Heating control method, system, device and medium for vertical continuous annealing furnace

Abstract

The application discloses a heating control method and system of a vertical continuous annealing furnace, computer equipment and a medium, the method comprising: obtaining a holding time threshold value and a recrystallization temperature determined based on the steel grade and composition of a strip steel to be heated; determining the temperature of the strip steel after heating through the Nth column of radiant tubes in the vertical continuous annealing furnace based on the temperature of the Nth column of radiant tubes and the temperature of the strip steel after heating through N-1 columns of radiant tubes; if the temperature of the strip steel after heating through the Nth column of radiant tubes reaches the recrystallization temperature, determining the holding time based on the remaining length of the strip steel not traveled in the vertical continuous annealing furnace and the traveling speed; and adjusting the traveling speed and / or adjusting the heating power of the Nth column of radiant tubes and subsequent radiant tubes based on the holding time and the holding time threshold value.

Description

Technical Field

[0001] This invention relates to the field of material heat treatment, and specifically to a heating control method, system, equipment, and medium for a vertical continuous annealing furnace. Background Technology

[0002] Vertical continuous annealing furnaces are key equipment in hot-dip galvanizing / continuous annealing units. Their function is to eliminate work hardening by heating cold-rolled coils above their recrystallization temperature. Simultaneously, through homogenization and heat preservation, the microstructure within the material is diffused and rearranged to achieve a more uniform structure, resulting in superior mechanical and physical properties. Currently, most mainstream vertical continuous annealing furnaces use pulse burners for furnace temperature control, offering advantages such as fast dynamic response and high combustion efficiency. However, this also presents the problem of overheating of the radiant tubes during the production of thin strip steel. This means that the strip steel may experience rapid heating and prolonged heat preservation within the annealing furnace, leading to coarse grains and affecting subsequent processing performance.

[0003] In the cold-rolled hot-dip galvanizing process, coarse grains often occur due to improper annealing temperature control or excessive holding time, affecting the stamping performance of the product and causing significant quality losses. Analysis shows that the heating rate and holding time are key factors affecting grain size. Especially in annealing furnaces with a single temperature detection point, the detected strip temperature cannot accurately reflect the point at which the strip has reached the recrystallization temperature or the high-temperature holding time. Therefore, it is easy for operators to mistakenly believe that the process is qualified, but stamping wrinkles or cracks occur during the stamping process. Summary of the Invention

[0004] In view of this, in order to overcome at least one aspect of the above problems, embodiments of the present invention propose a heating control method for a vertical continuous annealing furnace, comprising the following steps: Obtain the holding time threshold and recrystallization temperature based on the steel grade and composition of the strip to be heated; The temperature of the strip after heating through the Nth column of radiant tubes is determined based on the temperature of the Nth column of radiant tubes in the vertical continuous annealing furnace and the temperature of the strip after heating through the N-1th column of radiant tubes. If the temperature of the strip reaches the recrystallization temperature after the Nth column of radiant tubes is heated, the holding time is determined based on the remaining untraveled length and travel speed of the strip in the vertical continuous annealing furnace. The traveling speed and / or the heating power of the Nth column of radiant tubes and subsequent radiant tubes are adjusted based on the heat preservation time and the heat preservation time threshold.

[0005] In some embodiments, determining the temperature of the strip after heating through the Nth column of radiant tubes, based on the temperature of the Nth column of radiant tubes in the vertical continuous annealing furnace and the temperature of the strip after heating through the N-1th column of radiant tubes, further includes: Obtain the initial absolute temperature and heating factor parameters of the strip steel; The temperature of the strip after heating by the first row of radiant tubes is determined based on the initial absolute temperature of the strip, the absolute temperature of the first row of radiant tubes, and the heating factor parameters. The temperature of the strip after being heated by the first row of radiant tubes is determined based on the temperature of the strip after being heated by the first row of radiant tubes, the temperature of each subsequent row of radiant tubes, and the heating factor parameters.

[0006] In some embodiments, obtaining the heating factor parameter further includes: The combined emissivity between the radiant tubes and the strip, the Stefan Boltzmann constant, the density and thickness of the strip, the specific heat capacity of the strip, the length of each row of radiant tubes, and the traveling speed of the strip are obtained. The heating time of the strip on each row of radiant tubes is determined based on the length of each row of radiant tubes and the traveling speed of the strip.

