Method and system for calculating minimum thickness of strip steel passing through ultrafast cooling area safely

Abstract

The invention provides a method and system for calculating the minimum thickness of strip steel safely passing through an ultra-fast cooling area, and relates to the technical field of hot rolling. In order to solve the problem that the head of strip steel flies up due to the fact that the cooling water impact force of a lower collecting pipe of hot continuous rolling strip steel after-rolling cooling ultrafast cooling equipment is larger than the jet flow impact force of an upper collecting pipe, real-time stress analysis is carried out on the stress state of the head of the strip steel after entering an ultrafast cooling area; according to the critical stress state of the strip steel, the minimum thickness that the head of the strip steel can safely pass through the position under each collecting pipe is obtained, and therefore the minimum thickness that the strip steel can safely pass through the ultra-fast cooling area under the specific working condition is obtained. According to the invention, the strip steel can safely pass through an ultrafast cooling area, the problem of head warping caused by ultrafast cooling jet impact in production is effectively solved, and the production stability is ensured.

Description

Technical Field

[0001] The present invention relates to the field of hot rolling technology, and in particular to a method and system for calculating the minimum thickness of a steel strip for safely passing through an ultra-fast cooling zone. Background Art

[0002] As market demands for hot-rolled strip quality continue to rise, and to achieve higher-strength hot-rolled products, hot-rolling lines are increasingly equipped with ultra-rapid cooling equipment for post-rolling cooling. To achieve higher cooling efficiency and improved cooling uniformity between the upper and lower surfaces, the upper header of the ultra-rapid cooling system is installed closer to the conveyor rollers, and the flow rate of the lower header is greater than that of the upper header. While this yields higher profits, it also presents a serious problem. Due to the higher flow rate of the lower header, the impact force of the jet on the strip is generally greater than that exerted by the upper header. This can easily cause the strip head to warp when producing thinner strip. In severe cases, the strip head can directly impact the upper header, resulting in scrap. This can cause severe damage to the cooling equipment and severely impact production stability. Therefore, determining the minimum thickness that can safely pass through the ultra-rapid cooling zone under specific operating conditions is crucial for the stability of hot-rolling production.

[0003] In order to solve the problem of warping of strip steel in the ultra-fast cooling area and improve the stability of the hot rolling production process, domestic scholars have successively proposed various measures and achieved certain results. The Chinese patent "CN 202606526 U Ultra-fast cooling system protection device" proposes to install an ultra-fast cooling protection device in front of the ultra-fast cooling manifold, and the protective beam above the protection device can rotate freely around its axis, avoiding the problem of steel piling caused by the warping of the strip steel hitting the protection device. The Chinese patent "CN 209349281 U A device for detecting warping of steel plates before ultra-fast cooling" proposes a device for detecting warping of steel plates before ultra-fast cooling, which can effectively detect the degree of warping of warped steel plates and control whether the ultra-fast cooling frame is quickly lifted according to the detection results to prevent the warped steel plates from entering the ultra-fast cooling frame and damaging the ultra-fast cooling equipment. Chinese patent "CN 106391727 A A method for controlling the uncooling of the head of a hot-rolled strip in the ultra-fast cooling zone" proposes setting a fixed length as the uncooling section when the head of the strip enters the ultra-fast cooling zone. After the uncooling section passes through the ultra-fast cooling zone, the ultra-fast cooling headers are opened in sequence. Chinese patent "CN 113020293 B A protective device for ultra-fast cooling equipment" avoids collisions with the ultra-fast cooling equipment due to poor plate shapes such as wave-shaped and warped shapes by installing a rectangular hollow protective frame under the ultra-fast cooling upper header. Chinese patent "CN 103551388 B A protective device for ultra-fast cooling equipment" also proposes a protective device for ultra-fast cooling equipment. The difference from the aforementioned protective device is that this device includes a guide plate, a plate shape defect detection device, an air purge device, an intercepting water purge device, and first and second side water spray purge devices.

