An adaptive air knife control method, device and system for high-strength steel hot-dip galvanizing process

Abstract

The invention relates to the field of hot-dip galvanizing of high-strength steel, and specifically to an adaptive air knife control method, device and system for hot-dip galvanizing of high-strength steel; the central coordinates of each air knife micro-nozzle are calculated by first data to obtain the warpage distribution at the corresponding position, and the initial value of the air knife pressure is calculated according to second data; if the variance of the coating thickness on the surface of the strip does not meet the required coating distribution conditions, the hydraulic cylinder configured by the micro-nozzle is further used to adjust the optimal value of the expansion and contraction amount of each air knife micro-nozzle according to the coating thickness at each position, thereby realizing the individual adjustment of each air knife, and the air knife parameters can be adjusted in real time according to the warpage degree of the plate shape of the strip, thereby solving the defect of uneven distribution of the lateral coating thickness of the strip due to the residual warpage plate shape; and solving the problem that it is difficult to adjust the corresponding parameters of the air knife in sections according to the different coating thicknesses at different lateral locations of the strip in the prior art, resulting in uneven coating thickness at different lateral locations of the steel.

Description

Technical Field

[0001] The invention relates to the field of high-strength steel hot-dip galvanizing, and in particular to a method, device and system for adaptive air knife control in a high-strength steel hot-dip galvanizing process. Background Art

[0002] The continuous annealing process is one of the most critical processes that affects the quality of the strip coating in the production of hot-dip aluminum-zinc strip. If the strip has shape defects after the continuous annealing process, common shape defects include lateral warping, complex wave shape, etc., it will inevitably lead to the strip not being able to obtain a relatively uniform coating when the air knife is scraped with zinc, and the coating thickness on the upper and lower surfaces of the strip will be seriously out of tolerance, thereby reducing the quality grade of the strip product. In addition, if the strip shape is severely warped, it will also cause scratching between the strip surface and the air knife, causing the air knife nozzle to be blocked and the strip to break, which will bring great economic losses to the company.

[0003] However, the air knife devices currently used in the hot-dip production lines of steel companies all control the coating thickness by changing process parameters such as jet pressure, air knife angle, and the distance between the air knife nozzle outlet and the strip surface. At the same time, the air knife is controlled in an integrated manner, and it is impossible to adjust the parameters in sections as the coating thickness at different locations in the strip is horizontal. Although the upstream process section can suppress some plate shape defects, it cannot fundamentally eliminate them. Therefore, there is still a problem of uneven lateral zinc scraping at the air knife. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides an adaptive air knife control method for the hot-dip galvanizing process of high-strength steel, which solves the problem in the prior art that it is difficult to adjust the corresponding parameters of the air knife in sections according to the different coating thicknesses at different transverse locations of the strip, resulting in uneven coating thickness at different transverse locations of the steel.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] An adaptive air knife control method for a high-strength steel hot-dip galvanizing process includes air knives symmetrically arranged on the upper and lower surfaces of the strip and capable of being extended and retracted by a hydraulic cylinder in a vertical direction along the strip surface. The control method includes the following steps:

[0007] S1. Acquire first data including equipment parameters, physical parameters of the air knife, specification parameters of the strip steel, and production process parameters of the strip steel;

[0008] S2, calculating the average immersion plating thickness of the steel strip before zinc scraping, the number of effective micro-nozzles of the air knife, the effective length of the air knife jet acting on the steel strip, and the center coordinates of each micro-nozzle of the air knife according to the first data, so as to obtain the second data;

[0009] S3, obtaining the warpage distribution of each micro-nozzle of the air knife corresponding to the position, and adding it to the second data;

[0010] S4, calculating an initial value of the air knife pressure according to the first data and the second data;

[0011] S5. Re-obtain the distribution of the coating thickness on the upper and lower surfaces of the strip according to the set air knife pressure and determine the distribution of the strip surface in the influence area of ​​each micro-nozzle of the air knife and the initial value of the optimization value of the expansion and contraction amount of the air knife micro-nozzle;

[0012] S6, adjusting the expansion and contraction amount of the air knife micro-nozzle according to the distribution of the strip surface in the influence area of ​​each air knife micro-nozzle and the first data to obtain an optimized value of the expansion and contraction amount of the air knife micro-nozzle;

[0013] S7, outputting the optimized values ​​of air knife parameters including the optimized value of the air knife micro nozzle extension and contraction amount and the air knife pressure.

[0014] Preferably, in step S2, the following steps are specifically included:

[0015] S21, calculating the average thickness of the steel strip surface before zinc scraping according to the first data; the calculation formula for the average thickness of the steel strip surface before zinc scraping is:

[0016] ;

[0017] In the above formula, It indicates the average thickness of the strip surface before zinc scraping. Indicates the zinc consumption per coil of strip steel, Density of zinc liquid at 520℃-650℃, Indicates the width of the strip. Indicates the length of each coil of strip steel;

[0018] S22, calculating the number of effective micro-nozzles of the air knife and the effective length of the air knife jet acting on the strip according to the first data; the number of effective micro-nozzles of the air knife and the effective length of the air knife jet acting on the strip satisfy the following relationship:

[0019] ;

[0020] In the above formula, is a rounding function that rounds the calculated result to the nearest integer. is the number of effective micro nozzles of the air knife, is the total number of air knife micro nozzles, is the cross-sectional length of a single micro-nozzle, is the effective length of the air knife jet acting on the strip, is the width of the strip;

[0021] S23, calculating the center coordinates of each micro-nozzle of the air knife according to the first data; the expression of the center coordinates of each micro-nozzle of the air knife is:

[0022] ;

[0023] In the above formula, is the number of the air knife micro nozzle, , is the center coordinate of each micro-nozzle of the air knife;

[0024] S24, the average thickness of the strip surface before zinc scraping, the number of effective micro nozzles of the air knife , the effective length of the air knife jet acting on the strip and the center coordinates of each micro-nozzle of the air knife are marked as the second data.

