Method and device, medium, and terminal for determining process parameters of strip continuous casting machine

Abstract

The present application discloses a method and device, medium, and terminal for determining process parameters of a thin strip continuous casting machine, relating to the field of casting technology. The main purpose is to solve the problems of increased risk of operation errors caused by manual adjustment of the casting machine process parameters in the prior art, as well as the situation of untimely adjustment, which may lead to a decline in product quality. It includes: pre-constructing a full-coupling model of the process parameters of the thin strip continuous casting machine, determining the process parameters required for controlling the casting machine according to the full-coupling model of the process parameters of the thin strip continuous casting machine, and determining the initial value of the process parameters of the casting machine for this casting by optimizing from the process parameters recorded in the historical casting production data. Then, according to the periodic production data of the stable state period and the full-coupling model of the process parameters of the thin strip continuous casting machine, calculate the correction value of the solidification parameter, the correction value of the rolling parameter, the set casting and rolling force, and the set drawing speed, and adjust the initial value of the process parameters of the casting machine based on the above parameters.

Description

Technical Field

[0001] The present application relates to the field of casting technology, and particularly to a method and device, medium, and terminal for determining process parameters of a thin strip continuous casting machine. Background Art

[0002] Thin strip continuous casting is a cutting-edge technology with great application potential in the iron and steel industry. In this process flow, after casting starts, molten steel is poured from the tundish nozzle into the tundish, and the tundish accumulates a certain amount of molten steel; the distribution ladle evenly distributes the molten steel poured into it from the tundish to the molten pool area of the casting machine to ensure the formation of a uniform and stable flow field in the molten pool; the molten steel solidifies after passing through the casting roll to form a cast strip, and a free loop is formed at the lower part of the casting roll. At the loop, the movement direction of the cast strip changes from vertical to horizontal, and then it is led out of the casting machine to the horizontal roller table; the free cast strip is sent into the rolling mill after the posture is corrected by the pinch rolls; the hot rolled strip after rolling by the rolling mill enters the coiler after a certain degree of cooling to be coiled into the final finished hot rolled steel coil. Among them, the casting machine, as the core equipment in the entire process flow, has a decisive impact on the production quality of the entire production line. Since thin strip continuous casting combines the two process links of "casting" and "rolling" into one, realizing a rapid transformation from molten steel to a near-net-shape thin strip, this makes the adjustment space of the casting machine process parameters very limited.

[0003] Currently, during the thin strip continuous casting process, operators need to continuously manually adjust the process parameters of the casting machine. This process highly depends on the personal experience of the operators, increasing the risk of operation errors, and thus leading to a decline in product quality; at the same time, due to the narrow adjustment space, it is very easy to have a situation where the adjustment is not timely, further increasing the risk of product quality decline. Summary of the Invention

[0004] In view of this, the present application provides a method and device, medium, and terminal for determining process parameters of a thin strip continuous casting machine, mainly aiming to solve the problem of increased risk of operation errors caused by the need to manually adjust the process parameters of the casting machine, as well as the possible situation of untimely adjustment, which in turn leads to a decline in product quality.

[0005] According to one aspect of the present application, a method for determining process parameters of a thin strip continuous casting machine is provided, including:

[0006] Obtain the specification parameters of the target thin strip, screen multiple historical casting production data that match the specification parameters, and determine the initial value of the casting machine process parameters of the target thin strip according to the casting machine process parameters in the multiple historical casting production data. The casting machine process parameters are determined according to a pre-constructed full-coupling model of thin strip continuous casting machine process parameters;

[0007] Control the operation of the casting machine based on the initial values of the casting machine process parameters, and monitor the liquid level height in the molten pool in real time. When the liquid level height is higher than the preset liquid level height threshold, collect periodic production data at preset time intervals, and determine the production status of the current period according to the periodic production data of the previous period;

[0008] If the production status of the current period is a stable state, then calculate the correction value of the solidification parameter and the correction value of the rolling parameter according to the periodic production data of the current period and the fully coupled model of the thin strip continuous casting machine process parameters, calculate the set casting and rolling force after correction for the current period according to the periodic production data of the current period, and calculate the set drawing speed after correction for the current period according to the set casting and rolling force and the fully coupled model of the thin strip continuous casting machine process parameters, and adjust the initial values of the casting machine process parameters based on the correction value of the solidification parameter, the correction value of the rolling parameter, the set casting and rolling force, and the set drawing speed to obtain the updated values of the casting machine process parameters, so as to control the operation of the casting machine based on the updated values of the casting machine process parameters. The types of the casting machine process parameters include solidification parameters, rolling parameters, casting and rolling force, and drawing speed.

[0009] Preferably, the fully coupled model of the thin strip continuous casting machine process parameters is expressed by the following formula

[0010] ,

[0011] where represents the thickness of the cast strip, represents the solidification parameter, represents the latent heat of solidification, represents the specific heat capacity of molten steel, represents the tundish temperature, represents the empirical temperature drop from the tundish to the molten pool, represents the liquidus temperature of molten steel, represents the liquid level height in the molten pool, represents the radius of the casting roll, represents the drawing speed, represents the meniscus size proportionality coefficient, represents the rolling parameter, represents the casting and rolling force, represents a constant.

[0012] Preferably, pre-construct the fully coupled model of the thin strip continuous casting machine process parameters, including:

[0013] Construct an expression for the superheat of molten steel, which is expressed by the following formula

[0014] ,

[0015] where represents the superheat of molten steel;

[0016] Construct the expression of the molten steel solidification time according to the geometric relationship in the molten pool, which is expressed as the following formula:

[0017] ,

[0018] where, represents the molten steel solidification time; represents the meniscus size at the edge of the molten pool; represents the height of the Kiss point;

[0019] Construct the expression of the meniscus size at the edge of the molten pool according to the finite element simulation results, which is expressed as the following formula:

[0020] ;

[0021] According to the rolling theory, construct the first coupling relationship among the height of the Kiss point, the casting and rolling force, and the drawing speed, which is expressed as the following formula:

[0022] ;

[0023] According to the thermodynamics principle, construct the second coupling relationship among the thickness of the cast strip, the molten steel solidification time, and the superheat of the molten steel, which is expressed as the following formula:

[0024] ;

[0025] Substitute the molten steel superheat expression, the molten steel solidification time expression, the meniscus size expression at the edge of the molten pool, and the first coupling relationship into the second coupling relationship to obtain the full-coupling model of the process parameters of the thin slab continuous casting machine.

[0026] Preferably, the overall process of thin slab continuous casting includes a starting pouring stage, a production stage, and an ending stage. The steps of obtaining the specification parameters of the target thin strip, screening a plurality of historical pouring production data matching the specification parameters, and determining the initial values of the process parameters of the casting machine for the target thin strip according to the process parameters of the casting machine in the plurality of historical pouring production data include:

[0027] Obtain the specification parameters of the target thin strip, and screen a plurality of first historical pouring production data matching the specification parameters. The first historical pouring production data includes a pouring score, which is used to characterize the evaluation score for the overall process of thin slab continuous casting and is obtained by summing the weighted sum of the first-stage score in the starting pouring stage, the second-stage score in the production stage, and the third-stage score in the ending stage and the correction score;

[0028] Extract a preset number of second historical pouring production data from the plurality of first historical pouring production data in descending order of the pouring score;

[0029] Obtain the mean value of the casting machine process parameters corresponding to each of the second historical casting production data, and determine the weighted sum of the mean values of the casting machine process parameters as the initial value of the casting machine process parameters of the target thin strip. The mean value of the casting machine process parameters for each casting is used to represent the mean value of the casting machine process parameters in the overall thin strip continuous casting process.

[0030] Preferably, the first-stage score is used to represent the evaluation score for the data fluctuation degree in the starting casting stage. Calculating the first-stage score includes:

[0031] Obtain each criterion parameter and the corresponding target value included in the end criterion of the starting casting stage;

[0032] When the liquid level height is higher than the preset liquid level height threshold, collect the real-time values corresponding to each of the criterion parameters in real time;

[0033] When it is monitored that each of the real-time values reaches the corresponding target value, determine that the starting casting stage ends, and calculate the first-stage score according to the following formula,

[0034] ,

[0035] where, represents the first-stage score, , , , , all represent weight coefficients, represents the range of the actual drawing speed data during the starting casting process, represents the range of the molten pool liquid level data during the starting casting process, represents the range of the actual rolling force data during the starting casting process, represents the range of the actual roll gap data during the starting casting process, represents the duration of the starting casting stage.

[0036] Preferably, the second-stage score is used to represent the mean value of the stability scores of each stable state period included in the production stage. Calculating the second-stage score includes:

[0037] Take each period of each stable state as the target stable period one by one;

[0038] Obtain the periodic production data of the target stable period, and calculate the interquartile range value corresponding to each of the periodic production data;

[0039] Calculate the stability score of the target stable period according to the following formula,

[0040] ,

[0041] Among them, represents the stability score of the target stable period, represents the th weight coefficient of the production data of the cycle, represents the th interquartile range value of the production data of the cycle, represents the quantity of the production data of the cycle;

[0042] Determine the mean value of the stability scores of each target stable period as the second-stage score.