[0004] The aforementioned studies have improved the stability of the hot rolling process to a certain extent, but they generally involve installing protective devices before ultra-rapid cooling. While these devices vary, they all serve to detect steel plates that have not yet entered the ultra-rapid cooling zone or to prevent the warped strip heads from entering the ultra-rapid cooling zone and damaging the ultra-rapid cooling equipment. However, no research has yet reported on the issue of strip warping in the ultra-rapid cooling zone, caused by the jet impact force from the lower ultra-rapid cooling header being greater than that from the upper header. Summary of the Invention

[0005] In response to the shortcomings of the existing technology, the present invention proposes a method and system for calculating the minimum thickness of the strip for safe passage through the ultra-fast cooling zone. By performing real-time fluid dynamics force analysis on the strip in the ultra-fast cooling zone, the minimum thickness that can safely pass through the ultra-fast cooling zone is obtained based on the force applied to the strip when it is in a critical state, thereby improving production stability and yield rate.

[0006] A first aspect of the present invention provides a method for calculating the minimum thickness of a steel strip for safely passing through an ultra-rapid cooling zone, comprising the following steps:

[0007] Collecting cooling equipment parameters and strip parameters; the cooling equipment parameters include the maximum flow rate of a single header, the number of nozzles in a single header, the inner diameter of the nozzle, the distance from the nozzle to the strip surface, the nozzle width spacing, the nozzle rolling direction spacing, the running speed of the strip, and the maximum number of header openings; the strip parameters include the width and density of the strip;

[0008] Calculating the outlet area and outlet flow rate of a single nozzle on a single header in the cooling device according to the cooling device parameters; the nozzle includes an upper nozzle and a lower nozzle;

[0009] Calculate the dynamic pressure and area of a single jet reaching the strip surface based on the outlet flow rate of a single nozzle on a single header in the cooling equipment, the outlet area of a single nozzle on a single header in the cooling equipment, and the cooling equipment parameters;

[0010] When the strip head enters the ultra-fast cooling zone, the position of the strip head at any time and the number of jets acting on the upper and lower surfaces of the strip are determined according to the cooling equipment parameters and strip parameters;

[0011] The total impact force of the cooling water on the strip surface is calculated based on the dynamic pressure of a single jet on the strip surface, the number of jets acting on the upper and lower surfaces of the strip, and the area of the strip surface reached by a single jet; the total impact force of the cooling water on the strip surface includes the total impact force of the cooling water on the lower surface of the strip and the total impact force of the cooling water on the upper surface of the strip;

[0012] The safe thickness of the strip for passing through each header is calculated based on the total impact force of the cooling water reaching the strip surface, the strip parameters, and the position of the strip head at any time.

[0013] The minimum thickness required for the strip to pass through each header is used as the minimum thickness required for the strip to pass through the ultra-fast cooling zone.

[0014] Furthermore, the calculation method of the outlet area of the single nozzle is:

[0015]

[0016] Where s is the outlet area of a single nozzle, m 2 ; d is the inner diameter of the nozzle;

[0017] The calculation method for the outlet flow rate of a single nozzle on a single header in the cooling device is:

[0018]

[0019] Where, v n V is the outlet flow rate of a single nozzle on a single header in the cooling equipment; max is the maximum flow rate of a single header; n is the number of nozzles in a single header.

[0020] Furthermore, the dynamic pressure and area of a single jet reaching the strip surface are calculated based on the outlet flow rate of a single nozzle on a single header in the cooling device, the outlet area of a single nozzle on a single header in the cooling device, and the cooling device parameters, specifically:

[0021] A1: Calculate the velocity of a single jet reaching the strip surface based on the outlet velocity of a single nozzle on a single header in the cooling equipment and the cooling equipment parameters;

[0022] The method for calculating the flow velocity of a single jet reaching the strip surface is:

[0023]

[0024] Where, v s is the velocity of a single jet reaching the strip surface; g is the acceleration due to gravity; h is the distance from the nozzle to the strip surface;