[0025] Preferably, in step S4, the following steps are specifically included:

[0026] S41, setting the initial value of the gas knife pressure optimization variable to 0, the initial value of the pressure optimization incremental adjustment coefficient to 1, setting the gas knife pressure optimization step number, and calculating the gas knife pressure optimization incremental amount; the calculation formula of the gas knife pressure optimization incremental amount is:

[0027] ;

[0028] In the above formula, Optimize the increment for air knife pressure, Optimize the incremental adjustment factor for air knife pressure, Optimize the number of steps for air knife pressure, and are the minimum and maximum values ​​of the air knife pressure, respectively;

[0029] S42, setting an initial value of the vertical distance between the air knife and the strip surface, and calculating an initial value of the air knife pressure according to the first data; the initial value of the air knife pressure satisfies the following relationship:

[0030] ;

[0031] In the above formula, is the initial value of the vertical distance between the air knife and the strip surface, is the initial value of the air knife pressure, is the viscosity coefficient of zinc liquid, is the gap between a single micro nozzle, is the velocity attenuation coefficient of the gas ejected from the air knife nozzle, is the flow attenuation coefficient of zinc liquid along the strip surface during zinc scraping process, is the running speed of the strip, is the air knife performance coefficient, Set the value for the coating thickness of the steel strip of this specification. is the density of nitrogen sprayed by the air knife at room temperature;

[0032] S43, obtaining the coating thickness distribution at each location on the strip surface corresponding to each micro-nozzle position of the air knife, and calculating the average coating thickness on the strip surface in the area according to the first data; the calculation formula for the average coating thickness on the strip surface is:

[0033] ;

[0034] In the above formula, is the average thickness of the coating on the strip surface at each location on the strip surface corresponding to each micro-nozzle position of the air knife, For the The thickness of the coating on the strip steel surface in the area affected by the air knife micro nozzle is is the number of effective micro nozzles for the air knife;

[0035] S44, judging whether the average thickness of the coating on the surface of the steel strip is within the thickness range of the coating on the steel strip of this specification;

[0036] If yes, the air knife pressure is set to the initial value of the air knife pressure, and the process goes to step S49;

[0037] If not, proceed to step S45;

[0038] S45, setting the air knife pressure optimization index to 0, adding 1 to the air knife pressure optimization variable, and determining whether the air knife pressure optimization variable is less than or equal to the air knife pressure optimization step number;

[0039] If yes, proceed to step S47;

[0040] If not, go to S46;

[0041] S46, accumulating the number of times the air knife pressure is adjusted, and calculating the air knife pressure optimization incremental adjustment coefficient, and then entering step S41; the calculation formula of the air knife pressure optimization incremental adjustment coefficient is:

[0042] ;

[0043] In the above formula, Optimize the incremental adjustment factor for air knife pressure, is the number of times the air knife pressure is adjusted;

[0044] S47, calculating the optimal value of the air knife pressure; the calculation formula of the optimal value of the air knife pressure is:

[0045] ;

[0046] In the above formula, Optimize the value for the air knife pressure; is the air knife pressure optimization index, Optimize variables for air knife pressure;

[0047] S48, and determining whether the optimized value of the air knife pressure is between the maximum value and the minimum value of the air knife pressure;

[0048] If yes, proceed to step S49;

[0049] If not, proceed to step S42;

[0050] S49, setting the actual air knife pressure to the current air knife pressure optimization value, and then entering step S5.

[0051] Preferably, in step S5, the following steps are specifically included:

[0052] S51, re-obtain the coating thickness distribution on the upper and lower surfaces of the strip according to the set air knife pressure, and calculate the variance of the coating thickness distribution on the upper and lower surfaces of the strip at this time ; The variance calculation formula of the coating thickness distribution on the upper and lower surfaces of the strip is as follows:

[0053] ;

[0054] In the above formula, is the variance of the coating thickness distribution on the upper and lower surfaces of the strip, For the The coating thickness on the upper and lower surfaces of the strip in the affected area of ​​the upper and lower air knife micro nozzles;

[0055] S52, determining whether the thickness distribution variance of the coating on the upper surface of the strip is less than the rated variance;

[0056] If so, the optimal value of the air knife micro nozzle extension amount is set to the air knife micro nozzle extension amount, and then the process goes to step S6; that is, the following relationship is satisfied:

[0057] ;

[0058] In the above formula, For the The optimal value of the air knife micro nozzle extension and contraction amount, For the The initial value of the extension and contraction of the air knife micro nozzle;

[0059] If not, go to step S6.

