A casting state judgment method, system and equipment for metal horizontal continuous casting

Abstract

The present application relates to the field of metal casting technology, and specifically to a method, system and device for judging the casting state of metal horizontal continuous casting, the method comprising: setting a measurement area and a measurement point on a horizontal continuous casting production line; obtaining a measurement time interval, collecting the crystallizer temperature and the temperature measured between rollers; obtaining a heat conduction model of the casting; obtaining the comprehensive temperature error at each measurement moment; optimizing the heat conduction model in combination with an optimization algorithm; setting the measurement moment and sampling point, obtaining the relative discrete value at each measurement moment; and judging the casting state of the horizontal continuous casting production line. The present application aims to improve the accuracy of obtaining the surface temperature of the casting by optimizing the heat transfer model of the casting in real time, thereby enhancing the judgment of the casting state of the casting.

Description

Technical Field

[0001] The present application relates to the technical field of metal casting, and in particular to a casting state judgment method, system and equipment for horizontal continuous casting of metal. Background Art

[0002] During the horizontal continuous casting process, hot molten metal is continuously injected into water-cooled molds, which cool the molten metal through water and gradually solidify it into long strips of ingots. Compared with traditional casting methods, horizontal continuous casting has obvious advantages in equipment investment and production efficiency, and is a modern high-quality metal casting technology. During the horizontal continuous casting process, the casting begins to solidify through the mold contact surface, and then is gradually pulled to the secondary cooling zone until the entire interior is completely solidified. In this process, the quality of the casting mainly depends on the cooling uniformity during the solidification process. Therefore, it is crucial to accurately measure the temperature of the casting surface, which can help determine whether the casting state is normal or abnormal.

[0003] At present, the industry usually adopts the method of establishing a heat conduction model of castings to obtain the surface temperature of castings. The traditional heat transfer model only performs steady-state analysis on the secondary cooling process of castings. The heat transfer model established under steady state lacks real-time dynamics and self-correction functions. After being put into operation, it is greatly affected by complex process environment and time-varying factors. As time goes by and working conditions change, the error of the model will gradually increase, resulting in the inability to accurately obtain the surface temperature of the casting, which in turn affects the judgment of the casting state of the casting. Summary of the invention

[0004] In view of the above, it is necessary to provide a casting state judgment method, system and equipment for horizontal continuous casting of metal to solve the above problems.

[0005] According to one aspect of the present application, a method for judging the casting state of horizontal continuous casting of metal is provided, the method comprising:

[0006] Setting a measurement area and a measurement point on a horizontal continuous casting production line; collecting the crystallizer temperature at each measurement time and the inter-roller measurement temperature of the measurement point in the measurement area based on the measurement time interval;

[0007] According to the geometric characteristics and length variation characteristics of the casting, combined with the mold temperature and the temperature measured between the rolls, the heat conduction model of the casting is obtained;

[0008] Based on the position distribution of each measurement area at each measurement time and the measured temperature between the rollers at all measurement points, combined with the heat conduction model of the casting, the comprehensive temperature error at each measurement time is obtained;

[0009] Based on the comprehensive temperature error at each measurement moment, the heat conduction model is optimized in combination with the optimization algorithm; the sampling points are set, and the relative discrete values ​​at each measurement moment are obtained according to the distribution of each sampling point in the heat conduction model at each measurement moment;

[0010] The casting state of the horizontal continuous casting production line is judged according to the relative discrete values ​​at the continuous measurement moments.

[0011] The measurement time interval is specifically an upward rounded value of the ratio of the distance between the center positions of adjacent measurement areas to the average speed of the horizontal continuous casting production line.

[0012] The process of obtaining the heat conduction model of the casting is specifically as follows:

[0013] Obtain the differential equation for solidification heat transfer of castings;

[0014] Setting the crystallizer temperature as the initial condition of the differential equation;

[0015] According to the density of the cooling water flow and the preset constant, the comprehensive heat transfer coefficient of the secondary cooling zone is obtained; according to the difference between the average of the roller temperature measured at all measuring points on the casting and the cooling water temperature, combined with the comprehensive heat transfer coefficient of the secondary cooling zone, the boundary conditions of the differential equation are obtained;

[0016] According to the initial conditions and the boundary conditions, the differential equation is solved using a finite element method to obtain a heat conduction model of the casting.