[0025] A2: Based on the outlet flow rate of a single nozzle on a single header in the cooling equipment, the outlet area of a single nozzle on a single header in the cooling equipment, and the flow rate of a single jet reaching the strip surface, and according to the principle of constant flow, calculate the area of the strip surface reached by a single jet;

[0026] The method for calculating the area of the strip surface reached by a single jet is:

[0027]

[0028] Where s sis the area of the strip surface reached by a single jet;

[0029] A3: Based on the velocity of a single jet reaching the strip surface and the conservation of mechanical energy, the dynamic pressure of a single jet reaching the strip surface is calculated;

[0030] The method for calculating the dynamic pressure of a single jet reaching the strip surface is:

[0031]

[0032] Where P is the dynamic pressure when a single jet reaches the strip surface; ρ w is the density of cooling water.

[0033] Furthermore, the position of the strip head at any moment is:

[0034] l t =vt (6)

[0035] Where, l t is the distance from the strip head to the first header at time t; v is the strip running speed; t is the running time of the strip head in the ultra-fast cooling zone;

[0036] The calculation method for the number of jets acting on the upper and lower surfaces of the strip is:

[0037]

[0038] Where n t is the number of jets acting on the upper and lower surfaces of the strip at time t; N t is the number of headers opened at time t; w is the width of the strip; l p is the nozzle width distance.

[0039] Furthermore, the total impact force of the cooling water reaching the strip surface is calculated as follows:

[0040] F p =PN t s s (8)

[0041] Where, F p It is the total impact force of cooling water reaching the strip surface.

[0042] Furthermore, the calculation method of the safe thickness of the strip steel for safely passing through each header is as follows:

[0043]

[0044] Among them, h s is the safety thickness, F pb F is the total impact force of cooling water reaching the lower surface of the strip; ptIt is the total impact force of cooling water reaching the upper surface of the strip.

[0045] A second aspect of the present invention provides a system for calculating the minimum thickness of a steel strip for safely passing through an ultra-rapid cooling zone, which is used to implement the method for calculating the minimum thickness of a steel strip for safely passing through an ultra-rapid cooling zone, comprising:

[0046] Parameter acquisition module, used to collect cooling equipment parameters and strip parameters;

[0047] An outlet area and outlet flow rate calculation module, used to calculate the outlet area of a single nozzle on a single header in the cooling device and the outlet flow rate of a single nozzle on a single header in the cooling device according to the cooling device parameters;

[0048] The dynamic pressure and area calculation module is used to calculate the dynamic pressure and area of a single jet reaching the strip surface based on the outlet flow rate of a single nozzle on a single header in the cooling equipment, the outlet area of a single nozzle on a single header in the cooling equipment, and the cooling equipment parameters;

[0049] The module for determining the position of the strip head and the number of jets is used to determine the position of the strip head and the number of jets acting on the upper and lower surfaces of the strip at any time based on the parameters of the cooling equipment and the strip parameters;

[0050] The total impact force calculation module of the strip surface is used to calculate the total impact force of the cooling water on the strip surface based on the dynamic pressure of a single jet reaching the strip surface, the number of jets acting on the upper and lower surfaces of the strip, and the area of the strip surface reached by a single jet;

[0051] The safe thickness calculation module is used to calculate the safe thickness that can safely pass through each header based on the total impact force of cooling water reaching the strip surface, strip parameters and the position of the strip head at any time. The minimum value of the safe thickness of each header is determined as the minimum thickness for passing through the ultra-fast cooling area.

[0052] The third aspect of the present invention provides an electronic device, comprising: a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor and the memory communicate through the bus, and when the machine-readable instructions are executed by the processor, the method for calculating the minimum thickness of a strip for safely passing through an ultra-fast cooling zone is executed.

