A three-dimensional temperature field dynamic modeling method for a steel plate production process

Abstract

The application discloses a kind of three-dimensional temperature field dynamic modeling methods for steel plate production process, it is related to three-dimensional temperature field modeling field;The application is by discretizing the cross-sectional area of steel plate, and each cross section is divided into several rectangular grid units;Based on the detection position of existing temperature measuring point and the temperature real-time value corresponding to each temperature measuring point, the temperature of each grid node on the cross section is calculated using finite difference model, and the two-dimensional temperature field corresponding to each cross section is constructed;Based on the two-dimensional temperature field on the cross section, the space is expanded along the length direction of steel plate, and the initial model of three-dimensional temperature field is constructed;The temperature correction value corresponding to each grid node on the cross section of steel plate in the initial model of three-dimensional temperature field is calculated;According to temperature correction value, the temperature correction amount for reflecting time-distance dimension difference is calculated, and the grid node temperature calculated based on finite difference model is corrected by temperature correction amount;The method realizes the fine modeling of steel plate three-dimensional temperature field.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of three-dimensional temperature field modeling, in particular to a three-dimensional temperature field dynamic modeling method for steel plate production process. BACKGROUND

[0002] Temperature is a core process parameter in hot-rolled steel plate production process, which has a decisive influence on product quality. The uniformity of the steel plate temperature field is directly related to the flow stress characteristics of the metal during the rolling process, which in turn affects the thickness control and shape quality; while in the cooling stage, the temperature gradient determines the material's microstructure evolution and final mechanical properties, such as strength and toughness. In addition, temperature changes are closely related to key process issues such as iron oxide scale generation, roller thermal fatigue and wear, significantly affecting production cost and energy consumption control. Therefore, accurately grasping the three-dimensional temperature distribution of the steel plate at each process stage is of great significance for optimizing the production process, improving the dimensional accuracy and mechanical properties of the product.

[0003] However, the steel plate rolling process is a complex thermal-mechanical coupling process, which is affected by various process parameters and environmental factors, making temperature field modeling a great challenge. Existing temperature measurement methods have limitations: contact temperature measurement has a lagging response and installation limitations, making it difficult to meet the dynamic monitoring needs of high-speed production lines; non-contact infrared temperature measurement has a fast response, but is easily disturbed by water mist, oxide scale and emissivity fluctuations, resulting in large measurement errors and inability to obtain complete width direction temperature information. At the same time, traditional temperature field modeling is mostly based on one-dimensional or two-dimensional simplified models, which are difficult to fully reflect the complex heat transfer behavior of the steel plate in three-dimensional space. Therefore, it is urgent to develop a high-precision three-dimensional temperature field modeling method that can integrate measured data and perform dynamic correction, to realize accurate prediction and real-time updating of the steel plate temperature distribution, and promote the development of hot rolling process towards intelligentization, high quality and low energy consumption. SUMMARY

[0004] In order to realize accurate prediction and real-time updating of the steel plate temperature distribution, the present application proposes a three-dimensional temperature field dynamic modeling method for steel plate production process, which includes:

[0005] Based on the temperature measurement points arranged on the steel plate production line, real-time temperature data of the steel plate at each process stage is collected; the process stages include heating, rough rolling, finishing rolling and cooling;

[0006] The real-time temperature data is preprocessed to obtain temperature real-time values;

[0007] constructing a two-dimensional temperature field: discretizing a cross-sectional area of the steel plate, and dividing each cross section into a plurality of rectangular grid cells; the cross section is composed of a width direction and a thickness direction of the steel plate; based on the detection positions of the existing temperature measuring points and the real-time temperature values corresponding to each temperature measuring point, the temperature of each grid node on the cross section is calculated using a finite difference model, and a two-dimensional temperature field corresponding to each cross section is constructed;

[0008] The distance between adjacent cross sections at each process stage is set as a spatial step in the length direction of the steel plate by using a variable grid size method, and based on the two-dimensional temperature field on the cross section and the spatial step corresponding to the current process stage, the spatial expansion is carried out along the length direction of the steel plate to construct an initial model of the three-dimensional temperature field;

[0009] According to the type of temperature measuring equipment corresponding to the temperature measuring point and the position of the temperature measuring point, the temperature correction value corresponding to each grid node on the cross section of the steel plate in the initial model of the three-dimensional temperature field is calculated;

[0010] According to the distance between any two temperature measuring devices, the temperature detection time and the running speed of the steel plate, the time when the cross section of the steel plate reaches the corresponding temperature measuring points of the two temperature measuring devices in the steel plate production process is obtained, the temperature correction amount reflecting the time-distance dimension difference is calculated according to these time and temperature correction value, the grid node temperature calculated based on the finite difference model is corrected by the temperature correction amount, and the target three-dimensional temperature field corresponding to the current time is obtained; based on the latest two-dimensional temperature field, the target three-dimensional temperature field is continuously updated, so as to construct a dynamically evolving three-dimensional temperature field model.

[0011] Further, the two-dimensional temperature field is constructed as follows:

[0012] Obtaining model parameters of the steel plate;

[0013] Discretizing the cross-sectional area of the steel plate, and dividing each cross section into a plurality of rectangular grid cells; the cross section is composed of a width direction and a thickness direction of the steel plate, and the spatial step ΔX in the width direction and the spatial step ΔY in the thickness direction are determined;

[0014] According to the spatial steps ΔX and ΔY, and the material thermal physical parameters of the steel plate, a stability condition is set, and a time step Δt is set based on the stability condition;

[0015] Using the detection positions of the existing temperature measuring points and the real-time temperature values corresponding to each temperature measuring point at the set time, the grid nodes are preliminarily interpolated;

[0016] Based on the heat transfer control equation, the model parameters and the real-time temperature values of the steel plate are used to calculate the temperature of each grid node on the cross section at each time step using the finite difference model at the set time step Δt;

[0017] Based on the temperature of each grid node, the temperature of each point inside the grid unit is calculated by using an interpolation method;

[0018] Based on the temperature of each grid node and the temperature of each point inside the grid, a two-dimensional temperature field on the cross section corresponding to each time is constructed.

[0019] Further, the construction of the two-dimensional temperature field is specifically:

[0020] The cross section of the steel plate is discretely processed, each cross section is divided into several rectangular grid units, the detection position of the existing temperature measuring point and the real-time temperature value of each temperature measuring point at the set time are used to preliminarily interpolate the grid nodes, the correction coefficients of each grid node in the width direction of the steel plate and the thickness direction of the steel plate are calculated, the real-time temperature value of the corresponding grid node is adjusted through the correction coefficient, the temperature of each grid node on the cross section is calculated based on the adjusted temperature data by using the finite difference model, and a two-dimensional temperature field on the cross section is constructed.

