Method and device for optimizing uniformity of electromagnetic induction heating of large diameter billets

Abstract

The present application provides a method and device for optimizing the uniformity of electromagnetic induction heating of large-diameter billets, relating to the field of data processing. The method is applied to a controller of an electromagnetic induction heating furnace, wherein the heating mechanism of the electromagnetic induction heating furnace includes multiple heating chambers, each of which is equipped with an independently controlled electromagnetic coil for harmonic heating. The multiple electromagnetic coils are distributed along the length of the target billet. The method includes: during the heating process of the target billet, measuring the temperature data of the target billet surface based on an infrared temperature sensor to obtain the temperature distribution of the target billet surface; inverting the center temperature of the target billet by combining the temperature distribution and the heating parameters of the heating mechanism with an established heat conduction mathematical model for the target billet; determining the heating process parameters of each electromagnetic coil based on the center temperature and the temperature distribution of the target billet surface; and heating the target billet according to the heating process parameters. Implementation of this technical solution facilitates uniform heating of large-diameter billets.

Description

Technical Field

[0001] The present application relates to the technical field of data processing, and in particular to a method and device for optimizing the uniformity of electromagnetic induction heating of large-diameter billets. Background Art

[0002] The billets required for aerospace forgings are typically heated and held in a large-hearth resistance furnace for a long period of time before being forged. However, this traditional process not only results in low forging efficiency and high energy consumption, but also easily leads to coarse material structure. In recent years, electromagnetic induction heating technology has been widely used and highly recognized in the industrial field due to its significant advantages, such as rapid heating, efficient energy conversion, precise temperature control, the flexibility of contactless heating, and environmental protection and energy saving. This technology can quickly and accurately transfer energy to the heating body, adapting to the heating needs of a variety of materials and complex shapes, while significantly reducing energy consumption and environmental pollution.

[0003] Despite this, traditional electromagnetic induction heating technology still faces significant challenges in heating large-diameter billets, such as steel bars. Due to the bulk of the billets, the heating process is prone to problems such as uneven temperature distribution, low energy efficiency, and prolonged heating cycles. This, in turn, increases equipment investment costs and technical implementation difficulties. Heating large-diameter steel bars is particularly challenging, as their large size further exacerbates the difficulty of controlling temperature uniformity.

[0004] Therefore, there is an urgent need for a method and device for optimizing the uniformity of electromagnetic induction heating of large-diameter billets. Summary of the Invention

[0005] The present application provides a method and apparatus for optimizing the uniformity of electromagnetic induction heating of large-diameter billets, which facilitates uniform heating of large-diameter billets.

[0006] In a first aspect of the present application, a method for optimizing the uniformity of electromagnetic induction heating of large-diameter billets is provided, which is applied to a controller of an electromagnetic induction heating furnace. The heating mechanism of the electromagnetic induction heating furnace includes multiple heating chambers, each of which is provided with an independently controlled electromagnetic coil for harmonic heating, and the multiple electromagnetic coils are distributed along the length direction of the target billet. The method includes: during the heating process of the target billet, measuring the temperature data of the surface of the target billet based on an infrared temperature sensor to obtain the temperature distribution of the surface of the target billet; inverting the center temperature of the target billet by establishing a mathematical model of heat conduction for the target billet, combining the temperature distribution and the heating parameters of the heating mechanism; determining the heating process parameters of each electromagnetic coil based on the center temperature and the temperature distribution of the target billet surface; and heating the target billet according to the heating process parameters.

[0007] By employing this technical solution, infrared temperature sensors monitor the temperature distribution of the billet's surface in real time. Combined with a heat conduction mathematical model, the core temperature of the billet can be accurately estimated during the heating process. This real-time feedback mechanism enables dynamic adjustment of the heating process to minimize the temperature difference between the billet's surface and core, effectively addressing the temperature unevenness inherent in traditional methods. Traditional heating methods require long periods of heat preservation and heating, resulting in energy waste and low heating efficiency. By precisely controlling the power and frequency of each heating chamber, this method allows targeted heating of each part of the billet according to actual needs, reducing unnecessary energy consumption. Furthermore, harmonic heating technology, through multi-frequency modulation, enables more efficient heat transfer to the billet, further improving heating efficiency. In this method, multiple electromagnetic coils are distributed along the length of the target billet, each of which can be independently controlled. This means that each zone can be adjusted in real time based on temperature feedback during the heating process. This segmented control allows the heating process to be optimized for each zone to meet the heating requirements of each region. This segmented control approach effectively avoids the temperature unevenness often encountered in traditional heating of large-diameter billets, improving heating flexibility and adaptability. By real-time monitoring of the temperature distribution on the billet surface and combining it with the inverted center temperature, precise temperature control can be achieved. In traditional heating systems, temperature control often relies on experience or preset parameters, lacking real-time feedback and adjustment mechanisms. This method, however, achieves more refined temperature control through mathematical modeling and real-time data feedback, not only improving forming quality but also ensuring the stability of the heating process. This makes it easier to uniformly heat large-diameter billets.

[0008] Optionally, before inverting the center temperature of the target blank by establishing a mathematical model of heat conduction for the target blank and combining it with the temperature distribution and the heating parameters of the heating mechanism, the method also includes: determining the electromagnetic field distribution of the area where the target blank is located based on the coil parameters, frequency and position of each electromagnetic coil; determining the internal heat source density generated by heating of multiple electromagnetic coils based on the electromagnetic field distribution of the area where the target blank is located; calculating the total power generated by heating of multiple electromagnetic coils based on the internal heat source density generated by heating of multiple electromagnetic coils; constructing a basic heat conduction model, introducing multi-coil heating correction into the basic heat conduction model based on the total power generated by heating of multiple electromagnetic coils, and obtaining the mathematical model of heat conduction; determining the boundary conditions for the mathematical model of heat conduction, the boundary conditions including surface heat loss boundary conditions, blank center axis symmetric boundary conditions and end adiabatic boundary conditions.

[0009] By employing the above technical solution and inverting the temperature model, the temperature distribution on the billet surface and center can be accurately determined, avoiding the problem of uneven or unstable temperatures during the heating process. By optimizing the electromagnetic field distribution and internal heat source density in each region, temperature uniformity can be achieved during the heating process, improving forming quality. By properly selecting the parameters and frequency of each coil, energy transfer in the heating area can be precisely controlled, avoiding excessive energy concentration or waste. By calculating the internal heat source density generated by each coil, the heat distribution during the heating process can be optimized, thus avoiding concentrated energy waste or localized overheating. Based on the basic heat conduction model, a multi-coil heating correction is introduced to make the heat conduction model more consistent with actual heating conditions. This correction allows the model to more accurately reflect the non-uniformity of electromagnetic induction heating and improves the accuracy of the prediction of billet temperature changes. The complex electromagnetic field interactions and heat source density variations during electromagnetic induction heating are addressed by the model correction, which can account for the different effects of multi-coil heating and provide a more accurate heating process. The effectiveness of the heat conduction mathematical model is closely related to the boundary conditions set. Surface heat loss boundary conditions take into account the heat loss that occurs on the billet surface, such as through radiation and convection. Appropriate boundary conditions can help accurately describe the surface heat exchange process and prevent the impact of heat loss on temperature predictions. Since billets are typically circular or symmetrical, the symmetry around the central axis helps simplify the model while ensuring computational efficiency. Using a central axis-symmetric boundary condition can reduce the amount of computation and ensure accurate results. Since there is often no significant heat exchange between the two ends of a billet, adiabatic boundary conditions can help simulate this heat flow restriction, thereby improving the accuracy of temperature predictions.

[0010] Optionally, the center temperature of the target blank is inverted by establishing a mathematical model of heat conduction for the target blank, combined with the temperature distribution and the heating parameters of the heating mechanism, specifically including: in the axisymmetric coordinate system of the target blank, dividing the target blank into radial and axial finite element grids; using the finite volume method to discretize the model and construct a discretized heat conduction equation; inputting the boundary conditions, electromagnetic parameters and internal heat source density into the discretized heat conduction equation to solve the instantaneous temperature of the target blank surface; setting the initial temperature of the target blank to the ambient temperature of the heating mechanism, inputting the temperature data into the mathematical model of heat conduction, and using the mathematical model of heat conduction to solve the heat conduction equation to obtain a solution result, which is the predicted surface temperature at the next moment; comparing the predicted surface temperature with the actual temperature at the corresponding moment, and when the temperature error between the predicted surface temperature and the actual temperature is within a preset range, extracting the center temperature of the target blank.