[0053] A fourth aspect of the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, executes the method for calculating the minimum thickness of a steel strip for safely passing through an ultra-fast cooling zone.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] To address the problem of strip head warping caused by the impact force of cooling water in the lower header of ultra-rapid cooling equipment after hot strip rolling being greater than the impact force of the jet from the upper header, the present invention provides a method for calculating the minimum thickness of the strip required to safely pass through the ultra-rapid cooling zone. By performing real-time stress analysis on the stress state of the strip head after entering the ultra-rapid cooling zone, the minimum thickness required for the strip head to safely pass directly under each header is determined based on the critical stress state of the strip, thereby determining the minimum thickness required for the strip to safely pass through the ultra-rapid cooling zone under specific operating conditions. This method ensures the safe passage of the strip through the ultra-rapid cooling zone, effectively resolving the problem of strip head warping caused by the impact of ultra-rapid cooling jets during production and ensuring production stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is an illustration of the state of a steel strip at a certain moment in the ultra-fast cooling zone according to an embodiment of the present invention;

[0057] Figure 2 This is an illustration of the distribution of upper and lower header nozzles in an embodiment of the present invention;

[0058] Figure 3 This is a force analysis diagram of a steel strip in a critical state in an ultra-fast cooling region according to an embodiment of the present invention;

[0059] Figure 4 This is a diagram illustrating the safe thickness of the strip head passing through each header in an embodiment of the present invention. DETAILED DESCRIPTION

[0060] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0061] To verify the rationality of the calculation process of the present invention, the implementation process of the present invention is further described in combination with the distribution of post-rolling cooling equipment and the specific cooling process of a hot rolling production line. This embodiment provides a method for calculating the minimum thickness of a steel strip that can safely pass through the ultra-rapid cooling zone, including the following steps:

[0062] like Figure 1 The figure shows the state of the strip at a certain moment when it passes through the ultra-fast cooling zone;

[0063] Step 1: Collect cooling equipment parameters and strip parameters;

[0064] The cooling equipment parameters include the maximum flow rate of a single manifold, the number of nozzles in a single manifold, the inner diameter of the nozzle, the distance from the nozzle to the strip surface, the nozzle width spacing, the nozzle rolling direction spacing, the running speed of the strip and the maximum number of manifold openings. The strip parameters include the width and density of the strip.

[0065] The cooling equipment and strip steel parameters used in this embodiment are shown in Table 1:

[0066] Table 1 Cooling equipment and strip parameters

[0067]

[0068] Step 2: Calculate the outlet area and outlet flow rate of a single nozzle on a single header in the cooling device based on the cooling device parameters; the nozzle includes an upper nozzle and a lower nozzle;

[0069] Step 2.1: Calculate the outlet area of a single nozzle on a single header in the cooling equipment;

[0070] The calculation method of the outlet area of a single nozzle is:

[0071]

[0072] Where s is the outlet area of a single nozzle, m 2 ; d is the inner diameter of the nozzle. In this embodiment, the values of the upper and lower nozzles are 0.0045m and 0.004m respectively;

[0073] Step 2.2: Calculate the outlet flow rate of a single nozzle on a single header in the cooling device based on the outlet area of a single nozzle on a single header in the cooling device;

[0074] The calculation method for the outlet flow rate of a single nozzle on a single header in the cooling device is:

[0075]

[0076] Where, v n V is the outlet flow rate of a single nozzle on a single header in the cooling equipment, m / s; max The maximum flow rate of a single header. In this embodiment, the maximum flow rates of the upper and lower headers are 80 and 100 m 3 / h; n is the number of nozzles in a single header, and the number of nozzles in the upper and lower headers is 159;

[0077] Step 3: Calculate the dynamic pressure and area of a single jet reaching the strip surface based on the outlet flow rate of a single nozzle on a single header in the cooling equipment, the outlet area of a single nozzle on a single header in the cooling equipment, and the cooling equipment parameters;

[0078] Step 3.1: Calculate the velocity of a single jet reaching the strip surface based on the outlet velocity of a single nozzle on a single header in the cooling equipment and the cooling equipment parameters;

[0079] The method for calculating the flow velocity of a single jet reaching the strip surface is:

[0080]

[0081] Where, v s is the velocity of a single jet reaching the strip surface, m / s; g is the acceleration due to gravity, m / s 2 ; h is the distance from the nozzle to the strip surface. The distances from the nozzle to the strip surface on the upper and lower single headers are 0.5 and -0.14m respectively.

