Method for controlling cooling rate in ultrafast cooling technology

Abstract

The application relates to the rolling technology field of metal, in particular to a control method of a cooling rate in super-fast cooling technology, which is applied to a super-fast cooling system, the super-fast cooling system comprises a cold header, the method comprises the following steps: setting a pressure value, acquiring a maximum water spraying amount of the cold header corresponding to the pressure value, so as to determine an upper limit value of a flow of the cold header; based on the upper limit value of the flow, acquiring an equivalent cooling rate of the strip steel; based on the equivalent cooling rate, establishing a post-rolling cooling mathematical model, so as to correct the temperature of the strip steel; based on the heat exchange coefficient and the equivalent cooling efficiency, establishing a post-rolling cooling self-learning model, so as to match actual cooling rates corresponding to different pressure values, thereby meeting the demand of different strip steels for cooling rate control and improving the product quality of the strip steel.

Description

Technical Field

[0001] This application relates to the field of metal rolling technology, and more particularly to a method for controlling the cooling rate in ultrafast cooling technology. Background Technology

[0002] Because the cooling rate provided by the laminar flow cooling system during the post-rolling cooling process of strip steel is limited, a certain amount of alloying elements are usually added to the strip steel to compensate for the insufficient cooling rate through methods such as grain refinement strengthening and precipitation strengthening. In order to achieve precise control of the post-rolling cooling path of strip steel, and reduce the consumption of alloying elements while improving product quality, ultra-fast cooling technology is adopted on hot strip mill lines.

[0003] In the application of ultra-fast cooling technology, the cooling rate of the strip is the most critical process parameter, crucial for controlling the product's microstructure and mechanical properties. Currently, ultra-fast cooling technology primarily controls the cooling rate using high and low cooling rate modes. However, these two methods cannot meet the cooling rate requirements of hundreds of hot-rolled products, thus affecting the quality of the finished strip. Summary of the Invention

[0004] To meet the different requirements of strip steel for cooling rate control and improve the quality of finished strip steel products,

[0005] In a first aspect, this application provides a method for controlling the cooling rate in ultrafast cooling technology, applied to an ultrafast cooling system, the ultrafast cooling system including a cooling manifold, and the method comprising,

[0006] Set a pressure value, obtain the maximum water spray volume of the cold manifold corresponding to the pressure value, and determine the upper limit of the flow rate of the cold manifold;

[0007] Based on the upper limit of the flow rate, the equivalent cooling rate of the strip is obtained;

[0008] Based on the equivalent cooling rate, a mathematical model for post-rolling cooling is established to correct the temperature of the strip.

[0009] Based on the heat transfer coefficient and the equivalent cooling efficiency, a self-learning model for post-rolling cooling is established to match the actual cooling rate corresponding to different pressure values.

[0010] Furthermore, the set pressure value includes,

[0011] The flow control valve of the cold manifold is set to open at 100%.

[0012] The pressure value of the cold manifold is obtained by setting and based on the maximum pressure value, minimum pressure value, and step size value of the cold manifold.

[0013] Furthermore, the maximum pressure value Pmax is 0.8-1.2 MPa; the minimum pressure value Pmin is 0.2-0.4 MPa; and the step size n is 0.05 MPa or 0.1 MPa.

[0014] Furthermore, obtaining the equivalent cooling rate of the strip includes...

[0015] Obtain the inlet temperature T of the strip in the ultrafast cooling system. F ; Obtain the outlet temperature T of the strip in the ultra-fast cooling system. UFC ; Obtain the cooling time t of the strip;

[0016] The equivalent cooling rate R is calculated. i =(T F -T UFC ) / t.

[0017] Furthermore, establishing a post-rolling cooling mathematical model to correct the strip temperature includes setting and adjusting a pressure correction factor P. c Through a mathematical model of post-rolling cooling: strip temperature h UFC = Heat transfer coefficient f × Pressure correction factor P c Adjust the strip temperature h UFC .

[0018] Furthermore, regarding the set pressure value P S The pressure correction factor

[0019] P c = -0.3197 × P S 2 +1.042×P S +0.3232.

[0020] The heat transfer coefficient f is determined by parameters such as the strip material, strip speed, strip width, and strip thickness.