[0011] By implementing this technical solution, the model's accuracy can be effectively calibrated by comparing the predicted surface temperature with the actual temperature. This method allows for real-time evaluation of the prediction accuracy at every moment. If the error between the predicted and actual temperatures is within a preset range, the model is effectively calibrated, which helps improve the accuracy of the overall heating process. This error comparison mechanism facilitates real-time adjustment of the heat conduction model, ensuring that the temperature control system promptly responds to changes during the actual heating process and avoiding losses caused by overheating or underheating. By monitoring and predicting the surface temperature in real time, control parameters during the heating process can be dynamically adjusted to ensure optimal temperature distribution throughout the billet during different heating stages, particularly avoiding excessive temperature gradients that could damage the material. Using an axisymmetric coordinate system and finite element meshing, the billet heating process can be transformed into a computable mathematical model. This method is suitable for heat conduction problems in large-diameter billets, accurately describing the temperature distribution along both the radial and axial directions and accounting for heating characteristics at different locations. Using the finite volume method to discretize the heat conduction equation ensures high numerical accuracy. This method is suitable for dynamic heat conduction problems, particularly when considering temporal variations, accurately simulating the transfer, distribution, and changes of heat during the heating process. Inputting electromagnetic heating parameters and internal heat source density into the model directly reflects the characteristics of the heating source, allowing the heat conduction equation to fully account for the effects of electromagnetic induction heating. The accuracy of these inputs directly affects the accuracy of temperature predictions.

[0012] Optionally, the heating process parameters of each electromagnetic coil are determined based on the center temperature and the temperature distribution on the surface of the target blank, specifically including: calculating the standard deviation of the temperature field of the target blank to evaluate the overall temperature uniformity of the target blank; based on the evaluation result of the overall temperature uniformity of the target blank, if it is determined that the evaluation result indicates that the overall temperature uniformity of the target blank does not meet the preset requirements, then calculating the temperature difference between the actual temperature of the target temperature field and the target temperature with respect to the center temperature and the temperature distribution on the surface of the target blank, the target temperature being the temperature of the target temperature field under the premise that the overall temperature uniformity of the target blank meets the preset requirements, and the target temperature field being any one of the multiple temperature fields of the target blank; if it is determined that the temperature difference is greater than or equal to a preset threshold, then determining that the heating chamber corresponding to the target temperature field among the multiple heating chambers is the first heating chamber; and determining the adjusted heating power of the electromagnetic coil in the first heating chamber based on the temperature difference.

[0013] By employing the above technical solution, the overall temperature uniformity of the billet can be quantitatively assessed by calculating the standard deviation of the billet's temperature field. A smaller standard deviation indicates a more uniform temperature distribution, while a larger standard deviation indicates an uneven temperature distribution. This step provides an objective basis for subsequent adjustments to the heating power, preventing excessive temperature differences or hot spots during the billet heating process, which is crucial for maintaining material properties. Dynamically assessing the temperature distribution using the standard deviation of the temperature field ensures real-time monitoring and adjustment of temperature uniformity during the heating process. This method enables continuous monitoring of heating effectiveness and timely response, preventing the negative impact of localized overheating or underheating on billet quality. After assessing overall temperature uniformity, the temperature difference between the actual and target temperatures is calculated to further analyze whether the set uniformity requirements are met. If the difference exceeds a set threshold, the system automatically identifies and adjusts the heating power of the first heating chamber. This precise control not only avoids overheating or underheating, but also makes the heating process more efficient. In traditional heating processes, large temperature gradients between the center and surface of the billet can lead to uneven material microstructure, affecting forging quality and mechanical properties. This standard deviation-based uniformity assessment and adjustment method can reduce structural defects caused by temperature non-uniformity and ensure more consistent billet quality. By adjusting the heating power, especially when there are large temperature differences, localized overheating or slow cooling is avoided, ensuring that every part of the billet reaches the desired temperature uniformly, avoiding problems such as internal stress and material cracking caused by large temperature differences.

[0014] Optionally, the method also includes: determining a second heating chamber adjacent to the first heating chamber among the multiple heating chambers; determining a first segment of the target blank in the first heating chamber, and a second segment of the target blank in the second heating chamber; determining a first overall temperature of the first segment and a second overall temperature of the second segment; adjusting the heating process parameters corresponding to the first coil and the second coil according to the first overall temperature and the second overall temperature to reduce the difference between the first overall temperature and the second overall temperature, the first coil is the electromagnetic coil of the first heating chamber among the multiple electromagnetic coils, and the second coil is the electromagnetic coil of the second heating chamber among the multiple electromagnetic coils.

[0015] By employing the above technical solution, the temperature differences between adjacent heating chambers can be effectively reduced by monitoring the overall temperature of the first and second sections, calculating the difference, and adjusting the corresponding electromagnetic coil heating parameters. This adjustment directly affects the temperature gradient between the heating chambers, ensuring a more uniform temperature distribution throughout the target billet's heating process. Uneven temperatures can lead to structural defects, stress concentrations, and material performance issues during subsequent forging. Reducing the temperature difference between the heating chambers effectively mitigates these effects, ensuring uniform heating of the billet and providing a more stable foundation for subsequent forging and processing. Even if the temperature distribution changes during the heating process, the system automatically detects and adjusts to ensure that every part of the billet receives appropriate heating. By adjusting the corresponding heating process parameters of the first and second coils, the heating power between the two sections is more closely matched, avoiding unnecessary energy waste caused by excessive power in one heating chamber. This optimization effectively reduces energy consumption and minimizes unnecessary waste. Areas with large temperature differences require longer to heat or maintain a stable temperature. Precisely adjusting the heating power allows the billet to be heated more quickly and evenly, shortening the overall heating time and improving production efficiency.

[0016] Optionally, the method also includes: if it is determined that the difference between the segment center temperature and the segment surface temperature of the target segment is greater than or equal to a preset difference, adjusting the coil frequency of the target coil, the target coil is an electromagnetic coil among the multiple electromagnetic coils that heats the target segment, and the target segment is any one of the multiple segments corresponding to the target blank; calculating the temperature change rate of the target temperature field; and adjusting the heating time of the electromagnetic coil in the first heating chamber according to the temperature change rate to extend the heating time of the cold zone and shorten the heating time of the hot zone.

[0017] By adopting the above technical solution, by comparing the difference between the center temperature and the surface temperature of the target segment, the system can determine whether there is obvious temperature unevenness in the segment. For cold zones with slower heating progress, extending the heating time can ensure that the area can get enough heat. For overheated areas, shortening the heating time can help prevent overheating and heat loss, thereby effectively controlling energy consumption and avoiding overheating of materials. By dynamically adjusting the heating time, the distribution of heating power can be accurately controlled, avoiding the energy waste that may exist in the traditional heating process. Extending the heating time of the cold zone can ensure that its temperature reaches the predetermined value as soon as possible, avoiding insufficient heating of the cold zone for too long, resulting in inefficient heating of the billet. Shortening the heating time of the hot zone can avoid heat waste, accelerate the overall heating process, and improve production efficiency.

[0018] Optionally, during the heating process of the target blank, the temperature data of the target blank surface is measured based on an infrared temperature sensor to obtain the temperature distribution of the target blank surface, specifically including: obtaining temperature data of multiple collection points located on the target blank surface; based on the multiple temperature data, using an interpolation algorithm to expand the multiple temperature data to the complete blank surface of the target blank, thereby obtaining the temperature distribution of the target blank surface.

[0019] By adopting the above technical solution, the data from multiple collection points can more comprehensively reflect the temperature distribution on the billet surface, thereby providing more accurate input data for subsequent heat conduction modeling. Directly expanding from multiple temperature collection points to the entire surface can overcome the problem of limited collection points of infrared sensors. Through the interpolation algorithm, the temperature values ​​of other unmeasured areas on the billet surface can be smoothed and extrapolated to obtain a more accurate temperature distribution and avoid errors caused by sparse temperature data. Through the interpolation algorithm, the data from each collection point is expanded to the entire surface, which can provide more comprehensive information for the overall temperature field and make up for the shortcomings of traditional measurement methods that cannot cover the entire surface. Accurate temperature distribution information can provide more accurate boundary conditions for the heat conduction mathematical model and reduce errors when solving the model. The accurate temperature distribution obtained by the interpolation algorithm helps to efficiently and accurately invert the center temperature and provide a reliable basis for the optimization of the heating process.

[0020] In a second aspect of the present application, a device for optimizing the uniformity of electromagnetic induction heating of large-diameter billets is provided. The device is a controller of an electromagnetic induction heating furnace. The heating mechanism of the electromagnetic induction heating furnace includes multiple heating chambers, each of which is provided with an independently controlled electromagnetic coil for harmonic heating. The multiple electromagnetic coils are distributed along the length direction of the target billet. The controller of the electromagnetic induction heating furnace includes an acquisition module and a processing module, wherein the acquisition module is used to measure the temperature data of the target billet surface based on an infrared temperature sensor during the heating process of the target billet to obtain the temperature distribution of the target billet surface; the processing module is used to invert the center temperature of the target billet by combining the temperature distribution and the heating parameters of the heating mechanism with a heat conduction mathematical model established for the target billet; the processing module is also used to determine the heating process parameters of each electromagnetic coil based on the center temperature and the temperature distribution of the target billet surface; the processing module is also used to heat the target billet according to the heating process parameters.

