the multiple cooling regions;

[0010] A data acquisition module, configured to obtain the real-time drawing speed of the copper tube and the real-time temperatures of multiple said temperature monitoring points in real time;

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

[0012] A constraint trigger module, configured to, when it is detected that the real-time drawing speed of the copper tube exceeds a preset drawing speed range, and / or the said temperature fluctuation characteristics exceed a preset fluctuation threshold, obtain the conditional constraints required by the production process and the real-time operation vectors of each said cooling zone;

[0013] A function optimization module, configured to convert the said conditional constraints into constraint vectors and fuse them into the control objective functions corresponding to each said cooling zone for function update;

[0014] A control decision module, configured to input the said real-time operation vectors into the corresponding updated said control objective functions to obtain the water-cooling control instructions corresponding to this cooling zone, and independently adjust the parameters of the water-cooling actuator of this cooling zone accordingly.

[0015] Combined with the first aspect, in a possible design, the multiple cooling zones include a mold 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 internally threaded copper tubes, including:

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

[0018] Setting multiple temperature monitoring points according to the multiple said cooling zones;

[0019] Obtaining the real-time drawing speed of the copper tube and the real-time temperatures of the multiple said temperature monitoring points;

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

[0021] In response to the real-time drawing speed of the copper tube not being within the preset drawing speed range, and / or the said temperature fluctuation characteristics exceeding the preset fluctuation threshold, obtaining the conditional constraints required by the production process and the real-time operation vectors of each said cooling zone;

[0022] Converting the said conditional constraints into constraint vectors and fusing them into the control objective functions corresponding to each said cooling zone for function update;

[0023] Input each of the real-time operation vectors into the corresponding updated control objective function to obtain the water cooling control instruction for the cooling area, and independently adjust the parameters of the water cooling actuator for the cooling area accordingly.

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

[0025] The real-time water flow rate, real-time water pressure, real-time water temperature, and the opening state of the cooling nozzles in each cooling area.

[0026] In combination with the second aspect, in a possible design, the real-time operation vector further includes: a cooling efficiency coefficient calculated based on the real-time drawing speed of the copper tube, and the calculation formula for the cooling efficiency coefficient is:

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

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

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

[0030] A first temperature sensor and a second temperature sensor are respectively arranged at the inlet and outlet of the crystallizer cooling area 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 equally spaced axial positions in the primary cooling area to capture the radial temperature gradient distribution data of the copper tube;

[0032] A distributed temperature sensor array is arranged at multiple cross-sections in the secondary cooling area to obtain the axial temperature gradient distribution data of the copper tube.

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

[0034] Comprehensively calculate the standard deviation of the real-time temperatures of multiple cooling areas as the first fluctuation feature;

[0035] Perform frequency domain analysis on the temperature sequences of multiple temperature monitoring points in the same cooling area, and extract the proportion of the fluctuation energy above the preset characteristic frequency as the second fluctuation feature.

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

[0037] f c = k ⋅ v;

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

[0039] Combined with the second aspect, in a possible design, the temperature fluctuation characteristic exceeding the preset fluctuation threshold includes:

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

[0041] Combined with the second aspect, in a possible design, the update of the control objective function includes:

[0042] Defining a differentiated objective function for each of the cooling zones:

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

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

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

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

[0047] Through the technical solution of the present invention, the following technical effects can be achieved:

[0048] Through the area 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 achieve regional temperature field perception. Differentiated regulation is carried out according to the cooling characteristics of different areas to avoid the imbalance between surface and internal cooling caused by traditional overall control, and significantly reduce crack 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 to trigger the constraint trigger module to dynamically adjust the control strategy. When the drawing speed changes, the system automatically predicts the change trend of the heat load and coordinately adjusts the water cooling intensity of each area to prevent grain coarsening or undercooling defects caused by drawing speed fluctuations. The function optimization module converts the production process constraints into a mathematical constraint vector and embeds it into the regional control objective function. While meeting the core process requirements of surface quality and internal structure, it synchronously optimizes energy consumption and water cooling efficiency, 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, avoiding global system downtime and ensuring the stability of continuous production. The energy efficiency balance coefficient is dynamically calculated through the real-time operation vector to constrain the generation of control instructions. Within the allowable range of the process, the water pressure setting value of the high-energy consumption area is preferentially reduced to reduce ineffective cooling and lower the comprehensive energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0050] Figure 1 It is a structural block diagram of the water cooling system for horizontal continuous casting of internal thread copper tubes;

[0051] Figure 2 It is a logic flow chart of the water cooling control method for horizontal continuous casting of internal thread copper tubes. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments.