[0082] Step 3.2: Based on the outlet flow rate of a single nozzle on a single header in the cooling equipment, the outlet area of a single nozzle on a single header in the cooling equipment, and the flow rate of a single jet reaching the strip surface, and based on the principle of constant flow rate, that is, the outlet flow rate of a single nozzle remains the same as when it reaches the strip surface, calculate the area of the strip surface reached by a single jet;

[0083] The method for calculating the area of the strip surface reached by a single jet is:

[0084]

[0085] Where s s is the area of the strip surface reached by a single jet, m 2 ;

[0086] Step 3.3: Based on the velocity of the single jet reaching the strip surface and the conservation of mechanical energy, calculate the dynamic pressure of the single jet reaching the strip surface;

[0087] The method for calculating the dynamic pressure of a single jet reaching the strip surface is:

[0088]

[0089] Where P is the dynamic pressure when a single jet reaches the strip surface, Pa; ρ w is the density of cooling water, which is 998.2 kg / m 3 ;

[0090] In this embodiment, the parameters in Table 1 are used. According to formula (1) to formula (5), the calculated values of each step are shown in Table 2:

[0091] Table 2 Calculation process parameters

[0092]

[0093]

[0094] Step 4: When the strip head enters the ultra-fast cooling zone, the position of the strip head at any time and the number of jets acting on the upper and lower surfaces of the strip are determined according to the cooling equipment parameters and strip parameters;

[0095] Step 4.1: Determine the position of the strip head in the ultra-fast cooling zone;

[0096] The position of the strip head in the ultra-fast cooling zone can be calculated by the following formula:

[0097] l t =vt (6)

[0098] Where, l t is the distance from the strip head to the first header at time t, m; v is the strip running speed, m / s; t is the running time of the strip head in the ultra-fast cooling zone, with the time when the strip head is directly below the first header being defined as time 0;

[0099] For illustration, in this embodiment, the state when the strip head is just below the second header is analyzed. When the strip head is just below the second header, the distance is exactly equal to the distance between the two nozzles in the rolling direction, which is 0.38m.

[0100] Step 4.2: Calculate the number of jets acting on the upper and lower surfaces of the strip based on the strip width and the nozzle width spacing. The upper and lower header nozzle distribution is as follows: Figure 2 As shown;

[0101] The calculation method for the number of jets acting on the upper and lower surfaces of the strip is:

[0102]

[0103] Where n t is the number of jets acting on the upper and lower surfaces of the strip at time t; N t is the number of headers opened at time t, which is 2 in this embodiment; w is the width of the strip, which is 1.2 m in this embodiment; l p The width distance of the nozzles is 0.042m in this embodiment;

[0104] Step 5: Calculate the total impact force of the cooling water on the strip surface based on the dynamic pressure of the single jet on the strip surface, the number of jets acting on the upper and lower surfaces of the strip, and the area of the strip surface reached by the single jet. The total impact force of the cooling water on the strip surface includes the total impact force of the cooling water on the lower surface of the strip and the total impact force of the cooling water on the upper surface of the strip.

[0105] The calculation method of the total impact force of the cooling water reaching the strip surface is:

[0106] E p =Pn t s s (8)

[0107] Where, F p is the total impact force of cooling water reaching the strip surface, N;

[0108] In this embodiment, the strip head just passes under the second header. According to formula (8), the total impact force of the cooling water on the upper and lower surfaces of the strip is:

[0109] F pt =43438.366×171×1.498×10 -5 =111.553N

[0110] F pb =95093.359×171×1.266×10 -5 =206.315N

[0111] Among them, F pb is the total impact force of cooling water reaching the lower surface of the strip, N; F pt The total impact force of cooling water reaching the upper surface of the strip;

[0112] Step 6: Calculate the safe thickness that can safely pass through each header based on the total impact force of the cooling water reaching the strip surface, the strip parameters, and the position of the strip head at any time;