[0021] In a third aspect of the present application, an electronic device is provided, which includes a processor, a memory, a user interface, and a network interface. The memory is used to store instructions, the user interface and the network interface are both used to communicate with other devices, and the processor is used to execute the instructions stored in the memory so that the electronic device performs the method described above.

[0022] In a fourth aspect of the present application, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores instructions. When the instructions are executed, the method described above is executed.

[0023] In summary, one or more technical solutions provided in this application have at least the following technical effects or advantages:

[0024] By using infrared temperature sensors to monitor the temperature distribution on the billet's surface in real time and combining this with a mathematical model of heat conduction, the billet's core temperature can be accurately estimated during the heating process. This real-time feedback mechanism enables dynamic adjustment of the heating process to minimize the temperature difference between the billet's surface and core, effectively addressing the temperature unevenness inherent in traditional methods. Traditional heating methods require long periods of heat preservation and heating, resulting in energy waste and low heating efficiency. This method, by precisely controlling the power and frequency of each heating chamber, allows targeted heating of each part of the billet according to actual needs, reducing unnecessary energy consumption. Furthermore, harmonic heating technology, through multi-frequency modulation, enables more efficient heat transfer to the billet, further improving heating efficiency. In this method, multiple electromagnetic coils are distributed along the length of the target billet, each of which can be independently controlled. This means that each zone can be adjusted in real time based on temperature feedback during the heating process. This segmented control allows the heating process to be optimized individually to meet the heating requirements of each region. This segmented control approach effectively avoids the temperature unevenness that can occur with traditional heating of large-diameter billets, improving heating flexibility and adaptability. By real-time monitoring of the billet's surface temperature distribution and combining it with the inverted core temperature, precise temperature control can be achieved. In traditional heating systems, temperature control often relies on experience or preset parameters, lacking real-time feedback and adjustment mechanisms. This method, however, achieves more refined temperature control through mathematical modeling and real-time data feedback. This not only improves forming quality but also ensures heating process stability. This makes it easier to uniformly heat even large-diameter billets. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic flow chart of a method for optimizing the uniformity of electromagnetic induction heating of large-diameter billets provided in an embodiment of the present application;

[0026] Figure 2This is a schematic diagram of an example of a heating mechanism of an electromagnetic induction heating furnace provided in an embodiment of the present application;

[0027] Figure 3 A schematic diagram of a module for optimizing the uniformity of electromagnetic induction heating of large-diameter billets provided in an embodiment of the present application;

[0028] Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0029] Explanation of the reference numerals: 31, acquisition module; 32, processing module; 41, processor; 42, communication bus; 43, user interface; 44, network interface; 45, memory. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments.

[0031] In the description of the embodiments of this application, words such as "for example" or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "for example" or "for instance" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "for example" or "for instance" is intended to present the relevant concepts in a concrete manner.

[0032] In the description of the embodiments of the present application, the term "multiple" means two or more. For example, multiple systems refer to two or more systems, and multiple screen terminals refer to two or more screen terminals. In addition, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0033] The billets required for the formation of aviation forgings are usually heated and kept warm for a long time in a large-hearth resistance furnace before being forged. However, this traditional heating process has obvious drawbacks: it not only leads to low forging forming efficiency and high energy consumption, but also easily causes problems such as material microstructure coarsening. In recent years, electromagnetic induction heating technology has been widely used and recognized in many industrial fields due to its outstanding advantages such as rapid heating, efficient energy conversion, precise temperature control, the flexibility of contactless heating, and environmental protection and energy saving. This technology can efficiently and accurately transfer energy to the heating body, adapting to the heating needs of various materials and complex shapes, and effectively reducing energy consumption and environmental pollution.

[0034] However, traditional electromagnetic induction heating technology still faces significant challenges when applied to heating large-diameter billets, such as large-diameter steel bars. Due to the bulk of the billets, the heating process is prone to problems such as uneven temperature distribution, low energy efficiency, and prolonged heating cycles. Furthermore, the sheer scale of the heating system increases equipment investment costs and the technical implementation complexity. This is particularly true for heating large-diameter steel bars, where the larger billet size makes temperature uniformity control even more difficult.

[0035] In order to solve the above technical problems, the present application provides a method for optimizing the uniformity of electromagnetic induction heating of large diameter billets, referring to Figure 1 , Figure 1 This is a flow chart of a method for optimizing the uniformity of electromagnetic induction heating of large diameter billets provided in an embodiment of the present application. The method for optimizing the uniformity of electromagnetic induction heating of large diameter billets is applied to a controller of an electromagnetic induction heating furnace. Figure 2 , Figure 2 This is a schematic diagram of an example heating mechanism of an electromagnetic induction heating furnace provided in an embodiment of the present application. The heating mechanism of the electromagnetic induction heating furnace includes multiple heating chambers. The number and length of the heating chambers are segmented according to the temperature control requirements of the operator. Each heating chamber is equipped with an independently controlled electromagnetic coil for harmonic heating. The multiple electromagnetic coils are distributed along the length direction of the target blank. The method specifically includes steps S110 to S140, which are as follows:

[0036] S110 , during the heating process of the target blank, measuring temperature data of the target blank surface based on an infrared temperature sensor to obtain temperature distribution of the target blank surface.

[0037] Specifically, during the heating process, an electromagnetic induction furnace generates a magnetic field through induced current, heating the billet. To achieve efficient and uniform heating, a controller needs to monitor the billet's temperature in real time. The controller here refers to the electromagnetic induction furnace's control system, which is responsible for adjusting various parameters during the heating process, such as power, frequency, and heating duration. To ensure accurate heating, the controller must obtain temperature data on the billet's surface so it can make appropriate adjustments. An infrared temperature sensor is a non-contact temperature measurement device that infers the object's temperature by detecting infrared radiation emitted from the surface. The advantage of this sensor is that it can monitor temperature remotely and in real time, avoiding direct contact with the billet. Therefore, it is unaffected by high-temperature environments and is suitable for measuring the temperature of high-temperature objects. In an electromagnetic induction furnace, an infrared temperature sensor is used to measure the target billet's surface temperature. Because the billet's surface temperature often fluctuates, the sensor needs to continuously acquire real-time data to monitor the billet's surface temperature distribution. After acquiring the billet's surface temperature data, the controller processes and analyzes the data to determine the temperature distribution across the entire billet surface. This temperature distribution refers to the varying temperatures across different regions, including the temperature variations at various points on the billet's surface. For example, the surface temperature of the blank may vary at different locations; the surface may be hotter near the heating coils and cooler at locations further away from the heating coils.

[0038] In one possible embodiment, during the heating process of the target blank, the temperature data of the target blank surface is measured based on an infrared temperature sensor to obtain the temperature distribution of the target blank surface, specifically including: obtaining temperature data of multiple collection points located on the target blank surface; based on the multiple temperature data, using an interpolation algorithm to expand the multiple temperature data to the complete blank surface of the target blank, thereby obtaining the temperature distribution of the target blank surface.

[0039] Specifically, in this process, infrared temperature sensors are installed at multiple locations on the target billet surface. Each sensor measures and records the temperature data at a specific location. This temperature data reflects the temperature state at different locations on the billet surface. Infrared temperature sensors can only collect data at fixed locations, but the billet surface is continuous, making it impossible to place sensors at every point. Therefore, an interpolation algorithm is needed to infer and supplement the temperature data of unmeasured areas. An interpolation algorithm is a mathematical method that can infer the temperature value at an unknown location based on known data points, i.e., the temperature data collected by the sensor. Interpolation methods used in the embodiments of the present application may include: linear interpolation: calculating the temperature value between two known data points; polynomial interpolation: using multiple known points and using a polynomial function to estimate the temperature at other locations; and spline interpolation: using piecewise polynomials for interpolation, which can provide smoother results. The above interpolation algorithms are not limited; the specific type is determined based on actual conditions. By combining the temperature data expanded by the interpolation algorithm with the actual collected data, a complete target billet surface temperature distribution can be obtained. At this time, the temperature distribution not only includes the data directly measured by the sensor, but also supplements the data of the area not covered by the sensor through interpolation.

[0040] S120 , inverting the center temperature of the target blank by using the established heat conduction mathematical model for the target blank, combined with the temperature distribution and the heating parameters of the heating mechanism.

[0041] Specifically, the mathematical model of heat conduction is based on the heat conduction equation, which describes how heat transfers from high-temperature to low-temperature regions within an object through conduction. For the case of billet heating, this model considers the billet's thermophysical properties, such as thermal conductivity and specific heat capacity, as well as possible heat sources during the heating process, such as localized heating caused by electromagnetic heating. When the billet's surface temperature is measured by an infrared sensor, a temperature distribution map is generated. The inversion process infers the core temperature based on the surface temperature data and the heat conduction model. Since heat conduction occurs from the surface inward, the billet's surface temperature provides sufficient information to estimate the internal temperature. The inversion technique infers the core temperature by solving the heat conduction equation and incorporating boundary conditions. The core of the inversion process is to use known surface temperature data and numerical methods, such as the finite element method and the finite difference method, to gradually infer the temperature at each location within the billet. The inverted core temperature is a key parameter for evaluating the billet heating process. Because temperature non-uniformity during heating can lead to variations in material properties, such as hardness and ductility, real-time acquisition and control of the billet's core temperature is crucial to ensuring heating uniformity and forging quality.