[0007] In some embodiments, the temperature of the strip after heating by the first row of radiant tubes is determined based on the initial absolute temperature of the strip, the absolute temperature of the first row of radiant tubes, and heating factor parameters. This further includes calculating the temperature of the strip after heating by the first row of radiant tubes based on the following formula:

[0008] Where ε is the combined emissivity between the radiating tube and the strip, and 0≤ε≤1; σ is the Stefan Boltzmann constant; ρ is the strip density, kg / m³; h is the strip thickness, m; c is the strip specific heat capacity, J / (kg•K); t is the heating time, s; Temp 初 Temp is the initial absolute temperature of the strip, in K. RaA Let K be the absolute temperature of the first column of radiant tubes.

[0009] In some embodiments, the temperature of the strip after heating through each subsequent row of radiant tubes is determined based on the temperature of the strip after heating through the first row of radiant tubes, the temperature of each subsequent row of radiant tubes, and a heating factor parameter. This further includes calculating the temperature of the strip after heating through each subsequent row of radiant tubes based on the following formula:

[0010] Where ε is the combined emissivity between the radiating tube and the strip, and 0≤ε≤1; σ is the Stefan Boltzmann constant; ρ is the strip density, kg / m³; h is the strip thickness, m; c is the strip specific heat capacity, J / (kg•K); t is the heating time, s; Temp n-1 Temp is the temperature of the strip steel after it has been heated by the (N-1)th column of radiant tubes, in K. Ran-1 The absolute temperature of the (N-1)th column radiator, in K; Temp Ran Let be the absolute temperature of the Nth column of radiant tubes, in K.

[0011] In some embodiments, adjusting the traveling speed and / or adjusting the heating power of the Nth column of radiant tubes and subsequent radiant tubes based on the heat preservation time and the heat preservation time threshold further includes: If the heat preservation time is less than the heat preservation time threshold, it is determined that there is no risk of coarse grains in the strip steel, and the traveling speed and / or the heating power of the Nth column of radiant tubes and thereafter remains unchanged. If the heat preservation time is greater than the heat preservation time threshold, it is determined that the strip steel has a risk of coarse grains, and the traveling speed and / or the heating power of the Nth column of radiant tubes and subsequent radiant tubes are adjusted.

[0012] In some embodiments, adjusting the traveling speed and / or adjusting the heating power of the Nth column of radiant tubes and subsequent radiant tubes further includes: Increase the travel speed and recalculate the heat preservation time; If the travel speed reaches its maximum value and the recalculated heat preservation time is still greater than the heat preservation time threshold, reduce the heating power of the Nth column of radiant tubes and subsequent radiant tubes.

[0013] Based on the same inventive concept, according to another aspect of the present invention, embodiments of the present invention also provide a heating control system for a vertical continuous annealing furnace, comprising: The acquisition module is configured to acquire the holding time threshold and recrystallization temperature determined based on the steel type and composition of the strip to be heated; The first calculation module is configured to determine the temperature of the strip after it has been heated by the Nth column of radiant tubes based on the temperature of the Nth column of radiant tubes in the vertical continuous annealing furnace and the temperature of the strip after it has been heated by the N-1th column of radiant tubes. The second calculation module is configured to determine the holding time based on the remaining untraveled length and travel speed of the strip in the vertical continuous annealing furnace if the temperature of the strip reaches the recrystallization temperature after the heating of the Nth column of radiant tubes. The adjustment module is configured to adjust the traveling speed and / or adjust the heating power of the Nth column of radiant tubes and subsequent radiant tubes based on the heat preservation time and the heat preservation time threshold.

[0014] Based on the same inventive concept, according to another aspect of the present invention, embodiments of the present invention also provide a computer device, comprising: At least one processor; and The memory stores a computer program that can run on the processor, which, when executing the program, performs the steps of any of the heating control methods for a vertical continuous annealing furnace as described above.

[0015] Based on the same inventive concept, according to another aspect of the present invention, embodiments of the present invention also provide a computer-readable storage medium storing a computer program that, when executed by a processor, performs the steps of any of the heating control methods for a vertical continuous annealing furnace as described above.

