A method and system for regulating the temperature of cooling water of a crystallizer
By monitoring temperature differences and fluctuations in the front and rear end areas of the crystallizer, calculating the degree of cooling unevenness and solidification possibility, dynamically adjusting the cooling water temperature, solving the problem of cooling water temperature adjustment in horizontal continuous casting, significantly improving the quality and production of the casting billet efficiency.
Patent Information
- Application Number
- CN202411068657.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-06
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2044-08-06
AI Technical Summary
During horizontal continuous casting, the temperature of the cooling water of the crystallizer is difficult to dynamically adjust, resulting in premature solidification of the metal liquid and scarring, affecting the quality and mechanical properties of the casting billet.
By installing temperature sensors in the front and back end areas of the crystallizer, temperature differences and fluctuations are monitored, the degree of cooling unevenness and the possibility of metal solidification are calculated, the cooling water temperature adjustment coefficient is obtained, and the cooling water inlet temperature is adjusted using clustering algorithm to achieve High-precision dynamic adjustment of cooling water.
It significantly reduces the cracks and scars on the surface of the profile, improves the quality stability and mechanical properties of the blank shell, and ensures uniform cooling and efficient production of the cast blank.
Smart Images
Figure CN118577755B_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of metal casting, and in particular to a method and system for regulating the temperature of cooling water of a crystallizer. Background Art
[0002] The production method of horizontal continuous casting cast iron profiles is to inject the treated high-temperature molten metal into the insulation furnace, solidify it into a billet shell under the action of the water-cooled graphite sleeve crystallizer, and pull it into a profile under the action of the tractor. As one of the key components of horizontal continuous casting equipment, the crystallizer can achieve the production of billets of required specifications and shapes by changing the shape and size of the crystallizer and related process parameters. The cooling water of the crystallizer is mainly used to cool the molten metal in the crystallizer to ensure that the molten metal solidifies into a billet shell of the required thickness and shape when it leaves the crystallizer. The cooling system of the crystallizer directly affects the mechanical properties of the billet, and puts higher requirements on the temperature control of the crystallizer cooling water.
[0003] At present, the purpose of adjusting the cooling water inlet temperature of the crystallizer is achieved by controlling the outlet water temperature of the cooling water treatment device, which is heavily dependent on pre-setting. However, in the horizontal continuous casting process of large-section profiles, in order to avoid the crystallizer heat transfer state being too high, the overall temperature of the molten metal dropping, the molten metal partially solidifying prematurely, and the formation of scars in the continuous casting, the cooling water temperature needs to be dynamically adjusted. Summary of the invention
[0004] In order to solve the technical problem of premature solidification and scarring at the front end of the crystallizer, the present application provides a method and system for regulating the temperature of cooling water in the crystallizer. The technical solution adopted is as follows:
[0005] The present application proposes a method and system for regulating the temperature of cooling water of a crystallizer, the method comprising the following steps:
[0006] The temperature of each sampling period is collected at each monitoring position in the front end area and the rear end area of the crystallizer by using a temperature sensor;
[0007] For the rear end area of the crystallizer, the degree of cooling unevenness of the rear end area of the crystallizer is obtained according to the temperature differences between all monitoring positions and several monitoring positions closest to them and the fluctuation of the temperature values at all monitoring positions;
[0008] At each sampling moment, the temperature gradient is calculated based on the temperature difference between the front end area and the rear end area of the crystallizer. After subtracting the temperature gradient from the gradient threshold, all differences in the sampling period are sorted to calculate the slope; the molten metal injection time is obtained, and the possibility of molten metal solidification in the front end area of the crystallizer is obtained based on the molten metal injection time and the slope; the cooling water temperature adjustment coefficient of the crystallizer is obtained based on the possibility of molten metal solidification in the front end area of the crystallizer and the degree of uneven cooling in the rear end area of the crystallizer;
[0009] Obtain the cooling water inlet temperature of the sampling period, collect historical data, cluster the historical data and the sampling period according to the cooling water temperature adjustment coefficient and the cooling water inlet temperature, and obtain the temperature adjustment value of the sampling period according to the adjusted temperature value of the historical data in the same class; adjust the cooling water inlet temperature of the sampling period to the temperature adjustment value to complete the dynamic adjustment of cooling water.
[0010] In the above scheme, based on the uneven temperature distribution and temperature fluctuation in the rear end area of the crystallizer, the degree of uneven cooling in the rear end area of the crystallizer is obtained. Its beneficial effect is to analyze the uniformity of cooling of the molten metal in the crystallizer, significantly avoid the poor stability of the shell quality when the cooling water temperature is set too low, and significantly reduce the incidence of surface cracks in the profile; according to the uneven cooling in the rear end area of the crystallizer and the possibility of solidification of the molten metal in the front end area of the crystallizer, the cooling water temperature adjustment coefficient of the crystallizer is obtained to avoid horizontal continuous casting of large-section profiles, a large proportion of the molten metal injection stop time, uniform cooling in the rear end area of the crystallizer, but partial solidification in the front end area of the crystallizer, and high-precision adjustment of the cooling water of the crystallizer to greatly reduce the scar phenomenon.