[0042] In a possible embodiment, before inverting the center temperature of the target blank by establishing a mathematical model of heat conduction for the target blank and combining the temperature distribution and the heating parameters of the heating mechanism, the method also includes: determining the electromagnetic field distribution of the area where the target blank is located based on the coil parameters, frequency and position of each electromagnetic coil; determining the internal heat source density generated by heating of multiple electromagnetic coils based on the electromagnetic field distribution of the area where the target blank is located; calculating the total power generated by heating of multiple electromagnetic coils based on the internal heat source density generated by heating of multiple electromagnetic coils; constructing a basic heat conduction model, introducing multi-coil heating correction to the basic heat conduction model based on the total power generated by heating of multiple electromagnetic coils, and obtaining a mathematical model of heat conduction; determining the boundary conditions for the mathematical model of heat conduction, the boundary conditions including surface heat loss boundary conditions, blank center axis symmetric boundary conditions and end insulation boundary conditions.

[0043] Specifically, the electromagnetic coil's parameters, such as the number of turns, frequency, and position, affect the efficiency and range of electromagnetic induction heating. Therefore, the distribution of the electromagnetic field needs to be determined based on these characteristics of the electromagnetic coil. The number of turns, frequency, and position of each coil affect the effectiveness of electromagnetic induction. For example, high-frequency coils result in a shallower heating layer, while low-frequency coils heat deeper areas. The electromagnetic field is generated by the electromagnetic coil, with alternating electric and magnetic fields generating induced currents, which in turn induce heating. The distribution of the electromagnetic field determines which areas of the blank will be heated more and which will be heated less.

[0044] For example, consider three different electromagnetic coils, positioned at different locations within a blank. The first coil is near one end of the blank, the second coil is in the middle, and the third coil is at the other end. Each coil operates at a different frequency—for example, the first coil uses a high frequency, the second a medium frequency, and the third a low frequency. Due to these different frequencies, the electromagnetic field generates heat differently within the blank: the high-frequency coil heats more of the surface, while the low-frequency coil heats deeper into the blank.

[0045] In electromagnetic induction heating, heat generation primarily stems from the interaction between the induced current and the electrical resistance of the billet material. By knowing the internal heat source density in each region, the total power consumed during the heating process can be calculated. The power is calculated by integrating the internal heat source density within each region to obtain the total heating power. Once the total power is known, a basic heat conduction model can be constructed based on this information. This basic heat conduction model considers the billet's thermophysical properties, such as thermal conductivity and specific heat capacity, and combines the heat generated by electromagnetic heating to calculate the billet's temperature distribution. Boundary conditions describe the heat exchange within the billet during heating. Surface heat loss boundary conditions: Since the billet surface exchanges heat with the surrounding environment, this heat exchange results in heat loss. Axisymmetric boundary conditions: Since billets are typically axisymmetric, the central axis of the billet can be assumed to be symmetrical along the axis, meaning that the temperature changes on both sides of the billet are symmetrical. End adiabatic boundary conditions: Since there may not be significant heat flow at the ends of the billet, the ends can be assumed to be adiabatic, meaning that no heat is transferred through them.

[0046] In the embodiment of the present application, the electromagnetic field distribution in the area where the target blank is located is specifically calculated using the following formula:

[0047] ;

[0048] Among them, E i (z, r) is the magnetic field intensity at the position (z, r), E 0i is the maximum electric field strength value at the center of the coil, Z i is the center position of the i-th electromagnetic coil in the heating mechanism, L i is the effective length of the i-th electromagnetic coil, δ i is the skin depth of the i-th electromagnetic coil, which is used to indicate the penetration depth of the induced current in the blank.

[0049] In the embodiment of the present application, the specific calculation method of skin depth is as follows:

[0050] ;

[0051] Among them, δ i is the skin depth of the i-th electromagnetic coil, μ i is the material permeability of the i-th electromagnetic coil, σ i is the conductivity of the target blank, ω i is the angular frequency of the electromagnetic field corresponding to the i-th electromagnetic coil.

[0052] Specifically, the purpose of the above formula is to describe the energy transfer during the heating process through the electric field intensity generated by the electromagnetic coil. Since the energy transfer of electromagnetic induction heating is non-uniform, the intensity of the electric field varies with different positions. The exponential term included in the formula represents the distribution of the electric field intensity in the target blank. The radial distribution means that the electric field intensity gradually decays along the radial direction from the center of the coil. The rate of decay is determined by the skin depth. The smaller the skin depth, the greater the intensity of the electric field in the surface area and the faster the decay. The axial distribution represents the change in the distribution of the electric field intensity along the axial direction of the blank. This term represents the range of action of the electromagnetic coil. The longer the effective length of the coil, the larger the range of action of the electric field in the axial direction.

[0053] In the embodiment of the present application, the specific calculation method of the internal heat source density is as follows:

[0054] ;

[0055] Among them, Q i (z,r) is the internal heat source density at the position (z,r), σ i is the conductivity of the target blank, |E i (z,r)| is the magnetic field strength at the position (z,r).

[0056] In the embodiment of the present application, the total power is calculated by the following formula:

[0057] ;

[0058] Among them, Q(z,r,t) is the total power generated by the heating of multiple electromagnetic coils at time t, Q i (z,r,t) is the internal heat source density at the position (z,r) at time t.

[0059] Specifically, in electromagnetic induction heating, the electric field intensity generates a current that passes through the resistance of the blank, generating heat. Q(z,r,t) reflects the power generated by electromagnetic induction. The electrical conductivity can be used to calculate the heat source density generated by the current per unit volume. Each location has a corresponding internal heat source density value. During electromagnetic induction heating, the heat generated by each electromagnetic coil is generated through the interaction between the induced current and the electrical conductivity of the blank. Each coil generates a different internal heat source density at different locations and times. For each location, the total internal heat source density must be calculated based on the contribution of all electromagnetic coils to determine the total heating power. Using these formulas, the internal heat source density generated by the electromagnetic coils can be calculated, and the heating power applied to the blank can be inferred. These calculations are crucial for optimizing the heating process because they help assess heating uniformity, energy efficiency, and whether electromagnetic coil operating parameters, such as frequency and power, need to be adjusted for more efficient heating.

[0060] In the embodiment of the present application, the heat conduction mathematical model is expressed as follows:

[0061] ;

[0062] Wherein, ρ is the density of the target blank, c is the specific heat capacity of the target blank, k is the thermal conductivity of the target blank, T is the instantaneous temperature inside the target blank, is the rate of change of the instantaneous temperature inside the target blank with time, ∇T is the temperature gradient vector, which is used to represent the rate of change of the target blank temperature in the heating mechanism, ∇⋅(k∇T) represents the heat conduction process inside the blank, called the divergence of the heat flux, which describes the diffusion and transmission of heat in the blank, and Q(z,r,t) is the total power generated by multiple electromagnetic coils at time t.

[0063] In the embodiment of the present application, the surface heat loss boundary condition is expressed as follows:

[0064] ;

[0065] Where n is the normal unit vector, T s is the instantaneous temperature of the target blank surface, T ∞ is the ambient temperature of the heating mechanism, h is the convective heat transfer coefficient, which is used to describe the convective heat transfer intensity between the blank surface and the environment, σ is the Stefan-Boltzmann constant, which is used for radiation heat transfer calculation, and ε is the emissivity of the material surface, which is used to describe the radiation capacity of the material.

[0066] In the embodiment of the present application, the symmetrical boundary condition of the blank center axis is expressed as follows:

[0067] ;

[0068] Among them, this formula indicates that the radial temperature gradient of the billet is zero at the central axis, that is, the temperature distribution of the central axis is symmetrical. In the axisymmetric model, since the geometric structure of the billet is symmetrical about the central axis r = 0, the temperature at the center does not change with the radial position. No heat passes through the central axis of the billet, which means that there is no radial heat flow in the center of the billet.

[0069] In the embodiment of the present application, the end adiabatic boundary condition is expressed as follows:

[0070] ;

[0071] The formula indicates that there is no heat loss at the two axial ends of the billet (z = 0 and z = L), and the heat flux is zero. It is assumed that the heat exchange at the ends of the billet can be ignored, or that the area is protected, such as covered by an insulating cover, and there is no obvious heat loss.

[0072] Specifically, in the heat conduction equation, density combined with specific heat capacity determines the rate of temperature change after the billet absorbs heat. The larger the specific heat capacity, the slower the billet heats up. The rate of change of the instantaneous temperature inside the target billet with respect to time reflects the rate of temperature change over time during the heat conduction process. The larger the temperature gradient, the faster the heat transfer rate. The total internal heat source density generated by multiple electromagnetic coils at time t represents the heat density generated by electromagnetic induction. The larger the convective heat transfer coefficient, the faster the heat exchange. Different materials have different radiation capabilities, so the contribution of ε to radiation heat transfer is crucial. Using these boundary conditions and the mathematical model of heat conduction, it is possible to accurately simulate how the billet is heated during electromagnetic induction heating, how it exchanges heat with the environment, and how heat is transferred within the billet. Each boundary condition plays a significant role in the heat transfer process, helping to optimize the heating process, ensure temperature uniformity within the billet, and improve heating efficiency.