[0060] Preferably, in step S6, the following steps are specifically included:

[0061] S61, sequentially judging whether the coating thickness on the surface of the steel strip corresponding to the air knife at any position is within the coating thickness range of the steel strip of this specification;

[0062] If both are true, proceed to step S7;

[0063] If not, proceed to step S62;

[0064] S62, setting the number of optimization steps for the hydraulic cylinder volume of the air knife micro nozzle, setting the initial value of the hydraulic cylinder volume optimization variable to 1, and calculating the hydraulic cylinder volume increment of the corresponding air knife micro nozzle; the calculation formula for the hydraulic cylinder volume increment is:

[0065] ;

[0066] In the above formula, is the volume increment of the hydraulic cylinder corresponding to the air knife micro nozzle, and are the maximum and minimum values ​​of the volume in the hydraulic cylinder corresponding to the micro nozzle of the air knife, Optimize the number of steps for the hydraulic cylinder volume of the air knife micro nozzle;

[0067] S63, calculating the expansion and contraction amount of the air knife micro nozzle after the hydraulic cylinder volume is optimized;

[0068] S64, calculating a first spacing between the strip surface and the air knife nozzle according to an initial value of a vertical distance between the air knife and the strip surface, a telescopic amount of the air knife micro-nozzle after the volume of the hydraulic cylinder is optimized, and a strip warping amount in an area affected by the j-th air knife micro-nozzle, and determining whether the first spacing is greater than a safety margin between the strip surface and the air knife nozzle;

[0069] If yes, the optimized value of the air knife micro nozzle extension amount is made equal to the corresponding air knife micro nozzle extension amount, and then the process goes to step S61;

[0070] If not, proceed to step S65;

[0071] S65, determining whether the hydraulic cylinder volume optimization variable is less than or equal to the hydraulic cylinder volume optimization step number;

[0072] If yes, then the value of the hydraulic cylinder volume optimization variable is increased by one and the process proceeds to step S63;

[0073] If not, go to step S62.

[0074] Preferably, in step S64, the calculation formula of the first spacing is:

[0075] ;

[0076] In the above formula, represents the first spacing, Indicates the initial value of the vertical distance between the air knife and the strip surface. Indicates the expansion and contraction of the air knife micro nozzle after the hydraulic cylinder volume is optimized. Represents the amount of strip warping in the area affected by the j-th air knife micro nozzle.

[0077] Preferably, in step S63, the extension amount of the air knife micro nozzle after the hydraulic cylinder volume is optimized is:

[0078] ;

[0079] In the above formula, The extension and contraction of the air knife micro nozzle after the hydraulic cylinder volume is optimized. The expansion and contraction of the air knife micro nozzle before the hydraulic cylinder volume is optimized. is the hydraulic cylinder volume optimization index. When the strip steel surface coating thickness corresponding to the air knife is greater than the maximum value of the strip steel coating thickness range, , when the strip steel surface coating thickness corresponding to the air knife is less than the minimum value of the strip steel coating thickness range, , is the cross-sectional diameter of the piston driving the hydraulic cylinder, Optimize variables for hydraulic cylinder volume.

[0080] The present invention also provides a control system, including a processor and a memory, wherein the memory is used to store a computer program, and when the computer program is executed by the processor, the adaptive air knife control method for the high-strength steel hot-dip galvanizing process is implemented.

[0081] The present invention also provides an air knife device, comprising a plurality of air knife bodies symmetrically arranged on both sides of the upper and lower surfaces of the strip, an air knife micro-nozzle is arranged on the side of the air knife body facing the strip, and also comprises a hydraulic cylinder for controlling the extension and retraction amount of the air knife micro-nozzle, and a micro-nozzle for air supply is also arranged on the air knife micro-nozzle.

[0082] Compared with the prior art, the present invention provides an adaptive air knife control method, device and system for hot-dip galvanizing of high-strength steel, which has the following beneficial effects:

[0083] 1. The present invention calculates the center coordinates of each air knife micro-nozzle through the first data, thereby obtaining the warping distribution at the corresponding position, and then calculates the initial value of the air knife pressure according to the second data, and adjusts the actual value of the air knife pressure by comparing the average thickness of the coating on the surface of the strip with the required coating thickness conditions. If the variance of the coating thickness on the surface of the strip does not meet the required coating distribution conditions, the coating thickness at each position is further used to use the hydraulic cylinder configured by the micro-nozzle to adjust the optimal value of the extension and contraction of each air knife micro-nozzle, thereby realizing individual adjustment of each air knife, and can adjust the air knife parameters in real time according to the degree of warping of the strip plate shape, thereby solving the defect of uneven distribution of the lateral coating thickness of the strip due to residual warping plate shape.

[0084] 2. The present invention obtains the average immersion thickness of the strip surface before zinc scraping, the number of effective micro-nozzles of the air knife, the effective length of the air knife jet acting on the strip and the center coordinates of each micro-nozzle of the air knife to obtain relevant theoretical data, that is, the second parameter value, so as to complete the overall rapid adjustment of the subsequent air knife pressure, save the adjustment time of the subsequent steps, and also serve as the adjustment benchmark for the subsequent steps.

[0085] 3. The present invention distributes the warping at the corresponding positions of the micro-nozzles of the air knife, and accordingly adjusts the expansion and contraction amount of the air knife at each position synchronously according to the warping amount at each position, so that the warping amount at each part maintains dynamic consistency, thereby keeping the transverse coating thickness of the strip relatively uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0087] Figure 1 It is a flow chart of the adaptive air knife control method for the high-strength steel hot-dip galvanizing process of the present invention;

[0088] Figure 2 Schematic diagram of the air knife device of the present invention.