[0113] First, the stress on the strip entering the ultra-rapid cooling zone is analyzed to calculate the critical stress of the strip; the critical state is when the support force of the roller on the strip in the ultra-rapid cooling zone is zero;

[0114] The calculation method of the vertical upward force of the strip is shown in formula (9):

[0115] F b =F s +F pb (9)

[0116] Where, F b is the vertical upward force of the strip, N; F s is the support force of the roller on the strip, N;

[0117] The calculation method of the vertical downward force of the strip is shown in formula (10):

[0118] F t =mg+F pt =wh s vtρ s g+F pt (10)

[0119] Where, F t is the vertical downward force on the strip, N; m is the mass of the strip, kg; w is the width of the strip, which is 1.2 m; h s is the minimum strip thickness to be solved, m; v is the strip running speed, which is 5 m / s; t is the running time of the strip head in the ultra-fast cooling area, which is 0.076 s; ρs is the density of the strip steel, which is 7850kg / m 3 ;

[0120] When the support force of the roller on the strip in the ultra-fast cooling zone is 0, the strip is in a critical state. At this time, the force on the strip in the ultra-fast cooling zone is as follows: Figure 3 As shown, the force relationship should satisfy formula (11). Here, the constraint effect of the strip outside the ultra-fast cooling zone on the strip in the ultra-fast cooling zone is ignored. Therefore, in order to ensure that the strip can pass through the ultra-fast cooling zone safely, it should be ensured that all parts of the strip do not leave the roller.

[0121] F pb -mg-F pt =0 (11)

[0122] Substituting equations (9) and (10) into equation (11), the calculation method of the safety thickness should be as shown in equation (12):

[0123]

[0124] Among them, h s is the safety thickness, m;

[0125] In this embodiment, the calculation results of formula (8) to formula (11) are used. When the strip is directly below the second header, the safe thickness is:

[0126]

[0127] That is, when the strip head runs just below the second header, the minimum thickness that can safely pass through the cooling zone is 2.7mm;

[0128] Step 7: Repeat steps 4 to 6 to obtain the safe thickness of the strip when it passes directly under each header until the head of the strip exceeds the last opened header. The minimum thickness that can safely pass through the ultra-fast cooling area is the minimum value of the safe thickness passing through each header.

[0129] In this embodiment, the safe thickness of the strip head passing through each header is as follows: Figure 4 As shown in the figure, it can be seen that when the strip head runs to the bottom of the tenth header, the safe thickness is the minimum, which is 1.5 mm. Therefore, in this embodiment, the minimum thickness that can safely pass through the ultra-fast cooling zone is 1.5 mm.

[0130] This embodiment further provides a system for calculating the minimum thickness of a steel strip for safely passing through an ultra-rapid cooling zone, which is used to implement the method for calculating the minimum thickness of a steel strip for safely passing through an ultra-rapid cooling zone, including:

[0131] Parameter acquisition module, used to collect cooling equipment parameters and strip parameters;

[0132] An outlet area and outlet flow rate calculation module, used to calculate the outlet area of a single nozzle on a single header in the cooling device and the outlet flow rate of a single nozzle on a single header in the cooling device according to the cooling device parameters;

[0133] The dynamic pressure and area calculation module is used to calculate the dynamic pressure and area of a single jet reaching the strip surface based on the outlet flow rate of a single nozzle on a single header in the cooling equipment, the outlet area of a single nozzle on a single header in the cooling equipment, and the cooling equipment parameters;

[0134] The module for determining the position of the strip head and the number of jets is used to determine the position of the strip head and the number of jets acting on the upper and lower surfaces of the strip at any time based on the parameters of the cooling equipment and the strip parameters;

[0135] The total impact force calculation module of the strip surface is used to calculate the total impact force of the cooling water on the strip surface based on the dynamic pressure of a single jet reaching the strip surface, the number of jets acting on the upper and lower surfaces of the strip, and the area of the strip surface reached by a single jet;

[0136] The safe thickness calculation module is used to calculate the safe thickness that can safely pass through each header based on the total impact force of cooling water reaching the strip surface, strip parameters and the position of the strip head at any time. The minimum value of the safe thickness of each header is determined as the minimum thickness for passing through the ultra-fast cooling area.