[0073] In one possible embodiment, a mathematical model of heat conduction is established for the target blank, combined with the temperature distribution and the heating parameters of the heating mechanism, to invert the center temperature of the target blank, specifically including: in the axisymmetric coordinate system of the target blank, dividing the target blank into radial and axial finite element grids; using the finite volume method to discretize the model and construct a discretized heat conduction equation; inputting boundary conditions, electromagnetic parameters and internal heat source density into the discretized heat conduction equation to solve the instantaneous temperature of the target blank surface; setting the initial temperature of the target blank to the ambient temperature of the heating mechanism, inputting the temperature data into the mathematical model of heat conduction, and using the mathematical model of heat conduction to solve the heat conduction equation to obtain a solution result, which is the predicted surface temperature at the next moment; comparing the predicted surface temperature with the actual temperature at the corresponding moment, and extracting the center temperature of the target blank when the temperature error between the predicted surface temperature and the actual temperature is within a preset range.

[0074] Specifically, first, a large-diameter steel bar is set to be calculated in an axisymmetric coordinate system. In the axisymmetric coordinate system, the temperature distribution problem is simplified because the billet is symmetrical on both sides of the axis, so the change in the temperature field only involves the radial and axial directions. The radial direction is the direction from the center of the billet to the surface. The axial direction is along the length of the billet. The target billet is divided into finite element meshes. Finite element meshes are a numerical calculation method that converts complex physical problems into simple small areas. The temperature change in each small area can be obtained by solving equations, thereby solving the temperature distribution of the entire billet as a whole. The finite volume method is a numerical method used to solve physical problems such as fluid dynamics and heat conduction. In the case of heat conduction, the core purpose of the finite volume method is to divide the physical field into several volume units and solve the temperature change of each unit through conservation equations. According to the heat conduction equation of the target billet, the finite volume method is used to convert it into a discrete form. These equations describe how the temperature changes over time and how the heat diffuses inside the billet.

[0075] To solve the temperature field, boundary conditions and parameters must be input. Boundary conditions include heat loss from the billet surface and insulation conditions at the ends. Electromagnetic parameters, such as the frequency, position, and power of the electromagnetic coil, determine the intensity of electromagnetic heating. Due to electromagnetic induction heating, each location within the billet has a certain internal heat source density, which depends on the distribution of the electromagnetic field and the electrical conductivity of the billet. Inputting this information into the discretized heat conduction equation allows the instantaneous surface temperature of the billet to be calculated at each moment. At the beginning of the calculation, the initial temperature of the target billet is typically set to the ambient temperature of the heating equipment, typically room temperature. Based on the initial conditions, boundary conditions, electromagnetic heating parameters, and internal heat source density, the heat conduction equation is solved to obtain the temperature distribution at the next moment. In practice, the billet surface temperature is measured using an infrared temperature sensor. This data is input into the heat conduction mathematical model and compared with the predicted surface temperature. Based on the heat conduction model, the target billet surface temperature change is calculated. The actual billet surface temperature is measured in real time using an infrared temperature sensor. The two are compared. If the error between the predicted and actual temperatures is within the preset tolerance, the model is confirmed to be accurate, allowing the next calculation to proceed. Through continuous iteration, the target billet's center temperature can be estimated. Through inversion, based on the known billet surface temperature data and the solution to the heat conduction equation, the internal temperature of the billet, including the center temperature, can be inferred. If the temperature error meets the preset requirements, the current model can accurately predict the billet's center temperature.

[0076] For example, suppose a large-diameter steel bar is being heated. Its initial temperature is room temperature, or 20°C. An infrared temperature sensor measures a temperature of 300°C at a point on the billet's surface. First, the steel bar is meshed using an axisymmetric coordinate system, and the finite volume method is used to establish the heat conduction equation. The controller also inputs boundary conditions, electromagnetic parameters, and the internal heat source density. Using these inputs, the heat conduction equation is solved to obtain a predicted surface temperature of the billet. Assume the predicted temperature is 310°C. The controller compares the predicted temperature with the actual temperature measured by the infrared sensor and finds an error of 10°C. Based on the error, the model parameters are adjusted and the calculation is repeated. The model is considered accurate until the error falls within a preset range, such as ±5°C. Using the heat conduction mathematical model, the temperature at the center of the billet can be reversed, assuming it is 320°C.

[0077] In the embodiment of the present application, the discretized heat conduction equation is expressed as follows:

[0078] ;

[0079] Among them, T i,j n+1 is the temperature of the target blank internal point (i, j) at time step n+1, T i,j n is the temperature of the target blank internal point (i, j) at time step n, Δt is the time step, and Q(z,r,t) is the total power generated by multiple electromagnetic coils at time t.

[0080] Specifically, the core purpose of this formula is to calculate the temperature at the next moment based on the current temperature, heat source, and heat diffusion through the time step. It calculates the temperature at the next time step based on the current temperature of the target billet at each location and the energy change during heat conduction.

[0081] In the embodiment of the present application, k∇T is a heat diffusion term, which is specifically expressed as follows:

[0082] ;

[0083] Where k is the thermal conductivity of the target blank, T i+1,j is the temperature at position i+1 inside the blank (the adjacent position on the z axis), T i,j is the temperature of the current calculation point inside the blank, T i−1,j is the temperature at position i−1 inside the blank, T i−1,j is the temperature at position i−1 inside the blank, T i,j+1 is the temperature at position j+1 inside the blank (the adjacent position on the r axis), T i,j−1 is the temperature at position j−1 inside the blank, and Δr is the spatial step size in the r-axis direction.

[0084] Specifically, this part of the formula approximates the heat diffusion process within the billet through discretization. The temperature gradient, that is, the rate of temperature change, is calculated by the temperature difference between adjacent points. Because the temperature change within each small unit of the billet is smooth, this formula can approximate the heat flow and heat diffusion within the billet. Therefore, by considering factors such as heat diffusion, internal heat sources, and time step, the temperature of each point in the target billet is gradually updated. This method uses numerical simulation to accurately calculate the temperature distribution during the heating process, ensuring the controllability and uniformity of the heating process.

[0085] S130 , determining heating process parameters of each electromagnetic coil based on the center temperature and the temperature distribution of the target blank surface.

[0086] Specifically, the electromagnetic coil's heating process parameters include heating power, heating frequency, and heating time. These parameters determine the electromagnetic coil's heating efficiency for the blank. By adjusting these parameters based on the target blank's temperature data, the controller ensures that the heating effect in different areas meets the desired requirements. Specifically, the power and frequency of each electromagnetic coil can be adjusted based on the blank's surface and core temperatures, ensuring a more even distribution of heat across different parts of the blank.

[0087] In one possible embodiment, the heating process parameters of each electromagnetic coil are determined based on the center temperature and the temperature distribution on the surface of the target blank, specifically including: calculating the standard deviation of the temperature field of the target blank to evaluate the overall temperature uniformity of the target blank; based on the evaluation result of the overall temperature uniformity of the target blank, if it is determined that the evaluation result indicates that the overall temperature uniformity of the target blank does not meet the preset requirements, then with respect to the center temperature and the temperature distribution on the surface of the target blank, calculating the temperature difference between the actual temperature of the target temperature field and the target temperature, the target temperature being the temperature of the target temperature field under the premise that the overall temperature uniformity of the target blank meets the preset requirements, and the target temperature field being any one of the multiple temperature fields of the target blank; if it is determined that the temperature difference is greater than or equal to the preset threshold, then determining that the heating chamber corresponding to the target temperature field among the multiple heating chambers is the first heating chamber; and determining the adjusted heating power of the electromagnetic coil in the first heating chamber based on the temperature difference.

[0088] Specifically, standard deviation is a measure of temperature distribution variation. A smaller standard deviation indicates a more uniform temperature distribution; a larger standard deviation indicates more pronounced temperature variations. The controller calculates the standard deviation of the target billet's temperature field during heating and uses this standard deviation to assess the temperature uniformity of the billet. A large standard deviation indicates higher temperatures in some areas of the billet and lower temperatures in others. If the calculated standard deviation indicates uneven temperature distribution, or significant temperature nonuniformity, further adjustments to the heating strategy are necessary to optimize temperature uniformity. The controller evaluates the overall heating effect based on the target billet's surface and center temperature distribution. If temperature nonuniformity exceeds a preset tolerance, the controller adjusts the heating parameters. The target temperature is the ideal temperature field set, representing the temperature distribution that the billet should achieve under ideal conditions during heating. The actual temperature represents the actual temperature variations at the billet's surface and center during the actual heating process. The controller determines heating uniformity by comparing the actual temperature field with the target temperature field. If the temperature variation is excessive, exceeding a preset threshold, adjustments are required. If the temperature difference is greater than or equal to the set threshold, the controller will identify which area of ​​the heating chamber needs to increase or decrease the heating power. The first heating chamber refers to the heating chamber where the temperature difference is the largest among the multiple electromagnetic coils. The corresponding heating chamber is called the first heating chamber. The controller will give priority to adjusting the power of the electromagnetic coil of this heating chamber. Based on the calculated temperature difference, the controller will increase or decrease the power of the electromagnetic coil of the first heating chamber to optimize the heating effect. For example, if the temperature in a certain area is low, the power of the electromagnetic coil in that area may be increased to speed up the heating of that area; conversely, if the temperature is high, the power may be reduced or the heating frequency may be adjusted to avoid overheating.