[0021] Further, the calculation of the correction coefficients of each grid node in the width direction of the steel plate and the thickness direction of the steel plate, the adjustment of the real-time temperature value of the corresponding grid node through the correction coefficient, and the construction of the two-dimensional temperature field on the cross section based on the adjusted temperature data by using the finite difference model are specifically:

[0022] Based on the temperature non-uniformity of the grid node in the width direction, a horizontal correction function is constructed;

[0023] Based on the temperature gradient of the grid node in the thickness direction, a vertical correction function is constructed;

[0024] The horizontal correction coefficient of the grid node in the width direction of the steel plate and the vertical correction coefficient of the grid node in the thickness direction of the steel plate are calculated by using the horizontal correction function and the vertical correction function;

[0025] The real-time temperature value of the grid node is corrected by the horizontal correction coefficient and the vertical correction coefficient to obtain a temperature adjustment value;

[0026] Based on the heat transfer control equation, the temperature of each grid node on the cross section is calculated by using the model parameters of the steel plate and the temperature adjustment value by using the finite difference model;

[0027] Based on the temperature adjustment value and the calculated grid node temperature, the temperature value of the interpolation point inside the grid unit is calculated by using an interpolation algorithm;

[0028] The two-dimensional temperature field on the cross section is constructed by combining the temperature adjustment value of the grid node, the calculated grid node temperature and the temperature value of the interpolation point inside the grid.

[0029] Furthermore, the model parameters of the steel plate include: preset geometric dimension information, material thermophysical property parameters and convection heat transfer coefficient under various boundary conditions; the boundary conditions include: Dirichlet boundary conditions and Neumann boundary conditions.

[0030] Furthermore, the temperature measuring device type includes a single-point pyrometer and / or a transverse scanning pyrometer; based on the temperature measuring device type corresponding to the temperature measuring point and the position of the temperature measuring point, the temperature correction value corresponding to each grid node on the cross section of the steel plate in the three-dimensional temperature field initial model is calculated, specifically:

[0031] When only the upper surface of the steel plate has a temperature measurement point arranged by a single-point pyrometer, the temperature correction value corresponding to each grid node in the width direction of the cross section of the steel plate in the initial three-dimensional temperature field model is calculated using the first single-point temperature correction model;

[0032] When there are temperature measurement points on both the upper and lower surfaces of the steel plate using single-point pyrometers, the temperature correction value corresponding to each grid node in the thickness direction of the steel plate cross section in the initial three-dimensional temperature field model is calculated using the second single-point temperature correction model.

[0033] When there are temperature measurement points on the steel plate surface arranged by transverse scanning pyrometers, the transverse temperature correction model is used to calculate the temperature correction values ​​corresponding to each grid node in the width and thickness directions of the steel plate cross section in the initial three-dimensional temperature field model.

[0034] Furthermore, the formula expression of the first single-point temperature correction model is:

[0035] ;in:

[0036] ;

[0037] Where, Indicates the temperature correction at the center point of the upper surface of the steel plate, which is used to compensate for the deviation between the calculated value of the finite difference model and the measured temperature value; represents the grid node temperature at the kth moment of the grid node in the i-th column in the width direction and the j-th row in the thickness direction on the cross section of the steel plate calculated based on the finite difference model; It represents the temperature correction value of the grid node with the i-th column in the width direction and the j-th row in the thickness direction on the cross section of the steel plate at the k-th moment;

[0038] represents the measured temperature value at the center point of the steel plate surface, where represents the actual measurement; n represents the total number of mesh nodes in the width direction of the steel plate cross section, and m represents the total number of mesh nodes in the thickness direction of the steel plate cross section; The center point of the steel plate surface calculated by the finite difference model is The grid node temperature of the mth column and the mth row at the kth time.

[0039] Furthermore, the formula expression of the second single-point temperature correction model is:

[0040] ;in:

[0041] ;

[0042] ;

[0043] Where, It represents the temperature correction value of the grid node with the i-th column in the width direction and the j-th row in the thickness direction on the cross section of the steel plate at the k-th moment; represents the grid node temperature at the kth moment of the grid node in the i-th column in the width direction and the j-th row in the thickness direction on the cross section of the steel plate calculated based on the finite difference model; Indicates the temperature correction at the center point of the upper surface of the steel plate; Indicates the temperature correction at the center point of the lower surface of the steel plate; Represents the distance between adjacent mesh nodes along the thickness direction of the steel plate in the cross section of the steel plate; Indicates the coordinate position of the current grid node in the thickness direction; Represents the total height of the steel plate, which is equal to the sum of the spacings of all mesh nodes in the thickness direction; represents the measured temperature value at the center point of the steel plate surface, where Indicates actual measurement; The center point of the steel plate surface calculated by the finite difference model is The grid node temperature of the grid node in the mth column and the mth row at the kth moment; n represents the total number of grid nodes in the width direction of the steel plate cross section, and m represents the total number of grid nodes in the thickness direction of the steel plate cross section; Indicates the measured temperature value at the center point of the lower surface of the steel plate; The center point of the lower surface of the steel plate calculated by the finite difference model is The grid node temperature of the grid node in column 0 and row 0 at the kth moment.

[0044] Furthermore, the formula expression of the lateral temperature correction model is:

[0045] ;in:

[0046] ;

[0047] Where, It represents the temperature correction value of the grid node with the i-th column in the width direction and the j-th row in the thickness direction on the cross section of the steel plate at the k-th moment; represents the grid node temperature at the kth moment of the grid node in the i-th column in the width direction and the j-th row in the thickness direction on the cross section of the steel plate calculated based on the finite difference model; represents the overall transverse correction corresponding to the i-th column in the width direction; It represents the measured temperature value of the grid node on the steel plate, which is in the i-th column in the width direction and the top layer in the thickness direction, i.e., the m-th row; represents the grid node temperature at the kth moment on the cross section of the steel plate with the i-th column in the width direction and the m-th row in the thickness direction, calculated based on the finite difference model.