[0016] The present invention has one of the following beneficial technical effects: The solution proposed in this invention adopts real-time dynamic analysis, judgment and flexible adjustment to timely grasp the heating status of strip steel in each area of ​​the heating section, and can provide the unit speed or radiant tube temperature that should be adjusted in a timely manner according to the judgment results, so as to realize the online judgment and adjustment of the quality risk of coarse grains in hot-dip galvanized products, thereby reducing the quality accidents and batch quality disputes caused by excessive fluctuations in furnace temperature control, and effectively improving the stability of product performance. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic flowchart of a heating control method for a vertical continuous annealing furnace provided for an embodiment of the present invention; Figure 2 A schematic diagram of the heating section / soaking section structure inside a vertical continuous annealing furnace provided for an embodiment of the present invention; Figure 3 A schematic diagram of data on the strip steel after heating in each section, provided for an embodiment of the present invention; Figure 4 A schematic diagram of data on the strip steel after heating each section, provided as another embodiment of the present invention; Figure 5A schematic diagram of the heating control system of a vertical continuous annealing furnace provided for an embodiment of the present invention; Figure 6 A schematic diagram of the structure of a computer device provided for an embodiment of the present invention; Figure 7 A schematic diagram of the structure of a computer-readable storage medium provided for an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0020] It should be noted that all uses of "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of the present invention. Subsequent embodiments will not explain this in detail.

[0021] According to one aspect of the present invention, embodiments of the present invention provide a heating control method for a vertical continuous annealing furnace, such as... Figure 1 As shown, it may include the following steps: S1, obtain the holding time threshold and recrystallization temperature determined based on the steel grade and composition of the strip to be heated; S2, Based on the temperature of the Nth column of radiant tubes in the vertical continuous annealing furnace and the temperature of the strip after heating through the N-1th column of radiant tubes, determine the temperature of the strip after heating through the Nth column of radiant tubes. S3, if the temperature of the strip reaches the recrystallization temperature after the heating of the Nth column of radiant tubes, the holding time is determined based on the remaining untraveled length and travel speed of the strip in the vertical continuous annealing furnace. S4, adjust the traveling speed and / or adjust the heating power of the Nth column of radiant tubes and subsequent radiant tubes based on the heat preservation time and the heat preservation time threshold.

[0022] The solution proposed in this invention uses real-time dynamic analysis, judgment, and flexible adjustment to promptly grasp the heating status of strip steel in each area of ​​the heating section. It can also provide the unit speed or radiant tube temperature that should be adjusted in a timely manner based on the judgment results, so as to realize the online judgment and adjustment of the quality risk of coarse grains in hot-dip galvanized products. This reduces quality accidents and batch quality disputes caused by excessive fluctuations in furnace temperature control, and effectively improves the stability of product performance.

[0023] In some embodiments, step S1 involves obtaining the holding time threshold and recrystallization temperature determined based on the steel grade and composition of the strip to be heated. Specifically, according to relevant standards, such as the ATSM E112 standard, when the grain size exceeds 40 μm, it is already considered a coarse grain. The holding time Time* for the current steel grade is confirmed by combining multiple literature sources, and then the recrystallization temperature Temp0 of the strip is determined based on the steel composition.

[0024] In some embodiments, determining the temperature of the strip after heating through the Nth column of radiant tubes, based on the temperature of the Nth column of radiant tubes in the vertical continuous annealing furnace and the temperature of the strip after heating through the N-1th column of radiant tubes, further includes: Obtain the initial absolute temperature and heating factor parameters of the strip steel; The temperature of the strip after heating by the first row of radiant tubes is determined based on the initial absolute temperature of the strip, the absolute temperature of the first row of radiant tubes, and the heating factor parameters. The temperature of the strip after being heated by the first row of radiant tubes is determined based on the temperature of the strip after being heated by the first row of radiant tubes, the temperature of each subsequent row of radiant tubes, and the heating factor parameters.

[0025] In some embodiments, obtaining the heating factor parameter further includes: The combined emissivity between the radiant tubes and the strip, the Stefan Boltzmann constant, the density and thickness of the strip, the specific heat capacity of the strip, the length of each row of radiant tubes, and the traveling speed of the strip are obtained. The heating time of the strip on each row of radiant tubes is determined based on the length of each row of radiant tubes and the traveling speed of the strip.

[0026] In some embodiments, the temperature of the strip after heating by the first row of radiant tubes is determined based on the initial absolute temperature of the strip, the absolute temperature of the first row of radiant tubes, and heating factor parameters. This further includes calculating the temperature of the strip after heating by the first row of radiant tubes based on the following formula:

[0027] Where ε is the combined emissivity between the radiating tube and the strip, and 0≤ε≤1; σ is the Stefan Boltzmann constant; ρ is the strip density, kg / m³; h is the strip thickness, m; c is the strip specific heat capacity, J / (kg•K); t is the heating time, s; Temp 初 Temp is the initial absolute temperature of the strip, in K. RaA Let K be the absolute temperature of the first column of radiant tubes.