[0017] The comprehensive temperature error at each measurement moment is specifically:

[0018] Calculate the difference between the value of each measuring point in the heat conduction model at each measuring time of the casting and the measured temperature between the rollers to obtain the deviation value of each measuring point at each measuring time;

[0019] According to the spatial distribution of all measurement points in each measurement area at each measurement time and the corresponding deviation value, the temperature error value of each measurement area at each time is obtained;

[0020] According to the temperature error values ​​of all measurement areas before each measurement time, combined with the position sequence number of the measurement area, the comprehensive temperature error at each measurement time is obtained, and its formula form is: ; Wherein, N represents the total number of measurement areas in the secondary cooling zone; exp() represents an exponential function with a natural constant as the base; i represents the position number of the measurement area in the secondary cooling zone; c is the error correction constant; is the temperature error value of the i-th measurement area at the k+iN-th measurement moment; is the comprehensive temperature error at the kth measurement moment.

[0021] Wherein, obtaining the temperature error value of each measurement area at each time includes:

[0022] The position serial number of the measuring point in the measuring area and the deviation value of the measuring point at each measuring time are merged, and the fusion results of all the measuring points in each measuring area are merged again to obtain the temperature error value of each measuring area at each measuring time.

[0023] The optimization of the heat conduction model is specifically as follows:

[0024] A first preset value of comprehensive heat transfer coefficient is generated at each measuring moment, and the comprehensive temperature error is used as a fitness function. An optimization algorithm is adopted to output the optimal comprehensive heat transfer coefficient, and an optimized heat conduction model of the casting is obtained.

[0025] The relative discrete value at each measurement moment is obtained as follows:

[0026] Evenly dividing the length of the casting in the secondary cooling zone to obtain a second preset number of length intervals;

[0027] The coefficients of variation of all length intervals at each measurement moment are combined into a coefficient of variation vector; the distance metric between each measurement moment and the coefficient of variation vector of the previous measurement moment is calculated and merged with the elements of the coefficient of variation vector at each measurement moment to obtain the relative discrete value of each measurement moment.

[0028] The process of judging the casting state of the horizontal continuous casting production line is specifically as follows:

[0029] Obtaining relative discrete values ​​of a third preset number of measurement moments under a normal casting state, and using the third quartile of all relative discrete values ​​as an abnormal threshold;

[0030] The mean of all relative discrete values ​​at the current measurement moment and the previous measurement moment is calculated. When the mean is greater than the abnormal threshold, it is determined that the casting state of the horizontal continuous casting is abnormal; otherwise, it is determined that the casting state of the horizontal continuous casting is normal.

[0031] According to another aspect of the present application, a casting state judgment system for horizontal continuous casting of metal is provided, comprising:

[0032] The casting state data acquisition module is used to set the measurement area and measurement points on the horizontal continuous casting production line; based on the measurement time interval, the crystallizer temperature at each measurement moment and the roller-inter-roller measurement temperature of the measurement point in the measurement area are collected;

[0033] The casting state data analysis module is used to obtain the heat conduction model of the casting according to the geometric characteristics and length change characteristics of the casting, combined with the crystallizer temperature and the temperature measured between the rollers; based on the position distribution of each measurement area at each measurement time and the temperature measured between the rollers of all measurement points, combined with the heat conduction model of the casting, the comprehensive temperature error at each measurement time is obtained; based on the comprehensive temperature error at each measurement time, combined with the optimization algorithm, the heat conduction model is optimized; the sampling points are set, and the relative discrete values ​​at each measurement time are obtained according to the distribution of each sampling point in the heat conduction model at each measurement time;

[0034] The casting state judgment module is used to judge the casting state of the horizontal continuous casting production line according to the relative discrete values ​​at the continuous measurement moments.

[0035] According to another aspect of the present application, a device for judging the casting state of horizontal continuous casting of metal is provided, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor implements operations corresponding to the above-mentioned method for judging the casting state of horizontal continuous casting of metal when executing the computer program.