[0021] Furthermore, the step of establishing a post-rolling cooling self-learning model based on the heat transfer coefficient and the equivalent cooling efficiency to match the actual cooling rate corresponding to different pressure values ​​includes the post-rolling cooling learning model acquiring the heat transfer coefficient and the equivalent cooling efficiency corresponding to the same pressure value as learning parameters.

[0022] Secondly, this application provides a cooling rate control device for ultrafast cooling technology, applied to an ultrafast cooling system, the ultrafast cooling system including a cooling manifold, and this device includes...

[0023] The pressure module is used to set a pressure value and obtain the maximum water spray volume of the cold manifold corresponding to the pressure value, so as to determine the upper limit of the flow rate of the cold manifold.

[0024] A speed measurement module is used to obtain the equivalent cooling rate of the strip steel based on the upper limit of the flow rate;

[0025] The correction module is used to establish a post-rolling cooling mathematical model based on the equivalent cooling rate to correct the temperature of the strip steel.

[0026] The judgment module establishes a self-learning model for post-rolling cooling based on the heat transfer coefficient and the equivalent cooling efficiency to match the actual cooling rate corresponding to different pressure values.

[0027] Thirdly, this application provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the method described in any of the first aspects.

[0028] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of any of the methods described in the first aspect.

[0029] Beneficial effects:

[0030] This application determines the upper limit of the flow rate of the cold manifold by setting a pressure value and obtaining the maximum water spray volume of the cold manifold corresponding to the pressure value; based on the upper limit of the flow rate, the equivalent cooling rate of the strip steel is obtained; based on the equivalent cooling rate, a post-rolling cooling mathematical model is established to correct the temperature of the strip steel; based on the heat transfer coefficient and the equivalent cooling efficiency, a post-rolling cooling self-learning model is established to match the actual cooling rate corresponding to different pressure values, thereby meeting the cooling rate control requirements of different strip steels and improving the quality of finished strip steel products. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a flowchart of a cooling rate control method in an ultrafast cooling technology provided in Embodiment 1 of this application;

[0033] Figure 2 This is a schematic diagram of the maximum flow rate of the ultrafast cooling manifold under different process pressure values ​​provided in Embodiment 1 of this application;

[0034] Figure 3 This is a schematic diagram of an electronic device structure for a cooling rate control method in an ultrafast cooling technology provided in Embodiment 3 of this application. Detailed Implementation

[0035] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0036] Example 1

[0037] Example 1 provides a method for controlling the cooling rate in ultrafast cooling technology, applied to an ultrafast cooling system, which includes a cooling manifold. Specifically, in conjunction with the attached... Figure 1 This includes the following steps:

[0038] S101, Set a pressure value, obtain the maximum water spray volume of the cold manifold corresponding to the pressure value, and determine the upper limit of the flow rate of the cold manifold;

[0039] S102, Based on the upper limit of the flow rate, obtain the equivalent cooling rate of the strip steel;

[0040] S103, Based on the equivalent cooling rate, establish a post-rolling cooling mathematical model to correct the temperature of the strip steel;

[0041] S104. Based on the heat transfer coefficient and the equivalent cooling efficiency, a self-learning model for post-rolling cooling is established to match the actual cooling rate corresponding to different pressure values.

[0042] The ultra-fast cooling system can be arranged between the finishing mill exit and the laminar flow cooling system, or between the laminar flow cooling system and the coiler. The ultra-fast cooling system provided in Example 1 is arranged between the finishing mill exit and the laminar flow cooling system of the hot strip mill, totaling three sets. The ultra-fast cooling system is equipped with a pressure closed-loop control system, which can set the pressure according to process requirements, thereby performing closed-loop control of the actual pressure of the ultra-fast cooling system to ensure the matching of the set pressure and the actual pressure.

[0043] Each ultra-fast cooling manifold is equipped with a flow regulating valve. By adjusting the opening of the flow regulating valve, closed-loop control of the flow rate of the ultra-fast cooling manifold can be achieved. Under the same pressure value, the actual flow rate of the manifold can be matched with the set flow rate.