[0089] For example, suppose an infrared temperature sensor measures the temperature at different locations on a steel bar's surface, finding a higher temperature of 800°C on one side and a lower temperature of 650°C on the other. Using a heat conduction model, the temperature at the center of the bar is estimated to be 700°C. The controller calculates the standard deviation of the temperature distribution across the entire billet. A large standard deviation indicates temperature non-uniformity. Based on a preset tolerance, the controller determines that the temperature uniformity does not meet the required standards. Assuming the target temperature field is an ideal uniform heating state, the controller calculates the difference between the actual and target temperatures. If the difference between the target and actual temperatures exceeds a set threshold, for example, a difference greater than 10°C, the controller begins adjusting the heating parameters. The controller analyzes the temperature differences and finds that the temperature difference is greater on one side of the bar, for example, in the cooler 650°C region. The heating chamber corresponding to this region is designated the primary heating chamber, and the controller increases the power to the electromagnetic coil in that chamber to accelerate heating in that region. Simultaneously, the heating power to the hotter regions, such as 800°C, may be reduced to balance the overall temperature distribution. As heating progresses, the controller monitors the surface and center temperatures of the steel bar in real time, and dynamically adjusts the heating power of the electromagnetic coil based on the real-time temperature data to ensure that the temperature distribution of the target billet tends to be uniform until the preset temperature uniformity requirements are met.

[0090] In the embodiment of the present application, the calculation formula for adjusting the heating power is as follows:

[0091] ;

[0092] Among them, P i To adjust the heating power, P base is the current power of the electromagnetic coil in the first heating chamber, k p is the gain coefficient, ΔT i is the temperature difference.

[0093] Specifically, the current power of the first heating chamber is first determined. This is the unadjusted electromagnetic coil power, which may be based on the previous heating settings or initial conditions. Based on the difference between the actual temperature of the target blank and the expected target temperature, the temperature difference of the area is calculated. If the actual temperature of a heating area is lower, ΔT i will be a positive value, indicating that the heating power needs to be increased; on the contrary, if the actual temperature is higher, ΔT iA negative value indicates that the power should be reduced. The gain factor is a constant that needs to be determined based on experimental data. It determines how temperature differences affect heating power adjustments. A large gain factor means that even small temperature differences will result in larger power adjustments; conversely, a small gain factor means that even large temperature differences will result in more moderate heating power adjustments. Ultimately, the new adjusted heating power is calculated by adding the base power to the adjustment value based on the temperature difference and the gain factor. This new heating power is used to adjust the heating intensity of the electromagnetic coil until the temperature of the target area is closer to the set target temperature, achieving a more uniform heating effect.

[0094] S140: heating the target blank according to the heating process parameters.

[0095] Specifically, the heating process parameters are key parameters that define the heating process, including: heating power: the power applied by the electromagnetic coil, which determines the heating speed and heat distribution; heating time: the duration of the heating process; frequency: the operating frequency of electromagnetic heating, different frequencies will affect the heating depth and speed; temperature distribution requirements: the requirements for the surface and internal temperature of the billet. These parameters determine the heating method of the billet, the uniformity of heating, whether the required temperature requirements can be achieved, etc. Based on the above heating process parameters, the controller controls the heating process by adjusting the working state of the electromagnetic coil. Specifically, the controller will continuously adjust the heating power, frequency, etc. according to the feedback of the billet surface temperature to ensure that the heating process of the billet meets the expected goals, the temperature is uniform, and overheating or insufficient heating is avoided.

[0096] In one possible embodiment, a second heating chamber adjacent to the first heating chamber among multiple heating chambers is determined; a first segment of the target blank in the first heating chamber and a second segment of the target blank in the second heating chamber are determined; a first overall temperature of the first segment and a second overall temperature of the second segment are determined; and according to the first overall temperature and the second overall temperature, heating process parameters corresponding to the first coil and the second coil are adjusted to reduce the difference between the first overall temperature and the second overall temperature, the first coil is an electromagnetic coil of the first heating chamber among the multiple electromagnetic coils, and the second coil is an electromagnetic coil of the second heating chamber among the multiple electromagnetic coils.

[0097] Specifically, in an electromagnetic induction heating furnace, the billet is heated through multiple heating chambers, each with a corresponding electromagnetic coil to heat the billet. These heating chambers can be understood as independent heating zones, and the controller needs to control the heating intensity of each heating chamber separately. The controller needs to determine which heating chambers are adjacent to each other based on the actual heating needs. For example, assuming there are multiple heating chambers, the controller will determine which two heating chambers are located close to each other and then decide how to optimize the heating. The target billet is usually long and rectangular. During the heating process, the billet is divided into multiple segmented areas, and the heating effect of each area is considered separately. Each heating chamber heats its corresponding segment, which means that the target billet is in different heating zones in different heating chambers. For example, the first segment refers to the heating zone of the target billet in the first heating chamber. The second segment refers to the heating zone of the target billet in the second heating chamber. The first overall temperature and the second overall temperature refer to the overall temperature of the billet in the first and second segmented areas, that is, the average or combined temperature of the temperature in these areas.

[0098] Using these two temperature values, the controller can assess whether the heating effect between two adjacent heating chambers is balanced. A large temperature difference between the two areas could indicate uneven heating, potentially leading to quality issues with the billet. Adjusting the heating process parameters involves adjusting the power, frequency, or other relevant parameters of each electromagnetic coil based on the target billet's temperature distribution to minimize the temperature difference between the two heating areas. For example, if the temperature of the first segment is higher than that of the second segment, the controller might reduce the power of the first heating chamber or increase the power of the second heating chamber to reduce the temperature difference between the two segments and achieve uniform heating. The first and second coils are electromagnetic coils located in different heating chambers. Each electromagnetic coil operates according to the controller's instructions, generating a corresponding electromagnetic field and induced current, thereby heating the target billet. The controller needs to adjust the operating parameters of the two electromagnetic coils, such as frequency and power, based on the temperature difference between the two segments to ensure uniform temperature.

[0099] In one possible embodiment, if it is determined that the difference between the segment center temperature and the segment surface temperature of the target segment is greater than or equal to a preset difference, the coil frequency of the target coil is adjusted, where the target coil is an electromagnetic coil among multiple electromagnetic coils that heats the target segment, and the target segment is any one of the multiple segments corresponding to the target blank; the temperature change rate of the target temperature field is calculated; and according to the temperature change rate, the heating time of the electromagnetic coil in the first heating chamber is adjusted to extend the heating time of the cold zone and shorten the heating time of the hot zone.

[0100] Specifically, the segment center temperature refers to the temperature at the center of the segment, i.e., the average temperature of the segment. The segment surface temperature refers to the temperature at the surface of the segment. The surface temperature may vary due to contact with the environment and is typically higher than the internal temperature. During the heating process, if the temperature difference between the segment center and the segment surface is excessive—that is, the difference is greater than or equal to a preset difference—this indicates that the heating of the segment may be uneven. In this case, the controller will take measures to adjust the heating parameters. The target coil refers to the electromagnetic coil that heats a specific target segment. During electromagnetic induction heating, different frequencies affect the depth and rate of heating. A high frequency may cause the surface to heat too quickly, while a low frequency may lead to uneven heating. When the difference between the segment center and surface temperatures is large, the controller will adjust the frequency of the target coil to control the heat distribution and achieve more uniform heating. For example, the controller may reduce the frequency to allow heating to penetrate deeper into the target segment and reduce the temperature difference between the surface and the center. The temperature change rate refers to the rate at which the temperature at a location in the target temperature field changes over time, i.e., the amount of temperature change per unit time. By calculating this rate, the controller can determine whether heating is too fast or too slow. The temperature change rate can be obtained by numerically solving the heat conduction equation, typically by measuring the temperature change over time for each segment. If the temperature changes too quickly or too slowly, it indicates uneven heat distribution during the heating process, potentially leading to overheating or cooling of the heated area. The heating time refers to the time it takes for the electromagnetic coil to heat the target material within a heating chamber. Based on the temperature change rate, the controller determines how to adjust the heating duration. If a region, such as a cold zone, heats slowly, the controller will extend the heating time to ensure sufficient heating. If a region, such as a hot zone, heats too quickly, the controller may shorten the heating time to prevent overheating. A cold zone is a region of the material with lower temperatures, typically during the initial heating phase or where heat transfer is uneven. The controller extends the heating time in the cold zone to ensure that its temperature rises and eventually reaches the same level as the rest of the material. A hot zone is a region that has already heated during the heating process. The controller shortens the heating time in the hot zone to prevent overheating and ensure uniform heating across the entire material.