[0048] Furthermore, the temperature correction amount used to reflect the time-distance dimension difference is calculated based on these moments and the temperature correction value, and the calculation formula used is:

[0049] ;

[0050] Where, Indicates the moment when the steel plate cross section reaches the first temperature measuring point S, Indicates the moment when the cross section of the steel plate reaches the second temperature measuring point E, Indicates that the cross section of the steel plate reaches the set position between the two temperature measurement points moment; Indicates the cross section of the steel plate The position is the difference between the temperature correction value of the grid node with the i-th column in the width direction and the j-th row in the thickness direction and the temperature of the grid node calculated by the corresponding finite difference model; represents the temperature correction corresponding to the grid node with the i-th column in the width direction and the j-th row in the thickness direction on the cross section of the steel plate;

[0051] The temperature correction amount is used to correct the grid node temperature calculated based on the finite difference model. The calculation formula used is:

[0052] ;

[0053] Where, represents the temperature of the grid node with the i-th column in the width direction and the j-th row in the thickness direction on the cross section of the steel plate at the k-th moment, calculated based on the finite difference model; It represents the final temperature value of the grid node with the i-th column in the width direction and the j-th row in the thickness direction on the cross section of the steel plate after the dimension correction at the k-th moment.

[0054] Compared with the prior art, the present application has at least the following beneficial effects:

[0055] (1) The present application divides the cross-sectional area of the steel plate into a plurality of rectangular grid cells by discretizing the cross-sectional area of the steel plate, and divides each cross section into a plurality of rectangular grid cells; based on the detection position of the existing temperature measurement point and the real-time temperature value corresponding to each temperature measurement point, the temperature of each grid node on the cross section is calculated using a finite difference model, and a two-dimensional temperature field corresponding to each cross section is constructed; based on the two-dimensional temperature field on the cross section and the corresponding space step of the current process stage, the space is expanded along the length direction of the steel plate to construct a three-dimensional temperature field initial model; according to the type of the temperature measurement equipment corresponding to the temperature measurement point and the position of the temperature measurement point, the temperature correction value of each grid node on the cross section of the steel plate in the three-dimensional temperature field initial model is calculated; the time when the cross section of the steel plate reaches the temperature measurement points corresponding to the two temperature measurement equipment in the production process of the steel plate is obtained, and the temperature correction amount reflecting the time-distance dimension difference is calculated according to these time and temperature correction value, and the grid node temperature calculated based on the finite difference model is corrected by the temperature correction amount; this method realizes the fine modeling of the three-dimensional temperature field of the steel plate, solves the problems of the traditional one-dimensional or two-dimensional model that is difficult to accurately reflect the complex heat transfer behavior, large temperature measurement error and poor model adaptability, and significantly improves the temperature field modeling accuracy and dynamic response ability, providing reliable data support for subsequent process control and product quality improvement.

[0056] (2) The present application calculates the temperature correction value of each grid node according to the type of the temperature measurement equipment corresponding to the temperature measurement point and the position information. This process not only considers the characteristics of different temperature measurement equipment (such as single-point pyrometer or transverse scanning pyrometer), but also accurately corrects and calculates the specific position of each grid node, significantly improving the accuracy of the target three-dimensional temperature field construction.

[0057] (3) The present application obtains the time when the cross section of the steel plate reaches the temperature measurement points corresponding to the two temperature measurement equipment based on the distance between any two temperature measurement equipment, the temperature detection time and the running speed of the steel plate, and calculates the temperature correction amount reflecting the time-distance dimension difference according to these time and temperature correction value. This correction amount dynamically adjusts the calculation results of the finite difference model through the time proportional interpolation method driven by physics, so that the final temperature field model is closer to the temperature distribution under actual production conditions. This multi-step, multi-level temperature correction mechanism ensures that the model not only accurately reflects the initial temperature field, but also continuously updates and optimizes with the changes of the production line, realizing high-precision simulation of the complex heat transfer behavior in the hot rolling process. Therefore, the present application solves the problem of inaccurate temperature field modeling caused by large measurement error and poor model adaptability in the traditional method, greatly improves the product quality control ability and the production process optimization level.

[0058] (4) The application realizes reasonable estimation and compensation of temperature deviation at different positions by introducing a temperature correction amount based on time-distance relationship. Compared with simple linear or empirical correction, the time scale interpolation method based on physical process has more theoretical basis and engineering applicability.

[0059] (5) The application superimposes the temperature correction amount obtained based on measured data on the calculation result of the finite difference model to form a corrected target temperature value, effectively fusing the continuity of the finite difference model and the authenticity of the measured data, and improving the overall reliability of the target three-dimensional temperature field. BRIEF DESCRIPTION OF DRAWINGS

[0060] Figure 1 A flow chart of a three-dimensional temperature field dynamic modeling method for a steel plate production process is provided for the embodiment of the application. DETAILED DESCRIPTION

[0061] The following is a specific embodiment of the application and further describes the technical solution of the application in combination with the drawings, but the application is not limited to these embodiments.

[0062] In order to realize accurate prediction and real-time update of the temperature distribution of the steel plate, as shown in the figure, the application provides a three-dimensional temperature field dynamic modeling method for a steel plate production process, which comprises the following steps: Figure 1

[0063] Based on the temperature measuring points arranged on the steel plate production line, real-time temperature data of the steel plate in each process stage is collected; the process stage includes heating, rough rolling, finishing rolling and cooling;

[0064] The temperature measuring equipment arranged on the steel plate production line in the embodiment is shown in Table 1 as follows:

[0065] Table 1:

[0066]

[0067] Wherein: R1 represents the first rough rolling mill, and R2 represents the second rough rolling mill.

[0068] The real-time temperature data is preprocessed to obtain temperature real-time values;

[0069] A two-dimensional temperature field is constructed: the cross-sectional area of the steel plate is discretized, and each cross section is divided into a plurality of rectangular grid units; the cross section is composed of the width direction and the thickness direction of the steel plate; based on the detection positions of the existing temperature measuring points and the temperature real-time values corresponding to each temperature measuring point, the temperature of each grid node on the cross section is calculated by using the finite difference model, and a two-dimensional temperature field corresponding to each cross section is constructed;

[0070] ​It should be noted that the construction of the two-dimensional temperature field in the embodiment includes two implementation manners, wherein:

[0071] The first implementation manner is:

[0072] The construction of the two-dimensional temperature field is specifically:

[0073] The model parameters of the steel plate are acquired; the model parameters of the steel plate include: preset geometric size information, material thermal physical property parameters, and a convective heat transfer coefficient under each boundary condition; the boundary conditions include: a Dirichlet boundary condition and a Neumann boundary condition.

[0074] The cross-sectional area of the steel plate is discretized, and each cross section is divided into a plurality of rectangular grid units; the cross section is composed of a width direction and a thickness direction of the steel plate, and a spatial step ΔX in the width direction and a spatial step ΔY in the thickness direction are determined;

[0075] A stability condition is set according to the spatial steps ΔX and ΔY and the material thermal physical property parameters of the steel plate, and a time step Δt is set based on the stability condition;

[0076] The formula expression of the stability condition is:

[0077] ;

[0078] In the formula, α represents a material thermal diffusivity.