[0053] The following describes the present application with reference to the drawings in the present application.

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

[0055] The region division module performs functional partitioning on the water-cooling system to generate multiple cooling regions; the multiple cooling regions include a mold cooling region, a primary cooling region, and a secondary cooling region; the temperature monitoring configuration module sets multiple temperature monitoring points according to the multiple cooling regions; the data acquisition module obtains the real-time pulling speed of the copper tube and the real-time temperatures of the multiple temperature monitoring points in real time; the fluctuation analysis module performs comprehensive fluctuation analysis on the multiple real-time temperatures to obtain temperature fluctuation characteristics; when the constraint trigger module detects that the real-time pulling speed of the copper tube exceeds the preset pulling speed range, and / or the temperature fluctuation characteristics exceed the preset fluctuation threshold, it obtains the condition constraints required by the production process and the real-time operation vectors of each cooling region; the function optimization module converts the condition constraints into constraint vectors and integrates them into the control objective function corresponding to each cooling region for function update; 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 region, and independently adjusts the parameters of the water-cooling actuator of the cooling region accordingly.

[0056] In this embodiment, through the region division module and the temperature monitoring configuration module, the cooling process is divided into multiple cooling regions, such as the mold, the primary and secondary cooling zones, and temperature monitoring points are independently configured to achieve regional temperature field perception. Differentiated regulation is carried out according to the cooling characteristics of different regions. For example, rapid solidification is required in the crystallization zone, and gradient control is required in the secondary zone, avoiding the surface and internal cooling imbalance caused by traditional overall control, and significantly reducing crack and deformation defects. The data acquisition module obtains the casting speed data in real time. The fluctuation analysis module combines the casting 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 casting speed changes, such as acceleration resulting in a shortened cooling time, the system automatically predicts the change trend of the heat load and coordinately adjusts the water cooling intensity of each region to prevent grain coarsening or undercooling defects caused by casting speed fluctuations. The function optimization module converts production process constraints, such as temperature gradient limits and energy consumption thresholds, into mathematical constraint vectors and embeds them into the regionalized control objective function. For example, the crystallization zone prioritizes the solidification rate, and the secondary zone aims for minimum gradient. While meeting the core process requirements of surface quality and internal structure, the energy consumption and water cooling efficiency are synchronously optimized, 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 region. In case of local temperature anomalies, such as nozzle blockage in a certain region, it can be quickly isolated and processed through independent regulation, avoiding global system downtime and ensuring the stability of continuous production. By means of real-time operation vectors, such as cumulative energy consumption and cooling efficiency coefficient, the energy efficiency balance coefficient is dynamically calculated to constrain the generation of control instructions. Within the process allowable range, the water pressure setting value of high-energy consumption regions, such as the secondary cooling zone, is preferentially reduced to reduce ineffective cooling and lower the comprehensive energy consumption.

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

[0058] Step S1: Divide the water cooling system into regions to obtain multiple cooling regions;

[0059] Step S2: Set multiple temperature monitoring points according to the multiple cooling regions; the temperature monitoring points are used to monitor the temperature of the copper tube during continuous casting, and each cooling region includes at least one of the temperature monitoring points;

[0060] Step S3: Obtain the real-time casting speed of the copper tube and the real-time temperatures of the multiple temperature monitoring points;

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

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

[0063] Step S6: Convert the condition constraints into constraint vectors and fuse them into the control objective function corresponding to each cooling zone for function update;

[0064] Step S7: Input each real-time operation vector into the updated control objective function corresponding thereto to obtain the water cooling control instruction for this cooling zone, and independently adjust the parameters of the water cooling actuator of this cooling zone accordingly.

[0065] In this embodiment, through the fine-grained zoning control of the water cooling system, precise regulation is implemented according to the functional requirements of different cooling zones, improving the uniformity of the copper tube temperature distribution, enhancing the internal organizational structure and surface quality, and reducing defects such as cracks and deformations; through the dynamic analysis of the real-time drawing speed and temperature fluctuation characteristics, a collaborative mechanism between the drawing speed change and cooling control is established to quickly respond to the fluctuation of process parameters and ensure the stability of the cooling process; the condition constraints required by the production process are incorporated into the control objective function to optimize the operation objective of the water cooling system, make full use of the process constraint information, and improve the production efficiency and product quality; through the input of the real-time operation vector and the update of the objective function, independent and intelligent control of each cooling zone is achieved, enhancing the adaptive ability and control accuracy; while improving the forming quality of the copper tube, this method optimizes the energy utilization efficiency, reduces the production cost, and meets the increasingly high production quality standards and energy-saving requirements.