[0043] Preferably, the third-stage score is used to characterize the evaluation score of the production quality of the overall thin slab continuous casting process. Calculating the third-stage score includes:

[0044] When it is monitored that the casting machine stops running, calculate the third-stage score according to the following formula,

[0045] ,

[0046] Among them, represents the third-stage score, , , all represent weight coefficients, represents the remaining molten steel weight in the ladle at the moment of stopping casting, represents the remaining molten steel weight in the tundish at the moment of stopping casting, represents the duration of the casting campaign.

[0047] According to another aspect of the present application, there is provided a device for determining process parameters of a thin slab continuous casting machine, including:

[0048] A casting machine process parameter initial setting module, configured to obtain the specification parameters of the target thin strip, screen a plurality of historical casting campaign production data that match the specification parameters, and determine the initial value of the casting machine process parameters of the target thin strip according to the casting machine process parameters in the plurality of historical casting campaign production data. The casting machine process parameters are determined according to a pre-constructed fully coupled model of thin slab continuous casting machine process parameters;

[0049] A cycle production state judgment module, configured to control the operation of the casting machine based on the initial value of the casting machine process parameters, monitor the liquid level height in the molten pool in real time, when the liquid level height is higher than a preset liquid level height threshold, periodically collect cycle production data at a preset time interval, and determine the production state of the current cycle according to the cycle production data of the previous cycle;

[0050] The casting machine process parameter update module is used to calculate the correction value of the solidification parameter and the correction value of the rolling parameter according to the cycle production data of the current cycle and the full-coupling model of the thin strip continuous casting machine process parameters if the production state of the current cycle is a stable state, calculate the set casting and rolling force corrected in the current cycle according to the cycle production data of the current cycle, and calculate the set drawing speed corrected in the current cycle according to the set casting and rolling force and the full-coupling model of the thin strip continuous casting machine process parameters, and adjust the initial values of the casting machine process parameters based on the correction value of the solidification parameter, the correction value of the rolling parameter, the set casting and rolling force, and the set drawing speed to obtain the updated value of the casting machine process parameters, so as to control the operation of the casting machine based on the updated value of the casting machine process parameters. The types of the casting machine process parameters include solidification parameters, rolling parameters, casting and rolling force, and drawing speed.

[0051] Preferably, the full-coupling model of the thin strip continuous casting machine process parameters is expressed by the following formula

[0052] ,

[0053] where represents the thickness of the cast strip, represents the solidification parameter, represents the latent heat of solidification, represents the specific heat capacity of molten steel, represents the tundish temperature, represents the empirical temperature drop from the tundish to the molten pool, represents the liquidus temperature of molten steel, represents the liquid level height in the molten pool, represents the radius of the casting roll, represents the drawing speed, represents the meniscus size proportionality coefficient, represents the rolling parameter, represents the casting and rolling force, represents a constant.

[0054] Preferably, the device further includes a model construction module for:

[0055] Construct a molten steel superheat expression, which is expressed by the following formula

[0056] ,

[0057] where represents the molten steel superheat;

[0058] Construct a molten steel solidification time expression according to the geometric relationship in the molten pool, which is expressed by the following formula

[0059] ,

[0060] Among them, represents the solidification time of molten steel, represents the meniscus size at the edge of the molten pool, represents the height of the Kiss point;

[0061] According to the finite element simulation results, an expression for the meniscus size at the edge of the molten pool is constructed, expressed as the following formula,

[0062] ;

[0063] According to rolling theory, a first coupling relationship among the height of the Kiss point, the casting and rolling force, and the drawing speed is constructed, expressed as the following formula,

[0064] ;

[0065] According to the principle of thermodynamics, a second coupling relationship among the thickness of the cast strip, the solidification time of molten steel, and the superheat of molten steel is constructed, expressed as the following formula,

[0066] ;

[0067] Substitute the molten steel superheat expression, the molten steel solidification time expression, the meniscus size expression at the edge of the molten pool, and the first coupling relationship into the second coupling relationship to obtain a full-coupling model of the process parameters of the thin slab continuous casting machine.

[0068] Preferably, the overall process of thin slab continuous casting includes a starting pouring stage, a production stage, and an ending stage. The initial setting module of the casting machine process parameters is used for:

[0069] Obtain the specification parameters of the target thin strip, screen multiple first historical pouring production data that match the specification parameters. The first historical pouring production data includes a pouring score, and the pouring score is used to characterize the evaluation score for the overall process of thin slab continuous casting, which is obtained by summing the weighted sum of the first stage score in the starting pouring stage, the second stage score in the production stage, and the third stage score in the ending stage and the correction score;

[0070] Extract a preset number of second historical pouring production data from the multiple first historical pouring production data in descending order of the pouring score;

[0071] Respectively obtain the corresponding pouring mean values of the casting machine process parameters from each of the second historical pouring production data, and determine the weighted sum of the pouring mean values of the casting machine process parameters as the initial values of the casting machine process parameters of the target thin strip. The pouring mean value of the casting machine process parameters is used to characterize the mean value of the casting machine process parameters in the overall process of thin slab continuous casting.

[0072] Preferably, the first-stage score is used to represent the evaluation score for the data fluctuation degree during the starting pouring stage. The device further includes a heat score calculation module, which is used for:

[0073] Calculate the first-stage score, specifically used for:

[0074] Obtain each criterion parameter and the corresponding target value included in the end criterion of the starting pouring stage;

[0075] When the liquid level height is higher than the preset liquid level height threshold, real-time collect the real-time values corresponding to each of the criterion parameters;

[0076] When it is monitored that each of the real-time values reaches the corresponding target value, determine that the starting pouring stage ends, and calculate the first-stage score according to the following formula,

[0077] ,

[0078] where, represents the first-stage score, , , , , all represent weight coefficients, represents the range of the actual drawing speed data during the starting pouring process, represents the range of the molten pool liquid level data during the starting pouring process, represents the range of the actual casting and rolling force data during the starting pouring process, represents the range of the actual roll gap data during the starting pouring process, represents the duration of the starting pouring stage.

[0079] Preferably, the second-stage score is used to represent the mean value of the stability scores of each stable state period included in the production stage. The heat score calculation module is further used for:

[0080] Calculate the second-stage score, specifically used for:

[0081] Take each period of each stable state as the target stable period;

[0082] Obtain the periodic production data of the target stable period, and calculate the interquartile range value corresponding to each of the periodic production data;

[0083] Calculate the stability score of the target stable period according to the following formula,

[0084] ,

[0085] where, represents the stability score of the target stable period, represents the weight coefficient of the production data of the th cycle, represents the interquartile range value of the production data of the th cycle, represents the quantity of the cycle production data;

[0086] Determine the mean value of the stability scores of each target stable cycle as the second-stage score.

[0087] Preferably, the third-stage score is used to represent the evaluation score of the production quality of the overall thin slab continuous casting process. The heat score calculation module is further configured to:

[0088] [[ID=1,7]]Calculate the third-stage score, specifically:

[0089] When it is monitored that the casting machine stops running, calculate the third-stage score according to the following formula

[0090] ,

[0091] wherein, represents the third-stage score, , , all represent weight coefficients, represents the remaining molten steel weight in the ladle at the moment of stopping casting, represents the remaining molten steel weight in the tundish at the moment of stopping casting, represents the heat duration. [[ID=_,8]]

[0092] According to another aspect of the present application, there is provided a storage medium storing at least one executable instruction, and the executable instruction causes the processor to perform operations corresponding to the method for determining the process parameters of the thin slab continuous casting machine as described above.

[0093] According to still another aspect of the present application, there is provided a terminal, including: a processor, a memory, a communication interface, and a communication bus, and the processor, the memory, and the communication interface complete communication with each other through the communication bus;

[0094] The memory is used to store at least one executable instruction, and the executable instruction causes the processor to perform operations corresponding to the method for determining the process parameters of the thin slab continuous casting machine as described above.