[0011] In one embodiment, the method for obtaining the degree of cooling unevenness in the rear end area of the crystallizer according to the temperature differences between all monitoring positions and the nearest monitoring positions and the fluctuation of the temperature values at all monitoring positions is:
[0012] For any monitoring position, record it as the target monitoring position, and take the d monitoring positions with the smallest distance between the target monitoring position and the remaining monitoring positions as the neighboring monitoring positions of the target monitoring position;
[0013] The temperature distribution non-uniformity of the rear end area of the crystallizer is obtained according to the temperature difference between each target monitoring position and its neighboring monitoring positions;
[0014] For the target monitoring position, the standard deviation of all temperature values in the target monitoring position is calculated, and the standard deviation is recorded as the volatility of each monitoring position; the result of averaging the volatility of all monitoring positions in the rear end area of the crystallizer is recorded as the temperature volatility of the rear end area of the crystallizer;
[0015] The degree of cooling unevenness in the rear end area of the crystallizer is obtained according to the temperature distribution unevenness and temperature fluctuation in the rear end area of the crystallizer;
[0016] The degree of cooling unevenness in the rear end area of the crystallizer is positively correlated with the temperature distribution unevenness and temperature fluctuation in the rear end area of the crystallizer.
[0017] In one embodiment, the method for obtaining the temperature distribution non-uniformity of the rear end area of the crystallizer according to the temperature difference between each target monitoring position and its neighboring monitoring position is:
[0018] The mean of all temperature values at the target monitoring position is calculated and recorded as the temperature mean of the target monitoring position; the expression of temperature distribution non-uniformity is: , represents the mean temperature of the nth target monitoring position, represents the mean temperature of the ith neighboring monitoring location of the nth target monitoring location, represents the number of neighboring monitoring locations of each target monitoring location, represents the number of target monitoring locations, Indicates the uneven temperature distribution in the rear end area of the crystallizer.
[0019] In one embodiment, the method for obtaining the temperature distribution non-uniformity of the rear end area of the crystallizer according to the temperature difference between each target monitoring position and its neighboring monitoring position is:
[0020] The product of the temperature distribution non-uniformity and the temperature fluctuation in the rear end area of the crystallizer is normalized by the maximum and minimum values and recorded as the degree of cooling non-uniformity in the rear end area of the crystallizer.
[0021] In one embodiment, for each sampling moment, the temperature gradient is calculated according to the temperature difference between the front end area of the crystallizer and the rear end area of the crystallizer, and after subtracting the temperature gradient from the gradient threshold, all differences in the sampling period are sorted to calculate the slope. The method is:
[0022] For any sampling moment, the average of the temperature values at all monitoring positions is calculated, and the average of the temperature values is recorded as the overall temperature of the rear end area of the crystallizer; the overall temperature of the front end area of the crystallizer is collected by the temperature sensor in the front end area of the crystallizer;
[0023] For any first sampling moment, the difference between the overall temperature of the front region of the crystallizer and the overall temperature of the rear region of the crystallizer is recorded as the temperature gradient of the crystallizer;
[0024] A temperature gradient threshold is preset, and the temperature gradient of the crystallizer is subtracted from the temperature gradient threshold, and the difference is recorded as the temperature difference gradient of the crystallizer;
[0025] The slope of the straight line is obtained by fitting a straight line according to the temperature difference gradient.
[0026] In one embodiment, the method for obtaining the slope of the straight line according to the temperature difference gradient fitting straight line is:
[0027] Sort the temperature difference gradients at all sampling moments in a sampling period in ascending order to obtain a temperature difference gradient sequence;
[0028] The temperature difference gradient sequence is obtained by a linear fitting algorithm and its corresponding straight line is recorded as the temperature difference gradient straight line; and the slope of the temperature difference gradient straight line is calculated.
[0029] In one embodiment, the method for obtaining the molten metal injection time and obtaining the possibility of molten metal solidification in the front end area of the crystallizer according to the molten metal injection time and slope is:
[0030] The time for injecting the molten metal into the crystallizer is recorded as the molten metal injection time; the ratio of the molten metal injection time to the sampling period is calculated and recorded as the molten metal injection time ratio;
[0031] The solidification possibility of the molten metal in the front end area of the crystallizer is obtained according to the slope of the temperature difference gradient straight line and the molten metal injection time ratio;
[0032] The possibility of molten metal solidification in the front end area of the crystallizer is negatively correlated with the slope of the temperature difference gradient line and the molten metal injection time ratio.