[0101] This application also provides a large diameter billet electromagnetic induction heating uniformity optimization device, refer to Figure 3 , Figure 3Schematic diagram of a module for optimizing the uniformity of electromagnetic induction heating of large-diameter billets provided in an embodiment of the present application. The device for optimizing the uniformity of electromagnetic induction heating of large-diameter billets is a controller for an electromagnetic induction heating furnace. The heating mechanism of the electromagnetic induction heating furnace includes multiple heating chambers, each of which is provided with an independently controlled electromagnetic coil for harmonic heating. The multiple electromagnetic coils are distributed along the length direction of the target billet. The controller of the electromagnetic induction heating furnace includes an acquisition module 31 and a processing module 32. The acquisition module 31 measures the temperature data of the target billet surface based on an infrared temperature sensor during the heating process of the target billet to obtain the temperature distribution of the target billet surface; the processing module 32 inverts the center temperature of the target billet by combining the temperature distribution and the heating parameters of the heating mechanism with the established thermal conduction mathematical model for the target billet; the processing module 32 determines the heating process parameters of each electromagnetic coil based on the center temperature and the temperature distribution of the target billet surface; and the processing module 32 heats the target billet according to the heating process parameters.

[0102] In a possible embodiment, before the processing module 32 inverts the center temperature of the target blank by establishing a mathematical model of heat conduction for the target blank, combined with the temperature distribution and the heating parameters of the heating mechanism, it also includes: the processing module 32 determines the electromagnetic field distribution of the area where the target blank is located based on the coil parameters, frequency and position of each electromagnetic coil; the processing module 32 determines the internal heat source density generated by the heating of multiple electromagnetic coils based on the electromagnetic field distribution of the area where the target blank is located; the processing module 32 calculates the total power generated by the heating of multiple electromagnetic coils based on the internal heat source density generated by the heating of multiple electromagnetic coils; the processing module 32 constructs a basic heat conduction model, introduces multi-coil heating correction to the basic heat conduction model based on the total power generated by the heating of multiple electromagnetic coils, and obtains a mathematical model of heat conduction; the processing module 32 determines the boundary conditions for the mathematical model of heat conduction, and the boundary conditions include surface heat loss boundary conditions, blank center axis symmetric boundary conditions, and end insulation boundary conditions.

[0103] In one possible embodiment, the processing module 32 inverts the center temperature of the target blank by establishing a heat conduction mathematical model for the target blank, combining the temperature distribution and the heating parameters of the heating mechanism, specifically including: the processing module 32 divides the target blank into radial and axial finite element grids in the axisymmetric coordinate system of the target blank; the processing module 32 uses the finite volume method to discretize the model and construct a discretized heat conduction equation; the processing module 32 inputs boundary conditions, electromagnetic parameters and internal heat source density into the discretized heat conduction equation to solve the instantaneous temperature of the target blank surface; the processing module 32 sets the initial temperature of the target blank to the ambient temperature of the heating mechanism, inputs the temperature data into the heat conduction mathematical model, and uses the heat conduction mathematical model to solve the heat conduction equation to obtain a solution result, and the solution result is the predicted surface temperature at the next moment; the processing module 32 compares the predicted surface temperature with the actual temperature at the corresponding moment, and when the temperature error between the predicted surface temperature and the actual temperature is within a preset range, the center temperature of the target blank is extracted.

[0104] In one possible embodiment, the processing module 32 determines the heating process parameters of each electromagnetic coil based on the center temperature and the temperature distribution on the surface of the target blank, specifically including: the processing module 32 calculates the standard deviation of the temperature field of the target blank to evaluate the overall temperature uniformity of the target blank; the processing module 32 calculates the temperature difference between the actual temperature of the target temperature field and the target temperature for the center temperature and the temperature distribution on the surface of the target blank based on the evaluation result of the overall temperature uniformity of the target blank, if it is determined that the evaluation result indicates that the overall temperature uniformity of the target blank does not meet the preset requirements, the target temperature is the temperature of the target temperature field under the premise that the overall temperature uniformity of the target blank meets the preset requirements, and the target temperature field is any one of the multiple temperature fields of the target blank; if the processing module 32 determines that the temperature difference is greater than or equal to the preset threshold, the heating chamber corresponding to the target temperature field in the multiple heating chambers is determined to be the first heating chamber; the processing module 32 determines the adjusted heating power of the electromagnetic coil in the first heating chamber based on the temperature difference.

[0105] In one possible embodiment, the processing module 32 determines a second heating chamber adjacent to the first heating chamber among multiple heating chambers; the processing module 32 determines a first segment of the target blank in the first heating chamber, and a second segment of the target blank in the second heating chamber; the processing module 32 determines a first overall temperature of the first segment and a second overall temperature of the second segment; the processing module 32 adjusts the heating process parameters corresponding to the first coil and the second coil according to the first overall temperature and the second overall temperature to reduce the difference between the first overall temperature and the second overall temperature, the first coil is an electromagnetic coil of the first heating chamber among the multiple electromagnetic coils, and the second coil is an electromagnetic coil of the second heating chamber among the multiple electromagnetic coils.

[0106] In one possible embodiment, if the processing module 32 determines that the difference between the segment center temperature and the segment surface temperature of the target segment is greater than or equal to a preset difference, the coil frequency of the target coil is adjusted, where the target coil is an electromagnetic coil among multiple electromagnetic coils that heats the target segment, and the target segment is any one of the multiple segments corresponding to the target blank; the processing module 32 calculates the temperature change rate of the target temperature field; the processing module 32 adjusts the heating time of the electromagnetic coil in the first heating chamber according to the temperature change rate to extend the heating time of the cold zone and shorten the heating time of the hot zone.

[0107] In one possible embodiment, during the heating process of the target blank, the processing module 32 measures the temperature data of the target blank surface based on the infrared temperature sensor to obtain the temperature distribution of the target blank surface, specifically including: the acquisition module 31 obtains the temperature data of multiple collection points located on the target blank surface; the processing module 32 uses an interpolation algorithm to expand the multiple temperature data to the complete blank surface of the target blank based on the multiple temperature data, thereby obtaining the temperature distribution of the target blank surface.

[0108] It should be noted that the above embodiments provide devices that implement their functions using only the division of the above functional modules as examples. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the device and method embodiments provided in the above embodiments are based on the same concept. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0109] This application also provides an electronic device, referring to Figure 4 , Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include: at least one processor 41, at least one network interface 44, a user interface 43, a memory 45, and at least one communication bus 42.

[0110] The communication bus 42 is used to realize the connection and communication between these components.

[0111] The user interface 43 may include a display screen (Display) and a camera (Camera). Optionally, the user interface 43 may also include a standard wired interface and a wireless interface.

[0112] The network interface 44 may optionally include a standard wired interface or a wireless interface (such as a WiFi interface).

[0113] The processor 41 may include one or more processing cores. Using various interfaces and circuits, the processor 41 connects to various components within the server. It executes instructions, programs, code sets, or instruction sets stored in the memory 45, as well as accesses data stored in the memory 45, to perform various server functions and process data. Optionally, the processor 41 may be implemented using at least one of the following hardware forms: a digital signal processing (DSP), a field-programmable gate array (FPGA), or a programmable logic array (PLA). The processor 41 may integrate one or a combination of a central processing unit (CPU), a graphics processing unit (GPU), and a modem. The CPU primarily processes the operating system, user interface, and application programs; the GPU is responsible for rendering and drawing content displayed on the display screen; and the modem handles wireless communications. It is understood that the modem may also be implemented as a separate chip, rather than integrated into the processor 41.

[0114] Among them, the memory 45 may include a random access memory (RAM) or a read-only memory (Read-Only Memory). Optionally, the memory 45 includes a non-transitory computer-readable storage medium. The memory 45 can be used to store instructions, programs, codes, code sets or instruction sets. The memory 45 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as a touch function, a sound playback function, an image playback function, etc.), instructions for implementing the above-mentioned various method embodiments, etc.; the data storage area may store data involved in the above-mentioned various method embodiments, etc. The memory 45 may also be optionally at least one storage device located away from the aforementioned processor 41. As Figure 4 As shown, the memory 45 as a computer storage medium may include an operating system, a network communication module, a user interface module, and an application program for the method for optimizing the uniformity of electromagnetic induction heating of large-diameter billets.

[0115] exist Figure 4In the electronic device shown, the user interface 43 is mainly used to provide an input interface for the user and obtain data input by the user; and the processor 41 can be used to call the application program for optimizing the uniformity of electromagnetic induction heating of large-diameter billets stored in the memory 45. When executed by one or more processors, the electronic device executes one or more methods as in the above-mentioned embodiments.