[0095] By means of the above technical solutions, the technical solutions provided by the embodiments of the present application have at least the following advantages:

[0096] The present application provides a method and device, medium, and terminal for determining process parameters of a thin strip continuous casting machine. First, the specification parameters of a target thin strip are obtained, and multiple historical casting data matching the specification parameters are screened. Based on the casting machine process parameters in the multiple historical casting data, an initial value of the casting machine process parameters for the target thin strip is determined. The casting machine process parameters are determined according to a fully coupled model of thin strip continuous casting machine process parameters pre-constructed; the casting machine is controlled based on the initial value of the casting machine process parameters, and the liquid level height in the molten pool is monitored in real time. When the liquid level height is higher than a preset liquid level height threshold, periodic production data is collected periodically at a preset time interval, and the production state of the current period is determined according to the periodic production data of the previous period; if the production state of the current period is a stable state, then according to the periodic production data of the current period and the fully coupled model of thin strip continuous casting machine process parameters, a correction value of the solidification parameter and a correction value of the rolling parameter are calculated, a set casting and rolling force corrected for the current period is calculated according to the periodic production data of the current period, and a set drawing speed corrected for the current period is calculated according to the set casting and rolling force and the fully coupled model of thin strip continuous casting machine process parameters. And the initial value of the casting machine process parameters is adjusted based on the correction value of the solidification parameter, the correction value of the rolling parameter, the set casting and rolling force, and the set drawing speed to obtain an updated value of the casting machine process parameters, so as to control the operation of the casting machine based on the updated value of the casting machine process parameters. The types of the casting machine process parameters include solidification parameters, rolling parameters, casting and rolling force, and drawing speed. Compared with the prior art, in the embodiment of the present application, first, by pre-constructing a fully coupled model of thin strip continuous casting machine process parameters, an objective description of the influence relationship between various factors in the thin strip continuous casting production process is realized; further, the casting machine process parameters required for controlling the casting machine are determined according to the fully coupled model of thin strip continuous casting machine process parameters, and the initial value of the casting machine process parameters for this casting is determined by the method of optimizing from the casting machine process parameters recorded in the historical casting data, solving the problem that the process parameters cannot be initially set in the prior art; then, according to the periodic production data of the stable state period and the fully coupled model of thin strip continuous casting machine process parameters, a correction value of the solidification parameter, a correction value of the rolling parameter, a set casting and rolling force, and a set drawing speed are calculated, and the initial value of the casting machine process parameters is adjusted based on the above parameters to realize automatic adjustment of the casting machine process parameters, avoiding the problem of increased risk of operation errors caused by manually adjusting the casting machine process parameters, and the problem of possible untimely adjustment, thereby avoiding the risk of product quality decline.

[0097] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other objects, features, and advantages of the present application more obvious and understandable, the specific embodiments of the present application are specifically exemplified below. Brief Description of the Drawings

[0098] Upon reading the following detailed description of the preferred embodiments, various other advantages and benefits will become apparent to those of ordinary skill in the art. The accompanying drawings are only for the purpose of showing the preferred embodiments and are not considered a limitation of the present application. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0099] Figure 1 A flowchart showing a method for determining process parameters of a thin strip continuous casting machine provided by an embodiment of the present application is shown;

[0100] Figure 2 A flowchart showing the construction of a fully coupled model of process parameters of a thin strip continuous casting machine provided by an embodiment of the present application is shown;

[0101] Figure 3 A flowchart showing a method for determining initial values of process parameters of a casting machine provided by an embodiment of the present application is shown;

[0102] Figure 4 A block diagram showing the composition of a device for determining process parameters of a thin strip continuous casting machine provided by an embodiment of the present application is shown;

[0103] Figure 5 A schematic structural diagram of a terminal provided by an embodiment of the present application is shown. Detailed Embodiments

[0104] Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully communicated to those skilled in the art.

[0105] At the same time, it should be understood that, for the sake of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationship.

[0106] The following description of at least one exemplary embodiment is merely illustrative and in no way limits the present application and its application or use.

[0107] Techniques, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods, and devices should be regarded as part of the specification.

[0108] It should be noted that: similar reference numerals and letters denote similar items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0109] Embodiments of the present application can be applied to a computer system / server, which can operate together with many other general-purpose or special-purpose computing system environments or configurations. Examples of well-known computing systems, environments, and / or configurations suitable for use with computer systems / servers include, but are not limited to: personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, microprocessor-based systems, set-top boxes, programmable consumer electronics, network personal computers, minicomputer systems, mainframe computer systems, and distributed cloud computing technology environments including any of the above systems, and so on.

[0110] The computer system / server can be described in the general context of computer system-executable instructions (such as program modules) executed by the computer system. Generally, program modules can include routines, programs, target programs, components, logic, data structures, etc., which perform specific tasks or implement specific abstract data types. The computer system / server can be implemented in a distributed cloud computing environment, where tasks are executed by remote processing devices linked through a communication network. In a distributed cloud computing environment, program modules can be located on local or remote computing system storage media including storage devices.

[0111] Embodiments of the present application provide a method for determining process parameters of a thin slab continuous casting machine, as Figure 1 shown, the method includes:

[0112] 101. Obtain the specification parameters of the target thin slab, screen multiple historical casting data that match the specification parameters, and determine the initial value of the casting machine process parameters of the target thin slab according to the casting machine process parameters in the multiple historical casting data.

[0113] Among them, the target thin slab is used to characterize the thin slab to be produced in the current casting; the specification parameters include, but are not limited to, thin slab specifications, production numbers, etc.; the historical casting production data is used to characterize the production data of the overall process of thin slab continuous casting; the casting machine process parameters are determined according to a pre-constructed fully coupled model of thin slab continuous casting machine process parameters, and can be expressed by the following formula,

[0114] ,

[0115] Among them, represents the thickness of the cast strip, represents the solidification parameter, represents the latent heat of solidification, represents the specific heat capacity of molten steel, represents the tundish temperature, represents the empirical temperature drop from the tundish to the molten pool, represents the liquidus temperature of molten steel, represents the liquid level height in the molten pool, represents the radius of the casting roll, represents the drawing speed, represents the meniscus size proportionality coefficient, represents the rolling parameters, represents the casting and rolling force, represents a constant. In the embodiments of the present application, the current execution end may be the control module of the thin slab continuous casting machine.

[0116] It should be noted that the initial values of the casting machine process parameters are determined by optimizing the casting machine process parameters recorded in the historical casting data. Specifically, they can be set according to the mean value, or can also be set according to other statistical values, such as the median, etc. In addition, before calculating the statistical value, the error value can be eliminated in advance, and then the mean value or median, etc. can be calculated to improve the accuracy of the statistical value.

[0117] 102. Control the operation of the casting machine based on the initial values of the casting machine process parameters, and real-time monitor the liquid level height in the molten pool. When the liquid level height is higher than the preset liquid level height threshold, periodically collect the periodic production data at preset time intervals, and determine the production status of the current period according to the periodic production data of the previous period.

[0118] Among them, the preset liquid level height threshold can be set according to the minimum stable height of the molten pool liquid level detection and the target molten pool liquid level. Preferably, it can take a value of 0.5r - 0.7r (r represents the radius of the casting roll); the preset time interval can take a value of 1 - 10 min; the periodic production data is used to characterize the production data within the preset time interval; the production status includes a stable state and an unstable state. In the embodiments of the present application, determining the production status of the current period according to the periodic production data of the previous period includes: obtaining each criterion parameter and the corresponding stable condition included in the production status stability criterion; obtaining the real-time values corresponding to each criterion parameter from the periodic production data of the previous period; when it is monitored that each real-time value reaches the corresponding stable condition, determining that the production status of the current period is a stable state.

[0119] Among them, each criterion parameter and the corresponding stable condition included in the production status stability criterion are as follows:

[0120] (1) The target thickness, the target molten pool liquid level, and the tundish target temperature have not changed;

[0121] (2) The range of the target drawing speed data is less than ( represents the maximum allowable fluctuation of the target drawing speed in the stable state, and can take a value of 0.1 - 1 m / min), and the range of the target casting and rolling force data is less than ( represents the maximum allowable fluctuation of the target casting and rolling force in the stable state, and can take a value of 0.2 - 2 kN);

[0122] (3) The range of the actual thickness data of the casting belt is less than ( which represents the maximum allowable fluctuation of the actual thickness of the casting belt in the stable state and can take values from 0.05 to 0.1 mm), and the range of the actual casting speed data is less than ( which represents the maximum allowable fluctuation of the actual casting speed of the casting machine in the stable state and can take values from 0.2 to 2 m / min), and the range of the actual casting rolling force data is less than ( which represents the maximum allowable fluctuation of the actual casting rolling force of the casting machine in the stable state and can take values from 0.2 to 3 kN);

[0123] (4) The deviation of the actual temperature of the tundish is less than ( which represents the maximum allowable deviation of the tundish temperature in the stable state and can take values from 10 to 20 °C), and the deviation of the molten pool liquid level height is less than ( which represents the maximum allowable error of the liquid level height in the stable state and can take values from 0.5 to 2 mm).

[0124] It should be noted that in the initial stage of the operation of the casting machine, the molten steel is poured from the ladle nozzle into the tundish. The tundish accumulates a certain amount of molten steel, and then the distribution ladle evenly distributes the molten steel in the tundish into the molten pool area of the casting machine to form a uniform and stable flow field in the molten pool. In this process, the continuous casting process has not started and there is no need to collect production data. Therefore, in the embodiments of the present application, setting to start collecting production data when the liquid level height is higher than the preset liquid level height threshold can effectively avoid unnecessary consumption of storage space.

[0125] 103. If the production state in the current cycle is a stable state, then according to the cycle production data of the current cycle and the full-coupling model of the thin strip continuous casting machine process parameters, calculate the correction value of the solidification parameters and the correction value of the rolling parameters, calculate the corrected set casting rolling force of the current cycle according to the cycle production data of the current cycle, and calculate the corrected set casting speed of the current cycle according to the set casting rolling force and the full-coupling model of the thin strip continuous casting machine process parameters, and adjust the initial values of the casting machine process parameters based on the correction value of the solidification parameters, the correction value of the rolling parameters, the set casting rolling force, and the set casting speed to obtain the updated values of the casting machine process parameters, so as to control the operation of the casting machine based on the updated values of the casting machine process parameters.