[0044] S101, Set a pressure value, obtain the maximum water spray volume of the cold manifold corresponding to the pressure value, and determine the upper limit of the flow rate of the cold manifold;

[0045] The maximum pressure value P of the ultra-fast cooling system max The value range is 0.8-1.2 MPa, and the minimum pressure value P min The value range is 0.2-0.4 MPa. In Example 1, P max The minimum pressure is 0.9 MPa, and the minimum pressure is P. min It is 0.2 MPa;

[0046] The opening of each cold manifold flow regulating valve is adjusted to 100%. Let n represent the distinguishable step size of the process pressure. The step size n can be 0.05MPa or 1.0MPa. In Example 1, n is taken as 0.05, that is, with a step size of 0.05MPa, the maximum water spray volume of each cold manifold is obtained under the process pressures of 0.2MPa, 0.25MPa, 0.3MPa, 0.35MPa, 0.4MPa, 0.45MPa, ..., 0.85MPa, 0.9MPa respectively.

[0047] As attached Figure 2 The figure shows the normalized flow rate of a cold manifold under different process pressures. The water spray volume of each cold manifold is defined as the preset upper limit of the flow rate of the cold manifold under the corresponding pressure value.

[0048] S102, Based on the upper limit of the flow rate, obtain the equivalent cooling rate of the strip steel;

[0049] Under the corresponding pressure value, the equivalent cooling rate is calculated by selecting the front, middle and rear sections of a strip as typical sections along the length of the strip.

[0050] The calculation process is as follows: Take a length of approximately 15m from the front of the strip as L. h The strip steel is used as the front equivalent cooling rate R ih The data source, of which L h It needs to be divisible by the total length of the ultra-fast cooling system. Front ultra-fast cooling time t h The calculation method is to divide the total length L of the ultrafast cooling system into L... h The unit length is divided into m segments, each segment having a length of L. S =L / L h They are labeled L respectively S1 L S2 , ..., L Sm The cooling time for each strip of steel is denoted as t1, t2, ..., t m The selected length is L. h The strip steel is divided into m segments of length Ls as it passes through the ultrafast cooling system. The inlet and outlet velocities of each segment are determined using the maximum flow rate, and denoted as V. 10 V 11 V 20 V 21 …V m0 V m1 , where V 10 L represents S1 The entry velocity of the segment, V 11 L represents S1 The exit velocity of the segment, V 20 L representsS2 The entry velocity of the segment, V 21 L represents S2 The exit speed of the segment, and so on, V m1 L represents Sm The exit speed of the segment. Due to L S The segmentation is continuous; therefore, the exit velocity of each segment is equal to the inlet velocity of the next segment, i.e., V. 11 =V 20 V 21 =V 30 …Within each section, the strip steel is processed at a uniformly varying speed. L S1 The formula for calculating the transit time t1 of the strip steel is: L S2 The formula for calculating the transit time t2 of the strip steel section is: By analogy, L can be derived. Sm Time t of the strip steel passage m The calculation formula is: Front ultra-fast cooling time: Equivalent cooling rate R of the front of the strip ih The calculation formula is: Where T Fh T is the selected ultra-fast cooling inlet temperature of a typical section at the front of the strip. UFCh The selected ultra-fast cooling exit temperature is shown in the figure. The equivalent cooling rate R in the typical middle section of the strip is also shown. ib Equivalent cooling rate R of the typical rear section it The calculation method is the same. The middle part is usually taken as the midpoint of the strip length, and the rear part can be taken as the 20m position of the rear part as the calculation point for cooling rate. The average of the equivalent cooling rates at the three positions is the equivalent cooling rate of the strip under that pressure.

[0051] This cooling rate will serve as an important support for product organization and mechanical performance control.

[0052] S103, Based on the equivalent cooling rate, establish a post-rolling cooling mathematical model to correct the temperature of the strip steel;

[0053] Based on the equivalent cooling rate, a mathematical model for post-rolling cooling is established. A pressure correction factor is introduced into this model to correct the heat transfer coefficient of the strip steel under different pressure values. The calculation model is: h UFC = f(S,V,B,H,TF,…)×P c In the formula, f(S,V,B,H,TF,…) is the heat transfer coefficient determined by parameters such as S as the strip material, V as the strip speed, B as the strip width, and H as the strip thickness. c P is the pressure correction factor. c P can be calculated using the following formula: c= -0.3197 × P S 2 +1.042×P S +0.3232, where P S To set the pressure.

[0054] S104. Based on the heat transfer coefficient and the equivalent cooling efficiency, a self-learning model for post-rolling cooling is established to match the actual cooling rate corresponding to different pressure values.

[0055] Based on the heat transfer coefficient and the equivalent cooling efficiency, a self-learning model for post-rolling cooling is established.