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

[0067] The mold cooling zone is located at the outlet end of the mold (0 - 0.5 m), responsible for the rapid solidification of the molten copper to form a uniform surface solidification shell, and high-density cooling is achieved by using high-pressure atomizing nozzles (pressure 1.5 - 3.0 MPa);

[0068] The primary cooling zone is located downstream of the mold (0.5 - 2.0 m), used to control the refinement of the internal grains of the copper tube, and wide-angle fan nozzles (pressure 0.8 - 1.5 MPa) are configured to achieve circumferential uniform heat dissipation;

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

[0070] Each cooling zone is independently configured with a closed-loop water circuit system, including a water pump, a regulating valve, a pressure sensor, and a flow meter, to ensure control isolation between zones. Heat insulation baffles are set at the zone boundaries to reduce thermal interference.

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

[0072] Real-time water flow rate: It represents the volume of water flowing through the cooling zone per unit time, and is measured and collected by an electromagnetic flow meter or a turbine flow meter installed on the inlet pipe 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 change in casting speed.

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

[0074] Real-time water temperature: It represents the inlet temperature of the cooling water, and is measured and collected by a PT100 thermal resistor or an infrared thermometer installed on the cooling water circulation pipeline. The water temperature determines the driving force of heat conduction. For example, if the water temperature is too high (>35°C), auxiliary refrigeration equipment needs to be started to prevent the decline of cooling capacity; low-temperature water (15 - 25°C) can increase the solidification rate.

[0075] Cooling nozzle opening state: It represents the percentage of the nozzle valve opening, which is used to control the cross-sectional area of the water flow. Data is collected through the feedback signal of the electric regulating valve. By adjusting the cooling nozzle opening state, the cooling coverage range and uniformity can be adjusted. For example, the nozzle opening in the primary cooling zone above 80% ensures full circumferential coverage; the adjustment of the nozzle opening difference in the sub-zones of the secondary cooling zone (such as the combination of 45° and 60° openings) can optimize the axial temperature gradient.

[0076] Specifically, the real-time operation vector can be controlled by a single parameter or by a combination of multiple parameters. Single-parameter control, for example, only takes water pressure as the input. At this time, it is applicable to simple process scenarios, such as constant flow control under steady casting speed. Multi-parameter combined control, for example, simultaneously monitors water pressure, flow rate, and water temperature, and is used for complex dynamic working conditions, such as synchronously adjusting the flow rate and pressure when the casting speed suddenly changes. Multi-dimensional parameter monitoring covers the key physical quantities in the cooling process, avoiding the control blind area caused by single-signal control. Through parameter correlation analysis, the high-energy efficiency parameters are preferentially adjusted under the premise of meeting the process requirements.

[0077] In this embodiment, by introducing multi-dimensional operating parameters and calculating the cooling efficiency coefficient, the operating state 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 drawing 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, it provides clear guidance for the implementation of the water-cooling control system and facilitates engineering application; the definition of the real-time operating vector not only supports the current control requirements but also provides basic data for subsequent algorithm optimization, enhancing the scalability and intelligence level of the system.

[0078] More specifically, the real-time operating vector can also adopt the cooling efficiency coefficient, which is used to quantify the matching efficiency between the drawing speed and the target temperature under a unit of cooling resources. Its calculation formula is:

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

[0080] Where η is the cooling efficiency coefficient, v is the real-time drawing speed, T target is the set target temperature of this cooling area, P water is the real-time water pressure, and Q is the real-time water flow; v⋅T target reflects the production process requirements. The higher the drawing speed or the target temperature, the greater the demand for cooling intensity; P water ⋅Q represents the consumption of cooling resources. The product of water pressure and flow is approximately proportional to the pump power; the higher the cooling efficiency coefficient, the higher the matching efficiency between the target drawing speed and temperature under a unit of cooling resource input, that is, the better the energy efficiency ratio; by introducing the cooling efficiency coefficient, the process requirements and resource consumption are dynamically correlated, solving the pain point of the lack of quantitative indicators for energy efficiency optimization in traditional methods, and significantly improving the economy and reliability of the water-cooling system.