[0126] Among them, the types of the casting machine process parameters include solidification parameters, rolling parameters, casting rolling force, and casting speed. As a possible implementation manner, in the embodiments of the present application, when calculating the correction value of the solidification parameters, the correction value of the rolling parameters, the set casting rolling force, and the set casting speed, it can be calculated according to the mean value of the cycle production data of the current cycle, including:

[0127] First, according to the mean value of the periodic production data in the current period and the fully coupled model of the thin strip continuous casting machine process parameters, calculate the correction value of the solidification parameters and the correction value of the rolling parameters. Specifically, first perform a first mathematical transformation on the fully coupled model of the thin strip continuous casting machine process parameters to obtain an expression for the correction value of the solidification parameters, which is expressed as the following formula:

[0128] ,

[0129] ,

[0130] where, represents the actual solidification parameters in the current period; represents the mean value of the strip thickness in the current period; represents the mean value of the tundish temperature in the current period; represents the mean value of the liquid level height in the molten pool in the current period; represents the mean value of the casting speed in the current period; represents the mean value of the casting and rolling force in the current period; represents the correction value of the solidification parameters; represents the correction coefficient, which can take values from 0.4 to 0.9; represents the actual solidification parameters in the previous period.

[0131] At the same time, perform a second mathematical transformation on the fully coupled model of the thin strip continuous casting machine process parameters to obtain an expression for the correction value of the rolling parameters, which is expressed as the following formula:

[0132] ,

[0133] ,

[0134] ,

[0135] where, represents the rolling parameters in the extreme state where the casting and rolling force is the maximum and the strip thickness is the minimum in the current period; represents the maximum value of the casting and rolling force in the current period; represents the minimum value of the strip thickness in the current period; represents the rolling parameters in the extreme state where the casting and rolling force is the minimum and the strip thickness is the maximum in the current period; represents the minimum value of the casting and rolling force in the current period; represents the maximum value of the strip thickness in the current period; represents the correction value of the rolling parameters. It should be noted that in the expression for the correction value of the rolling parameters is the correction value of the solidification parameters, that is, .

[0136] Further, substituting the mean value of the periodic production data of the current period into the expression of the correction value of the solidification parameter, the correction value of the solidification parameter can be calculated. Then, substituting the mean value of the periodic production data of the current period and the correction value of the solidification parameter into the expression of the correction value of the rolling parameter, the correction value of the rolling parameter can be calculated.

[0137] Further, the set casting and rolling force after correction for the current period is calculated according to the mean value of the periodic production data of the current period, and specifically, it can be calculated according to the following formula:

[0138] ,

[0139] where, represents the set casting and rolling force after correction for the current period, represents the coefficient, and the value can be taken from 1 to 2.5.

[0140] Further, substituting the set casting and rolling force into the fully coupled model of the process parameters of the thin strip continuous casting machine, the set drawing speed after correction for the current period can be obtained. Specifically, the Newton iteration method can be used for iterative calculation and approximate solution, and the constructed function can be expressed as the following formula:

[0141] ,

[0142] ,

[0143] where, represents the constructed function, represents the result of the previous round of iterative calculation, represents the result of the current round of iterative calculation, represents the derivative of

[0144] Preferably, the initial value of the iterative calculation can be set to the mean value of the drawing speed of the current period , and the number of iterative calculations per period is 10 to 30 times.

[0145] Finally, based on the correction value of the solidification parameter, the correction value of the rolling parameter, the set casting and rolling force, and the set drawing speed, the initial values of the process parameters of the casting machine are adjusted to obtain the updated values of the process parameters of the casting machine, and the operation of the casting machine is controlled based on the updated values of the process parameters of the casting machine, thereby realizing the automatic adjustment of the process parameters of the casting machine, avoiding the problem of increased risk of operation errors caused by manual adjustment of the process parameters of the casting machine, and the problem of possible untimely adjustment, and avoiding the risk of product quality decline.

[0146] It should be noted that based on the same principle as in step 101 of the embodiment, when calculating the correction value of the solidification parameter, the correction value of the rolling parameter, setting the casting and rolling force, and setting the drawing speed, in addition to calculating according to the mean value, it can also be calculated according to other statistical values, such as the median, etc. Similarly, the error value can also be eliminated in advance before calculating the statistical value, and then the mean value or median, etc. can be calculated.

[0147] Compared with the prior art, in the embodiment of the present application, first, a full-coupling model of the process parameters of the thin strip continuous casting machine is pre-constructed to objectively describe the influence relationship between various factors in the thin strip continuous casting production process; further, according to the full-coupling model of the process parameters of the thin strip continuous casting machine, the process parameters required for controlling the casting machine are determined, and the initial value of the process parameters of the current casting is determined by the method of optimizing from the process parameters recorded in the production data of historical casting sequences, which solves the problem in the prior art that the initial setting of the process parameters cannot be carried out; then, according to the periodic production data of the stable state period and the full-coupling model of the process parameters of the thin strip continuous casting machine, the correction value of the solidification parameter, the correction value of the rolling parameter, the setting of the casting and rolling force, and the setting of the drawing speed are calculated, and the initial value of the process parameters of the casting machine is adjusted based on the above parameters to realize the automatic adjustment of the process parameters of the casting machine, avoiding the problem of increased risk of operation errors caused by manually adjusting the process parameters of the casting machine, and the problem of possible untimely adjustment, thereby avoiding the risk of deterioration of product quality.

[0148] In an embodiment of the present application, for further limitation and illustration, as Figure 2 shown, pre-constructing a full-coupling model of the process parameters of the thin strip continuous casting machine includes:

[0149] 201. Construct an expression for the superheat of molten steel.

[0150] The expression for the superheat of molten steel can be expressed by the following formula,

[0151] ,

[0152] where, represents the superheat of molten steel;

[0153] It should be noted that since the temperature of molten steel in the molten pool cannot be directly measured, in the embodiment of the present application, it is indirectly calculated by constructing an expression for the superheat of molten steel, where the empirical temperature drop from the tundish to the molten pool can take a value of 20 - 70 °C.

[0154] 202. Construct an expression for the solidification time of molten steel according to the geometric relationship in the molten pool.

[0155] The expression for the solidification time of molten steel can be expressed by the following formula,

[0156] ,

[0157] Among them, represents the solidification time of molten steel, represents the meniscus size at the edge of the molten pool, represents the height of the Kiss point;

[0158] It should be noted that under the condition of constant casting speed, the solidification time should be the ratio between the solidification arc length and the casting speed, that is, the expression of the solidification time of molten steel.

[0159] 203. Construct an expression for the meniscus size at the edge of the molten pool according to the finite element simulation results.

[0160] The expression for the meniscus size at the edge of the molten pool can be expressed as the following formula,

[0161] ;

[0162] It should be noted that since the meniscus size at the edge of the molten pool cannot be directly measured, therefore, an expression for the meniscus size at the edge of the molten pool can be constructed according to the finite element simulation results, where the meniscus size proportionality coefficient can take values from 0.00014 to 0.00044.

[0163] 204. According to the rolling theory, construct the first coupling relationship among the height of the Kiss point, the casting and rolling force, and the casting speed.

[0164] The first coupling relationship can be expressed as the following formula,

[0165] ;

[0166] Since the height of the Kiss point in the expression of the solidification time of molten steel cannot be directly obtained by measurement, in the embodiments of the present application, it is indirectly calculated based on the rolling theory. Specifically, first, substitute the actual working conditions of thin strip continuous casting into the Sims formula of the Orowan deformation zone equilibrium theory, and it can be deduced that:

[0167] ,

[0168] Among them, represents the influence coefficient considering the stress state caused by the friction force on the contact arc length, represents the deformation resistance of the billet shell, represents the width of the cast strip.

[0169] Furthermore, substitute the actual working condition parameters of thin strip continuous casting into the Shida Mao formula to calculate the stress state influence coefficient

[0170] ​ ,

[0171] ,

[0172] Among them, represents the thickness of the shell at the Kiss point.

[0173] In the thin strip continuous casting process, the average deformation rate of the shell can be calculated according to the following formula:

[0174] ,

[0175] Among them, represents the average deformation rate during the thin strip continuous casting process, that is .

[0176] Furthermore, using the expressions of , , to construct an iterative formula, substituting the production data under different casting sequences and different process parameters, and iteratively calculating to obtain the stress state influence coefficient and the Kiss point height , and further calculating the corresponding average deformation rate according to the expression. According to the results, there is an obvious linear relationship between and , which can be expressed by the following formula:

[0177] ,

[0178] Among them, , both represent constants.

[0179] Furthermore, multiplying the casting speed and the rolling force in the production data, there is also an obvious linear relationship between the product and , which can be expressed by the following formula:

[0180] ,

[0181] Among them, , both represent constants.

[0182] Furthermore, substituting and into , the following formula can be obtained:

[0183] ,

[0184] Let , ,

[0185] The first coupling relationship among the Kiss point height, the casting and rolling force, and the drawing speed can be obtained. Among them, can take values from 0.047 to 0.151, can take values from 74 to 222.

[0186] 205. According to the principle of thermodynamics, a second coupling relationship among the thickness of the cast strip, the solidification time of the molten steel, and the superheat of the molten steel is constructed.