[0028] Specifically, based on the temperature of the radiant tube, the temperature of the strip in the first column is calculated as follows:

[0029] Where ε is the combined emissivity of the radiating tube and the strip steel, which is dimensionless and 0 ≤ ε ≤ 1; σ is the Stefan Boltzmann constant, with a value of 5.67 × 10⁻⁶. 8 W / (m 2 K 4 ); ρ is the density of the strip, kg / m³; h is the thickness of the strip, m; c is the specific heat capacity of the strip, J / (kg•K); t is the heating time, s; Temp 初 Temp is the initial absolute temperature of the strip, in K. RaA Let K be the absolute temperature of the first column of radiant tubes.

[0030] In some embodiments, the temperature of the strip after heating through each subsequent row of radiant tubes is determined based on the temperature of the strip after heating through the first row of radiant tubes, the temperature of each subsequent row of radiant tubes, and a heating factor parameter. This further includes calculating the temperature of the strip after heating through each subsequent row of radiant tubes based on the following formula:

[0031] Where ε is the combined emissivity between the radiating tube and the strip, and 0≤ε≤1; σ is the Stefan Boltzmann constant; ρ is the strip density, kg / m³; h is the strip thickness, m; c is the strip specific heat capacity, J / (kg•K); t is the heating time, s; Temp n-1 Temp is the temperature of the strip steel after it has been heated by the (N-1)th column of radiant tubes, in K. Ran-1 The absolute temperature of the (N-1)th column radiator, in K; Temp Ran Let be the absolute temperature of the Nth column of radiant tubes, in K.

[0032] Specifically, in a vertical continuous annealing furnace, the strip runs in an S-shape. Starting from the downward section of the first column, the strip becomes heated on both sides. Therefore, considering the influence of heat flux, the temperature after the heating of each subsequent column of radiant tubes is completed is calculated using the following formula:

[0033] Where ε is the combined emissivity between the radiating tube and the strip steel, and 0 ≤ ε ≤ 1; σ is the Stefan Boltzmann constant, with a value of 5.67 × 10⁻⁶. 8 W / (m 2 K 4 ); ρ is the density of the strip, kg / m³; h is the thickness of the strip, m; c is the specific heat capacity of the strip, J / (kg•K); t is the heating time, s; Tempn-1 Temp is the temperature of the strip steel after it has been heated by the (N-1)th column of radiant tubes, in K. Ran-1 The absolute temperature of the (N-1)th column radiator, in K; Temp Ran Let be the absolute temperature of the Nth column of radiant tubes, in K.

[0034] In some embodiments, adjusting the traveling speed and / or adjusting the heating power of the Nth column of radiant tubes and subsequent radiant tubes based on the heat preservation time and the heat preservation time threshold further includes: If the heat preservation time is less than the heat preservation time threshold, it is determined that there is no risk of coarse grains in the strip steel, and the traveling speed and / or the heating power of the Nth column of radiant tubes and subsequent radiant tubes remain unchanged. If the heat preservation time is greater than the heat preservation time threshold, it is determined that the strip has a risk of coarse grains, and the traveling speed and / or the heating power of the Nth column of radiant tubes and subsequent radiant tubes are adjusted.

[0035] Specifically, if Temp n When the recrystallization temperature Temp0 is reached, the strip enters the initial stage of recrystallization. Since the length of each row of radiant tubes and the traveling speed of the strip are known, the holding time after the strip has been heated by the Nth row of radiant tubes can be determined by the remaining untraveled length and traveling speed of the strip in the vertical continuous annealing furnace. The specific calculation formula is as follows: T 保 =(L 总 -L N ) / V Among them, L 总 L is the total length of all sections of the annealing furnace. N V is the length of the Nth column of radiant tubes through which the strip passes, and V is the speed of the strip, which is also the unit speed of the annealing furnace (m / s).