[0033] In one embodiment, the method for obtaining the cooling water temperature adjustment coefficient of the crystallizer according to the solidification possibility of the molten metal in the front end area of the crystallizer and the degree of cooling unevenness in the rear end area of the crystallizer is:
[0034] The sum of the degree of cooling unevenness in the rear end area of the crystallizer and the possibility of molten metal solidification in the front end area of the crystallizer is recorded as the cooling water temperature adjustment coefficient of the crystallizer.
[0035] In one embodiment, the method of clustering the historical data and the sampling period according to the cooling water temperature adjustment coefficient and the cooling water inlet temperature, and obtaining the temperature adjustment value of the sampling period according to the adjusted temperature value of the historical data in the same class is:
[0036] The sampling period and the cooling water inlet temperature and the cooling water temperature adjustment coefficient of each historical data are combined into a tuple, and the tuple is classified by a clustering algorithm;
[0037] The binary group corresponding to the sampling period is recorded as the target binary group, the cluster where the target binary group is located is obtained, and the mean value of the adjusted temperature of all historical data in the cluster is calculated as the temperature adjustment value of the crystallizer sampling period.
[0038] In the second aspect, an embodiment of the present application also provides a crystallizer cooling water temperature control system, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor implements the steps of any one of the above-mentioned methods for regulating the cooling water temperature of the crystallizer when executing the computer program.
[0039] The beneficial effects of this application are:
[0040] Based on the uneven temperature distribution and temperature fluctuation in the rear end area of the crystallizer, the degree of uneven cooling in the rear end area of the crystallizer is obtained. Its beneficial effect is to analyze the uniformity of cooling of the molten metal in the crystallizer, avoid the problem of poor stability of the shell quality when the cooling water temperature is set too low, and significantly reduce the incidence of surface cracks in the profile; according to the uneven cooling in the rear end area of the crystallizer and the possibility of solidification of the molten metal in the front end area of the crystallizer, the cooling water temperature adjustment coefficient of the crystallizer is obtained to avoid horizontal continuous casting of large-section profiles, a large proportion of the molten metal injection stop time, uniform cooling in the rear end area of the crystallizer, but partial solidification in the front end area of the crystallizer, and high-precision adjustment of the cooling water of the crystallizer to greatly reduce the scar phenomenon. BRIEF DESCRIPTION OF THE DRAWINGS
[0041] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0042] Figure 1 A flow chart of a method for adjusting the temperature of cooling water for a crystallizer provided in one embodiment of the present application;
[0043] Figure 2 The flowchart of the method for obtaining the cooling water temperature adjustment coefficient is shown in FIG. DETAILED DESCRIPTION
[0044] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following is a detailed description of a crystallizer cooling water temperature adjustment method and system proposed in the present application, its specific implementation, structure, features and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.
[0045] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
[0046] A method for adjusting the temperature of cooling water of a crystallizer:
[0047] The specific scheme of a crystallizer cooling water temperature regulation method provided by the present application is described in detail below with reference to the accompanying drawings.
[0048] See also Figure 1 , which shows a flow chart of a method for adjusting the temperature of a crystallizer cooling water provided by an embodiment of the present application, the method comprising the following steps:
[0049] Step S001, collecting the temperature of each sampling period at each monitoring position in the front end area and the rear end area of the crystallizer through a temperature sensor.
[0050] The horizontal continuous casting crystallizer is composed of a graphite sleeve and an iron sleeve. The specific composition method is that the graphite sleeve is pressed into a special iron sleeve with a spiral cooling water channel. The graphite sleeve is pressed into two sections. The protruding end of the first section of the graphite sleeve is sealed and connected to the insulation furnace wall by a special sealing mud. The first section of the graphite sleeve corresponds to the crystallizer area as the front end area of the crystallizer; the second section of the graphite sleeve is pressed into the iron sleeve with cooling water as a whole, and the second section of the graphite sleeve corresponds to the crystallizer area as the rear end area of the crystallizer.
[0051] The present application arranges one temperature sensor in the front end area of the crystallizer to measure the temperature of the front end area of the crystallizer, arranges N temperature sensors in the rear end area of the crystallizer to measure the temperature of different monitoring positions in the rear end area of the crystallizer, wherein the specific installation position of each temperature sensor is determined by the implementer according to the specific situation. In this embodiment, the temperature sensors arranged at the rear end of the crystallizer are evenly distributed, and N is described as 10. The sampling frequency of each temperature sensor is 1Hz, and the sampling period is 1min. The present application adjusts the crystallizer temperature once every sampling period to achieve dynamic adjustment of the crystallizer cooling water temperature.