[0089] In the figure: 1. air knife body; 2. air knife micro nozzle; 3. hydraulic cylinder; 4. micro nozzle. DETAILED DESCRIPTION

[0090] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0091] Those skilled in the art can understand that all or part of the steps in the following embodiments can be completed by instructing the relevant hardware through a program, so the present application can be in the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application can be in the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0092] High-strength steel hot-dip galvanized aluminum sheets are widely used in the back panels of smart home appliances and the covering parts of new energy vehicle products. This type of sheet requires a hard coating, can form a variety of textures, and has a large market demand. At present, the important quality indicators for measuring this type of sheet are the uniformity of the coating thickness on the strip surface, the surface texture, and the deviation of the coating thickness on the upper and lower surfaces of the strip. The production process of hot-dip aluminum-zinc strip steel mainly includes uncoiling, cleaning, drying, continuous annealing (referred to as continuous annealing), hot-dip, post-plating cooling, leveling, roller coating, surface quality inspection, coiling and other process processes. Uncoiling, cleaning, and drying are the pre-treatment processes of the strip to ensure that the surface of the strip is clean and prepare for the continuous hot-dip coating of the strip. The continuous annealing process is to anneal the strip to reduce the work hardening of the strip, improve the plasticity of the strip, and increase the temperature of the strip to ensure that the strip is within the plating temperature range. The hot-dip process includes two steps: hot-dip plating and air-knife zinc scraping. The strip quickly enters the zinc pot filled with zinc liquid to produce a series of alloy reactions, so that the strip surface obtains a stable coating. Then the strip enters the air knife arranged just above the zinc pot for zinc scraping, ensuring that the strip surface obtains a thickness value that meets the process requirements and a relatively uniform coating. Post-plating cooling, leveling, roller coating, etc. are all post-treatment processes for the strip, which enable the strip to cool quickly, correct the plate shape, and add a protective layer to the strip surface. It can be seen that the continuous annealing process is one of the most critical processes that affect the quality of the strip coating in the production of hot-dip aluminum-zinc strip steel. The continuous annealing process mainly ensures that the strip obtains a good plate shape and reasonable temperature conditions for aluminum-zinc plating. If the strip has a plate shape defect after the continuous annealing process, common plate shape defects include transverse warping and complex wave shape, which will inevitably lead to the strip not being able to obtain a relatively uniform coating during the air-knife zinc scraping, and the coating thickness on the upper and lower surfaces of the strip will be seriously out of tolerance, thereby reducing the quality grade of the strip product. In addition, if the strip shape is severely warped, it will cause scratches between the strip surface and the air knife, causing the air knife nozzle to become clogged and the strip to break, which will bring great economic losses to the company.

[0093] However, the air knife devices currently used in the hot-dip production lines of steel enterprises all control the coating thickness by changing process parameters such as jet pressure, air knife angle, and the distance between the air knife nozzle outlet and the strip surface. At the same time, the air knife is an integrated control, and it is impossible to adjust the parameters in sections as the coating thickness at different locations in the transverse direction of the strip is different. Although the upstream process section can suppress some plate shape defects, it cannot be fundamentally eliminated. Therefore, there is still a problem of uneven zinc scraping at the air knife. For this reason, this embodiment proposes an adaptive air knife device and a control method thereof, which can adjust the air knife parameters in real time according to the warping degree of the strip, thereby realizing a segmented control method for the defect of uneven distribution of transverse coating thickness of the strip caused by residual warping plate shape, including air knives symmetrically arranged on the upper and lower surfaces of the strip and retractable in the vertical direction of the strip surface, such as Figure 1 As shown, the control method includes the following steps:

[0094] S1. Acquire first data including equipment parameters, physical parameters of the air knife, specification parameters of the strip steel, and production process parameters of the strip steel; the first data generally includes the total number of air knife micro nozzles , single micro nozzle cross-sectional length , single micro nozzle gap , minimum value of air knife pressure , maximum value , the maximum and minimum values ​​of the volume in the driving hydraulic cylinder of the micro-nozzle of the upper and lower air knives , , the cross-sectional diameter of the piston driving the hydraulic cylinder , air knife performance coefficient The density of nitrogen sprayed by the air knife at room temperature is , density of zinc liquid at 520℃-650℃ , viscosity coefficient of zinc liquid , strip width and strip thickness , coil length , zinc consumption per coil , also includes production process parameters, including the strip running speed , the initial position of each micro nozzle of the upper and lower air knife , the attenuation coefficient of the gas velocity of the air knife nozzle , the attenuation coefficient of the flow of zinc liquid along the strip surface during the zinc scraping process , the set value of the coating thickness of this specification strip steel , initial value of upper and lower air knife pressure adjustment times , safety margin between the strip surface and the air knife nozzle , the maximum deviation between the set value and the actual value of the coating thickness , the maximum value allowed for the variance of the coating thickness distribution .

[0095] S2, according to the first data, calculate the average thickness of the strip steel surface before zinc scraping, the number of effective micro-nozzles of the air knife, the effective length of the air knife jet acting on the strip steel and the center coordinates of each micro-nozzle of the air knife to obtain the second data; the second data is further calculated on the basis of the first data, and a calculation method for each parameter in the second data is provided below, in step S2, specifically including the following steps:

[0096] S21, calculating the average thickness of the steel strip surface before zinc scraping according to the first data; the calculation formula for the average thickness of the steel strip surface before zinc scraping is:

[0097] ;

[0098] In the above formula, It indicates the average thickness of the strip surface before zinc scraping. Indicates the zinc consumption per coil of strip steel, Density of zinc liquid at 520℃-650℃, Indicates the width of the strip. Indicates the length of each coil of strip steel;

[0099] S22, calculating the number of effective micro-nozzles of the air knife and the effective length of the air knife jet acting on the strip according to the first data; the number of effective micro-nozzles of the air knife and the effective length of the air knife jet acting on the strip satisfy the following relationship:

[0100] ;

[0101] In the above formula, is a rounding function that rounds the calculated result to the nearest integer. is the number of effective micro nozzles of the air knife, is the total number of air knife micro nozzles, is the cross-sectional length of a single micro-nozzle, is the effective length of the air knife jet acting on the strip, is the width of the strip;

[0102] S23, calculating the center coordinates of each micro-nozzle of the air knife according to the first data; the expression of the center coordinates of each micro-nozzle of the air knife is:

[0103] ;

[0104] In the above formula, is the number of the air knife micro nozzle, , is the center coordinate of each micro-nozzle of the air knife;

[0105] S24, the average thickness of the strip surface before zinc scraping, the number of effective micro nozzles of the air knife , the effective length of the air knife jet acting on the strip and the center coordinates of each micro-nozzle of the air knife are marked as the second data.