[0079] Before the finite difference calculation is performed, the time step Δt is set according to the set stability condition, so that the stability requirement of numerical calculation is met, to avoid numerical instability phenomenon in the temperature field simulation process.

[0080] The grid nodes are preliminarily interpolated according to the detection positions of the existing temperature measuring points and the real-time temperature values corresponding to each temperature measuring point at the set time;

[0081] Based on the heat transfer control equation, the temperature of each grid node on the cross section at each time is calculated at the set time step Δt by using the model parameters of the steel plate and the real-time temperature values by using the finite difference model;

[0082] Based on the temperature of each grid node, the temperature of each point inside the grid unit is calculated by using an interpolation method.

[0083] Based on the temperature of each grid node and the temperature of each point inside the grid unit, a two-dimensional temperature field on the cross section corresponding to each time is constructed.

[0084] ​The first embodiment firstly acquires the geometric size information of the steel plate, the material thermal physical parameters and the convective heat transfer coefficient under the boundary condition, so as to ensure that the model can accurately reflect the actual physical characteristics of the steel plate. By determining the spatial steps in the width direction and the thickness direction, the time step satisfying the stability condition is set, so that the finite difference model has good stability and accuracy in the calculation process. This method not only provides a solid foundation for subsequent temperature field calculation, but also avoids numerical instability or calculation error caused by inappropriate step setting. Then, the temperature of each grid node on the cross section is calculated at each time by using the preliminary interpolation and the heat transfer control equation, and then the two-dimensional temperature field corresponding to each time is constructed. This method based on actual physical parameters and strict mathematical model can accurately capture the temperature change of the steel plate in different process stages, and improves the accuracy and reliability of the temperature field modeling. At the same time, the calculation process at each time ensures the continuity and consistency of the dynamic change of the temperature field with time, further improving the practicability and prediction ability of the model.

[0085] The second embodiment is:

[0086] The two-dimensional temperature field is constructed as follows:

[0087] The cross section of the steel plate is discretized, each cross section is divided into a plurality of rectangular grid units, the detection position of the existing temperature measuring point and the real-time temperature of each temperature measuring point at the set time are used to preliminarily interpolate the grid nodes, the correction coefficients of each grid node in the width direction of the steel plate and the thickness direction of the steel plate are calculated, the real-time temperature of the corresponding grid node is adjusted by the correction coefficient, the temperature of each grid node on the cross section is calculated based on the adjusted temperature data by using the finite difference model, and the two-dimensional temperature field on the cross section is constructed based on the temperature data.

[0088] The correction coefficients of each grid node in the width direction of the steel plate and the thickness direction of the steel plate are calculated, the real-time temperature of the corresponding grid node is adjusted by the correction coefficient, the temperature of each grid node on the cross section is calculated based on the adjusted temperature data by using the finite difference model, and the two-dimensional temperature field on the cross section is constructed, which is specifically:

[0089] A transverse correction function is constructed based on the temperature non-uniformity of the grid node in the width direction.

[0090] The formula expression of the transverse correction function is:

[0091] ;

[0092] In the formula, the transverse correction coefficient of the i-th column grid node is represented by

[0093] The column index of the grid node in the width direction is represented by​

[0094] represents the total number of grid nodes along the width direction of the steel plate cross section;

[0095] is a temperature non-uniformity correction factor in the width direction (set according to actual conditions, usually an empirical parameter).

[0096] Based on the temperature gradient of the grid node in the thickness direction, a vertical correction function is constructed;

[0097] The formula expression of the vertical correction function is:

[0098]

[0099] In the formula, represents the vertical correction coefficient of the jth row of grid nodes;

[0100] j represents the row index of the grid node in the thickness direction;

[0101] m represents the total number of grid nodes along the thickness direction of the steel plate cross section;

[0102] is a temperature gradient correction factor in the thickness direction (set according to actual conditions, usually an empirical parameter).

[0103] Using the horizontal correction function and the vertical correction function, the horizontal correction coefficient of the grid node in the width direction of the steel plate and the vertical correction coefficient of the grid node in the thickness direction of the steel plate are calculated;

[0104] The temperature real-time value of the grid node is corrected by the horizontal correction coefficient and the vertical correction coefficient to obtain a temperature adjustment value;

[0105] The calculation formula of the temperature adjustment value in this embodiment is:

[0106]

[0107] In the formula, represents the temperature real-time value of the grid node in the width direction as the ith column and in the thickness direction as the jth row; represents the temperature adjustment value corresponding to the grid node in the width direction as the ith column and in the thickness direction as the jth row.

[0108] ​​In the second embodiment, the steel plate cross-section is first discretized into a plurality of rectangular grid cells, and the grid nodes are preliminarily interpolated using the detection positions of the existing temperature measurement points and the real-time temperature values corresponding to the set time. In order to accurately reflect the temperature non-uniformity in the width direction and the temperature gradient change in the thickness direction, the method further introduces a horizontal correction function and a vertical correction function. Through these correction functions, the horizontal correction coefficient in the width direction and the vertical correction coefficient in the thickness direction of each grid node are calculated, and the temperature values after preliminary interpolation are corrected accordingly to obtain temperature adjustment values closer to the actual temperature distribution. Specifically, the horizontal correction function is used to adjust the temperature non-uniformity in the width direction caused by the edge effect, and the vertical correction function is used to compensate for the temperature gradient difference in the thickness direction. Based on these corrected temperature data, the finite difference model is used to calculate the temperature of each grid node on the cross-section, thereby constructing an accurate two-dimensional temperature field. This method ensures that the initial temperature field can accurately reflect the actual temperature distribution characteristics of the steel plate at that time, providing a reliable foundation for subsequent dynamic evolution of the three-dimensional temperature field modeling.

[0109] Based on the heat transfer control equation, the temperature of each grid node on the cross-section is calculated using the model parameters and temperature adjustment values of the steel plate by the finite difference model;

[0110] Based on the temperature adjustment values and the calculated grid node temperatures, the temperature values of the interpolation points inside the grid cells are calculated using the interpolation algorithm;

[0111] The two-dimensional temperature field on the cross-section is constructed based on the temperature adjustment values of the grid nodes, the calculated grid node temperatures, and the temperature values of the interpolation points inside the grid cells.