[0036] In the above scheme, a measurement area and a measurement point are set on the horizontal continuous casting production line to obtain a measurement time interval, which can obtain the surface temperature change of the measurement point within a period of time according to a certain rule; the crystallizer temperature at each measurement moment and the roller measurement temperature of the measurement point in the measurement area are collected, which has the beneficial effect of providing a data basis for the subsequent construction of a heat conduction model of the casting and the verification of the model; the heat conduction model of the casting is obtained, which has the beneficial effect of retaining the main factors affecting the heat transfer of the casting while simplifying the heat transfer process and reducing unnecessary complex calculations; according to the spatial characteristics and time characteristics of the casting during horizontal continuous casting, the comprehensive temperature at each measurement moment is obtained. The beneficial effect is that by weighting the temperature estimation errors of measuring points at different positions, the adaptability of the casting heat transfer model to the horizontal continuous casting production process is enhanced, and the error of obtaining the casting surface temperature by the casting heat transfer model is reduced; and by utilizing the characteristics of castings in horizontal continuous casting production, the degree of optimization of the casting heat transfer model is improved, the error caused by complex process environment and time-varying factors is reduced, and the accuracy of obtaining the casting surface temperature is improved; finally, the comprehensive temperature error is used as the fitness function, and the optimization algorithm is adopted to construct the optimal casting heat transfer model; the surface temperature of the casting is sampled, and the relative discrete value is calculated to judge the casting state, thereby improving the accuracy of the judgment result. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A flowchart of the steps of a method for judging the casting state of metal horizontal continuous casting provided in the present application;

[0038] Figure 2A schematic diagram of the structure of the horizontal continuous casting production line provided in this application;

[0039] Figure 3 A block diagram of a casting state judgment system for horizontal continuous casting of metal provided in this application. DETAILED DESCRIPTION

[0040] In the description of the embodiments of the present application, words such as "exemplary", "or", "for example" and the like are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "or", "for example" and the like is intended to present related concepts in a concrete manner.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the present application. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0042] It should also be noted that the terms "first" and "second" in this application and the accompanying drawings are used to distinguish similar objects, rather than to describe a specific order or sequence. The method disclosed in the embodiments of the present application or the method shown in the flowchart includes one or more steps for implementing the method. Without departing from the scope of the present application, the execution order of multiple steps can be interchanged with each other, and some steps can also be deleted.

[0043] See also Figure 1 , which shows a flowchart of a method for judging the casting state of metal horizontal continuous casting provided by an embodiment of the present application, the method comprising the following steps:

[0044] Step 1: Set up a measurement area and measurement points on the horizontal continuous casting production line; collect the crystallizer temperature at each measurement time and the inter-roller measurement temperature of the measurement points in the measurement area based on the measurement time interval.

[0045] A thermocouple sensor is installed in the crystallizer of the horizontal continuous casting production line to measure the temperature of the casting in the crystallizer. The inter-roller area in the secondary cooling zone is obtained, and the area between adjacent rollers in the direction of the embryo is recorded as the inter-roller area. The length corresponding to the inter-roller area is recorded as the inter-roller distance. N inter-roller areas are selected at equal intervals as measurement areas, and M infrared temperature sensors are installed at equal intervals above each measurement area along the direction of the embryo to obtain the temperature of each measurement point of the casting below. As an embodiment, the method for selecting the measurement area is: one inter-roller area is selected as a measurement area every L inter-roller areas, and the value of L is 1; the value of N is 10, and the value of M is 5; the implementer can adjust it according to the actual situation.

[0046] Among them, the structural diagram of the horizontal continuous casting production line is as follows: Figure 2 As shown, 1 represents the crystallizer; 2 represents the secondary cooling zone; 3 represents the measuring area, that is, the distance between the rollers; 4 represents the thermocouple sensor; 5 represents the infrared temperature sensor; and 6 represents the throwing direction.

[0047] As an embodiment, the ratio of the distance between the center positions of adjacent measurement areas to the average speed of the horizontal continuous casting production line is rounded up as the measurement interval. The infrared temperature sensor performs a measurement every other measurement interval to obtain the surface temperature of the measurement point on the casting in all measurement areas, and measure the surface temperature change of the measurement point over a period of time.

[0048] Through the thermocouple sensor and infrared temperature sensor installed on the horizontal continuous casting production line, the temperature of the casting at the measuring point in the crystallizer and the secondary cooling zone is obtained at each measuring moment, which is recorded as the crystallizer temperature and the measured temperature between the rolls.

[0049] Step 2: According to the geometric characteristics and length variation characteristics of the casting, combined with the distribution of the mold temperature and the temperature measured between the rollers, the heat conduction model of the casting is obtained.