[0187] The second coupling relationship can be expressed by the following formula,

[0188] ;

[0189] According to the solidification theory, on the premise that process conditions such as superheat and molten steel composition remain unchanged, the thickness of the cast strip conforms to the mathematical relationship , among which, represents the empirical solidification coefficient. However, in the actual thin slab continuous casting process, due to certain differences in the molten steel composition and temperature between different casting heats, the relationship between the thickness of the cast strip and the square root of the solidification time is not an ideal proportional relationship. Moreover, under different process conditions, the distance between the end position of the meniscus and the Kiss point will also change accordingly, which makes the accurate calculation of the solidification time complicated. Based on this, in the embodiments of the present application, according to the principle of thermodynamics, a heat balance relationship expression is constructed, that is, the heat flux through this interface is equal to the latent heat flux released by the solidification of the molten steel and the heat flux generated by the molten steel when its temperature drops from the injection temperature to the solidification temperature . It can be expressed by the following formula,

[0190] ,

[0191] Among them, represents the thermal conductivity, [[ID=4i]] represents the temperature, represents the distance along the diameter direction of the casting roll, represents the density, represents the enthalpy generated by the temperature drop of the molten steel.

[0192] Furthermore, the left side of the heat balance relationship expression represents the total heat flux through the solid-liquid interface. Since most of the heat transfer behaviors in the thin slab continuous casting process occur between the molten pool and the casting roll, this value can be represented by the on-site measured heat flux density calculated from the temperature difference of the cooling water of the casting roll. It can be expressed by the following formula,

[0193] ,

[0194] Among them, It should be noted that in the translation, "4i" in "[[ID=4i]] " is likely a misprint in the original text. It should probably be "41" as per the context. represents the measured heat flux density on site, represents the cooling water flow rate through the casting roll, represents the specific heat capacity of water, represents the temperature rise of the cooling water at the outlet of the casting roll compared to that at the inlet, represents the cooling arc length, i.e., the actual contact length between the molten pool and the casting roll, represents the bandwidth.

[0195] Furthermore, the two terms on the right side of the heat balance relationship expression are respectively the latent heat of solidification released during the solidification process and the heat flux generated by the molten steel when its temperature drops from temperature to temperature, which can be expressed by the following formula,

[0196] ,

[0197] ,

[0198] wherein, represents the specific heat capacity of the molten steel, represents the molten steel flow rate in the current molten pool, which can be expressed as .

[0199] Furthermore, since the relationship is satisfied in the molten pool, therefore, combining , , , , , the heat balance relationship expression can be rewritten as the following expression,

[0200] .

[0201] Furthermore, rewrite the rewritten heat balance relationship expression in the form of , and the following expression can be obtained,

[0202] ,

[0203] Let ,

[0204] and substitute the actual production data into and , it can be known that during the actual production process, the solidification parameter changes very little, so it can be regarded as a constant, and thus the second coupling relationship between the strip thickness, the solidification time of the molten steel, and the superheat of the molten steel is obtained.

[0205] 206. Substitute the expressions of molten steel superheat, solidification time of molten steel, dimensions of the meniscus at the edge of the molten pool, and the first coupling relation into the second coupling relation to obtain the fully coupled model of the process parameters of the thin slab continuous casting machine.

[0206] In an embodiment of the present application, for further limitation and illustration, the overall process of thin slab continuous casting includes a starting pouring stage, a production stage, and an ending stage. As Figure 3 shown, in step 101 of the embodiment, obtain the specification parameters of the target thin strip, screen a plurality of historical pouring production data that match the specification parameters, and determine the initial values of the process parameters of the casting machine for the target thin strip according to the process parameters of the casting machine in the plurality of historical pouring production data, including:

[0207] 301. Obtain the specification parameters of the target thin strip, and screen a plurality of first historical pouring production data that match the specification parameters.

[0208] Among them, the first historical pouring production data is used to represent all the historical pouring production data in the database that have the same specification parameters as the specification parameters of the target thin strip; the first historical pouring production data includes a pouring score; the pouring score is used to represent the evaluation score for the overall process of thin slab continuous casting, and is calculated based on the first-stage score in the starting pouring stage, the second-stage score in the production stage, and the third-stage score in the ending stage. The first-stage score is used to represent the evaluation score for the data fluctuation degree in the starting pouring stage, the second-stage score is used to represent the average value of the stability scores of each stable state period included in the production stage, and the third-stage score is used to represent the evaluation score for the production quality of the overall process of thin slab continuous casting.

[0209] Specifically, the calculation process of the pouring score includes:

[0210] First, calculate the first-stage score, including: obtain each criterion parameter and the corresponding target value included in the ending criterion of the starting pouring stage; when the liquid level height is higher than the preset liquid level height threshold, collect the real-time values corresponding to each criterion parameter in real time; when it is monitored that all the real-time values reach the corresponding target values, determine that the starting pouring stage ends, and calculate the first-stage score according to the following formula,

[0211] ,

[0212] Among them, represents the first-stage score, , , , , all represent weight coefficients, represents the range of the actual drawing speed data during the starting pouring process, represents the range of the molten pool liquid level data during the starting pouring process, Represents the range of the actual casting and rolling force data during the starting pouring process. Represents the range of the actual roll gap data during the starting pouring process. Represents the duration of the starting pouring stage.

[0213] Among them, each criterion parameter included in the end criterion of the starting pouring stage may include the casting speed, the molten pool liquid level height, the casting and rolling force, and the loop height. The end criterion of the starting pouring stage is as follows:

[0214] (1) The actual casting speed reaches the target casting speed, and the error ( represents the maximum allowable error between the actual casting speed and the target casting speed, and can take values from 0.5 to 2 m / min) and the duration within this range reaches (represents the casting speed stability determination time, and can take values from 2 to 10 s);

[0215] (2) The actual molten pool liquid level reaches the target molten pool liquid level, and the error ( represents the maximum allowable error between the actual molten pool liquid level and the target molten pool liquid level, and can take values from 0.2 to 3 mm) and the duration within this range reaches (represents the molten pool liquid level stability determination time, and can take values from 3 to 15 s);

[0216] (3) The actual casting and rolling force reaches the target casting and rolling force, and the error ( represents the maximum allowable error between the actual casting and rolling force and the target casting and rolling force, and can take values from 0.1 to 5 kN) and the duration within this range reaches (represents the casting and rolling force stability determination time, and can take values from 2 to 10 s);

[0217] (4) The actual loop height reaches the target loop height, and the error ( represents the maximum allowable error between the actual loop height and the target loop height, and can take values from 5 to 50 mm) and the duration within this range reaches (represents the loop stability determination time, and can take values from 2 to 10 s).

[0218] It should be noted that the data ranges , , , and the starting pouring duration , the smaller the numerical value, the more stable the starting pouring process, the smaller the adjustment made by the current execution end, and the more reference value the parameters set in the initial stage have.

[0219] Further, calculate the second-stage score, including: taking each cycle of the stable states as the target stable cycle one by one; obtaining the cycle production data of the target stable cycle, and calculating the interquartile range value corresponding to each cycle production data; calculating the stability score of the target stable cycle according to the following formula,

[0220]

[0221] where, represents the stability score of the target stable cycle, represents the weight coefficient of the th cycle production data, represents the th interquartile range value of the cycle production data (i.e., IOR, used to evaluate the dispersion degree of the data), represents the number of cycle production data;

[0222] Determine the mean value of the stability scores of each target stable cycle as the second-stage score.

[0223] Further, calculate the third-stage score, including: when it is monitored that the casting machine stops running, calculate the third-stage score according to the following formula,

[0224] ,

[0225] where, represents the third-stage score, , , all represent weight coefficients, represents the remaining molten steel weight of the tundish at the moment of stopping casting, represents the remaining molten steel weight of the intermediate tundish at the moment of stopping casting, represents the duration of the casting campaign.

[0226] It should be noted that at the end of a single casting campaign, due to the erosion of refractories and the out-of-control of the molten steel temperature in the intermediate tundish, the problems existing in a single casting campaign will be amplified at the end of casting, resulting in the decline of product quality and strip breakage, and finally forced to stop casting in advance. Based on this, in the embodiments of the present application, the remaining molten steel weights of the tundish and the intermediate tundish at the moment of stopping casting and the duration of the entire casting campaign are used to evaluate the production quality of the overall process of thin slab continuous casting.

[0227] Finally, sum the weighted sum of the first-stage score, the second-stage score, and the third-stage score with the correction score to obtain the casting campaign score.

[0228] Specifically, the casting campaign score can be expressed by the following formula,

[0229] ,

[0230] Among them, represents the casting heat score, represents the score in the first stage, represents the score in the second stage, represents the score in the third stage, represents the corrected score (used to represent the manual evaluation score for this casting heat), , , all represent the weight coefficients.

[0231] 302. Extract a preset number of second historical casting heat production data from multiple first historical casting heat production data in descending order of the casting heat score.

[0232] Among them, the second historical casting heat production data is used to represent a part of the historical casting heat production data extracted from the first historical casting heat production data.