[0112] The method of variable grid size is used to set the distance between adjacent cross-sections in each process stage as the spatial step ΔZ in the length direction of the steel plate, and based on the two-dimensional temperature field on the cross-section and the spatial step ΔZ corresponding to the current process stage, the spatial expansion is carried out along the length direction of the steel plate to construct the initial model of the three-dimensional temperature field;

[0113] In order to simulate the temperature change in the full length range of the steel plate during the entire hot rolling process, the above two-dimensional temperature field needs to be expanded along the length direction of the steel plate. Specifically, the steps of constructing the two-dimensional temperature field in this embodiment are to repeatedly apply the same two-dimensional temperature field modeling process to different length positions of the steel plate. By splicing multiple such two-dimensional temperature fields along the length direction of the steel plate, a three-dimensional temperature field is finally formed which can accurately reflect the actual temperature distribution.

[0114] In this embodiment, the variable grid size method is used to set the distance between adjacent cross sections as the spatial step size in the length direction of the steel plate. Specifically, the size of the grid unit in the length direction is dynamically adjusted according to the process characteristics of each process stage and the requirements of the temperature field change. For example, in areas where the temperature changes drastically (such as the heating section or the cooling section), a smaller spatial step size is used to improve the model resolution and ensure accurate capture of the temperature distribution; while in areas where the temperature changes relatively slowly (such as the finishing rolling section), a larger spatial step size can be used to reduce the computational complexity and improve the computational efficiency. In this way, not only can the spatial resolution of the model be flexibly adjusted at different process stages, but the requirements of computational accuracy and computational resources can also be effectively balanced, thereby constructing an initial three-dimensional temperature field model that is more in line with actual production conditions.

[0115] Calculate the temperature correction value corresponding to each grid node on the cross section of the steel plate in the initial three-dimensional temperature field model based on the type of temperature measuring equipment corresponding to the temperature measuring point and the location of the temperature measuring point;

[0116] This method calculates temperature correction values ​​for each grid node based on the type and location of the temperature measurement device corresponding to the temperature measurement point. This process not only takes into account the characteristics of different temperature measurement devices (such as single-point pyrometers or transverse scanning pyrometers), but also accurately calculates corrections for the specific location of each grid node, significantly improving the accuracy of the target three-dimensional temperature field construction.

[0117] The temperature measurement equipment types include single-point pyrometers and / or transverse scanning pyrometers;

[0118] According to the type of temperature measuring equipment corresponding to the temperature measuring point and the position of the temperature measuring point, the temperature correction value corresponding to each grid node on the cross section of the steel plate in the initial three-dimensional temperature field model is calculated.

[0119] As can be seen from Table 1, this embodiment provides a variety of pyrometer types, and the second single-point temperature correction model or the transverse temperature correction model can be preferentially selected to calculate the temperature correction value.

[0120] When only the upper surface of the steel plate has a temperature measurement point arranged by a single-point pyrometer, the temperature correction value corresponding to each grid node in the width direction of the cross section of the steel plate in the initial three-dimensional temperature field model is calculated using the first single-point temperature correction model;

[0121] The formula expression of the first single-point temperature correction model is:

[0122] ;in:

[0123] ;

[0124] Where, represents a temperature correction amount at the center point of the upper surface of the steel plate, used to compensate for the deviation between the calculated value of the finite difference model and the measured temperature value; represents the grid node temperature of the grid node at the i-th column in the width direction and the j-th row in the thickness direction on the steel plate cross section at the k-th moment, calculated based on the finite difference model; represents the temperature correction value of the grid node at the i-th column in the width direction and the j-th row in the thickness direction on the steel plate cross section at the k-th moment;

[0125] represents the measured temperature value at the center point of the upper surface of the steel plate, wherein, represents measured; n represents the total number of grid nodes in the width direction on the steel plate cross section, and m represents the total number of grid nodes in the thickness direction on the steel plate cross section; represents the grid node temperature of the grid node at the i-th column in the width direction and the j-th row in the thickness direction on the steel plate cross section at the k-th moment, calculated based on the finite difference model. represents the grid node temperature of the grid node at the i-th column in the width direction and the j-th row in the thickness direction on the steel plate cross section at the k-th moment, calculated based on the finite difference model.

[0126] When the upper surface and the lower surface of the steel plate both have temperature measuring points arranged by single-point pyrometers, the temperature correction value corresponding to each grid node in the thickness direction of the steel plate cross section in the initial model of the three-dimensional temperature field is calculated by the second single-point temperature correction model;

[0127] The formula expression of the second single-point temperature correction model is:

[0128] ; wherein:

[0129] ;

[0130] ;

[0131] In the formula, represents the temperature correction value of the grid node at the i-th column in the width direction and the j-th row in the thickness direction on the steel plate cross section at the k-th moment;

[0132] represents the grid node temperature of the grid node at the i-th column in the width direction and the j-th row in the thickness direction on the steel plate cross section at the k-th moment, calculated based on the finite difference model;

[0133] represents the temperature correction amount at the center point of the upper surface of the steel plate;

[0134] represents the temperature correction amount at the center point of the lower surface of the steel plate;

[0135] represents the distance between adjacent grid nodes along the thickness direction of the steel plate in the cross section of the steel plate; represents the coordinate position of the current grid node in the thickness direction; represents the total height of the steel plate, which is equal to the sum of the distances of all the grid nodes in the thickness direction;

[0136] represents the measured temperature value at the center point of the upper surface of the steel plate, wherein, represents the measured;

[0137] represents the grid node temperature of the grid node at the center point of the upper surface of the steel plate, i.e., the grid node at the i-th column and the 0-th row, at the k-th moment, calculated by the finite difference model. represents the grid node temperature of the grid node at the center point of the upper surface of the steel plate, i.e., the grid node at the i-th column and the 0-th row, at the k-th moment, calculated by the finite difference model.

[0138] n represents the total number of grid nodes in the cross section of the steel plate along the width direction, and m represents the total number of grid nodes in the cross section of the steel plate along the thickness direction;

[0139] represents the measured temperature value at the center point of the lower surface of the steel plate;

[0140] represents the grid node temperature of the grid node at the center point of the lower surface of the steel plate, i.e., the grid node at the i-th column and the 0-th row, at the k-th moment, calculated by the finite difference model. represents the grid node temperature of the grid node at the center point of the lower surface of the steel plate, i.e., the grid node at the i-th column and the 0-th row, at the k-th moment, calculated by the finite difference model.

[0141] When there is a temperature measuring point arranged by a transverse scanning pyrometer on the surface of the steel plate, the temperature correction value corresponding to each grid node in the initial model of the three-dimensional temperature field in the width direction and the thickness direction of the cross section of the steel plate is calculated by a transverse temperature correction model.