[0137] This embodiment also provides an electronic device, including: a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor and the memory communicate through the bus, and when the machine-readable instructions are executed by the processor, the method for calculating the minimum thickness of a strip for safely passing through an ultra-fast cooling zone is executed.

[0138] This embodiment also provides a computer-readable storage medium, which stores a computer program. When the computer program is run by a processor, it executes the method for calculating the minimum thickness of a steel strip for safely passing through an ultra-fast cooling zone as described above.

[0139] The above description is merely a preferred embodiment of the present disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in the embodiments of the present disclosure is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but should also encompass other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the above-mentioned inventive concept. For example, a technical solution formed by mutually replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in the embodiments of the present disclosure.

Claims

1. A method for calculating the minimum thickness of a steel strip for safely passing through an ultra-fast cooling zone, characterized in that: The following steps are involved: Collecting cooling equipment parameters and strip parameters; the cooling equipment parameters include the maximum flow rate of a single header, the number of nozzles in a single header, the inner diameter of the nozzle, the distance from the nozzle to the strip surface, the nozzle width spacing, the nozzle rolling direction spacing, the running speed of the strip, and the maximum number of header openings; the strip parameters include the width and density of the strip; Calculating the outlet area and outlet flow rate of a single nozzle on a single header in the cooling device according to the cooling device parameters; the nozzle includes an upper nozzle and a lower nozzle; Calculate the dynamic pressure and area of a single jet reaching the strip surface based on the outlet flow rate of a single nozzle on a single header in the cooling equipment, the outlet area of a single nozzle on a single header in the cooling equipment, and the cooling equipment parameters; When the strip head enters the ultra-fast cooling zone, the position of the strip head at any time and the number of jets acting on the upper and lower surfaces of the strip are determined according to the cooling equipment parameters and strip parameters; The total impact force of the cooling water on the strip surface is calculated based on the dynamic pressure of a single jet reaching the strip surface, the number of jets acting on the upper and lower surfaces of the strip, and the area of the strip surface reached by a single jet. The total impact force of the cooling water reaching the surface of the steel strip includes the total impact force of the cooling water reaching the lower surface of the steel strip and the total impact force of the cooling water reaching the upper surface of the steel strip; Calculate the safe thickness of the strip to pass through each header based on the total impact force of the cooling water reaching the strip surface, the strip parameters, and the position of the strip head at any time. The minimum thickness required for the strip to pass through each header is used as the minimum thickness required for the strip to pass through the ultra-fast cooling zone.

2. The method for calculating the minimum thickness of a steel strip for safely passing through an ultra-fast cooling zone according to claim 1, characterized in that: The calculation method of the outlet area of a single nozzle is: Where s is the outlet area of a single nozzle, m 2 ; d is the inner diameter of the nozzle; The calculation method for the outlet flow rate of a single nozzle on a single header in the cooling device is: Where, v n V is the outlet flow rate of a single nozzle on a single header in the cooling equipment; max is the maximum flow rate of a single header; n is the number of nozzles in a single header.