[0036] After obtaining the heat preservation time, if the heat preservation time is less than the heat preservation time threshold, it is determined that there is no risk of coarse grains in the strip steel, and the traveling speed and / or the heating power of the Nth column of radiant tubes and subsequent radiant tubes can be kept constant. If the heat preservation time is greater than the heat preservation time threshold, it is determined that the strip has a risk of coarse grains, and the traveling speed and / or the heating power of the Nth column of radiant tubes and subsequent radiant tubes are adjusted.

[0037] In some embodiments, adjusting the traveling speed and / or adjusting the heating power of the Nth column of radiant tubes and subsequent radiant tubes further includes: Increase the travel speed and recalculate the heat preservation time; If the travel speed reaches its maximum value and the recalculated heat preservation time is still greater than the heat preservation time threshold, reduce the heating power of the Nth column of radiant tubes and subsequent radiant tubes.

[0038] Specifically, the strip speed (unit speed) V can be increased by 5-10 m / min first, and then T can be recalculated according to the above process. 保 If the unit speed has reached the upper limit of the design capacity, the recrystallization can be reduced by lowering the heating power of the Nth column of radiant tubes, so that recrystallization begins at N+1, 2, ..., thereby reducing the heat preservation time of the strip.

[0039] Example 1: The steel grade is IF steel, containing stabilizing elements such as Ti and Nb. The rolling reduction rate is 75%, the strip thickness is 0.6 mm, the width is 1040 mm, the annealing temperature is 860℃, the mill speed is 85 m / min, and the strip temperature at the preheating section outlet is 180℃. Figure 2 As shown, the annealing furnace contains a total of 11 rows of burners. Row A has 7 radiant tubes, with an upward length of 25m and a downward length of 20m; rows B and C each have 13 radiant tubes, with a downward length of 20m and an upward length of 20m; rows D and H each have 14 radiant tubes, with an upward length of 20m and a downward length of 20m; row J has 7 radiant tubes, with an upward length of 25m and a downward length of 20m; and row K has 4 radiant tubes, with only an upward length of 25m. Furnace temperature readings: Row A 611℃, Row B 636℃, Row C 675℃, Row D 757℃, Row E 830℃, Row F 894℃, Row G 951℃, Row H 888℃, Row I 915℃, Row J 934℃, and Row K 961℃.

[0040] (1) Determine the critical size for grain coarsening and the holding time required to reach the critical size. According to the ATSM E112 standard, the optimal grain size for this material is 15-40μm. Grain sizes exceeding 40μm are considered coarse. Based on multiple literature sources, the maximum holding time for the current steel grade is confirmed to be Time*=50s.

[0041] (2) Determine the recrystallization temperature (Temp0) of the strip based on the steel composition. The current steel grade is IF steel, with the addition of stabilizing elements such as Ti and Nb. Based on the rolling reduction rate of 75%, and referring to relevant literature, the recrystallization temperature Temp0≈850℃.

[0042] (3) Calculation of strip temperature in the first column of the heating section:

[0043] in, ε≈0.6 σ = 5.67 × 10 8 W / (m 2 K 4 ), ρ=7850kg / m³, h=0.6, c=460J / (kg·K), Temp RaA =611 + 273.15 = 884.15K, Temp 初 =180+273.15=453.15K.

[0044] The following was calculated using the iterative integration method:

[0045] Calculation of strip temperature in the second column of the heating section: As shown in the schematic diagram of the annealing furnace, starting from the second column, the strip steel is heated on both sides, therefore a formula needs to be introduced:

[0046] Substituting the relevant data, we can obtain:

[0047]

[0048] The temperature was calculated sequentially up to column K according to the above process, and the final data is as follows: Figure 3 As shown, according to Figure 3 The data shown indicates that when the strip is in column 8 (GH column), the relative temperature Temp8 = 877℃ > 850℃, reaching the complete recrystallization temperature. The following three columns are all insulation sections, each 65m in length. The value is less than the longest holding time of the current steel grade, Time* (50s), indicating that there is no risk of coarse grains in the strip steel. Through metallographic observation, the grain size of the sample is 22.07-22.23μm, which is basically consistent with the calculated data results.

[0049] Example 2: The materials are the same as in Example 1, and the unit speed is still 85 m / min, but the temperature control of the radiant tubes is changed: A column 887℃, B column 911℃, C column 940℃, D column 956℃, E column 953℃, F column 970℃, G column 975℃, H column 920℃, I column 904℃, J column 900℃, K column 977℃.