[0081] In order to achieve precise temperature monitoring and cooling control, the specific deployment methods of temperature monitoring points in different cooling areas and the selection of sensors specifically include the following content:

[0082] Mold Cooling Zone: A first temperature sensor and a second temperature sensor are respectively arranged at the inlet and outlet of the mold cooling zone. The first temperature sensor is installed at the inlet of the molten copper in the mold, directly contacting the molten copper to measure the initial temperature. A K-type thermocouple is used to monitor the initial thermal state of the molten copper entering the mold. The second temperature sensor is located at the outlet of the mold, at a certain distance from the surface of the copper tube, to measure the temperature of the solidified shell surface. A wear-resistant armored thermocouple is used to prevent damage caused by friction during the movement of the copper tube. The mold cooling zone is the initial stage of the solidification of the copper tube, and the temperature difference on the surface of the solidified shell directly affects the surface quality of the copper tube. By arranging sensors at the inlet and outlet respectively, the temperature change of the copper tube during the initial solidification stage can be captured in real time, ensuring the rapid formation of a uniform shell on the surface and avoiding cracks or surface defects caused by excessive temperature difference.

[0083] Primary Cooling Zone: Ring-array infrared thermometers are arranged at equally spaced axial positions in the primary cooling zone to capture data on the radial temperature gradient distribution of the copper tube. The primary cooling zone is the main stage of the solidification of the copper tube, and the uniformity of the radial temperature gradient is crucial for the internal microstructure of the copper tube. The ring-array infrared thermometers can cover the entire circumference of the copper tube and monitor the radial temperature distribution in real time to ensure uniform cooling and avoid grain coarsening or deformation defects caused by excessive radial temperature difference.

[0084] Secondary Cooling Zone: Distributed temperature sensor arrays are arranged at multiple cross-sections in the secondary cooling zone to obtain data on the axial temperature gradient distribution of the copper tube. The secondary cooling zone is the later stage of the solidification of the copper tube, and the control of the axial temperature gradient directly affects the dimensional stability and internal quality of the copper tube. The distributed temperature sensor arrays can monitor the temperature change 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, according to the functional requirements of different cooling zones, suitable temperature monitoring point layout schemes are designed respectively. Multiple sensors and multiple layout methods are used to achieve multi-dimensional monitoring of the temperature distribution of the copper tube, covering multiple key parameters such as radial, axial, and surface layers. Through multi-point and multi-method temperature monitoring, the temperature distribution data of the copper tube in different cooling zones can be obtained in real time, providing accurate data support for subsequent fluctuation analysis, control objective function update, and water cooling control instruction generation, and improving the accuracy and reliability of cooling control.

[0086] In some preferred embodiments, by analyzing the temperature monitoring data, temperature fluctuation characteristics are extracted to judge the operating state of the cooling system and trigger corresponding control mechanisms. The temperature fluctuation characteristics include the first fluctuation characteristic and the second fluctuation characteristic. The extraction method of the first fluctuation characteristic includes:

[0087] Calculate the real-time temperature standard deviation of multiple real-time temperature data in each cooling area, and perform weighted calculation on the real-time temperature standard deviations corresponding to multiple cooling areas to obtain the first fluctuation feature; the standard deviation is an index to measure the degree of data dispersion, reflecting the temperature change range 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 indicates uneven temperature distribution, 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 feature is:

[0089]

[0090] Among them, represents the real-time temperature standard deviation of the i-th cooling area, represents the first fluctuation feature, represents the real-time temperature of the j-th 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 difference in the contribution of different cooling areas to the overall fluctuation is reflected by the weight; the larger the first fluctuation feature value, the more uneven the temperature distribution, and the high-weight area needs to be preferentially regulated.