[0106] S3, obtaining the warpage distribution of the corresponding position of each micro-nozzle of the air knife, and adding it to the second data; the expression of the warpage distribution is:

[0107] .

[0108] In the above formula, is the warpage distribution, For the The warpage of the strip in the area affected by each air knife micro nozzle;

[0109] S4, calculating the initial value of the air knife pressure according to the first data and the second data; the air knife pressure directly affects the surface coating thickness, so the surface coating thickness is used to feedback whether the value of the air knife pressure meets the requirements. Specifically, in step S4, the following steps are specifically included:

[0110] S41, setting the initial value of the gas knife pressure optimization variable to 0, the initial value of the pressure optimization incremental adjustment coefficient to 1, setting the gas knife pressure optimization step number, and calculating the gas knife pressure optimization incremental amount; the calculation formula of the gas knife pressure optimization incremental amount is:

[0111] ;

[0112] In the above formula, Optimize the increment for air knife pressure, Optimize the incremental adjustment factor for air knife pressure, Optimize the number of steps for air knife pressure, and are the minimum and maximum values ​​of the air knife pressure, respectively;

[0113] S42, setting an initial value of the vertical distance between the air knife and the strip surface, and calculating an initial value of the air knife pressure according to the first data; the initial value of the air knife pressure satisfies the following relationship:

[0114] ;

[0115] In the above formula, is the initial value of the vertical distance between the air knife and the strip surface, is the initial value of the air knife pressure, is the viscosity coefficient of zinc liquid, is the gap between a single micro nozzle, is the velocity attenuation coefficient of the gas ejected from the air knife nozzle, is the flow attenuation coefficient of zinc liquid along the strip surface during zinc scraping process, is the running speed of the strip, is the air knife performance coefficient, Set the value for the coating thickness of the steel strip of this specification. is the density of nitrogen sprayed by the air knife at room temperature;

[0116] S43, obtaining the coating thickness distribution at each location on the strip surface corresponding to each micro-nozzle position of the air knife, and calculating the average coating thickness on the strip surface in the area according to the first data; the calculation formula for the average coating thickness on the strip surface is:

[0117] ;

[0118] In the above formula, is the average thickness of the coating on the strip surface at each location on the strip surface corresponding to each micro-nozzle position of the air knife, For the The thickness of the coating on the strip steel surface in the area affected by the air knife micro nozzle is is the number of effective micro nozzles for the air knife;

[0119] S44, judging whether the average thickness of the coating on the surface of the steel strip is within the thickness range of the coating on the steel strip of this specification; the thickness range of the coating on the steel strip of this specification is , is the set value of the coating thickness of the steel strip of this specification. The maximum deviation between the set value and the actual value of the coating thickness is ;

[0120] If yes, the air knife pressure is set to the initial value of the air knife pressure, and the process goes to step S49;

[0121] If not, proceed to step S45;

[0122] S45, setting the air knife pressure optimization index to 0, adding 1 to the air knife pressure optimization variable, and determining whether the air knife pressure optimization variable is less than or equal to the air knife pressure optimization step number;

[0123] If yes, proceed to step S47;

[0124] If not, go to S46;

[0125] S46, accumulating the number of times the air knife pressure is adjusted, and calculating the air knife pressure optimization incremental adjustment coefficient, and then entering step S41; the calculation formula of the air knife pressure optimization incremental adjustment coefficient is:

[0126] ;

[0127] In the above formula, Optimize the incremental adjustment factor for air knife pressure, is the number of times the air knife pressure is adjusted;

[0128] S47, calculating the optimal value of the air knife pressure; the calculation formula of the optimal value of the air knife pressure is:

[0129] ;

[0130] In the above formula, Optimize the value for the air knife pressure; is the air knife pressure optimization index, Optimize variables for air knife pressure;

[0131] S48, and determining whether the optimized value of the air knife pressure is between the maximum value and the minimum value of the air knife pressure;

[0132] If yes, proceed to step S49;

[0133] If not, proceed to step S42;

[0134] S49, setting the actual air knife pressure to the current air knife pressure optimization value, and then entering step S5.

[0135] S5. According to the set air knife pressure, the distribution of the coating thickness on the upper and lower surfaces of the strip is re-obtained, and the distribution of the strip surface in the influence area of ​​each micro-nozzle of the air knife and the initial value of the optimization value of the expansion and contraction amount of the air knife micro-nozzle are determined; since the pressure of each air knife is the same, it is necessary to re-obtain the distribution of the coating thickness on the upper and lower surfaces of the strip, and adjust various parameters from other angles again to ensure the coating thickness on the upper and lower surfaces of the strip. In step S5, the following steps are specifically included:

[0136] S51, re-obtain the coating thickness distribution on the upper and lower surfaces of the strip according to the set air knife pressure, and calculate the variance of the coating thickness distribution on the upper and lower surfaces of the strip at this time ; The variance calculation formula of the coating thickness distribution on the upper and lower surfaces of the strip is as follows:

[0137] ;