[0142] The formula expression of the transverse temperature correction model is:

[0143] ; wherein:

[0144] ;

[0145] In the formula, represents the temperature correction value of the grid node at the i-th column in the width direction and the j-th row in the thickness direction of the cross section of the steel plate at the k-th moment; represents the grid node temperature of the grid node at the i-th column in the width direction and the j-th row in the thickness direction of the cross section of the steel plate at the k-th moment, calculated based on the finite difference model; represents the transverse overall correction amount corresponding to the i-th column in the width direction; represents the measured temperature value of the grid node at the i-th column in the width direction and the m-th row in the thickness direction, which is the uppermost layer, of the upper surface of the steel plate. represents the grid node temperature at the kth moment on the cross section of the steel plate with the i-th column in the width direction and the m-th row in the thickness direction, calculated based on the finite difference model.

[0146] Based on the distance between any two temperature measuring devices, the temperature detection time and the steel plate running speed, the moments when the steel plate cross section reaches the corresponding temperature measuring points of the two temperature measuring devices during the steel plate production process are obtained. Based on these moments and the temperature correction value, the temperature correction amount used to reflect the difference in the time-distance dimension is calculated. The grid node temperature calculated based on the finite difference model is corrected by the temperature correction amount to obtain the target three-dimensional temperature field corresponding to the current moment; based on the latest two-dimensional temperature field, the target three-dimensional temperature field is continuously updated to construct a dynamically evolving three-dimensional temperature field model.

[0147] The temperature correction value used to reflect the time-distance dimension difference is calculated based on these moments and the temperature correction value. The calculation formula used is:

[0148] ;

[0149] Where, Indicates the moment when the cross section of the steel plate reaches the first temperature measuring point S, Indicates the moment when the cross section of the steel plate reaches the second temperature measuring point E, Indicates that the cross section of the steel plate reaches the set position between the two temperature measurement points moment; Indicates the cross section of the steel plate The position is the difference between the temperature correction value of the grid node with the i-th column in the width direction and the j-th row in the thickness direction and the temperature of the grid node calculated by the corresponding finite difference model; represents the temperature correction corresponding to the grid node with the i-th column in the width direction and the j-th row in the thickness direction on the cross section of the steel plate;

[0150] The application is based on the distance between any two temperature measuring devices, the temperature detection time and the running speed of the steel plate, obtains the time when the steel plate cross section reaches the corresponding temperature measuring points of the two temperature measuring devices respectively, and calculates the temperature correction amount for reflecting the time-distance dimension difference according to the time and the temperature correction value. The correction amount dynamically adjusts the calculation result of the finite difference model through the physically driven time proportional interpolation method, so that the final temperature field model is closer to the actual temperature distribution under the production condition. This multi-step and multi-level temperature correction mechanism ensures that the model can not only accurately reflect the initial temperature field, but also continuously update and optimize with the change of the production line, realizing high-precision simulation of the complex heat transfer behavior in the hot rolling process. Therefore, the application solves the problem of inaccurate temperature field modeling caused by large measurement error and poor model adaptability in the traditional method, greatly improving the product quality control ability and the production process optimization level.

[0151] The grid node temperature calculated based on the finite difference model is corrected by the temperature correction amount, and the calculation formula is:

[0152] ;

[0153] In the formula, represents the grid node temperature of the steel plate cross section on the width direction i column and the thickness direction j row grid node at the k time based on the finite difference model calculation; represents the final temperature value of the steel plate cross section on the width direction i column and the thickness direction j row grid node after dimension correction at the k time.

[0154] The application realizes reasonable estimation and compensation of temperature deviation at different positions by introducing the temperature correction amount based on the time-distance relationship. Compared with simple linear or empirical correction, the time proportional interpolation method based on physical process has more theoretical basis and engineering applicability.

[0155] At the same time, the application superimposes the temperature correction amount obtained based on the measured data on the calculation result of the finite difference model to form the corrected target temperature value, i.e. the final temperature value, effectively combining the continuity of the finite difference model and the authenticity of the measured data, and improving the overall reliability of the target three-dimensional temperature field.

[0156] In the embodiment, the time when the steel plate cross section reaches the set position between the two temperature measuring points is obtained by the following method:

[0157] It is known that the two temperature measuring points are located at fixed positions on the production line, and the distance between them is ;

[0158] ​The speed of movement of the steel sheet on the production line is known as v (the unit is usually meters / second);

[0159] The time at which the cross section of the steel sheet reaches the first temperature measurement point S is known ;

[0160] The time at which the cross section of the steel sheet reaches the second temperature measurement point E is known ;

[0161] The set position is located between S and E and is a distance of from the first temperature measurement point S. The time difference ;

[0162] The distance of P from S is determined: assuming that the set position is a distance of from the first temperature measurement point S;

[0163] The time taken for the steel sheet to move from S to P is calculated: ;

[0164] The temperature correction value ; .

[0165] In the present application, based on the latest two-dimensional temperature field, the target three-dimensional temperature field is continuously updated, thereby constructing a dynamically evolving three-dimensional temperature field model. Specifically, at each process stage (including heating, rough rolling, finishing rolling and cooling), first, real-time temperature data is collected by the temperature measurement points arranged on the steel sheet production line and preprocessed to obtain real-time temperature values. Then, based on the positions of the existing temperature measurement points and their corresponding real-time temperature values, the temperature of each grid node on the cross section is calculated using a finite difference model to construct a two-dimensional temperature field at the current time. Next, based on the two-dimensional temperature field on the current cross section and the spatial step corresponding to the current process stage, the space is expanded along the length direction of the steel sheet to gradually construct an initial model of the three-dimensional temperature field. According to the type and position information of the temperature measurement equipment corresponding to the temperature measurement points, the temperature correction value of each grid node in the initial model of the three-dimensional temperature field is calculated; and by the distance between any two temperature measurement devices, the temperature detection time and the running speed of the steel sheet, the time at which the cross section of the steel sheet reaches different temperature measurement points is obtained, and the temperature correction value reflecting the difference in time-distance dimension is calculated. The temperature of the grid node calculated based on the finite difference model is corrected by the temperature correction value to obtain the target three-dimensional temperature field corresponding to the current time. This process will be repeated continuously, with each update based on the latest two-dimensional temperature field and the corresponding temperature correction value, ensuring that the three-dimensional temperature field model can reflect the actual temperature distribution characteristics of the steel sheet at each production stage in real time, achieving dynamic evolution and accurate prediction.