[0050] Through the calculation process of steps (1)-(3), the following results are obtained: Figure 4 The data shown is based on Figure 4The data shown indicates that when the strip is in column 7 (FG), the relative temperature Temp7 = 867℃ > 850℃, reaching the complete recrystallization temperature. The following four columns are all insulation sections, each 85m in length. If the temperature exceeds the maximum holding time of the current steel grade (Time* (50s), it is determined that the strip steel has a risk of coarse grains. Through metallographic observation, the grain size of the sample is about 47μm, which is basically consistent with the calculated data results.

[0051] Based on the same inventive concept, according to another aspect of the present invention, embodiments of the present invention also provide a heating control system 400 for a vertical continuous annealing furnace, such as... Figure 5 As shown, it includes: The acquisition module 401 is configured to acquire the holding time threshold and recrystallization temperature determined based on the steel type and composition of the strip to be heated; The first calculation module 402 is configured to determine the temperature of the strip after it has been heated by the Nth column of radiant tubes based on the temperature of the Nth column of radiant tubes in the vertical continuous annealing furnace and the temperature of the strip after it has been heated by the N-1th column of radiant tubes. The second calculation module 403 is configured to determine the holding time based on the remaining untraveled length and travel speed of the strip in the vertical continuous annealing furnace if the temperature of the strip reaches the recrystallization temperature after the heating of the Nth column of radiant tubes. The adjustment module 404 is configured to adjust the traveling speed and / or adjust the heating power of the Nth column of radiant tubes and subsequent radiant tubes based on the heat preservation time and the heat preservation time threshold.

[0052] Based on the same inventive concept, according to another aspect of the present invention, such as Figure 6 As shown, embodiments of the present invention also provide a computer device 501, comprising: At least one processor 520; and The memory 510 stores a computer program 511 that can run on a processor. When the processor 520 executes the program, it performs the steps of any of the heating control methods for the vertical continuous annealing furnace described above.

[0053] Based on the same inventive concept, according to another aspect of the present invention, such as Figure 7 As shown, embodiments of the present invention also provide a computer-readable storage medium 601, which stores a computer program 610. When the computer program 610 is executed by a processor, it performs the steps of any of the above-described heating control methods for a vertical continuous annealing furnace.

[0054] Finally, it should be noted that those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods.

[0055] Furthermore, it should be understood that the computer-readable storage medium (e.g., memory) described herein may be volatile memory or non-volatile memory, or may include both volatile memory and non-volatile memory.

[0056] Those skilled in the art will also understand that the various exemplary logic blocks, modules, circuits, and algorithm steps described in conjunction with the disclosure herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the functionality of various illustrative components, modules, circuits, and steps has been generally described. Whether this functionality is implemented as software or as hardware depends on the specific application and the design constraints imposed on the system as a whole. Those skilled in the art can implement the functionality in various ways for each specific application, but such implementation decisions should not be construed as departing from the scope of the embodiments disclosed herein.

[0057] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0058] It should be understood that, as used herein, the singular form “a” is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, “and / or” refers to any and all possible combinations of one or more of the associated listed items.

[0059] The embodiment numbers disclosed in the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0060] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0061] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A heating control method for a vertical continuous annealing furnace, characterized in that, Includes the following steps: Obtain the holding time threshold and recrystallization temperature based on the steel grade and composition of the strip to be heated; The temperature of the strip after heating through the Nth column of radiant tubes is determined based on the temperature of the Nth column of radiant tubes in the vertical continuous annealing furnace and the temperature of the strip after heating through the N-1th column of radiant tubes. If the temperature of the strip reaches the recrystallization temperature after the Nth column of radiant tubes is heated, the holding time is determined based on the remaining untraveled length and travel speed of the strip in the vertical continuous annealing furnace. The traveling speed and / or the heating power of the Nth column of radiant tubes and subsequent radiant tubes are adjusted based on the heat preservation time and the heat preservation time threshold.

2. The method as described in claim 1, characterized in that, Based on the temperature of the Nth column of radiant tubes in the vertical continuous annealing furnace and the temperature of the strip after heating through the N-1th column of radiant tubes, the temperature of the strip after heating through the Nth column of radiant tubes is determined, further including: Obtain the initial absolute temperature and heating factor parameters of the strip steel; The temperature of the strip after heating by the first row of radiant tubes is determined based on the initial absolute temperature of the strip, the absolute temperature of the first row of radiant tubes, and the heating factor parameters. The temperature of the strip after being heated by the first row of radiant tubes is determined based on the temperature of the strip after being heated by the first row of radiant tubes, the temperature of each subsequent row of radiant tubes, and the heating factor parameters.