[0233] Specifically, multiple first historical production data can be sorted according to the casting heat score in the historical production data to obtain a casting heat score sequence; extract a preset number of historical production data from the casting heat score sequence in descending order of the casting heat score as the second historical casting heat production data. Among them, the preset number can take values from 3 to 10.

[0234] 303. Obtain the average value of the casting machine process parameters for each corresponding second historical casting heat production data, and determine the initial value of the casting machine process parameters of the target thin strip as the weighted sum of the average values of the casting machine process parameters for each.

[0235] Among them, the average value of the casting machine process parameters for each casting heat is used to represent the average value of the casting machine process parameters in the overall process of thin strip continuous casting.

[0236] Specifically, the initial value of the casting machine process parameters can be determined according to the following formula,

[0237] ,

[0238] Among them, represents the initial value of the casting machine process parameters to be determined, represents the th average value of the casting machine process parameters for each casting heat, represents the weight parameter, represents the number of average values of the casting machine process parameters for each casting heat, .

[0239] The present application provides a method for determining the process parameters of a thin strip continuous casting machine. First, the specification parameters of the target thin strip are obtained, and multiple historical casting production data matching the specification parameters are screened. According to the casting machine process parameters in the multiple historical casting production data, the initial value of the casting machine process parameters for the target thin strip is determined. The casting machine process parameters are determined according to a pre-constructed fully coupled model of the thin strip continuous casting machine process parameters. Based on the initial value of the casting machine process parameters, the casting machine is controlled to operate, and the liquid level height in the molten pool is monitored in real time. When the liquid level height is higher than the preset liquid level height threshold, periodic production data is collected periodically at preset time intervals, and the production status of the current cycle is determined according to the production data of the previous cycle. If the production status of the current cycle is a stable state, then according to the production data of the current cycle and the fully coupled model of the thin strip continuous casting machine process parameters, the correction value of the solidification parameter and the correction value of the rolling parameter are calculated, the set rolling force corrected in the current cycle is calculated according to the production data of the current cycle, and the set drawing speed corrected in the current cycle is calculated according to the set rolling force and the fully coupled model of the thin strip continuous casting machine process parameters. And the initial value of the casting machine process parameters is adjusted based on the correction value of the solidification parameter, the correction value of the rolling parameter, the set rolling force, and the set drawing speed to obtain an updated value of the casting machine process parameters, so as to control the operation of the casting machine based on the updated value of the casting machine process parameters. The types of the casting machine process parameters include solidification parameters, rolling parameters, rolling force, and drawing speed. Compared with the prior art, in the embodiment of the present application, first, by pre-constructing a fully coupled model of the thin strip continuous casting machine process parameters, an objective description of the influence relationship between various factors in the thin strip continuous casting production process is realized; further, according to the fully coupled model of the thin strip continuous casting machine process parameters, the casting machine process parameters required for controlling the casting machine are determined, and the initial value of the casting machine process parameters for this casting is determined by the method of optimizing from the casting machine process parameters recorded in the historical casting production data, solving the problem that the process parameters cannot be initially set in the prior art; then, according to the production data of the stable state cycle and the fully coupled model of the thin strip continuous casting machine process parameters, the correction value of the solidification parameter, the correction value of the rolling parameter, the set rolling force, and the set drawing speed are calculated, and the initial value of the casting machine process parameters is adjusted based on the above parameters to realize the automatic adjustment of the casting machine process parameters, avoiding the problem of increased risk of operation errors caused by manually adjusting the casting machine process parameters, and the problem of possible untimely adjustment, thereby avoiding the risk of product quality decline.

[0240] Further, as an implementation of the above Figure 1 shown method, the embodiment of the present application provides a device for determining the process parameters of a thin strip continuous casting machine, as Figure 4 shown, the device includes:

[0241] Casting machine process parameter initialization module 41, periodic production status judgment module 42, casting machine process parameter update module 43;

[0242] A casting machine process parameter initialization module 41 is used to obtain the specification parameters of the target thin strip, screen multiple historical casting production data that match the specification parameters, and determine the initial values of the casting machine process parameters of the target thin strip based on the casting machine process parameters in the multiple historical casting production data. The casting machine process parameters are determined based on a pre-established fully coupled model of the process parameters of the thin strip continuous casting machine;

[0243] a cycle production status determination module 42 for controlling the operation of the casting machine based on the initial values of the casting machine process parameters, monitoring the liquid level in the molten pool in real time, and periodically collecting cycle production data at preset time intervals when the liquid level is higher than a preset liquid level threshold, and determining the production status of the current cycle based on the cycle production data of the previous cycle;

[0244] The casting machine process parameter updating module 43 is used to calculate the correction value of the solidification parameter and the correction value of the rolling parameter according to the cycle production data of the current cycle and the fully coupled model of the thin strip continuous casting casting machine process parameters if the production status of the current cycle is a stable state, calculate the set casting and rolling force after correction of the current cycle according to the cycle production data of the current cycle, and calculate the set pulling speed after correction of the current cycle according to the set casting and rolling force and the fully coupled model of the thin strip continuous casting casting machine process parameters, and adjust the initial value of the casting machine process parameter based on the correction value of the solidification parameter, the correction value of the rolling parameter, the set casting and rolling force and the set pulling speed to obtain the updated value of the casting machine process parameter, so as to control the operation of the casting machine based on the updated value of the casting machine process parameter, and the types of casting machine process parameters include solidification parameters, rolling parameters, casting and rolling force and pulling speed.

[0245] In a specific application scenario, the fully coupled model of process parameters of the thin strip continuous casting machine is expressed as the following formula:

[0246] ,

[0247] in, Indicates the thickness of the cast strip, represents the solidification parameter, represents the latent heat of solidification, represents the specific heat capacity of molten steel, Indicates the tundish temperature, Indicates the empirical temperature drop from the tundish to the molten pool, represents the liquidus temperature of molten steel, Indicates the liquid level in the molten pool. Indicates the radius of the casting roll, Indicates pulling speed, represents the meniscus size proportionality coefficient, represents the rolling parameters, represents the casting and rolling force, represents a constant.

[0248] In a specific application scenario, the device further includes a model construction module for:

[0249] Construct an expression for the superheat of molten steel, expressed as the following formula,

[0250] ,

[0251] where, represents the superheat of molten steel;

[0252] Construct an expression for the solidification time of molten steel based on the geometric relationship in the molten pool, expressed as the following formula,

[0253] ,

[0254] where, represents the solidification time of molten steel, represents the meniscus size at the edge of the molten pool, represents the height of the Kiss point;

[0255] Construct an expression for the meniscus size at the edge of the molten pool based on the finite element simulation results, expressed as the following formula,

[0256] ;

[0257] According to rolling theory, construct a first coupling relationship among the height of the Kiss point, the casting and rolling force, and the drawing speed, expressed as the following formula,

[0258] ;

[0259] According to the principle of thermodynamics, construct a second coupling relationship among the thickness of the cast strip, the solidification time of molten steel, and the superheat of molten steel, expressed as the following formula,

[0260] ;

[0261] Substitute the expression for the superheat of molten steel, the expression for the solidification time of molten steel, the expression for the meniscus size at the edge of the molten pool, and the first coupling relationship into the second coupling relationship to obtain a fully coupled model of the process parameters of the thin slab continuous casting machine.

[0262] In a specific application scenario, the overall process of thin slab continuous casting includes a starting pouring stage, a production stage, and an ending stage. The initial setting module of the casting machine process parameters is used for:

[0263] Obtain the specification parameters of the target thin strip, and screen multiple pieces of first historical casting production data that match the specification parameters. The first historical casting production data includes a casting score, which is used to represent the evaluation score for the overall process of thin strip continuous casting. It is obtained by summing the weighted sum of the first-stage score in the starting casting stage, the second-stage score in the production stage, and the third-stage score in the ending stage with a correction score;

[0264] Extract a preset number of second historical casting production data from the multiple pieces of first historical casting production data in descending order of the casting score;

[0265] Obtain the average value of the casting machine process parameters corresponding to each piece of the second historical casting production data respectively, and determine the weighted sum of the average values of the casting machine process parameters as the initial value of the casting machine process parameters of the target thin strip. The average value of the casting machine process parameters for each casting is used to represent the average value of the casting machine process parameters in the overall process of thin strip continuous casting.

[0266] In a specific application scenario, the first-stage score is used to represent the evaluation score for the data fluctuation degree in the starting casting stage. The device further includes a casting score calculation module, which is used for:

[0267] Calculate the first-stage score, specifically used for:

[0268] Obtain each criterion parameter and the corresponding target value included in the ending criterion of the starting casting stage;

[0269] When the liquid level height is higher than the preset liquid level height threshold, collect the real-time values corresponding to each criterion parameter in real time;

[0270] When it is monitored that all the real-time values reach the corresponding target values, determine that the starting casting stage ends, and calculate the first-stage score according to the following formula,

[0271] ,

[0272] Wherein, represents the first-stage score, , , , , all represent weight coefficients, represents the range of the actual drawing speed data during the starting casting process, represents the range of the molten pool liquid level data during the starting casting process, represents the range of the actual rolling force data during the starting casting process, represents the range of the actual roll gap data during the starting casting process, represents the duration of the starting casting stage.