[0052] At this point, the temperature value of each monitoring position in each sampling period of the front end area and the rear end area of the crystallizer is obtained.
[0053] Step S002, for the rear end area of the crystallizer, the degree of cooling unevenness of the rear end area of the crystallizer is obtained according to the temperature differences between all monitoring positions and several nearest monitoring positions and the fluctuation of the temperature values at all monitoring positions.
[0054] During the continuous casting process of profiles, the cooling water of the crystallizer is mainly used to cool the molten metal in the crystallizer to ensure that the molten metal solidifies into a shell of the required thickness and shape when it leaves the crystallizer. When the water temperature of the crystallizer inlet is low, the heat flux in the rear end area of the crystallizer increases, and the cooling uniformity is often poor, which can easily affect the stability of the shell quality and cause longitudinal cracks in the profile.
[0055] The degree of uneven cooling in the rear end area of the crystallizer is reflected in the uneven temperature distribution at each monitoring position in the rear end area of the crystallizer. Moreover, due to the uneven temperature distribution at each monitoring position, a temperature difference is easily formed between the monitoring positions, resulting in heat transfer phenomenon, which is easy to cause fluctuations in the temperature changes of the monitoring positions in time series.
[0056] For any monitoring position in the rear end area of the crystallizer, all temperatures collected in each sampling period are sorted in ascending time order to obtain a temperature monitoring sequence for each monitoring position.
[0057] Any monitoring position in the rear end area of the crystallizer is recorded as the target monitoring position. In this embodiment, the Euclidean distance between the target monitoring position and all monitoring positions is calculated as the distance between the target monitoring position and the monitoring position, and d monitoring positions with the smallest distance are selected as the neighborhood monitoring positions of the target monitoring position. In this embodiment, the value of d is 3.
[0058] Firstly, the temperature distribution non-uniformity of the rear end area of the crystallizer is obtained through the temperature difference between each monitoring position and its neighboring monitoring positions.
[0059] Preferably, in this embodiment, the mean of all temperature values in the temperature monitoring sequence of each monitoring position is obtained and recorded as the temperature mean of each monitoring position, and the absolute value of the difference between the temperature mean of the target monitoring position and its neighboring monitoring positions is recorded as the temperature difference between the monitoring positions; the temperature differences of all monitoring positions and all their neighboring monitoring positions are accumulated to obtain the temperature distribution unevenness of the rear end area of the crystallizer. , represents the mean temperature of the nth target monitoring position, represents the mean temperature of the ith neighboring monitoring location of the nth target monitoring location, represents the number of neighboring monitoring locations of each target monitoring location, represents the number of target monitoring locations, Indicates the uneven temperature distribution in the rear end area of the crystallizer.
[0060] Through the above calculation, the difference between the temperature means of monitoring positions that are close to each other is obtained. If the difference between the means is larger, it means that the difference in cooling degree between the molten metals is larger, which means that the temperature of several monitoring positions that are close to each other is not uniform. If the temperature difference between most monitoring positions and their neighboring monitoring positions is large, it means that the overall temperature distribution in the rear end area of the crystallizer is not uniform, which means that the more discrete the distribution of cooling performance in the airspace in the rear end area of the crystallizer is, the more uneven the cooling is.
[0061] Furthermore, the temperature fluctuation of the rear end area of the crystallizer is determined based on the temperature fluctuations at all monitoring positions.
[0062] Preferably, in this embodiment, the standard deviation of all temperature values in the temperature monitoring sequence of each monitoring position in the rear end area of the crystallizer is calculated, the standard deviation is recorded as the volatility of each monitoring position, and the result of averaging the volatility of all monitoring positions in the rear end area of the crystallizer is recorded as the temperature volatility of the rear end area of the crystallizer.
[0063] Since the standard deviation of the temperature value calculated at each monitoring position represents the volatility of each monitoring position, the mean of the volatility of all monitoring positions is taken as the temperature volatility of the rear end area of the crystallizer. The greater the temperature volatility, the more significant the temperature change at each monitoring position, and the more likely it is that the uneven cooling in the rear end area of the crystallizer causes a temperature difference between the monitoring positions, resulting in heat transfer, and the greater the degree of cooling unevenness.
[0064] Therefore, the degree of cooling unevenness in the rear end area of the crystallizer can be obtained through the temperature distribution unevenness and temperature fluctuation in the rear end area of the crystallizer.
[0065] The degree of cooling unevenness in the rear end area of the crystallizer is positively correlated with the temperature distribution unevenness and temperature fluctuation in the rear end area of the crystallizer.
[0066] It should be noted that positive correlation means that when one variable increases, the other variable also increases, and the two variables change in the same direction. When one variable changes from large to small or from small to large, the other variable also changes from large to small or from small to large; it is determined by actual application and this application does not impose any special restrictions.