[0166] The present invention discretizes the cross-sectional area of ​​the steel plate and divides each cross-sectional area into a number of rectangular grid units; based on the detection position of the existing temperature measuring point and the real-time temperature value corresponding to each temperature measuring point, the temperature of each grid node on the cross-sectional area is calculated using a finite difference model, and a two-dimensional temperature field corresponding to each cross-sectional area is constructed based on this; based on the two-dimensional temperature field on the cross-sectional area and the spatial step length corresponding to the current process stage, spatial expansion is performed along the length direction of the steel plate to construct an initial model of the three-dimensional temperature field; based on the type of temperature measuring equipment corresponding to the temperature measuring point and the position of the temperature measuring point, the temperature corresponding to each grid node on the cross-sectional area of ​​the steel plate in the initial model of the three-dimensional temperature field is calculated. Correction value; obtain the moments when the cross section of the steel plate reaches the corresponding temperature measuring points of the two temperature measuring devices during the steel plate production process, calculate the temperature correction amount used to reflect the difference in the time-distance dimension based on these moments and the temperature correction value, and correct the grid node temperature calculated based on the finite difference model by the temperature correction amount; this method realizes the refined modeling of the three-dimensional temperature field of the steel plate, solves the problems of traditional one-dimensional or two-dimensional models that are difficult to accurately reflect complex heat transfer behaviors, large temperature measurement errors, and poor model adaptability, significantly improves the temperature field modeling accuracy and dynamic response capabilities, and provides reliable data support for subsequent process control and product quality improvement.

[0167] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0168] In addition, in the present invention, descriptions such as "first," "second," and "one" are for descriptive purposes only and should not be understood to indicate or imply their relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0169] In the present invention, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0170] In addition, the technical solutions among various embodiments of the present application can be combined with each other, but it must be based on that a person skilled in the art can realize, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the present application.

Claims

1. A method for dynamic modeling of a three-dimensional temperature field in a steel sheet production process, characterized in that, The application relates to a method for constructing a dynamic evolution three-dimensional temperature field model of a steel plate. The method comprises the following steps: collecting real-time temperature data of the steel plate in each process stage based on temperature measuring points arranged on a steel plate production line; the process stage comprises heating, rough rolling, finishing rolling and cooling; preprocessing the real-time temperature data to obtain temperature real-time values; constructing a two-dimensional temperature field: discretizing a cross-section area of the steel plate, and dividing each cross-section into a plurality of rectangular grid units; the cross-section is composed of a width direction and a thickness direction of the steel plate; based on the detection positions of the existing temperature measuring points and the temperature real-time values corresponding to the temperature measuring points, the temperature of each grid node on the cross-section is calculated by using a finite difference model, and a two-dimensional temperature field corresponding to each cross-section is constructed; adopting a variable grid size method to set the distance between adjacent cross-sections in each process stage as a spatial step in the length direction of the steel plate, and based on the two-dimensional temperature field on the cross-section and the spatial step corresponding to the current process stage, the spatial expansion is carried out along the length direction of the steel plate, and an initial model of a three-dimensional temperature field is constructed; calculating the temperature correction values of each grid node on the cross-section of the steel plate in the initial model of the three-dimensional temperature field according to the types of temperature measuring equipment corresponding to the temperature measuring points and the positions of the temperature measuring points; the types of temperature measuring equipment include a single-point pyrometer and / or a transverse scanning pyrometer; the temperature correction values of each grid node on the cross-section of the steel plate in the initial model of the three-dimensional temperature field are calculated according to the types of temperature measuring equipment corresponding to the temperature measuring points and the positions of the temperature measuring points, and the calculation is specifically as follows: when there is only a temperature measuring point arranged by a single-point pyrometer on the upper surface of the steel plate, the temperature correction values of each grid node on the width direction of the cross-section of the steel plate in the initial model of the three-dimensional temperature field are calculated by using a first single-point temperature correction model; when there are temperature measuring points arranged by single-point pyrometers on the upper surface and the lower surface of the steel plate, the temperature correction values of each grid node on the thickness direction of the cross-section of the steel plate in the initial model of the three-dimensional temperature field are calculated by using a second single-point temperature correction model; when there is a temperature measuring point arranged by a transverse scanning pyrometer on the surface of the steel plate, the temperature correction values of each grid node on the width direction and the thickness direction of the cross-section of the steel plate in the initial model of the three-dimensional temperature field are calculated by using a transverse temperature correction model; according to the distance between any two temperature measuring equipment, the temperature detection time and the running speed of the steel plate, the time when the cross-section of the steel plate reaches the temperature measuring points corresponding to the two temperature measuring equipment in the steel plate production process is obtained, the temperature correction amount for reflecting the time-distance dimension difference is calculated according to the time and the temperature correction value, the grid node temperature calculated based on the finite difference model is corrected by using the temperature correction amount, and a target three-dimensional temperature field corresponding to the current time is obtained; the target three-dimensional temperature field is continuously updated based on the latest two-dimensional temperature field, so that a dynamic evolution three-dimensional temperature field model is constructed; ； Where, Indicates the moment when the steel plate cross section reaches the first temperature measuring point S, Indicates the moment when the cross section of the steel plate reaches the second temperature measuring point E, Indicates that the cross section of the steel plate reaches the set position between the two temperature measurement points moment; Indicates the cross section of the steel plate The position is the difference between the temperature correction value of the grid node with the i-th column in the width direction and the j-th row in the thickness direction and the temperature of the grid node calculated by the corresponding finite difference model; represents the temperature correction corresponding to the grid node with the i-th column in the width direction and the j-th row in the thickness direction on the cross section of the steel plate; the calculation formula for calculating the temperature correction amount for reflecting the time-distance dimension difference according to the time and the temperature correction value is as follows: ； In the formula, represents the grid node temperature of the grid node in the i-th column in the width direction and the j-th row in the thickness direction on the steel plate cross section at the k-th time calculated based on the finite difference model; represents the final temperature value of the grid node in the i-th column in the width direction and the j-th row in the thickness direction on the steel plate cross section after the dimensional correction at the k-th time.

2. A method for dynamic modeling of three-dimensional temperature field in the production process of steel plates according to claim 1, characterized in that, the calculation formula for correcting the grid node temperature calculated based on the finite difference model by using the temperature correction amount is as follows: the two-dimensional temperature field is constructed as follows: obtaining model parameters of the steel plate; Discretize the cross-section area of the steel plate, and divide each cross-section into a plurality of rectangular grid cells; the cross-section is composed of the width direction and the thickness direction of the steel plate, and the spatial step ΔX in the width direction and the spatial step ΔY in the thickness direction are determined; According to the spatial steps ΔX and ΔY, and the material thermal physical parameters of the steel plate, a stability condition is set, and a time step Δt is set based on the stability condition; Using the detection positions of the existing temperature measuring points and the real-time temperature values of each temperature measuring point at the set time, the grid nodes are preliminarily interpolated; Based on the heat transfer control equation, using the model parameters and the real-time temperature values of the steel plate, the temperature of each grid node on the cross-section is calculated at each time step using the finite difference model at the set time step Δt; Based on the temperature of each grid node, the temperature of each point inside the grid cell is calculated using the interpolation method; Based on the temperature of each grid node and the temperature of each point inside it, a two-dimensional temperature field corresponding to the cross-section at each time is constructed.