3. The method for calculating the minimum thickness of a steel strip for safely passing through an ultra-fast cooling zone according to claim 1, characterized in that: The dynamic pressure and area of a single jet reaching the strip surface are calculated based on the outlet flow rate of a single nozzle on a single header in the cooling device, the outlet area of a single nozzle on a single header in the cooling device, and the cooling device parameters, specifically: A1: Calculate the velocity of a single jet reaching the strip surface based on the outlet velocity of a single nozzle on a single header in the cooling equipment and the cooling equipment parameters; The method for calculating the flow velocity of a single jet reaching the strip surface is: Where, v s is the velocity of a single jet reaching the strip surface; g is the acceleration due to gravity; h is the distance from the nozzle to the strip surface; A2: Based on the outlet flow rate of a single nozzle on a single header in the cooling equipment, the outlet area of a single nozzle on a single header in the cooling equipment, and the flow rate of a single jet reaching the strip surface, and according to the principle of constant flow, calculate the area of the strip surface reached by a single jet; The method for calculating the area of the strip surface reached by a single jet is: Where s s is the area of the strip surface reached by a single jet; A3: Based on the velocity of a single jet reaching the strip surface and the conservation of mechanical energy, the dynamic pressure of a single jet reaching the strip surface is calculated; The method for calculating the dynamic pressure of a single jet reaching the strip surface is: Where P is the dynamic pressure when a single jet reaches the strip surface; ρ w is the density of cooling water.

4. The method for calculating the minimum thickness of a steel strip for safely passing through an ultra-fast cooling zone according to claim 1, characterized in that: The position of the strip head at any time is: l t =vt (6) Where, l t is the distance from the strip head to the first header at time t; v is the strip running speed; t is the running time of the strip head in the ultra-fast cooling zone; The calculation method for the number of jets acting on the upper and lower surfaces of the strip is: Where n t is the number of jets acting on the upper and lower surfaces of the strip at time t; N t is the number of headers opened at time t; w is the width of the strip; l p is the nozzle width distance.

5. The method for calculating the minimum thickness of a steel strip for safely passing through an ultra-fast cooling zone according to claim 1, characterized in that: The calculation method of the total impact force of the cooling water reaching the strip surface is: F p =Pn t s s (8) Where, F p It is the total impact force of cooling water reaching the strip surface.

6. The method for calculating the minimum thickness of a steel strip for safely passing through an ultra-fast cooling zone according to claim 1, characterized in that: The calculation method for the safe thickness of the strip steel passing through each header is as follows: Among them, h s is the safety thickness, F pb F is the total impact force of cooling water reaching the lower surface of the strip; pt It is the total impact force of cooling water reaching the upper surface of the strip.

7. A system for calculating the minimum thickness of a steel strip for safely passing through an ultra-rapid cooling zone, used to implement the method for calculating the minimum thickness of a steel strip for safely passing through an ultra-rapid cooling zone according to any one of claims 1 to 6, characterized in that: include: Parameter acquisition module, used to collect cooling equipment parameters and strip parameters; An outlet area and outlet flow rate calculation module, used to calculate the outlet area of a single nozzle on a single header in the cooling device and the outlet flow rate of a single nozzle on a single header in the cooling device according to the cooling device parameters; The dynamic pressure and area calculation module is used to calculate the dynamic pressure and area of a single jet reaching the strip surface based on the outlet flow rate of a single nozzle on a single header in the cooling equipment, the outlet area of a single nozzle on a single header in the cooling equipment, and the cooling equipment parameters; The module for determining the position of the strip head and the number of jets is used to determine the position of the strip head and the number of jets acting on the upper and lower surfaces of the strip at any time based on the parameters of the cooling equipment and the strip parameters; The total impact force calculation module of the strip surface is used to calculate the total impact force of the cooling water on the strip surface based on the dynamic pressure of a single jet reaching the strip surface, the number of jets acting on the upper and lower surfaces of the strip, and the area of the strip surface reached by a single jet; The safe thickness calculation module is used to calculate the safe thickness that can safely pass through each header based on the total impact force of cooling water reaching the strip surface, strip parameters and the position of the strip head at any time. The minimum value of the safe thickness of each header is determined as the minimum thickness for passing through the ultra-fast cooling area.

8. An electronic device, characterized in that: include: A processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor and the memory communicate via the bus. When the machine-readable instructions are executed by the processor, a method for calculating the minimum thickness of a steel strip for safely passing through an ultra-fast cooling zone as described in any one of claims 1 to 6 is executed.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, which, when executed by a processor, executes a method for calculating the minimum thickness of a steel strip for safely passing through an ultra-fast cooling zone as described in any one of claims 1 to 6.

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