[0056] In the process of calculating the self-learning coefficient or indexing similar historical data, the self-learning model uses the set pressure value as the basis for judgment on whether historical data is inherited.

[0057] Implementation Method 1: In the self-learning database, the set pressure value is used as a condition for layering. That is, when the self-learning model obtains self-learning parameters, only strip steel with the same ultra-fast cooling system set pressure value can be used as the data source for self-learning.

[0058] Method 2: Storing historical data in the same database, the self-learning model selects the same or similar historical data as its data source, using the same pressure value as one of the criteria. If the pressure values ​​set by the ultra-fast cooling system are different, it will not be considered as the same or similar data source for learning.

[0059] The post-rolling cooling learning model obtains the heat transfer coefficient and the equivalent cooling efficiency corresponding to the same pressure value as learning parameters; after determining the actual cooling rate, it outputs the actual cooling rate corresponding to the pressure value.

[0060] Example 2

[0061] Based on the same inventive concept, this application provides a cooling rate control device for ultrafast cooling technology, applied to an ultrafast cooling system, wherein the ultrafast cooling system includes a cooling manifold, and this device includes...

[0062] The pressure module is used to set a pressure value and obtain the maximum water spray volume of the cold manifold corresponding to the pressure value, so as to determine the upper limit of the flow rate of the cold manifold.

[0063] A speed measurement module is used to obtain the equivalent cooling rate of the strip steel based on the upper limit of the flow rate;

[0064] The correction module is used to establish a post-rolling cooling mathematical model based on the equivalent cooling rate to correct the temperature of the strip steel.

[0065] The judgment module establishes a self-learning model for post-rolling cooling based on the heat transfer coefficient and the equivalent cooling efficiency to match the actual cooling rate corresponding to different pressure values.

[0066] Example 3

[0067] Based on the same inventive concept, Embodiment 3 of this application provides an electronic device, such as... Figure 3 As shown, it includes a memory 304, a processor 302, and a computer program stored in the memory 304 and executable on the processor 302. When the processor 302 executes the program, it implements the steps of the cooling rate control method in the above-mentioned ultrafast cooling technology.

[0068] Among them, Figure 3 In this document, a bus architecture (represented by bus 300) is used. Bus 300 may include any number of interconnected buses and bridges, linking various circuits including one or more processors represented by processor 302 and memory represented by memory 304. Bus 300 may also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. Bus interface 306 provides an interface between bus 300 and receiver 301 and transmitter 303. Receiver 301 and transmitter 303 may be the same element, i.e., a transceiver, providing a unit for communicating with various other devices over a transmission medium. Processor 302 is responsible for managing bus 300 and general processing, while memory 304 can be used to store data used by processor 302 during operation.

[0069] Example 4

[0070] Based on the same inventive concept, Embodiment 4 of this application provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the cooling rate control method in the above-described ultrafast cooling technology.

[0071] The algorithms and displays provided herein are not inherently related to any particular computer, virtual system, or other device. Various general-purpose systems can also be used in conjunction with the teachings herein. The required structure for constructing such systems is apparent from the above description. Furthermore, this invention is not directed to any particular programming language. It should be understood that the contents of the invention described herein can be implemented using various programming languages, and the above description of specific languages ​​is for the purpose of disclosing the best mode of implementation of the invention.

[0072] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0073] Similarly, it should be understood that, in order to simplify this disclosure and aid in understanding one or more of the various aspects of the invention, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof. However, this method of disclosure should not be construed as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the following claims, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into this detailed description, wherein each claim itself is a separate embodiment of the invention.

[0074] Those skilled in the art will understand that modules in the device of the embodiments can be adaptively changed and placed in one or more devices different from that embodiment. Modules, units, or components in the embodiments can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components. Except where at least some of such features and / or processes or units are mutually exclusive, any combination can be used to combine all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or units of any method or device so disclosed. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose.

[0075] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0076] The various component embodiments of the present invention can be implemented in hardware, or as software modules running on one or more processors, or a combination thereof. Those skilled in the art will understand that microprocessors or digital signal processors (DSPs) can be used in practice to implement some or all of the functions of some or all of the components in the thermal simulation apparatus for aluminum substrates or electronic devices according to embodiments of the present invention. The present invention can also be implemented as a device or apparatus program (e.g., a computer program and computer program product) for performing part or all of the methods described herein. Such programs implementing the present invention can be stored on a computer-readable medium or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.