[0050] In the secondary cooling zone, the movement of the roller group and the casting will affect the uniformity and real-time monitoring of the casting surface temperature. In this case, the traditional direct measurement method may not accurately capture the surface temperature changes of various parts of the casting, so a heat conduction model of the casting is established and the surface temperature is predicted through numerical simulation.

[0051] Since the shape of the casting is a geometric cube, the length of the casting increases with the increase of the billet drawing time. The casting slice can be selected as a microelement to establish a heat conduction model. The cross-sectional area of ​​the casting slice is located according to the width and thickness of the casting. Therefore, a three-dimensional rectangular coordinate system is established according to the width, thickness and time of the casting, and the differential equation of the solidification heat transfer of the casting is obtained. The formula form is: ;in, represents the density of the casting; C represents the specific heat capacity of the casting; x and y represent the width and thickness of the casting respectively; T represents the casting temperature; t represents the time; Indicates the thermal conductivity of the casting; it should be noted that, It indicates the heat transferred from the center of the casting width to the microelement; It represents the heat transferred from the center of the casting thickness to the infinitesimal element; the differential equation of casting solidification heat transfer is a well-known technology, and its acquisition process will not be described in detail in this application.

[0052] The differential equation of casting solidification heat transfer retains the main factors affecting the heat transfer of castings and describes the temperature change of castings during the secondary cooling process of horizontal continuous casting. Since the cooling process of castings in the crystallizer is relatively stable, the initial condition of the differential equation of casting solidification heat transfer is set to the measured crystallizer temperature, and its formula form is: ;in, represents the casting temperature with respect to time t and space (x,y), Indicates the crystallizer temperature. In the secondary cooling zone, the casting is exposed to cooling water and air. With the real-time adjustment of the cooling process parameters, the degree of heat transfer between the casting surface and the outside world is constantly changing. Therefore, considering the heat transfer between the casting surface and the outside world, the heat transfer coefficient between the casting and the outside world is simplified to obtain the boundary conditions of the differential equation of casting solidification heat transfer: ;in, represents the thermal conductivity of the casting; x and y represent the width and thickness of the casting respectively; T represents the casting temperature; X and Y represent the width boundary and thickness boundary of the casting respectively; , They represent the mean of all the roller-inter-roller measured temperatures and the cooling water temperature in all the measuring areas respectively; It represents the comprehensive heat transfer coefficient of the secondary cooling zone, reflecting the degree of heat transfer of the casting in the secondary cooling zone. Its formula is: , where A is the heat transfer constant, which is 100 in this embodiment; W represents the density of the cooling water flow; n is the adjustment parameter, which is 1.4 in this embodiment; the implementer can obtain the adjustment parameter in the interval (1,2) by himself.

[0053] Based on the initial conditions and boundary conditions of the differential equation of solidification heat transfer of castings, the finite element method is used to solve the differential equation to obtain the heat conduction model of the casting. The temperature of the measurement point on the casting surface at each measurement time is calculated through the heat conduction model of the casting and recorded as the heat transfer model temperature, which represents the temperature of the measurement point obtained by the heat transfer model established by the initial comprehensive heat transfer coefficient.

[0054] Since the above process parameters will change in real time during the horizontal continuous casting process, the temperature distribution of the casting is different at each measurement moment. Therefore, the comprehensive heat transfer coefficient needs to be real-time dynamic to meet the self-correction function of the heat conduction model of the casting.

[0055] Step 3: Based on the position distribution of each measurement area at each measurement time and the measured temperature between the rollers of all measurement points, combined with the heat conduction model of the casting, the comprehensive temperature error at each measurement time is obtained.

[0056] Since the initial comprehensive heat transfer coefficient shows an error in the heat transfer efficiency of the casting surface in the secondary cooling zone, this error may be further amplified when the production parameters of the subsequent horizontal continuous casting production line are adjusted. This situation makes it difficult for the thermal conduction model of the casting to accurately predict the temperature distribution on the casting surface, thereby affecting the accurate judgment of the casting state. Therefore, the comprehensive heat transfer coefficient of the casting in the secondary cooling zone is optimized according to the temperature measured between the rollers at different times and positions, and the thermal conduction model of the casting is corrected in real time, thereby obtaining the final optimized thermal conduction model of the casting.