[0116] It should be noted that for the aforementioned method embodiments, for simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that this application is not limited by the order of the actions described, because according to this application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required for this application.

[0117] The present application also provides a computer-readable storage medium storing instructions, which, when executed by one or more processors, enable an electronic device to execute one or more of the methods described in the above embodiments.

[0118] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0119] In the several embodiments provided in this application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are merely schematic, such as the division of units, which is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some service interface, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0120] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0121] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0122] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of this application, or the portion that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the method of this application. The aforementioned memory includes various media that can store program code, such as USB flash drives, mobile hard drives, magnetic disks, or optical disks.

[0123] The above is only an exemplary embodiment of the present disclosure and cannot be used to limit the scope of the present disclosure. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the disclosure of the specification and the truth of practice, those skilled in the art will easily think of other embodiments of the present disclosure. This application is intended to cover any variation, use or adaptive change of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the art that are not recorded in the present disclosure. The description and examples are to be regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

Claims

1. A method for optimizing the uniformity of electromagnetic induction heating of large diameter billets, characterized in that: A controller for an electromagnetic induction heating furnace, wherein the heating mechanism of the electromagnetic induction heating furnace includes a plurality of heating chambers, each of the heating chambers is provided with an independently controlled electromagnetic coil for harmonic heating, and the plurality of electromagnetic coils are distributed along the length direction of a target blank, the method comprising: During the heating process of the target blank, measuring temperature data of the target blank surface based on an infrared temperature sensor to obtain the temperature distribution of the target blank surface; Inversely calculating the center temperature of the target blank by combining the temperature distribution and the heating parameters of the heating mechanism with the established heat conduction mathematical model for the target blank; Determining heating process parameters of each electromagnetic coil based on the center temperature and the temperature distribution of the target blank surface; heating the target blank according to the heating process parameters; The step of determining the heating process parameters of each electromagnetic coil based on the center temperature and the temperature distribution on the target blank surface specifically includes: Calculating the standard deviation of the temperature field of the target blank to evaluate the overall temperature uniformity of the target blank; According to the evaluation result of the overall temperature uniformity of the target blank, if it is determined that the evaluation result indicates that the overall temperature uniformity of the target blank does not meet the preset requirements, then calculating the temperature difference between the actual temperature of the target temperature field and the target temperature distribution on the center temperature and the surface of the target blank, where the target temperature is the temperature of the target temperature field under the premise that the overall temperature uniformity of the target blank meets the preset requirements, and the target temperature field is any one of the multiple temperature fields of the target blank; If it is determined that the temperature difference is greater than or equal to a preset threshold, determining that the heating chamber corresponding to the target temperature field among the plurality of heating chambers is the first heating chamber; The adjusted heating power of the electromagnetic coil in the first heating chamber is determined according to the temperature difference. The calculation formula of the adjusted heating power is as follows: ,in, To adjust the heating power, is the current power of the electromagnetic coil in the first heating chamber, is the gain coefficient, is the temperature difference; Before inverting the center temperature of the target blank by using the established heat conduction mathematical model for the target blank in combination with the temperature distribution and the heating parameters of the heating mechanism, the method further includes: Determining the electromagnetic field distribution of the target blank area according to the coil parameters, frequency and position of each electromagnetic coil; determining the internal heat source density generated by the heating of the plurality of electromagnetic coils according to the electromagnetic field distribution in the area where the target blank is located; Calculating the total power generated by the heating of the plurality of electromagnetic coils according to the internal heat source density generated by the heating of the plurality of electromagnetic coils; Constructing a heat conduction basic model, introducing a multi-coil heating correction into the heat conduction basic model based on the total power generated by the heating of the plurality of electromagnetic coils, and obtaining the heat conduction mathematical model; Determining boundary conditions for the heat conduction mathematical model, wherein the boundary conditions include a surface heat loss boundary condition, a blank center axis symmetric boundary condition, and an end adiabatic boundary condition; The method further comprises: determining a second heating chamber adjacent to the first heating chamber among the plurality of heating chambers; Determining a first segment of the target blank in the first heating chamber and a second segment of the target blank in the second heating chamber; determining a first bulk temperature of the first segment and a second bulk temperature of the second segment; According to the first overall temperature and the second overall temperature, the heating process parameters corresponding to the first coil and the second coil are adjusted to reduce the difference between the first overall temperature and the second overall temperature. The first coil is the electromagnetic coil of the first heating chamber among the multiple electromagnetic coils, and the second coil is the electromagnetic coil of the second heating chamber among the multiple electromagnetic coils.

2. The method for optimizing uniformity of electromagnetic induction heating of large diameter billets according to claim 1, characterized in that: The method of inverting the center temperature of the target blank by establishing a heat conduction mathematical model for the target blank and combining the temperature distribution and the heating parameters of the heating mechanism specifically includes: In an axisymmetric coordinate system of the target blank, dividing the target blank into radial and axial finite element grids; The finite volume method is used to discretize the model and construct the discretized heat conduction equation; Inputting the boundary conditions, electromagnetic parameters, and internal heat source density into the discretized heat conduction equation to solve the instantaneous temperature of the target blank surface; Setting the initial temperature of the target blank as the ambient temperature of the heating mechanism, inputting the temperature data into the heat conduction mathematical model, and solving the heat conduction equation using the heat conduction mathematical model to obtain a solution result, wherein the solution result is the predicted surface temperature at the next moment; The predicted surface temperature is compared with the actual temperature at a corresponding moment, and when a temperature error between the predicted surface temperature and the actual temperature is within a preset range, the center temperature of the target blank is extracted.

3. The method for optimizing uniformity of electromagnetic induction heating of large diameter billets according to claim 1, characterized in that: The method further comprises: If it is determined that the difference between the segment center temperature and the segment surface temperature of the target segment is greater than or equal to a preset difference, adjusting the coil frequency of the target coil, wherein the target coil is an electromagnetic coil among the plurality of electromagnetic coils that heats the target segment, and the target segment is any one of the plurality of segments corresponding to the target blank; Calculating the temperature change rate of the target temperature field; According to the temperature change rate, the heating time of the electromagnetic coil in the first heating chamber is adjusted to extend the heating time of the cold zone and shorten the heating time of the hot zone.

4. The method for optimizing uniformity of electromagnetic induction heating of large diameter billets according to claim 1, characterized in that: The method of measuring the temperature data of the target blank surface based on the infrared temperature sensor during the heating process of the target blank to obtain the temperature distribution of the target blank surface specifically includes: Acquiring temperature data of a plurality of acquisition points on the surface of the target blank; According to the plurality of temperature data, an interpolation algorithm is used to extend the plurality of temperature data to the complete surface of the target blank, thereby obtaining the temperature distribution of the surface of the target blank.

5. Large diameter billet electromagnetic induction heating uniformity optimization device, characterized in that: The method for optimizing uniformity of electromagnetic induction heating of large-diameter billets according to claim 1, wherein the device for optimizing uniformity of electromagnetic induction heating of large-diameter billets is a controller of an electromagnetic induction heating furnace, wherein the heating mechanism of the electromagnetic induction heating furnace comprises a plurality of heating chambers, each of the heating chambers is provided with an independently controlled electromagnetic coil for harmonic heating, and the plurality of electromagnetic coils are distributed along the length direction of the target billet, and the controller of the electromagnetic induction heating furnace comprises an acquisition module (31) and a processing module (32), wherein the acquisition module (31) is used to obtain the temperature distribution of the target billet surface by measuring the temperature data of the target billet surface based on an infrared temperature sensor during the heating process of the target billet; The processing module (32) is used to inversely calculate the center temperature of the target blank by combining the temperature distribution and the heating parameters of the heating mechanism with the established heat conduction mathematical model for the target blank; The processing module (32) is further configured to determine heating process parameters of each electromagnetic coil based on the center temperature and the temperature distribution of the target blank surface; The processing module (32) is further used to heat the target blank according to the heating process parameters; The processing module (32) is further configured to calculate a standard deviation of the temperature field of the target blank to evaluate the overall temperature uniformity of the target blank; According to the evaluation result of the overall temperature uniformity of the target blank, if it is determined that the evaluation result indicates that the overall temperature uniformity of the target blank does not meet the preset requirements, then calculating the temperature difference between the actual temperature of the target temperature field and the target temperature distribution on the center temperature and the surface of the target blank, where the target temperature is the temperature of the target temperature field under the premise that the overall temperature uniformity of the target blank meets the preset requirements, and the target temperature field is any one of the multiple temperature fields of the target blank; If it is determined that the temperature difference is greater than or equal to a preset threshold, determining that the heating chamber corresponding to the target temperature field among the plurality of heating chambers is the first heating chamber; The adjusted heating power of the electromagnetic coil in the first heating chamber is determined according to the temperature difference. The calculation formula of the adjusted heating power is as follows: ,in, To adjust the heating power, is the current power of the electromagnetic coil in the first heating chamber, is the gain coefficient, is the temperature difference.

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