[0067] Preferably, in this embodiment, the product of the temperature distribution non-uniformity and the temperature fluctuation in the rear end region of the crystallizer is normalized by the maximum and minimum values and recorded as the cooling non-uniformity degree of the rear end region of the crystallizer.
[0068] Preferably, in this embodiment, the sum of the temperature distribution non-uniformity and the temperature fluctuation in the rear end region of the crystallizer is linearly normalized and recorded as the cooling non-uniformity degree of the rear end region of the crystallizer.
[0069] It should be noted that a degree of cooling unevenness is obtained for each sampling period, so normalization is performed for all sampling periods to obtain the degree of cooling unevenness for each period.
[0070] So far, the degree of cooling non-uniformity in the rear end region of the crystallization in each sampling period is obtained.
[0071] Step S003, for each sampling moment, calculate the temperature gradient according to the temperature difference between the front end area and the rear end area of the crystallizer, subtract the temperature gradient from the gradient threshold, and then sort all the differences in the sampling period to calculate the slope; obtain the molten metal injection time, and obtain the possibility of molten metal solidification in the front end area of the crystallizer according to the molten metal injection time and the slope; obtain the cooling water temperature adjustment coefficient of the crystallizer according to the possibility of molten metal solidification in the front end area of the crystallizer and the degree of cooling unevenness in the rear end area of the crystallizer.
[0072] The rear end area of the crystallizer will be cooled by circulating cooling water, while the front end area of the crystallizer will not be cooled by circulating cooling water, and the front end area of the crystallizer is connected to the high-temperature molten metal, so the temperature of the front end area of the crystallizer is often higher than the temperature of the rear end of the crystallization zone; therefore, there is a certain temperature gradient between the front end area of the crystallizer and the rear end area of the crystallizer. If the temperature gradient is too small, the front end area of the crystallizer will partially solidify prematurely under the dual effects of gravity and temperature, forming a scar. In the actual continuous casting production process of large-section profiles, there is a problem that the rear end area of the crystallizer is cooled evenly, but the front end area of the crystallizer partially solidifies, so it is necessary to adjust the cooling water temperature with higher precision.
[0073] For any sampling moment, calculate the average temperature value of all monitoring positions in the rear end area of the crystallizer at this sampling moment, and record the average temperature value as the overall temperature of the rear end area of the crystallizer at this sampling moment; since there is only one temperature sensor in the front end area of the crystallizer, the temperature value collected by the temperature sensor is the overall temperature of the temperature sensor.
[0074] For any first sampling moment, the difference between the overall temperature of the front region of the crystallizer and the overall temperature of the rear region of the crystallizer is recorded as the temperature gradient of the crystallizer. Since a small gradient temperature will cause partial solidification in the front region of the crystallizer and form a scar, a temperature gradient threshold is set. The temperature gradient threshold is the lowest temperature gradient in the continuous casting process that can ensure that the front region of the crystallizer does not partially solidify. The value of this embodiment is 75 degrees.
[0075] For any sampling moment, the temperature gradient of the crystallizer is subtracted from the temperature gradient threshold, and the difference is recorded as the temperature difference gradient of the crystallizer. The temperature difference gradients of all sampling moments in a sampling period are sorted in ascending order to obtain a temperature difference gradient sequence.
[0076] The temperature difference gradient sequence is obtained by a linear fitting algorithm and its corresponding straight line is recorded as the temperature difference gradient straight line. The slope of the temperature difference gradient straight line is calculated. The fitting algorithm used in this embodiment is the least squares method.
[0077] The method of cooling the molten metal is to inject the molten metal from the holding furnace into the crystallizer. The molten metal will cool and solidify in the crystallizer. However, for large-section profiles, the size is large and the cooling capacity of the crystallizer is limited. Therefore, when injecting the molten metal, it is necessary to stop injecting the molten metal after a period of time. Therefore, the time when the molten metal is injected into the crystallizer is recorded as the molten metal injection time, and the time when the molten metal stops injecting is recorded as the molten metal injection stop time.
[0078] In each sampling cycle, the metal liquid injection time and the metal liquid injection stop time are counted. The ratio of the metal liquid injection time to the sampling cycle length is calculated and recorded as the metal liquid injection time ratio;
[0079] The solidification possibility of the molten metal in the front end area of the crystallizer is obtained according to the slope of the temperature difference gradient straight line and the molten metal injection time ratio;
[0080] The possibility of molten metal solidification in the front end area of the crystallizer is negatively correlated with the slope of the temperature difference gradient line and the molten metal injection time ratio.