[0057] First, the difference between the heat transfer model temperature of each measuring point of the casting at each measuring time and the measured temperature between the rollers is obtained to obtain the deviation value of each measuring point at each measuring time. As an embodiment, the difference between the heat transfer model temperature of the jth measuring point in the i-th measuring area at the k-th measuring time and the measured temperature between the rollers is calculated and recorded as ,Will As the deviation value of the jth measurement point in the ith measurement area at the kth measurement time; in other embodiments, Replace with , and obtain the deviation value; in some other embodiments, exp( ) as the deviation value, wherein exp() is an exponential function with a natural constant as the base.

[0058] According to the spatial distribution of all measurement points in each measurement area at each measurement time and the corresponding deviation value, the temperature error value of each measurement area at each time is obtained:

[0059] The position number of the measuring point in the measuring area is merged with the deviation value of the measuring point at each measuring time, and the fusion results of all the measuring points in each measuring area are merged again to obtain the temperature error value of each measuring area at each measuring time.

[0060] As an embodiment, the temperature error value of the ith measurement area at the kth measurement moment is expressed as follows: ; Wherein, M is the number of measurement points in the i-th measurement area; ln() represents a logarithmic function with a natural constant as the base; Indicates the deviation value of the jth measurement point in the ith measurement area at the kth measurement time; j indicates the position number of the measurement point in the measurement area; represents the temperature error value of the i-th measurement area at the k-th measurement moment. In other embodiments, the logarithmic function may be replaced by a sigmoid function.

[0061] It should be understood that, considering the long length of castings produced by horizontal continuous casting, in the same measurement area, the later the measurement point is located, the shorter the cooling time in the secondary cooling zone is, and the casting has a higher surface temperature. Due to the influence of thermal stress inside the casting, the uniformity of temperature distribution of the casting is more important when the temperature is high, and it is necessary to strengthen the correction of the heat conduction model of the casting in the higher temperature area. Therefore, a higher weight is given to the measurement points with later position numbers to enhance the adaptability of the heat conduction model of the casting to the horizontal continuous casting production process and improve the accuracy of obtaining the surface temperature of the casting.

[0062] Secondly, in order to improve the utilization of measurement data and strengthen the optimization of the heat conduction model of the casting, the comprehensive temperature error at each measurement moment is obtained according to the temperature error value of all measurement areas before each measurement moment and the position sequence number of the measurement area. The formula is: ; Wherein, N represents the total number of measurement areas in the secondary cooling zone; exp() represents an exponential function with a natural constant as the base; i represents the position number of the measurement area in the secondary cooling zone; c is an error correction constant, which is 0.5 in this embodiment; is the temperature error value of the i-th measurement area at the k+iN-th measurement moment; is the comprehensive temperature error at the kth measurement moment.

[0063] It should be noted that, since the surface temperature of the casting is not detected in the rear measurement area at the initial stage when the casting enters the secondary cooling zone, the comprehensive temperature difference is not calculated at the first N-1 measurement moments when the casting enters the secondary cooling zone.

[0064] It should be understood that It represents the temperature error value of the same part of the casting at different measurement times; the comprehensive temperature error measures the error of the thermal conduction model of the current comprehensive heat transfer coefficient at all measurement times in the secondary cooling zone, reflecting the difference distribution between the thermal conduction model of the casting and the actual surface temperature of the casting.

[0065] It should be further explained that for the measurement area with a forward position number, the cooling time of the casting is short, the surface temperature is high, the cooling water is seriously atomized, and the measurement accuracy of the infrared temperature sensor is reduced. In order to reduce the impact of measurement errors on the optimization of the heat conduction model, a lower weight is given to the temperature error value with a forward position number. In addition, since the temperature of the casting is lower in the measurement area with a backward position, the degree to which its heat transfer is affected by other factors is greater, the reliability of the heat conduction model of the casting is reduced, and the correction effect of the temperature error value on the model is limited; at the same time, when the temperature of the casting is low, the uniformity of its surface temperature has little effect on the quality of the casting. Therefore, a lower weight is given to the temperature error value with a backward measurement area to improve the accuracy of the comprehensive heat transfer coefficient evaluation.

[0066] Step 4: Based on the comprehensive temperature error at each measurement moment, the heat conduction model is optimized in combination with the optimization algorithm; the sampling points are set, and the relative discrete value at each measurement moment is obtained according to the distribution of each sampling point in the heat conduction model at each measurement moment.