3. The method for dynamic modeling of three-dimensional temperature field in the production process of steel plates according to claim 1, characterized in that, The two-dimensional temperature field is constructed as follows: Discretize the cross-section of the steel plate, divide each cross-section into a plurality of rectangular grid cells, preliminarily interpolate the grid nodes using the detection positions of the existing temperature measuring points and the real-time temperature values of each temperature measuring point at the set time, calculate the correction coefficients of each grid node in the width direction of the steel plate and in the thickness direction of the steel plate, adjust the real-time temperature values of the corresponding grid nodes through the correction coefficients, calculate the temperature of each grid node on the cross-section based on the adjusted temperature data using the finite difference model, and construct a two-dimensional temperature field on the cross-section.

4. The method for dynamic modeling of three-dimensional temperature field in the production process of steel plates according to claim 3, characterized in that, The calculation of the correction coefficients of each grid node in the width direction of the steel plate and in the thickness direction of the steel plate, the adjustment of the real-time temperature values of the corresponding grid nodes through the correction coefficients, the calculation of the temperature of each grid node on the cross-section based on the adjusted temperature data using the finite difference model, and the construction of a two-dimensional temperature field on the cross-section are as follows: Based on the temperature non-uniformity of the grid nodes in the width direction, a horizontal correction function is constructed; Based on the temperature gradient of the grid nodes in the thickness direction, a vertical correction function is constructed; Using the horizontal correction function and the vertical correction function, the horizontal correction coefficient of the grid node in the width direction of the steel plate and the vertical correction coefficient of the grid node in the thickness direction of the steel plate are calculated; The real-time temperature values of the grid nodes are corrected through the horizontal correction coefficient and the vertical correction coefficient to obtain temperature adjustment values; Based on the heat transfer control equation, using the model parameters and the temperature adjustment values of the steel plate, the temperature of each grid node on the cross-section is calculated using the finite difference model; Based on the temperature adjustment values and the calculated grid node temperatures, the temperature values of the interpolation points inside the grid cell are calculated using the interpolation algorithm; The two-dimensional temperature field on the cross-section is constructed by combining the temperature adjustment values of the grid nodes, the calculated grid node temperatures, and the temperature values of the interpolation points inside.

5. A method for dynamic modeling of three-dimensional temperature field in the production process of steel plates according to any one of claims 2 to 4, characterized in that, The model parameters of the steel plate include: pre-set geometric size information, material thermal physical parameters, and convective heat transfer coefficients under various boundary conditions; the boundary conditions include: Dirichlet boundary conditions and Neumann boundary conditions.

6. A method for dynamic modeling of three-dimensional temperature field in the production process of steel plates according to claim 4, characterized in that, The formula expression of the first single-point temperature correction model is: ; wherein: ； In the formula, represents a temperature correction amount at a center point of the upper surface of the steel plate, and is used to compensate for a deviation between a calculated value of the finite difference model and a measured temperature value; represents a grid node temperature of a grid node at the k-th time on the steel plate cross section in the i-th column in the width direction and the j-th row in the thickness direction calculated based on the finite difference model; represents a temperature correction value of the grid node at the k-th time on the steel plate cross section in the i-th column in the width direction and the j-th row in the thickness direction. represents the measured temperature value at the center point of the upper surface of the steel sheet, wherein, represents measured; n represents the total number of grid nodes along the width direction of the steel sheet cross section, and m represents the total number of grid nodes along the thickness direction of the steel sheet cross section; represents the grid node temperature of the grid node at the kth time in the n th row and m th column of the grid nodes calculated by the finite difference model. represents the grid node temperature of the grid node at the kth time in the n th row and m th column of the grid nodes calculated by the finite difference model.

7. A method for dynamic modeling of three-dimensional temperature field in the production process of steel plates according to claim 4, characterized in that, The formula expression of the second single-point temperature correction model is: ; wherein: ； ； Where, It represents the temperature correction value of the grid node with the i-th column in the width direction and the j-th row in the thickness direction on the cross section of the steel plate at the k-th moment; represents the grid node temperature at the kth moment of the grid node in the i-th column in the width direction and the j-th row in the thickness direction on the cross section of the steel plate calculated based on the finite difference model; Indicates the temperature correction at the center point of the upper surface of the steel plate; Indicates the temperature correction at the center point of the lower surface of the steel plate; Represents the distance between adjacent mesh nodes along the thickness direction of the steel plate in the cross section of the steel plate; Indicates the coordinate position of the current grid node in the thickness direction; Represents the total height of the steel plate, which is equal to the sum of the spacings of all mesh nodes in the thickness direction; represents the measured temperature value at the center point of the steel plate surface, where Indicates actual measurement; The center point of the steel plate surface calculated by the finite difference model is The grid node temperature of the grid node in the mth column and the mth row at the kth moment; n represents the total number of grid nodes in the width direction of the steel plate cross section, and m represents the total number of grid nodes in the thickness direction of the steel plate cross section; Indicates the measured temperature value at the center point of the lower surface of the steel plate; The center point of the lower surface of the steel plate calculated by the finite difference model is The grid node temperature of the grid node in column 0 and row 0 at the kth moment.

8. A method for dynamic modeling of three-dimensional temperature field in the production process of steel plates according to claim 4, characterized in that, The formula expression of the transverse temperature correction model is: ; wherein: ； In the formula, represents the temperature correction value of the grid node in the i-th column in the width direction and the j-th row in the thickness direction on the cross section of the steel plate at the k-th moment; represents the grid node temperature of the grid node in the i-th column in the width direction and the j-th row in the thickness direction on the cross section of the steel plate at the k-th moment calculated based on the finite difference model; represents the overall correction amount in the transverse direction corresponding to the i-th column in the width direction; represents the measured temperature value of the grid node in the i-th column in the width direction and the m-th row in the thickness direction which is the uppermost layer on the upper surface of the steel plate; represents the grid node temperature of the grid node in the i-th column in the width direction and the m-th row in the thickness direction on the cross section of the steel plate at the k-th moment calculated based on the finite difference model.

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