[0273] In a specific application scenario, the second-stage score is used to represent the mean of the stability scores of each stable state cycle included in the production stage. The heat score calculation module is further configured to:

[0274] Calculate the second-stage score, specifically for:

[0275] Take each cycle of each stable state as the target stable cycle one by one;

[0276] Obtain the cycle production data of the target stable cycle, and calculate the interquartile range value corresponding to each cycle production data;

[0277] Calculate the stability score of the target stable cycle according to the following formula,

[0278] ,

[0279] where, represents the stability score of the target stable cycle, represents the [Here, the content seems incomplete. It should be something like "the weight coefficient of the nth" but the specific "nth" is missing in the original] weight coefficient of the nth cycle production data, represents the [Same as above, incomplete "nth"] interquartile range value of the nth cycle production data, represents the number of cycle production data;

[0280] Determine the mean of the stability scores of each target stable cycle as the second-stage score.

[0281] In a specific application scenario, the third-stage score is used to represent the evaluation score of the production quality of the overall thin slab continuous casting process. The heat score calculation module is further configured to:

[0282] Calculate the third-stage score, specifically for:

[0283] When it is monitored that the casting machine stops running, calculate the third-stage score according to the following formula,

[0284] ,

[0285] where, represents the third-stage score, , , all represent weight coefficients, represents the remaining weight of the molten steel in the ladle at the moment of stopping casting, represents the remaining weight of the molten steel in the tundish at the moment of stopping casting, represents the heat duration.

[0286] The present application provides a device for determining process parameters of a thin strip continuous casting machine. First, the specification parameters of a target thin strip are obtained, and a plurality of historical casting data matching the specification parameters are screened. According to the casting machine process parameters in the plurality of historical casting data, an initial value of the casting machine process parameters for the target thin strip is determined. The casting machine process parameters are determined according to a fully coupled model of thin strip continuous casting machine process parameters pre-constructed; the casting machine is controlled based on the initial value of the casting machine process parameters, and the liquid level height in the molten pool is monitored in real time. When the liquid level height is higher than a preset liquid level height threshold, periodic production data is collected periodically at preset time intervals, and the production state of the current period is determined according to the periodic production data of the previous period; if the production state of the current period is a stable state, then according to the periodic production data of the current period and the fully coupled model of thin strip continuous casting machine process parameters, a correction value of the solidification parameter and a correction value of the rolling parameter are calculated, a set rolling force corrected in the current period is calculated according to the periodic production data of the current period, and a set drawing speed corrected in the current period is calculated according to the set rolling force and the fully coupled model of thin strip continuous casting machine process parameters. And the initial value of the casting machine process parameters is adjusted based on the correction value of the solidification parameter, the correction value of the rolling parameter, the set rolling force, and the set drawing speed to obtain an updated value of the casting machine process parameters, so as to control the operation of the casting machine based on the updated value of the casting machine process parameters. The types of the casting machine process parameters include solidification parameters, rolling parameters, rolling force, and drawing speed. Compared with the prior art, in the embodiment of the present application, first, by pre-constructing a fully coupled model of thin strip continuous casting machine process parameters, an objective description of the influence relationship between various factors in the thin strip continuous casting production process is realized; further, according to the fully coupled model of thin strip continuous casting machine process parameters, the casting machine process parameters required for controlling the casting machine are determined, and the initial value of the casting machine process parameters for this casting is determined by the method of optimizing from the casting machine process parameters recorded in the historical casting data, solving the problem that the process parameters cannot be initially set in the prior art; then, according to the periodic production data of the stable state period and the fully coupled model of thin strip continuous casting machine process parameters, a correction value of the solidification parameter, a correction value of the rolling parameter, a set rolling force, and a set drawing speed are calculated, and the initial value of the casting machine process parameters is adjusted based on the above parameters to realize the automatic adjustment of the casting machine process parameters, avoiding the problem of increased risk of operation errors caused by manually adjusting the casting machine process parameters, and the problem of possible untimely adjustment, thereby avoiding the risk of product quality decline.

[0287] According to an embodiment of the present application, a storage medium is provided. The storage medium stores at least one executable instruction, and the computer executable instruction can execute the method for determining the process parameters of the thin strip continuous casting machine in any of the above method embodiments.

[0288] Based on such understanding, the technical solution of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, a USB flash drive, a mobile hard disk, etc.), including several instructions for causing a computer device (such as a personal computer, a server, or a network device, etc.) to execute the methods described in various implementation scenarios of the present application.

[0289] Figure 5 FIG. shows a schematic structural diagram of a terminal provided according to an embodiment of the present application. The specific implementation of the terminal in the specific embodiments of the present application is not limited.

[0290] As Figure 5 shown, the terminal may include: a processor 502, a communication interface 504, a memory 506, and a communication bus 508.

[0291] Wherein: the processor 502, the communication interface 504, and the memory 506 communicate with each other through the communication bus 508.

[0292] The communication interface 504 is used to communicate with network elements of other devices such as clients or other servers, etc.

[0293] The processor 502 is used to execute the program 510, and specifically can execute the relevant steps in the embodiments of the method for determining the process parameters of the thin strip continuous casting machine described above.

[0294] Specifically, the program 510 may include program code, and the program code includes computer operation instructions.

[0295] The processor 502 may be a central processing unit CPU, or a specific integrated circuit ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present application. One or more processors included in the computer device may be of the same type of processor, such as one or more CPUs; or may be of different types of processors, such as one or more CPUs and one or more ASICs.

[0296] The memory 506 is used to store the program 510. The memory 506 may include a high-speed RAM memory, and may also include a non-volatile memory, such as at least one disk memory.

[0297] The program 510 is specifically used to cause the processor 502 to perform the following operations:

[0298] Obtain the specification parameters of the target thin strip, screen multiple historical casting production data that match the specification parameters, and determine the initial value of the casting machine process parameters of the target thin strip according to the casting machine process parameters in the multiple historical casting production data. The casting machine process parameters are determined according to a pre-constructed fully coupled model of the thin strip continuous casting machine process parameters;

[0299] Control the operation of the casting machine based on the initial value of the casting machine process parameters, and monitor the liquid level height in the molten pool in real time. When the liquid level height is higher than the preset liquid level height threshold, collect periodic production data at preset time intervals, and determine the production status of the current period according to the periodic production data of the previous period;

[0300] If the production status of the current period is a stable state, calculate the correction value of the solidification parameter and the correction value of the rolling parameter according to the periodic production data of the current period and the fully coupled model of the thin strip continuous casting machine process parameters, calculate the set casting and rolling force corrected in the current period according to the periodic production data of the current period, and calculate the set drawing speed corrected in the current period according to the set casting and rolling force and the fully coupled model of the thin strip continuous casting machine process parameters, and adjust the initial value of the casting machine process parameters based on the correction value of the solidification parameter, the correction value of the rolling parameter, the set casting and rolling force, and the set drawing speed to obtain an updated value of the casting machine process parameters, so as to control the operation of the casting machine based on the updated value of the casting machine process parameters. The types of the casting machine process parameters include solidification parameters, rolling parameters, casting and rolling force, and drawing speed.

[0301] The storage medium may also include an operating system and a network communication module. The operating system is a program that manages the hardware and software resources of the physical device for the method of determining the thin strip continuous casting machine process parameters, and supports the operation of the information processing program and other software and / or programs. The network communication module is used to implement the communication between the components inside the storage medium, and the communication between other hardware and software in the information processing physical device.

[0302] Each embodiment in this specification is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts between the embodiments, they can be referred to each other. For the system embodiment, since it basically corresponds to the method embodiment, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiment.

[0303] The methods and systems of the present application can be implemented in many ways. For example, the methods and systems of the present application can be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above order of the steps for the methods is only for illustration, and the steps of the methods of the present application are not limited to the specific order described above, unless otherwise specifically stated. In addition, in some embodiments, the present application can also be implemented as a program recorded in a recording medium, and these programs include machine-readable instructions for implementing the methods according to the present application. Therefore, the present application also covers a recording medium storing a program for executing the methods according to the present application.

[0304] Obviously, those skilled in the art should understand that the above-mentioned modules or steps of the present application can be implemented by a general-purpose computing device. They can be concentrated on a single computing device or distributed on a network composed of multiple computing devices. Optionally, they can be implemented by program codes executable by the computing device. Thus, they can be stored in a storage device and executed by the computing device. And in some cases, the steps shown or described can be executed in a different order from here, or they can be separately fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module for implementation. In this way, the present application is not limited to any specific combination of hardware and software.