[0067] At each measurement moment, a first preset value of comprehensive heat transfer coefficient is generated, and the comprehensive temperature error is used as the fitness function. The particle swarm optimization algorithm is used to output the optimal comprehensive heat transfer coefficient, and the optimized heat conduction model of the casting is obtained, and the surface temperature distribution of the casting at different times in the secondary cooling zone is obtained. In this embodiment, the first preset value is 30, and the maximum number of iterations of the particle swarm optimization algorithm is set to 100; wherein, the particle swarm algorithm is an existing well-known technology, and this application will not elaborate on it. In addition, the implementer can adjust the first preset value and the maximum number of iterations according to actual conditions.

[0068] It should be understood that the optimal heat conduction model of the casting reflects the temperature distribution at different positions of the casting in a continuous time and is a continuous function. In order to facilitate calculation, it is necessary to set sampling points to sample the surface temperature of the casting. Since there are 5 measurement points in one measurement area in this embodiment, the cross section of the casting is evenly divided into A square is formed, and the vertex of the square is used as a sampling point to obtain the model temperature of each sampling point at each measurement time. Due to the long length of the castings on the horizontal continuous casting production line, the temperature of the castings at different positions in the secondary cooling zone varies greatly. In order to improve data utilization and analyze the uniformity of the surface temperature distribution of the castings, the length of the castings in the secondary cooling zone is evenly divided to obtain a second preset number of length intervals. In this embodiment, the second preset number is set to 100.

[0069] According to the difference in the discrete degree of model temperature of all sampling points in all length intervals at each measurement moment and the adjacent measurement moments, the relative discrete value at each measurement moment is obtained:

[0070] It should be noted that, in this embodiment, the coefficient of variation is used to measure the discrete degree of the model temperature of all sampling points in each length interval at each measurement moment; the DTW distance is used to measure the distance metric between two vectors; the coefficients of variation of all length intervals at each measurement moment are combined into a coefficient of variation vector; the distance metric between the coefficient of variation vector at each measurement moment and the previous measurement moment is calculated, and merged with the elements of the coefficient of variation vector at each measurement moment to obtain the relative discrete value at each measurement moment.

[0071] The formula for the relative discrete value at the rth measurement moment is: ;in, represents the coefficient of variation of the temperature of the heat transfer model at the sampling point in the i-th length interval; , Respectively represent the coefficient of variation vectors of the r-1th and rth measurement moments; represents the DTW distance; It represents the relative discrete value at the rth measurement moment, indicating the degree of discreteness of the surface temperature distribution of the casting at the rth measurement moment.

[0072] It should be understood that when the temperature distribution of the casting in the length interval is abnormal, the more discrete the temperature distribution in the length interval, the larger the coefficient of variation, the larger the calculated relative discrete value, and the greater the probability that the casting state of the casting is abnormal. In addition, during the horizontal continuous casting process, when the casting state of the casting is normal, the temperature gradient in different length intervals does not change much, and the DTW distance of the coefficient of variation vector at adjacent measurement moments remains stable. When the casting state of the casting is abnormal, the coefficient of variation of some length intervals varies greatly, and the calculated DTW distance of the coefficient of variation vector at adjacent measurement moments becomes larger, and the relative discrete value becomes larger.

[0073] Step 5: According to the relative discrete values ​​at the continuous measurement moments, the casting state of the horizontal continuous casting production line is judged.

[0074] The relative discrete values ​​of the third preset number of measurement moments under the normal casting state are obtained, and the third quartile of all relative discrete values ​​is used as the abnormal threshold. Taking the current measurement moment as the starting point, the fourth preset number of measurement moments are taken forward to form a sampling interval. The mean of all relative discrete values ​​in the sampling interval is calculated. When the mean is greater than the abnormal threshold, it is determined that the casting state of the horizontal continuous casting at this time is abnormal, and an alarm signal is issued, which is transmitted by the communication device to the sound and light alarm for alarm; otherwise, it is determined that the casting state of the horizontal continuous casting is normal.

[0075] In this embodiment, the third preset number is 1000; the fourth preset number is 20.