[0138] In the above formula, is the variance of the coating thickness distribution on the upper and lower surfaces of the strip, For the The coating thickness on the upper and lower surfaces of the strip in the affected area of ​​the upper and lower air knife micro nozzles;

[0139] S52, determining whether the thickness distribution variance of the coating on the upper surface of the strip is less than the rated variance;

[0140] If so, the optimal value of the air knife micro nozzle extension amount is set to the air knife micro nozzle extension amount, and then the process goes to step S6; that is, the following relationship is satisfied:

[0141] ;

[0142] In the above formula, For the The optimal value of the air knife micro nozzle extension and contraction amount, For the The initial value of the extension and contraction of the air knife micro nozzle;

[0143] If not, proceed to step S6;

[0144] S6, according to the distribution of the strip surface in the influence area of ​​each micro-nozzle of the air knife and the first data, the optimization value of the expansion and contraction amount of the air knife micro-nozzle is adjusted; in step S5, after the optimization value of the expansion and contraction amount of the air knife micro-nozzle is set to the initial value, it is necessary to further gradually adjust the optimization value of the expansion and contraction amount of the air knife micro-nozzle so that the thickness of the coating on the surface of the strip meets the process requirements, in step S6, specifically including the following steps:

[0145] S61, sequentially judging whether the coating thickness on the surface of the steel strip corresponding to the air knife at any position is within the coating thickness range of the steel strip of this specification;

[0146] If both are true, proceed to step S7;

[0147] If not, proceed to step S62;

[0148] S62, setting the number of optimization steps for the hydraulic cylinder volume of the air knife micro nozzle, setting the initial value of the hydraulic cylinder volume optimization variable to 1, and calculating the hydraulic cylinder volume increment of the corresponding air knife micro nozzle; the calculation formula for the hydraulic cylinder volume increment is:

[0149] ;

[0150] In the above formula, is the volume increment of the hydraulic cylinder corresponding to the air knife micro nozzle, and are the maximum and minimum values ​​of the volume in the hydraulic cylinder corresponding to the micro nozzle of the air knife, Optimize the number of steps for the hydraulic cylinder volume of the air knife micro nozzle;

[0151] S63, calculating the expansion and contraction amount of the air knife micro nozzle after the hydraulic cylinder volume is optimized; the expansion and contraction amount of the air knife micro nozzle after the hydraulic cylinder volume is optimized is:

[0152] ;

[0153] In the above formula, The extension and contraction of the air knife micro nozzle after the hydraulic cylinder volume is optimized. The expansion and contraction of the air knife micro nozzle before the hydraulic cylinder volume is optimized. is the hydraulic cylinder volume optimization index. When the strip steel surface coating thickness corresponding to the air knife is greater than the maximum value of the strip steel coating thickness range, , when the strip steel surface coating thickness corresponding to the air knife is less than the minimum value of the strip steel coating thickness range, , is the cross-sectional diameter of the piston driving the hydraulic cylinder, Optimize variables for hydraulic cylinder volume.

[0154] S64, calculating a first spacing between the strip surface and the air knife nozzle according to an initial value of a vertical distance between the air knife and the strip surface, a telescopic amount of the air knife micro-nozzle after the volume of the hydraulic cylinder is optimized, and a strip warping amount in an area affected by the j-th air knife micro-nozzle, and determining whether the first spacing is greater than a safety margin between the strip surface and the air knife nozzle;

[0155] The calculation formula for the first spacing is: ;

[0156] If yes, the optimized value of the air knife micro nozzle extension amount is made equal to the corresponding air knife micro nozzle extension amount, and then the process goes to step S61;

[0157] If not, proceed to step S65;

[0158] S65, determining whether the hydraulic cylinder volume optimization variable is less than or equal to the hydraulic cylinder volume optimization step number;

[0159] If yes, then the value of the hydraulic cylinder volume optimization variable is increased by one and the process proceeds to step S63;

[0160] If not, go to step S62.

[0161] S7, outputting the optimized values ​​of air knife parameters including the optimized value of the air knife micro nozzle extension and contraction amount and the air knife pressure.

[0162] The expression of the optimized value of air knife parameters is: , , that is, the optimized value of the extension and contraction amount of each air knife micro nozzle and the optimized value of the air knife pressure.

[0163] In actual production, the adjustment of a single air knife is meaningless. Therefore, in the above calculation process, each step corresponds to the two air knives located on the upper and lower surfaces of the strip. Therefore, after the upper and lower air knives are calculated in each step, they proceed to the next step.

[0164] The present invention calculates the center coordinates of each air knife micro-nozzle through the first data, thereby obtaining the warping distribution at the corresponding position, and then calculates the initial value of the air knife pressure according to the second data, and adjusts the actual value of the air knife pressure by comparing the average thickness of the coating on the surface of the strip with the required coating thickness conditions. If the variance of the coating thickness on the surface of the strip does not meet the required coating distribution conditions, the coating thickness at each position is further used to use the hydraulic cylinder configured by the micro-nozzle to adjust the optimal value of the extension and contraction of each air knife micro-nozzle, thereby realizing individual adjustment of each air knife, and can adjust the air knife parameters in real time according to the degree of warping of the plate shape of the strip, thereby solving the defect of uneven distribution of the lateral coating thickness of the strip due to residual warping.

[0165] The present embodiment also provides an adaptive air knife control system for a high-strength steel hot-dip galvanizing process, comprising a processor and a memory, wherein the memory is used to store a computer program, and when the computer program is executed by the processor, an adaptive air knife control method for a high-strength steel hot-dip galvanizing process is implemented.