[0091] In addition, the extraction method of the second fluctuation feature includes:

[0092] Perform frequency-domain analysis on the temperature sequences of multiple temperature monitoring points in the same cooling area, and extract the proportion of the fluctuation energy above the preset characteristic frequency 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, the rapid temperature fluctuations caused by changes in the 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 indicates that the cooling system may be affected by external disturbances, 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 drawing speed of the copper tube. When the drawing speed increases, the time for the copper tube to pass through the cooling area is shortened, and higher-frequency temperature fluctuations need to be monitored to capture rapid thermal shocks. The preset characteristic frequency satisfies the following relationship:

[0094] f c =k⋅v;

[0095] Among them, f cLet \(f_0\) be the preset characteristic frequency, \(v\) be the real-time casting speed, and \(k\) be the process-related coefficient. The change in the casting speed directly affects the time for the copper tube to pass through the cooling area, thereby changing the frequency characteristics of the temperature fluctuation. When the casting speed increases, the time for the copper tube to pass through the cooling area shortens, and it is necessary to monitor the temperature fluctuations in a higher frequency band to capture rapid thermal shocks. When the casting speed decreases, the monitoring frequency band can be appropriately reduced. By dynamically adjusting the preset characteristic frequency, it is ensured that the frequency-domain analysis can adapt to the temperature fluctuation characteristics under different casting speed conditions, improving the applicability and accuracy of the fluctuation analysis.

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

[0097] The real-time casting speed of the copper tube is not within the preset casting speed range: The preset casting speed range is a reasonable casting speed interval set in advance according to factors such as the production process requirements of the copper tube and the performance of the equipment. When the monitored real-time casting speed of the copper tube exceeds this preset range, it indicates that the current casting speed state may affect the cooling effect and forming quality of the copper tube. For example, too fast a casting 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 casting speed may cause the copper tube to be over-cooled, resulting in problems such as internal stress. At this time, the condition constraints required by the production process (such as the maximum cooling capacity of the equipment, the requirements of the quality standard for temperature and cooling time, etc.) and the real-time operation vectors of each cooling area (including parameters such as real-time water flow rate, real-time water pressure, real-time water temperature, cooling nozzle opening state, etc., and also including the cooling efficiency coefficient calculated according to the real-time casting speed of the copper tube) will be obtained.

[0098] The temperature fluctuation characteristics exceed the preset fluctuation threshold: The temperature fluctuation characteristics are obtained through comprehensive fluctuation analysis of the data at the temperature monitoring points, including the first fluctuation characteristic and the second fluctuation characteristic. When any one or both of these two fluctuation characteristics exceed their corresponding preset fluctuation thresholds, it indicates that abnormal fluctuations have occurred in the temperature distribution during the continuous casting of the copper tube, which may affect the quality of the copper tube. At this time, the condition constraints required by the production process and the real-time operation vectors of each cooling area will also be obtained.

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

[0100] Further, how to determine whether the operation state of the cooling system is abnormal according to the first fluctuation characteristic and the second fluctuation characteristic is specifically implemented as follows:

[0101] When the first fluctuation characteristic and / or the second fluctuation characteristic exceeds its corresponding preset fluctuation threshold, it is determined that the temperature fluctuation characteristic is abnormal; specifically, if the first fluctuation characteristic exceeds the preset threshold, it indicates 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 a control mechanism needs to be triggered for adjustment; if the second fluctuation characteristic exceeds the preset threshold, it indicates 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 a timely manner to maintain the stability of the system; if both exceed the preset threshold at the same time, it indicates that there may be major problems in the operation state of the cooling system, and priority should be given to handling.

[0102] Among them, the preset fluctuation threshold is the upper limit value set for the first fluctuation characteristic and the second fluctuation characteristic respectively, and is used to judge 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 characteristic is set to 0.5 °C, and the preset threshold of the second fluctuation characteristic is set to that the proportion of the fluctuation energy does not exceed 10%.

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

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

[0105] Equipment cooling capacity limitation: For example, there are upper limit values for the maximum flow rate and the highest pressure of the water pump in the water cooling system; assume that the maximum flow rate of a certain type of water pump is 200 L / min. In the crystallizer cooling area, since a high flow rate is required to achieve the rapid solidification of the molten copper to form a uniform surface solidification shell, such as the normal working flow rate range is 120 - 150 L / min. When considering this condition constraint of the equipment cooling capacity, if an abnormal situation occurs during the system operation and the flow rate needs to be further increased, it cannot exceed the maximum flow rate of the water pump, which is 200 L / min; similarly, for the cooling nozzle, there is also a limit on the highest pressure it can withstand; taking the high-pressure atomizing nozzle in the crystallizer cooling area as an example, if its rated maximum working pressure is 3.0 MPa, when setting the control objective, the water pressure cannot exceed this value, otherwise it may damage the nozzle, affecting the cooling effect and the continuity of production.