[0076] Based on the same concept as the method embodiment of the present application, a casting state judgment system for horizontal continuous casting of metal is proposed, comprising:

[0077] The casting state data acquisition module is used to set the measurement area and measurement points on the horizontal continuous casting production line; based on the measurement time interval, the crystallizer temperature at each measurement moment and the roller-inter-roller measurement temperature of the measurement point in the measurement area are collected;

[0078] The casting state data analysis module is used to obtain the heat conduction model of the casting according to the geometric characteristics and length change characteristics of the casting, combined with the crystallizer temperature and the temperature measured between the rollers; based on the position distribution of each measurement area at each measurement time and the temperature measured between the rollers of all measurement points, combined with the heat conduction model of the casting, the comprehensive temperature error at each measurement time is obtained; based on the comprehensive temperature error at each measurement time, combined with the optimization algorithm, the heat conduction model is optimized; the measurement time and sampling points are reset, and the relative discrete value at each measurement time is obtained according to the distribution of each sampling point in the heat conduction model at each measurement time;

[0079] The casting state judgment module is used to judge the casting state of the horizontal continuous casting production line according to the relative discrete values ​​at the continuous measurement moments.

[0080] Among them, a block diagram of a casting state judgment system for metal horizontal continuous casting is shown as follows: Figure 3 shown.

[0081] Based on the same concept as the method embodiment of the present application, a casting state judgment device for horizontal continuous casting of metal is proposed, including a memory, a processor, and a computer program stored in the memory and running on the processor, and when the processor executes the computer program, it implements the operations corresponding to the above-mentioned method for judging the casting state of horizontal continuous casting of metal.

[0082] In summary, a measurement area and a measurement point are set on the horizontal continuous casting production line to obtain a measurement time interval, which can obtain the surface temperature change of the measurement point within a period of time according to a certain rule; the crystallizer temperature at each measurement moment and the roller measurement temperature of the measurement point in the measurement area are collected, which has the beneficial effect of providing a data basis for the subsequent construction of a thermal conduction model of the casting and the verification of the model; the thermal conduction model of the casting is obtained, which has the beneficial effect of retaining the main factors affecting the heat transfer of the casting while simplifying the heat transfer process and reducing unnecessary complex calculations; according to the spatial characteristics and time characteristics of the casting during horizontal continuous casting, the comprehensive temperature at each measurement moment is obtained. The beneficial effect is that by weighting the temperature estimation errors of measuring points at different positions, the adaptability of the casting heat transfer model to the horizontal continuous casting production process is enhanced, and the error of obtaining the casting surface temperature by the casting heat transfer model is reduced; and by utilizing the characteristics of castings in horizontal continuous casting production, the degree of optimization of the casting heat transfer model is improved, the error caused by complex process environment and time-varying factors is reduced, and the accuracy of obtaining the casting surface temperature is improved; finally, the comprehensive temperature error is used as the fitness function, and the optimization algorithm is adopted to construct the optimal casting heat transfer model; the surface temperature of the casting is sampled, and the relative discrete value is calculated to judge the casting state, thereby improving the accuracy of the judgment result.

[0083] It should be noted that the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the system, method and computer program product according to the embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. In the description corresponding to the flowchart and block diagram in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in an order different from that disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified functions or actions, or may be implemented by a combination of dedicated hardware and computer instructions.

[0084] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for judging the casting state of metal horizontal continuous casting, characterized in that: The method comprises the following steps: Setting a measurement area and a measurement point on a horizontal continuous casting production line; collecting the crystallizer temperature at each measurement time and the inter-roller measurement temperature of the measurement point in the measurement area based on the measurement time interval; According to the geometric characteristics and length variation characteristics of the casting, combined with the mold temperature and the temperature measured between the rolls, the heat conduction model of the casting is obtained; Based on the position distribution of each measurement area at each measurement time and the measured temperature between the rollers at all measurement points, combined with the heat conduction model of the casting, the comprehensive temperature error at each measurement time is obtained; Based on the comprehensive temperature error at each measurement moment, the heat conduction model is optimized in combination with the optimization algorithm; the sampling points are set, and the relative discrete values ​​at each measurement moment are obtained according to the distribution of each sampling point in the heat conduction model at each measurement moment; According to the relative discrete values ​​at the continuous measurement moments, the casting state of the horizontal continuous casting production line is judged; The comprehensive temperature error at each measurement moment is specifically: Calculate the difference between the value of each measuring point in the heat conduction model at each measuring time of the casting and the measured temperature between the rollers to obtain the deviation value of each measuring point at each measuring time; According to the spatial distribution of all measurement points in each measurement area at each measurement time and the corresponding deviation value, the temperature error value of each measurement area at each time is obtained; According to the temperature error values ​​of all measurement areas before each measurement time, combined with the position sequence number of the measurement area, the comprehensive temperature error at each measurement time is obtained, and its formula form is: ; Wherein, N represents the total number of measurement areas in the secondary cooling zone; exp() represents an exponential function with a natural constant as the base; i represents the position number of the measurement area in the secondary cooling zone; c is the error correction constant; is the temperature error value of the i-th measurement area at the k+iN-th measurement moment; is the comprehensive temperature error at the kth measurement moment; The optimization of the heat conduction model is specifically as follows: Generate a first preset value of comprehensive heat transfer coefficient at each measurement moment, take the comprehensive temperature error as the fitness function, adopt the optimization algorithm, output the optimal comprehensive heat transfer coefficient, and obtain the optimized heat conduction model of the casting; The relative discrete value at each measurement moment is obtained as follows: Evenly dividing the length of the casting in the secondary cooling zone to obtain a second preset number of length intervals; The coefficients of variation of all length intervals at each measurement moment are combined into a coefficient of variation vector; the distance metric between each measurement moment and the coefficient of variation vector of the previous measurement moment is calculated and merged with the elements of the coefficient of variation vector at each measurement moment to obtain the relative discrete value of each measurement moment.