[0077] The above descriptions are merely embodiments of this application. Commonly known structures and characteristics of the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, based on the guidance provided in this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of this application. These should also be considered within the scope of protection of this application, and will not affect the effectiveness of the implementation of this application or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for controlling the cooling rate in ultrafast cooling technology, applied to an ultrafast cooling system, the ultrafast cooling system comprising a cooling manifold, characterized in that, This method includes, Set a pressure value, obtain the maximum water spray volume of the cold manifold corresponding to the pressure value, and determine the upper limit of the flow rate of the cold manifold. The pressure value is set by the pressure closed-loop control system. Based on the upper limit of the flow rate, the equivalent cooling rate of the strip is obtained; Based on the equivalent cooling rate, a mathematical model for post-rolling cooling is established to correct the heat transfer coefficient of the strip. Based on the heat transfer coefficient and the equivalent cooling rate, a self-learning model for post-rolling cooling is established to match the actual cooling rate corresponding to different pressure values. The set pressure value includes: The flow control valve of the cold manifold is set to 100% opening. The pressure value of the cold manifold is obtained by setting and based on the maximum pressure value, minimum pressure value, and step size value of the cold manifold; The establishment of a post-rolling cooling mathematical model to correct the heat transfer coefficient of the strip includes setting and adjusting a pressure correction factor P. c Through the mathematical model of post-rolling cooling: the corrected heat transfer coefficient h of the strip. UFC = Heat transfer coefficient f × Pressure correction factor P c Adjust the heat transfer coefficient of the strip steel; For the set pressure value P S The pressure correction factor The heat transfer coefficient f is determined by at least the following parameters of the strip: strip material, strip speed, strip width, and strip thickness.

2. The method for controlling the cooling rate in an ultrafast cooling technology as described in claim 1, characterized in that: The maximum pressure value Pmax is 0.8-1.2 MPa; the minimum pressure value Pmin is 0.2-0.4 MPa; and the step size n is 0.05 MPa or 0.1 MPa.

3. The method for controlling the cooling rate in an ultrafast cooling technology as described in claim 1, characterized in that: The process of obtaining the equivalent cooling rate of the strip includes... Obtain the inlet temperature T of the strip in the ultrafast cooling system. F ; Obtain the outlet temperature T of the strip in the ultra-fast cooling system. UFC ; Obtain the cooling time t of the strip; The equivalent cooling rate R is calculated. i = (T F -T UFC ) / t.

4. The method for controlling the cooling rate in an ultrafast cooling technology as described in claim 1, characterized in that: The step of establishing a post-rolling cooling self-learning model based on the heat transfer coefficient and the equivalent cooling rate to match the actual cooling rate corresponding to different pressure values ​​includes the post-rolling cooling learning model acquiring the heat transfer coefficient and the equivalent cooling rate corresponding to the same pressure value as learning parameters.

5. A cooling rate control device for ultrafast cooling technology, applied to an ultrafast cooling system, the ultrafast cooling system comprising a cooling manifold, characterized in that, This device includes The pressure module is used to set a pressure value and obtain the maximum water spray volume of the cold manifold corresponding to the pressure value, so as to determine the upper limit of the flow rate of the cold manifold. The pressure value is set by the pressure closed-loop control system. The speed measurement module is used to obtain the equivalent cooling rate of the strip steel based on the upper limit of the flow rate. The correction module is used to establish a post-rolling cooling mathematical model based on the equivalent cooling rate in order to correct the heat transfer coefficient of the strip. The judgment module establishes a post-rolling cooling self-learning model based on the heat transfer coefficient and the equivalent cooling rate to match the actual cooling rate corresponding to different pressure values. When the pressure value is set, the pressure module is specifically used for: The flow control valve of the cold manifold is set to 100% opening. The pressure value of the cold manifold is obtained by setting and based on the maximum pressure value, minimum pressure value, and step size value of the cold manifold; The correction module is specifically used for: Set and adjust the pressure correction factor P. c Through the mathematical model of post-rolling cooling: the corrected heat transfer coefficient h of the strip. UFC = Heat transfer coefficient f × Pressure correction factor P c Adjust the heat transfer coefficient of the strip steel; For the set pressure value P S The pressure correction factor The heat transfer coefficient f is determined by at least the following parameters of the strip: strip material, strip speed, strip width, and strip thickness.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the method as described in any one of claims 1-4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps of the method as described in any one of claims 1-4.

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