[0166] The present invention also provides an air knife device, comprising a plurality of air knife bodies 1 symmetrically arranged on both sides of the upper and lower surfaces of the strip, an air knife micro-nozzle 2 is arranged on the side of the air knife body 1 facing the strip, and also comprises a hydraulic cylinder 3 for controlling the extension and retraction amount of the air knife micro-nozzle, and a micro-nozzle 4 for air supply is also arranged on the air knife micro-nozzle 2.

[0167] The above implementation methods have been described in detail. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. An adaptive air knife control method for high-strength steel hot-dip galvanizing process, comprising air knives symmetrically arranged on the upper and lower surfaces of the strip and capable of being controlled to extend and retract in the vertical direction of the strip surface by a hydraulic cylinder, characterized in that: The control method comprises the following steps: S1. Acquire first data including equipment parameters, physical parameters of the air knife, specification parameters of the strip steel, and production process parameters of the strip steel; S2, calculating the average immersion plating thickness of the steel strip before zinc scraping, the number of effective micro-nozzles of the air knife, the effective length of the air knife jet acting on the steel strip, and the center coordinates of each micro-nozzle of the air knife according to the first data, so as to obtain the second data; In step S2, the following steps are specifically included: S21, calculating the average thickness of the steel strip surface before zinc scraping according to the first data; the calculation formula for the average thickness of the steel strip surface before zinc scraping is: ； In the above formula, It indicates the average thickness of the strip surface before zinc scraping. Indicates the zinc consumption per coil of strip steel, Density of zinc liquid at 520℃-650℃, Indicates the width of the strip. Indicates the length of each coil of strip steel; S22, calculating the number of effective micro-nozzles of the air knife and the effective length of the air knife jet acting on the strip according to the first data; the number of effective micro-nozzles of the air knife and the effective length of the air knife jet acting on the strip satisfy the following relationship: ； In the above formula, is a rounding function that rounds the calculated result to the nearest integer. is the number of effective micro nozzles of the air knife, is the total number of air knife micro nozzles, is the cross-sectional length of a single micro-nozzle, is the effective length of the air knife jet acting on the strip, is the width of the strip; S23, calculating the center coordinates of each micro-nozzle of the air knife according to the first data; the expression of the center coordinates of each micro-nozzle of the air knife is: ； In the above formula, is the number of the air knife micro nozzle, , is the center coordinate of each micro-nozzle of the air knife; S24, the average thickness of the strip surface before zinc scraping, the number of effective micro nozzles of the air knife , the effective length of the air knife jet acting on the strip and the center coordinates of each micro-nozzle of the air knife, marked as the second data; S3, obtaining the warpage distribution of each micro-nozzle of the air knife corresponding to the position, and adding it to the second data; S4, calculating an initial value of the air knife pressure according to the first data and the second data; In step S4, the following steps are specifically included: S41, setting the initial value of the gas knife pressure optimization variable to 0, the initial value of the pressure optimization incremental adjustment coefficient to 1, setting the gas knife pressure optimization step number, and calculating the gas knife pressure optimization incremental amount; the calculation formula of the gas knife pressure optimization incremental amount is: ； In the above formula, Optimize the increment for air knife pressure, Optimize the incremental adjustment factor for air knife pressure, Optimize the number of steps for air knife pressure, and are the minimum and maximum values ​​of the air knife pressure, respectively; S42, setting an initial value of the vertical distance between the air knife and the strip surface, and calculating an initial value of the air knife pressure according to the first data; the initial value of the air knife pressure satisfies the following relationship: ； In the above formula, is the initial value of the vertical distance between the air knife and the strip surface, is the initial value of the air knife pressure, is the viscosity coefficient of zinc liquid, is the gap between a single micro nozzle, is the velocity attenuation coefficient of the gas ejected from the air knife nozzle, is the flow attenuation coefficient of zinc liquid along the strip surface during zinc scraping process, is the running speed of the strip, is the air knife performance coefficient, Set the value for the coating thickness of the steel strip of this specification. is the density of nitrogen sprayed by the air knife at room temperature; S43, obtaining the coating thickness distribution at each location on the strip surface corresponding to each micro-nozzle position of the air knife, and calculating the average coating thickness on the strip surface in the area according to the first data; the calculation formula for the average coating thickness on the strip surface is: ； In the above formula, is the average thickness of the coating on the strip surface at each location on the strip surface corresponding to each micro-nozzle position of the air knife, For the The thickness of the coating on the strip steel surface in the area affected by the air knife micro nozzle is is the number of effective micro nozzles for the air knife; S44, judging whether the average thickness of the coating on the surface of the steel strip is within the thickness range of the coating on the steel strip of this specification; If yes, the air knife pressure is set to the initial value of the air knife pressure and the process goes to step S49; If not, proceed to step S45; S45, setting the air knife pressure optimization index to 0, adding 1 to the air knife pressure optimization variable, and determining whether the air knife pressure optimization variable is less than or equal to the air knife pressure optimization step number; If yes, proceed to step S47; If not, go to S46; S46, accumulating the number of times the air knife pressure is adjusted, and calculating the air knife pressure optimization incremental adjustment coefficient, and then entering step S41; the calculation formula of the air knife pressure optimization incremental adjustment coefficient is: ； In the above formula, Optimize the incremental adjustment factor for air knife pressure, is the number of times the air knife pressure is adjusted; S47, calculating the optimal value of the air knife pressure; the calculation formula of the optimal value of the air knife pressure is: ； In the above formula, Optimize the value for the air knife pressure; is the air knife pressure optimization index, Optimize variables for air knife pressure; S48, and determining whether the optimized value of the air knife pressure is between the maximum value and the minimum value of the air knife pressure; If yes, proceed to step S49; If not, proceed to step S42; S49, setting the actual air knife pressure to the current air knife pressure optimization value, and then proceeding to step S5; S5. Re-obtain the distribution of the coating thickness on the upper and lower surfaces of the strip according to the set air knife pressure and determine the distribution of the strip surface in the influence area of ​​each micro-nozzle of the air knife and the initial value of the optimization value of the expansion and contraction amount of the air knife micro-nozzle; S6, adjusting the expansion and contraction amount of the air knife micro-nozzle according to the distribution of the strip surface in the influence area of ​​each air knife micro-nozzle and the first data to obtain an optimized value of the expansion and contraction amount of the air knife micro-nozzle; S7, outputting the optimized values ​​of air knife parameters including the optimized value of the air knife micro nozzle extension and contraction amount and the air knife pressure.