[0305] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A method for determining process parameters of a thin strip continuous casting machine, characterized in that, Including: Obtain the specification parameters of the target thin strip, screen multiple historical casting production data that match the specification parameters, and determine the initial value of the casting machine process parameters of the target thin strip according to the casting machine process parameters in the multiple historical casting production data. The casting machine process parameters are determined according to a fully coupled model of the thin strip continuous casting machine process parameters pre-constructed; Control the operation of the casting machine based on the initial value of the casting machine process parameters, and monitor the liquid level height in the molten pool in real time. When the liquid level height is higher than the preset liquid level height threshold, periodically collect periodic production data at preset time intervals, and determine the production status of the current period according to the periodic production data of the previous period; If the production status of the current period is a stable state, then calculate the correction value of the solidification parameter and the correction value of the rolling parameter according to the periodic production data of the current period and the fully coupled model of the thin strip continuous casting machine process parameters, calculate the set casting and rolling force corrected in the current period according to the periodic production data of the current period, and calculate the set drawing speed corrected in the current period according to the set casting and rolling force and the fully coupled model of the thin strip continuous casting machine process parameters, and adjust the initial value of the casting machine process parameters based on the correction value of the solidification parameter, the correction value of the rolling parameter, the set casting and rolling force, and the set drawing speed to obtain an updated value of the casting machine process parameters, so as to control the operation of the casting machine based on the updated value of the casting machine process parameters. The types of the casting machine process parameters include solidification parameters, rolling parameters, casting and rolling force, and drawing speed; The fully coupled model of the thin strip continuous casting machine process parameters is expressed by the following formula ， Among them, represents the thickness of the casting belt, represents the solidification parameter, represents the latent heat of solidification, represents the specific heat capacity of the molten steel, represents the tundish temperature, represents the empirical temperature drop from the tundish to the molten pool, represents the liquidus temperature of the molten steel, represents the liquid level height in the molten pool, represents the radius of the casting roll, represents the drawing speed, represents the meniscus size proportionality coefficient, represents the rolling parameter, represents the casting and rolling force, represents a constant.

2. The method according to claim 1, characterized in that, Pre-construct a fully coupled model of the thin strip continuous casting machine process parameters, including: Construct an expression for the superheat of molten steel, expressed by the following formula ， Among them, represents the superheat of molten steel; Construct an expression for the solidification time of molten steel according to the geometric relationship in the molten pool, expressed by the following formula ， Among them, represents the solidification time of molten steel, represents the meniscus size at the edge of the molten pool, represents the height of the Kiss point; Construct an expression for the meniscus size at the edge of the molten pool according to the finite element simulation results, expressed by the following formula ； According to rolling theory, construct a first coupling relationship between the Kiss point height, the casting and rolling force, and the drawing speed, expressed by the following formula ； According to the principle of thermodynamics, construct a second coupling relationship between the thickness of the cast strip, the solidification time of molten steel, and the superheat of molten steel, expressed by the following formula ； Substitute the superheat expression of molten steel, the solidification time expression of molten steel, the meniscus size expression at the edge of the molten pool, and the first coupling relationship into the second coupling relationship to obtain a fully coupled model of the thin strip continuous casting machine process parameters.

3. The method according to claim 1, wherein The overall process of thin strip continuous casting includes the starting casting stage, the production stage, and the ending stage. The obtaining of the specification parameters of the target thin strip, the screening of multiple historical casting production data that match the specification parameters, and the determination of the initial value of the casting machine process parameters of the target thin strip according to the casting machine process parameters in the multiple historical casting production data include: Obtain the specification parameters of the target thin strip, and screen a plurality of first historical casting production data that match the specification parameters. The first historical casting production data includes a casting score, which is used to characterize the evaluation score for the overall process of thin strip continuous casting, and is obtained by summing the weighted sum of the first-stage score in the starting casting stage, the second-stage score in the production stage, and the third-stage score in the ending stage with a correction score; Extract a preset number of second historical casting production data from the plurality of first historical casting production data in descending order of the casting score; Obtain the average value of the casting machine process parameters corresponding to each of the second historical casting production data respectively, and determine the initial value of the casting machine process parameters of the target thin strip as the weighted sum of the average values of the casting machine process parameters. The average value of the casting machine process parameters of each casting is used to characterize the average value of the casting machine process parameters in the overall process of thin strip continuous casting.

4. The method according to claim 3, wherein The first-stage score is used to characterize the evaluation score for the data fluctuation degree in the starting casting stage. Calculating the first-stage score includes: Obtain each criterion parameter and the corresponding target value included in the ending criterion of the starting casting stage; When the liquid level height is higher than the preset liquid level height threshold, collect the real-time values corresponding to each criterion parameter in real time; When it is monitored that all the real-time values reach the corresponding target values, determine that the starting casting stage ends, and calculate the first-stage score according to the following formula ， Among them, represents the score of the first stage, represents the weight coefficient of the range of the actual drawing speed data during the starting pouring process in the calculation of the score of the first stage, represents the weight coefficient of the range of the molten pool liquid level data during the starting pouring process in the calculation of the score of the first stage, represents the weight coefficient of the range of the actual rolling force data during the starting pouring process in the calculation of the score of the first stage, represents the weight coefficient of the range of the actual roll gap data during the starting pouring process in the calculation of the score of the first stage, represents the weight coefficient of the duration of the starting pouring stage in the calculation of the score of the first stage, represents the range of the actual drawing speed data during the starting pouring process, represents the range of the molten pool liquid level data during the starting pouring process, represents the range of the actual rolling force data during the starting pouring process, represents the range of the actual roll gap data during the starting pouring process, represents the duration of the starting pouring stage.

5. The method according to claim 3, characterized in that, The second-stage score is used to characterize the average value of the stability scores of each stable state period included in the production stage. Calculating the second-stage score includes: Take each period of each stable state as the target stable period; Obtain the periodic production data of the target stable period, and calculate the interquartile range value corresponding to each periodic production data; Calculate the stability score of the target stable period according to the following formula ， Among them, represents the stability score of the target stable period, represents the weight coefficient of the production data of the th cycle, represents the interquartile range value of the production data of the th cycle, represents the quantity of the production data of the cycle; Determine the average value of the stability scores of each target stable period as the second-stage score.

6. The method according to claim 3, wherein The third-stage score is used to characterize the evaluation score for the production quality of the overall process of thin strip continuous casting. Calculating the third-stage score includes: When it is monitored that the casting machine stops running, calculate the third-stage score according to the following formula ， Among them, represents the score in the third stage, represents the weight coefficient of the remaining molten steel weight in the ladle at the moment of stopping casting in the calculation of the score in the third stage, represents the weight coefficient of the remaining molten steel weight in the tundish at the moment of stopping casting in the calculation of the score in the third stage, represents the weight coefficient of the casting duration in the calculation of the score in the third stage, represents the remaining molten steel weight in the ladle at the moment of stopping casting, represents the remaining molten steel weight in the tundish at the moment of stopping casting, represents the casting duration.

7. An apparatus for determining process parameters of a thin strip continuous casting machine, characterized in that, Including: A casting machine process parameter initial setting module, which is used to obtain the specification parameters of the target thin strip, screen a plurality of historical casting production data that match the specification parameters, and determine the initial value of the casting machine process parameters of the target thin strip according to the casting machine process parameters in the plurality of historical casting production data. The casting machine process parameters are determined according to a fully coupled model of thin strip continuous casting machine process parameters constructed in advance; A periodic production state judgment module, which is used to control the operation of the casting machine based on the initial value of the casting machine process parameters, and monitor the liquid level height in the molten pool in real time. When the liquid level height is higher than the preset liquid level height threshold, periodically collect periodic production data at preset time intervals, and determine the production state of the current period according to the periodic production data of the previous period; The casting machine process parameter update module is used to, if the production status in the current cycle is a stable state, calculate the correction value of the solidification parameter and the correction value of the rolling parameter according to the cycle production data in the current cycle and the full-coupling model of the thin strip continuous casting machine process parameters, calculate the set casting and rolling force corrected in the current cycle according to the cycle production data in the current cycle, and calculate the set drawing speed corrected in the current cycle according to the set casting and rolling force and the full-coupling model of the thin strip continuous casting machine process parameters, and adjust the initial values of the casting machine process parameters based on the correction value of the solidification parameter, the correction value of the rolling parameter, the set casting and rolling force, and the set drawing speed to obtain the updated values of the casting machine process parameters, so as to control the operation of the casting machine based on the updated values of the casting machine process parameters. The types of the casting machine process parameters include solidification parameters, rolling parameters, casting and rolling force, and drawing speed; The full-coupling model of the thin strip continuous casting machine process parameters is expressed by the following formula ， Among them, represents the thickness of the casting belt, represents the solidification parameter, represents the latent heat of solidification, represents the specific heat capacity of molten steel, represents the tundish temperature, represents the empirical temperature drop from the tundish to the molten pool, represents the liquidus temperature of molten steel, represents the liquid level height in the molten pool, represents the radius of the casting roll, represents the casting speed, represents the meniscus size proportionality coefficient, represents the rolling parameter, represents the casting and rolling force, represents a constant.

8. A storage medium storing at least one executable instruction, characterized in that, The executable instructions cause the processor to perform the operations corresponding to the method for determining the thin strip continuous casting machine process parameters according to any one of claims 1-6.

9. A terminal, comprising: A processor, a memory, a communication interface, and a communication bus. The processor, the memory, and the communication interface complete communication with each other through the communication bus; The memory is used to store at least one executable instruction, wherein the executable instruction causes the processor to perform the operations corresponding to the method for determining the thin strip continuous casting machine process parameters according to any one of claims 1-6.

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