[0106] Requirements of the quality standard for temperature and cooling time: In the primary cooling area, to control the grain refinement inside the copper tube, the quality standard requires that the temperature at a specific position of the copper tube in this area needs to be stable within a certain temperature range for a certain period of time, such as maintaining at 800 - 850 °C 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 rate, water pressure, etc., the copper tube can meet the quality standard requirements of this temperature and time in the primary cooling area; in the secondary cooling area, 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; assume that the quality standard requires that in the 3.0 - 4.0 m sub-area of the secondary cooling area, the axial temperature gradient of the copper tube cannot exceed 5 °C / m, which becomes a constraint condition that must be considered in the control objective function, and this requirement is met by adjusting parameters such as the angle and water flow rate of the cooling nozzles in this area.

[0107] Constraints related to the drawing speed of copper tubes: The real-time drawing speed of copper tubes 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 tubes, the preset drawing speed range is 0.8 - 1.2 m / min; when the drawing speed exceeds this range, it will affect the cooling effect and forming quality of the copper tubes; if the drawing speed is too fast, such as reaching 1.5 m / min, the residence time of the copper tubes in the cooling area is too short, and they may not be sufficiently cooled, resulting in the internal organizational structure not meeting the quality standards; if the drawing speed is too slow, such as 0.5 m / min, the copper tubes may be over-cooled, causing problems such as internal stress; therefore, the drawing speed range becomes an important conditional constraint, and corresponding adjustments should be made in the control objective function according to the relationship between the real-time drawing speed and the preset drawing speed range.

[0108] Quantify and mathematically express the conditional constraints required by the above various production processes, and transform them into vector form; for example, for the conditional constraints such as the maximum flow rate and maximum pressure of the water pump in the equipment cooling capacity limit, the requirements of the quality standard for temperature and cooling time, and the copper tube drawing speed range, respectively assign their corresponding dimensions in the vector; assume a three-dimensional constraint vector is constructed , where C 1 represents the constraint value related to the water pump flow rate, such as the value after normalizing the maximum flow rate; C 2 represents the constraint value related to temperature, such as the normalized representation of a specific temperature range in a certain area; C 3 represents the constraint value related to the drawing speed, such as the relationship value between the real-time drawing speed and the preset drawing speed range; in this way, the complex conditional constraints are concisely represented in the form of a mathematical vector, which is convenient for subsequent application in the control objective function.

[0109] For the functional requirements of different cooling areas, define a differentiated objective function for each cooling area to describe the cooling control objective of that cooling area;

[0110] Mold cooling area: The objective function of this area prioritizes maximizing the solidification rate of the copper tube surface; Since the mold cooling area is located at the outlet end of the mold and is responsible for the rapid solidification of the molten copper to form a uniform surface solidification shell, a rapid and uniform surface solidification is crucial for the subsequent forming quality of the copper tube; Therefore, when constructing the objective function of this area, it will be designed around how to maximize the solidification rate of the copper tube surface by adjusting the water cooling parameters;

[0111] Primary cooling zone: The objective function of this zone prioritizes the stability of heat flux density. The primary cooling zone is located downstream of the mold and is used to control the grain refinement inside the copper tube. A stable heat flux density helps achieve a uniform cooling effect, thereby ensuring the grain refinement inside the copper tube and the uniformity of the organizational structure. Therefore, the objective function will consider measures such as configuring wide-angle sector nozzles to achieve circumferential uniform heat dissipation to maintain the stability of the heat flux density.

[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, and the 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 will be placed on how to use adjustable-angle nozzles to control the axial temperature gradient to achieve the purpose of minimizing the axial temperature gradient.

[0113] After defining the differential objective functions for each cooling zone, the previously obtained constraint vectors are embedded into the corresponding objective functions 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 constraint conditions are combined with the objective function to form a new constrained optimization control objective function. For example, for the objective function of the mold cooling zone, assuming there are constraint conditions such as the maximum flow rate limit of the water pump, after introducing the Lagrange multiplier, the new control objective function will include the original objective function terms and terms related to the constraint conditions. Through the above method, the updated control objective function can more accurately calculate the water cooling control instructions for each cooling zone according to the specific objectives of each cooling zone under the condition constraints of meeting the production process requirements, so as to achieve precise adjustment of the parameters of the water cooling actuators in each cooling zone, improve the control effect of the water cooling system, and ensure the production quality of internally threaded copper tubes.