2. The control method according to claim 1, characterized in that: In step S5, the following steps are specifically included: S51, re-obtain the coating thickness distribution on the upper and lower surfaces of the strip according to the set air knife pressure, and calculate the variance of the coating thickness distribution on the upper and lower surfaces of the strip at this time ; The variance calculation formula of the coating thickness distribution on the upper and lower surfaces of the strip is as follows: ； In the above formula, is the variance of the coating thickness distribution on the upper and lower surfaces of the strip, For the The coating thickness on the upper and lower surfaces of the strip in the affected area of ​​the upper and lower air knife micro nozzles; S52, determining whether the thickness distribution variance of the coating on the upper surface of the strip is less than the rated variance; If so, the optimal value of the air knife micro nozzle extension amount is set to the air knife micro nozzle extension amount, and then the process goes to step S6; that is, the following relationship is satisfied: ； In the above formula, For the The optimal value of the air knife micro nozzle extension amount, For the The initial value of the extension and contraction of the air knife micro nozzle; If not, go to step S6.

3. The control method according to claim 1, characterized in that: In step S6, the following steps are specifically included: S61, sequentially judging whether the coating thickness on the surface of the steel strip corresponding to the air knife at any position is within the coating thickness range of the steel strip of this specification; If both are true, proceed to step S7; If not, proceed to step S62; S62, setting the number of optimization steps for the hydraulic cylinder volume of the air knife micro nozzle, setting the initial value of the hydraulic cylinder volume optimization variable to 1, and calculating the hydraulic cylinder volume increment of the corresponding air knife micro nozzle; the calculation formula for the hydraulic cylinder volume increment is: ； In the above formula, is the volume increment of the hydraulic cylinder corresponding to the air knife micro nozzle, and are the maximum and minimum values ​​of the volume in the hydraulic cylinder corresponding to the micro nozzle of the air knife, Optimize the number of steps for the hydraulic cylinder volume of the air knife micro nozzle; S63, calculating the expansion and contraction amount of the air knife micro nozzle after the hydraulic cylinder volume is optimized; S64, calculating a first spacing between the strip surface and the air knife nozzle according to an initial value of a vertical distance between the air knife and the strip surface, a telescopic amount of the air knife micro-nozzle after the volume of the hydraulic cylinder is optimized, and a strip warping amount in an area affected by the j-th air knife micro-nozzle, and determining whether the first spacing is greater than a safety margin between the strip surface and the air knife nozzle; If yes, the optimized value of the air knife micro nozzle extension amount is made equal to the corresponding air knife micro nozzle extension amount, and then the process goes to step S61; If not, proceed to step S65; S65, determining whether the hydraulic cylinder volume optimization variable is less than or equal to the hydraulic cylinder volume optimization step number; If yes, then the value of the hydraulic cylinder volume optimization variable is increased by one and the process proceeds to step S63; If not, go to step S62.

4. The control method according to claim 3, characterized in that: In step S64, the calculation formula of the first spacing is: ； In the above formula, represents the first spacing, Indicates the initial value of the vertical distance between the air knife and the strip surface. Indicates the expansion and contraction of the air knife micro nozzle after the hydraulic cylinder volume is optimized. Represents the amount of strip warping in the area affected by the j-th air knife micro nozzle.

5. The control method according to claim 3, characterized in that: In step S63, the extension and contraction amount of the air knife micro nozzle after the hydraulic cylinder volume is optimized is: ； In the above formula, The extension and contraction of the air knife micro nozzle after the hydraulic cylinder volume is optimized. The expansion and contraction of the air knife micro nozzle before the hydraulic cylinder volume is optimized. is the hydraulic cylinder volume optimization index. When the strip steel surface coating thickness corresponding to the air knife is greater than the maximum value of the strip steel coating thickness range, , when the strip steel surface coating thickness corresponding to the air knife is less than the minimum value of the strip steel coating thickness range, , is the cross-sectional diameter of the piston driving the hydraulic cylinder, Optimize variables for hydraulic cylinder volume.

6. A system for implementing the control method according to any one of claims 1 to 5, characterized in that: It comprises a processor and a memory, wherein the memory is used to store a computer program, and when the computer program is executed by the processor, the adaptive air knife control method for the high-strength steel hot-dip galvanizing process as claimed in any one of claims 1 to 5 is implemented.

7. An air knife device controlled by the control method according to any one of claims 1 to 5, characterized in that: The invention comprises a plurality of air knife bodies (1) symmetrically arranged on both sides of the upper and lower surfaces of the steel strip, an air knife micro nozzle (2) being arranged on the side of the air knife body (1) facing the steel strip, and a hydraulic cylinder (3) for controlling the extension and retraction amount of the air knife micro nozzle, and a micro nozzle (4) for supplying air is also arranged on the air knife micro nozzle (2).

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