3. The method as described in claim 2, characterized in that, Obtaining heating factor parameters further includes: The combined emissivity between the radiant tubes and the strip, the Stefan Boltzmann constant, the density and thickness of the strip, the specific heat capacity of the strip, the length of each row of radiant tubes, and the traveling speed of the strip are obtained. The heating time of the strip on each row of radiant tubes is determined based on the length of each row of radiant tubes and the traveling speed of the strip.

4. The method as described in claim 3, characterized in that, The temperature of the strip after heating by the first row of radiant tubes is determined based on the initial absolute temperature of the strip, the absolute temperature of the first row of radiant tubes, and the heating factor parameters. This further includes calculating the temperature of the strip after heating by the first row of radiant tubes using the following formula: Where ε is the combined emissivity between the radiating tube and the strip, and 0≤ε≤1; σ is the Stefan Boltzmann constant; ρ is the strip density, kg / m³; h is the strip thickness, m; c is the strip specific heat capacity, J / (kg•K); t is the heating time, s; Temp 初 Temp is the initial absolute temperature of the strip, in K. RaA Let K be the absolute temperature of the first column of radiant tubes.

5. The method as described in claim 3, characterized in that, The temperature of the strip after heating through the first row of radiant tubes is determined based on the temperature of the strip after heating through the first row of radiant tubes, the temperature of each subsequent row of radiant tubes, and the heating factor parameters. This further includes calculating the temperature of the strip after heating through each subsequent row of radiant tubes using the following formula: Where ε is the combined emissivity between the radiating tube and the strip, and 0≤ε≤1; σ is the Stefan Boltzmann constant; ρ is the strip density, kg / m³; h is the strip thickness, m; c is the strip specific heat capacity, J / (kg•K); t is the heating time, s; Temp n-1 Temp is the temperature of the strip steel after it has been heated by the (N-1)th column of radiant tubes, in K. Ran-1 The absolute temperature of the (N-1)th column radiator, in K; Temp Ran Let be the absolute temperature of the Nth column of radiant tubes, in K.

6. The method as described in claim 1, characterized in that, Adjusting the traveling speed and / or adjusting the heating power of the Nth column of radiant tubes and subsequent radiant tubes based on the heat preservation time and the heat preservation time threshold, further includes: If the heat preservation time is less than the heat preservation time threshold, it is determined that there is no risk of coarse grains in the strip steel, and the traveling speed and / or the heating power of the Nth column of radiant tubes and subsequent radiant tubes remain unchanged. If the heat preservation time is greater than the heat preservation time threshold, it is determined that the strip has a risk of coarse grains, and the traveling speed and / or the heating power of the Nth column of radiant tubes and subsequent radiant tubes are adjusted.

7. The method as described in claim 6, characterized in that, Adjusting the travel speed and / or adjusting the heating power of the Nth column of radiant tubes and subsequent radiant tubes further includes: Increase the travel speed and recalculate the heat preservation time; If the travel speed reaches its maximum value and the recalculated heat preservation time is still greater than the heat preservation time threshold, reduce the heating power of the Nth column of radiant tubes and subsequent radiant tubes.

8. A heating control system for a vertical continuous annealing furnace, characterized in that, include: The acquisition module is configured to acquire the holding time threshold and recrystallization temperature determined based on the steel type and composition of the strip to be heated; The first calculation module is configured to determine the temperature of the strip after it has been heated by the Nth column of radiant tubes based on the temperature of the Nth column of radiant tubes in the vertical continuous annealing furnace and the temperature of the strip after it has been heated by the N-1th column of radiant tubes. The second calculation module is configured to determine the holding time based on the remaining untraveled length and travel speed of the strip in the vertical continuous annealing furnace if the temperature of the strip reaches the recrystallization temperature after the heating of the Nth column of radiant tubes. The adjustment module is configured to adjust the traveling speed and / or adjust the heating power of the Nth column of radiant tubes and subsequent radiant tubes based on the heat preservation time and the heat preservation time threshold.

9. A computer device, comprising: At least one processor; as well as A memory storing a computer program executable on the processor, characterized in that the processor executes the program by performing the steps of the method as described in any one of claims 1-7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it performs the steps of the method as described in any one of claims 1-7.

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