[0114] In this embodiment, by defining differential objective functions for each cooling zone and embedding the process constraint conditions into the objective function in the form of Lagrange multipliers to generate a constrained optimization control objective function, the refined and intelligent control of the cooling system is realized, which not only improves the forming quality of the copper tube, but also enhances the adaptability and energy utilization efficiency of the system, providing an important guarantee for the 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 condition constraints of the process requirements and the real-time operation vector. The control objective function of each cooling zone reflects the priority objective of the cooling control in that zone. The updated control objective function takes the real-time operation vector as an input variable and calculates the optimal water cooling control instruction. The output is the water cooling control instruction for this cooling zone, which is used to adjust the parameters of the water cooling actuator.

[0116] Among them, the control objective functions of each cooling area are optimized independently, so the water cooling control instructions are also generated independently for that area; by independently adjusting the parameters of the water cooling actuators, precise control of each cooling area can be achieved; for example:

[0117] Mold cooling area: Adjust the water flow rate and water pressure of the high-pressure atomizing nozzles to ensure that the molten copper rapidly solidifies to form a uniform surface solidification shell;

[0118] Primary cooling area: Adjust the water flow rate and water pressure of the wide-angle sector nozzles to ensure grain refinement inside the copper tube;

[0119] Secondary cooling area: Adjust the water flow rate, water pressure, and angle of the adjustable-angle nozzles to minimize the axial temperature gradient of the copper tube.

[0120] More specifically, the water cooling actuators include devices such as water pumps, regulating valves, and nozzles, and their adjustment methods include:

[0121] Water pump: Control the water flow rate by adjusting the rotational speed of the water pump through a frequency converter;

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

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

[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 parameters of the water cooling actuators in each cooling area are independently adjusted to ensure that the cooling system can dynamically adjust the operation 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 internal thread copper tubes and improving product quality and production efficiency.

[0125] In some solutions, multiple embodiments of the present application can be combined and the combined solution can be implemented. Optionally, some operations in the processes of the method embodiments are optionally combined, and / or the order of some operations is optionally changed. And, 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. Those of ordinary skill in the art will think of various ways to reorder the operations described herein. Additionally, it should be noted that the process details involved in a certain embodiment herein are equally applicable to other embodiments in a similar manner, or different embodiments can be combined and used.

[0126] In addition, some steps in the method embodiments can be equivalently replaced with other possible steps. Alternatively, some steps in the method embodiments may be optional and can be deleted in certain usage scenarios. Or, other possible steps can be added to the method embodiments. Moreover, the method embodiments can be implemented independently or in combination with each other.

[0127] The various variations and specific embodiments of the water-cooling control method for horizontal continuous casting of internally threaded copper tubes in the foregoing embodiments are equally applicable to the water-cooling system for horizontal continuous casting of internally threaded copper tubes in this embodiment. Through the foregoing detailed description of the water-cooling control method for horizontal continuous casting of internally threaded copper tubes, those skilled in the art can clearly know the implementation method of the water-cooling system for horizontal continuous casting of internally threaded copper tubes in this embodiment. Therefore, for the sake of brevity of the specification, it will not be elaborated herein.

[0128] The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by 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 area division module is used to divide the water cooling system into functional areas and generate multiple cooling areas; A temperature monitoring configuration module, used for setting a plurality of temperature monitoring points according to the plurality of cooling areas; A data acquisition module, used for obtaining the copper tube drawing speed and the real-time temperature of the plurality of temperature monitoring points in real time; A fluctuation analysis module, used to perform comprehensive fluctuation analysis on the multiple real-time temperatures to obtain temperature fluctuation characteristics; A constraint trigger module, for obtaining 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 the preset pulling speed range and / or the temperature fluctuation characteristic exceeds the preset fluctuation threshold; A function optimization module, used for converting the conditional constraints into constraint vectors, and integrating the constraint vectors into the control objective function corresponding to each cooling zone, and performing 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; Convert the conditional constraints into constraint vectors, and integrate them into the control objective function corresponding to each cooling area 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 is 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 is 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 is characterized in that: The setting of the temperature monitoring points includes: A first temperature sensor and a second temperature sensor are respectively arranged at the inlet and the outlet of the cooling zone of the crystallizer to monitor the temperature difference of the solidified shell on the surface of the copper tube; An annular array type infrared thermometer 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 arranged 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; The temperature sequences of the plurality of temperature monitoring points in the same cooling area are subjected to frequency domain analysis, 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 pulling 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 drawing 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 on 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 minimization of 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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