[0081] It should be noted that negative correlation means that when one variable increases, the other variable decreases accordingly, and the two variables change in opposite directions. When one variable changes from large to small or from small to large, the other variable also changes from small to large or from large to small; it is determined by actual application and this application does not impose any special restrictions.
[0082] Preferably, in this embodiment, the expression for the solidification possibility of the molten metal in the front end area of the crystallizer is: , The slope of the temperature difference gradient line is represented by Indicates the metal liquid injection time ratio, represents an exponential function with a natural constant as base, Indicates the possibility of solidification of molten metal in the front area of the crystallizer. represents a normalization function. In this embodiment, the normalization function is maximum and minimum value normalization.
[0083] Preferably, in another embodiment, the expression for the solidification possibility of the molten metal in the front end area of the crystallizer is: , The slope of the temperature difference gradient line is represented by Indicates the metal liquid injection time ratio, Indicates the possibility of solidification of molten metal in the front area of the crystallizer. represents a normalization function, and in this embodiment, the normalization function is linear normalization.
[0084] It should be noted that a metal liquid solidification possibility is obtained for each sampling period, so the normalization is calculated for all sampling periods.
[0085] When the slope of the temperature difference gradient line is less than 0, and the smaller the value is, the more significant the heat transfer phenomenon between the rear end area of the crystallizer and the front end area of the crystallizer is, the more likely it is that the partial solidification of the molten metal occurs in the front end area of the crystallizer, and the molten metal is more likely to solidify at the front end of the crystallizer. The smaller the molten metal injection time ratio is, the shorter the injection time of the molten metal in the holding furnace is. Without the hot molten metal supplement, the temperature of the molten metal will be lower, and it will be unable to transfer a large amount of temperature to the front end area of the crystallizer. Therefore, the molten metal is more likely to solidify at the front end of the crystallizer.
[0086] The cooling water temperature adjustment coefficient of the crystallizer is obtained according to the uneven cooling degree of the rear end area of the crystallizer and the possibility of molten metal solidification in the front end area of the crystallizer.
[0087] The cooling water temperature adjustment coefficient of the crystallizer is positively correlated with the degree of cooling unevenness in the rear end area of the crystallizer and the possibility of metal liquid solidification in the front end area of the crystallizer.
[0088] Preferably, in this embodiment, the sum of the degree of cooling unevenness in the rear end area of the crystallizer and the possibility of molten metal solidification in the front end area of the crystallizer is recorded as the cooling water temperature adjustment coefficient of the crystallizer.
[0089] Preferably, in another embodiment, the product of the degree of cooling unevenness in the rear end area of the crystallizer and the possibility of solidification of the molten metal in the front end area of the crystallizer is recorded as the cooling water temperature adjustment coefficient of the crystallizer.
[0090] When the degree of cooling unevenness in the rear end area of the crystallizer is greater, the cooling effect of the cooling water is worse. In order to improve the solidification continuity and stability of the molten metal, the cooling water temperature should be appropriately increased to ensure the stability of the quality of the mold. When the possibility of solidification of the molten metal in the front end area of the crystallizer is greater, it means that the phenomenon of partial solidification of the molten metal in the front end area of the crystallizer is more likely to occur. In order to avoid continued solidification in the front end area of the crystallizer, the cooling water temperature should be increased to reduce the heat conduction between the front end area and the rear end area of the crystallizer. The method of obtaining the crystallizer cooling water temperature adjustment coefficient through the characteristics of the front end area and the rear end area of the crystallizer is as follows: Figure 2 shown.
[0091] At this point, the cooling water temperature adjustment coefficient of the crystallizer is obtained.
[0092] Step S004, obtain the cooling water inlet temperature of the sampling period, collect historical data, cluster the historical data and the sampling period according to the cooling water temperature adjustment coefficient and the cooling water inlet temperature, and obtain the temperature adjustment value of the sampling period according to the adjusted temperature value of the historical data in the same class; adjust the cooling water inlet temperature of the sampling period to the temperature adjustment value to complete the dynamic adjustment of the cooling water.
[0093] The cooling water of the crystallizer in the factory adopts a circulating cooling treatment mode. The water outlet of the crystallizer and the water inlet of the cooling water treatment device are connected through a circulating cooling water pipeline. The water outlet of the cooling water treatment device and the water inlet of the crystallizer are also connected through a circulating cooling water pipeline. A water pipeline temperature sensor is placed at the water inlet of the crystallizer to obtain the cooling water inlet temperature. Since the database contains a large amount of valid historical adjustment data, this application obtains historical data of 100 historical temperature adjustments from the database, where the historical data specifically includes the cooling water inlet temperature during the historical temperature adjustment, the cooling water temperature adjustment coefficient of the crystallizer, and the adjusted temperature.