2. A method for judging the casting state of metal horizontal continuous casting according to claim 1, characterized in that: The measurement time interval is specifically an upward rounded value of the ratio of the distance between the center positions of adjacent measurement areas to the average speed of the horizontal continuous casting production line.

3. A method for judging the casting state of metal horizontal continuous casting according to claim 1, characterized in that: The process of obtaining the heat conduction model of the casting is specifically as follows: Obtain the differential equation for solidification heat transfer of castings; Setting the crystallizer temperature as the initial condition of the differential equation; According to the density of the cooling water flow and the preset constant, the comprehensive heat transfer coefficient of the secondary cooling zone is obtained; according to the difference between the average of the roller temperature measured at all measuring points on the casting and the cooling water temperature, combined with the comprehensive heat transfer coefficient of the secondary cooling zone, the boundary conditions of the differential equation are obtained; According to the initial conditions and the boundary conditions, the differential equation is solved using a finite element method to obtain a heat conduction model of the casting.

4. A method for judging the casting state of metal horizontal continuous casting according to claim 1, characterized in that: The step of obtaining the temperature error value of each measurement area at each time comprises: The position serial number of the measuring point in the measuring area and the deviation value of the measuring point at each measuring time are merged, and the fusion results of all the measuring points in each measuring area are merged again to obtain the temperature error value of each measuring area at each measuring time.

5. The method for judging the casting state of metal horizontal continuous casting according to claim 1, characterized in that: The process of judging the casting state of the horizontal continuous casting production line is specifically as follows: Obtaining relative discrete values ​​of a third preset number of measurement moments under a normal casting state, and using the third quartile of all relative discrete values ​​as an abnormal threshold; The mean of all relative discrete values ​​at the current measurement moment and the previous measurement moment is calculated. When the mean is greater than the abnormal threshold, it is determined that the casting state of the horizontal continuous casting is abnormal; otherwise, it is determined that the casting state of the horizontal continuous casting is normal.

6. A casting state judgment system for metal horizontal continuous casting, implementing the method according to any one of claims 1 to 5, characterized in that: The system includes: The casting state data acquisition module is used to set the measurement area and measurement points on the horizontal continuous casting production line; based on the measurement time interval, the crystallizer temperature at each measurement moment and the roller-inter-roller measurement temperature of the measurement point in the measurement area are collected; The casting state data analysis module is used to obtain the heat conduction model of the casting according to the geometric characteristics and length change characteristics of the casting, combined with the crystallizer temperature and the temperature measured between the rollers; based on the position distribution of each measurement area at each measurement time and the temperature measured between the rollers of all measurement points, combined with the heat conduction model of the casting, the comprehensive temperature error at each measurement time is obtained; based on the comprehensive temperature error at each measurement time, combined with the optimization algorithm, the heat conduction model is optimized; the sampling points are set, and the relative discrete values ​​at each measurement time are obtained according to the distribution of each sampling point in the heat conduction model at each measurement time; The casting state judgment module is used to judge the casting state of the horizontal continuous casting production line according to the relative discrete values ​​at the continuous measurement moments.

7. A casting state judgment device for horizontal continuous casting of metal, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, operations corresponding to the method for judging the casting state of horizontal continuous casting of metal as described in any one of claims 1 to 5 are implemented.

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