[0094] The cooling water inlet temperature and the cooling water temperature adjustment coefficient of the sampling period are combined into a tuple, and the cooling water inlet temperature and the cooling water temperature adjustment coefficient of each historical data obtained are combined into a tuple, and the tuples are classified by a clustering algorithm.
[0095] Preferably, in this embodiment, the clustering algorithm used is the AP clustering algorithm, and the clustering distance is the Euclidean distance between binary groups.
[0096] Preferably, in another embodiment, the clustering algorithm used is the DBSCAN clustering algorithm, which calculates the absolute value of the difference between each item in two tuples, and records the sum of the absolute values of the two differences as the clustering distance.
[0097] The binary group corresponding to the sampling period is recorded as the target binary group, and the cluster where the target binary group is located is obtained. The mean of the adjusted temperature of all historical data in this cluster is calculated and recorded as the historical adjustment mean, and the historical adjustment mean is used as the temperature adjustment value of the crystallizer sampling period.
[0098] Through the cooling water treatment device, for each sampling period, the inlet temperature of the cooling water of the crystallizer is adjusted to the temperature adjustment value. This embodiment controls this through PID control, and the input is the cooling water inlet temperature of the sampling period and the temperature adjustment value of the sampling period, and the cooling water inlet temperature is adjusted to the temperature adjustment value. This application adjusts the inlet temperature of the cooling water of the crystallizer once every sampling period to achieve dynamic adjustment of the cooling water of the crystallizer during the horizontal casting process of large-section profiles.
[0099] At this point, the temperature adjustment of the crystallizer cooling water is completed.
[0100] Based on the same inventive concept as the above method, an embodiment of the present invention also provides a crystallizer cooling water temperature control system, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor implements the steps of any one of the above-mentioned crystallizer cooling water temperature control methods when executing the computer program.
[0101] It should be noted that the above-described 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.
[0102] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.
Claims
1. A method for regulating the temperature of cooling water of a crystallizer, characterized in that: The method comprises the following steps: The temperature of each sampling cycle is collected at each monitoring position in the front end area and the rear end area of the crystallizer by a temperature sensor; the crystallizer is composed of a graphite sleeve and an iron sleeve, and the graphite sleeve is pressed into two sections. The extended end of the first section of the graphite sleeve is sealed and connected to the insulation furnace wall by a special sealing mud. The first section of the graphite sleeve corresponds to the crystallizer area as the front end area of the crystallizer; the second section of the graphite sleeve is pressed into the iron sleeve with cooling water as a whole, and the second section of the graphite sleeve corresponds to the crystallizer area as the rear end area of the crystallizer. For the rear end area of the crystallizer, the degree of cooling unevenness of the rear end area of the crystallizer is obtained according to the temperature differences between all monitoring positions and several nearest monitoring positions and the fluctuation of the temperature values at all monitoring positions; At each sampling moment, the temperature gradient is calculated based on the temperature difference between the front end area and the rear end area of the crystallizer. After subtracting the temperature gradient from the temperature gradient threshold, all differences in the sampling period are sorted to calculate the slope; the molten metal injection time is obtained, and the possibility of molten metal solidification in the front end area of the crystallizer is obtained based on the molten metal injection time and the slope; the cooling water temperature adjustment coefficient of the crystallizer is obtained based on the possibility of molten metal solidification in the front end area of the crystallizer and the degree of cooling unevenness in the rear end area of the crystallizer; Obtain the cooling water inlet temperature of the sampling period, collect historical data, cluster the historical data and the sampling period according to the cooling water temperature adjustment coefficient and the cooling water inlet temperature, and obtain the temperature adjustment value of the sampling period according to the adjusted temperature value of the historical data in the same class; adjust the cooling water inlet temperature of the sampling period to the temperature adjustment value to complete the dynamic adjustment of cooling water; The method for obtaining the degree of cooling unevenness in the rear end area of the crystallizer according to the temperature differences between all monitoring positions and the nearest monitoring positions and the fluctuation of the temperature values at all monitoring positions is: For any monitoring position, record it as the target monitoring position, and take the d monitoring positions with the smallest distance between the target monitoring position and the remaining monitoring positions as the neighboring monitoring positions of the target monitoring position; The temperature distribution non-uniformity of the rear end area of the crystallizer is obtained according to the temperature difference between each target monitoring position and its neighboring monitoring positions; For the target monitoring position, the standard deviation of all temperature values in the target monitoring position is calculated, and the standard deviation is recorded as the volatility of each monitoring position; the result of averaging the volatility of all monitoring positions in the rear end area of the crystallizer is recorded as the temperature volatility of the rear end area of the crystallizer; The degree of cooling unevenness in the rear end area of the crystallizer is obtained according to the temperature distribution unevenness and temperature fluctuation in the rear end area of the crystallizer; The degree of cooling non-uniformity in the rear end area of the crystallizer is positively correlated with the temperature distribution non-uniformity and temperature fluctuation in the rear end area of the crystallizer. For each sampling moment, the temperature gradient is calculated according to the temperature difference between the front end area of the crystallizer and the rear end area of the crystallizer, and after subtracting the temperature gradient from the temperature gradient threshold, all differences in the sampling period are sorted to calculate the slope. The method is: For any sampling moment, the average of the temperature values at all monitoring positions is calculated, and the average of the temperature values is recorded as the overall temperature of the rear end area of the crystallizer; the overall temperature of the front end area of the crystallizer is collected by the temperature sensor in the front end area of the crystallizer; At any sampling time, the difference between the overall temperature of the front end area of the crystallizer and the overall temperature of the rear end area of the crystallizer is recorded as the temperature gradient of the crystallizer; A temperature gradient threshold is preset, and the temperature gradient of the crystallizer is subtracted from the temperature gradient threshold, and the difference is recorded as the temperature difference gradient of the crystallizer; The slope of the straight line is obtained by fitting the straight line according to the temperature difference gradient; The method for obtaining the slope of a straight line by fitting a straight line according to the temperature difference gradient is: Sort the temperature difference gradients at all sampling moments in a sampling period in ascending order to obtain a temperature difference gradient sequence; The temperature difference gradient sequence is obtained by a linear fitting algorithm and its corresponding straight line is recorded as the temperature difference gradient straight line; the slope of the temperature difference gradient straight line is calculated; The method for obtaining the injection time of the molten metal and obtaining the possibility of solidification of the molten metal in the front end area of the crystallizer according to the injection time and slope of the molten metal is as follows: The time for injecting the molten metal into the crystallizer is recorded as the molten metal injection time; the ratio of the molten metal injection time to the sampling period is calculated and recorded as the molten metal injection time ratio; The solidification possibility of the molten metal in the front end area of the crystallizer is obtained according to the slope of the temperature difference gradient straight line and the molten metal injection time ratio; The possibility of molten metal solidification in the front end area of the crystallizer is negatively correlated with the slope of the temperature difference gradient line and the molten metal injection time ratio.
2. A method for regulating the temperature of cooling water of a crystallizer according to claim 1, characterized in that: The method for obtaining the temperature distribution non-uniformity of the rear end area of the crystallizer according to the temperature difference between each target monitoring position and its neighboring monitoring position is: The mean of all temperature values at the target monitoring position is calculated and recorded as the temperature mean of the target monitoring position; the expression of temperature distribution non-uniformity is: , represents the mean temperature of the nth target monitoring position, represents the mean temperature of the ith neighboring monitoring location of the nth target monitoring location, represents the number of neighboring monitoring locations of each target monitoring location, represents the number of target monitoring locations, Indicates the uneven temperature distribution in the rear end area of the crystallizer.
3. A method for regulating the temperature of cooling water of a crystallizer according to claim 1, characterized in that: The method for obtaining the temperature distribution non-uniformity of the rear end area of the crystallizer according to the temperature difference between each target monitoring position and its neighboring monitoring position is: The product of the temperature distribution non-uniformity and the temperature fluctuation in the rear end area of the crystallizer is normalized by the maximum and minimum values and recorded as the degree of cooling non-uniformity in the rear end area of the crystallizer.
4. A method for regulating the temperature of cooling water of a crystallizer according to claim 1, characterized in that: The method for obtaining the cooling water temperature adjustment coefficient of the crystallizer according to the solidification possibility of the molten metal in the front end area of the crystallizer and the degree of uneven cooling in the rear end area of the crystallizer is: The sum of the degree of cooling unevenness in the rear end area of the crystallizer and the possibility of molten metal solidification in the front end area of the crystallizer is recorded as the cooling water temperature adjustment coefficient of the crystallizer.
5. A method for regulating the temperature of cooling water of a crystallizer according to claim 1, characterized in that: The method of clustering the historical data and the sampling period according to the cooling water temperature adjustment coefficient and the cooling water inlet temperature, and obtaining the temperature adjustment value of the sampling period according to the adjusted temperature value of the historical data in the same class is: The sampling period and the cooling water inlet temperature and the cooling water temperature adjustment coefficient of each historical data are combined into a tuple, and the tuple is classified by a clustering algorithm; The binary group corresponding to the sampling period is recorded as the target binary group, the cluster where the target binary group is located is obtained, and the mean value of the adjusted temperature of all historical data in the cluster is calculated as the temperature adjustment value of the crystallizer sampling period.
6. A crystallizer cooling water temperature control system, 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, the steps of a method for regulating the temperature of crystallizer cooling water as described in any one of claims 1 to 5 are implemented.