JP7205517B2 - Rolled material cooling control method and cooling control device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cooling control method and a cooling control device for a rolled material.

In the control of the rolling process, each piece of equipment is driven so that the rolled material has the desired dimensions and temperature when production is completed. In general, the control of the rolling process consists of preset control and dynamic control. Preset control is performed at the beginning of rolling, and when sufficient performance data is obtained after rolling is started, preset control is shifted to dynamic control. In the preset control, a physical model formula is used to predict the rolling/cooling phenomenon, and based on the obtained predicted values, the set values for the equipment actuators, etc. are determined. Examples of set values to be determined include the rolling speed and the amount of cooling water. However, the rolling/cooling phenomenon cannot be completely expressed by a physical model formula. In some cases, the physics model formula is simplified in order to reduce the computational load. Against this background, a learning term is provided in the physical model formula, and a learning coefficient to be reflected in the learning term is updated based on performance data (see Patent Literatures 1 and 2).

JP 2014-108446 A JP 2014-180670 A

In the process of cooling the hot-rolled material by the cooling equipment and winding it with the coiler, the inventors of the present invention used the actual temperature data of the tip of the rolled material to learn the physical model formula for calculating the heat transfer coefficient of the rolled material. is used, the accuracy of predicting the heat transfer coefficient of the rolled material decreases due to variations in the learned value due to variations in the temperature of the tip, and as a result, the accuracy of controlling the coiling temperature decreases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a cooling control method and a cooling control device for a rolled material that can accurately control the coiling temperature of the rolled material.

A method for controlling the cooling of a rolled material according to the present invention uses the heat transfer coefficient of the hot-rolled material determined by a physical model formula in the process of cooling the hot-rolled material by the cooling equipment and winding it by the coiler. A cooling control method for a rolled material that calculates a set value of cooling equipment for controlling the temperature of the material to a predetermined coiling temperature, and controls the cooling equipment using the calculated set value, a temperature difference calculation step of calculating a temperature difference between a plurality of hot-rolled materials and adjacent actual values using actual values of temperature distribution in the length direction of the hot-rolled materials on the delivery side of the cooling equipment; A standard deviation calculation step of calculating the standard deviation of the temperature difference for each length direction position using the data of the temperature difference at the same length direction position calculated in the difference calculation step as a population, and the standard deviation calculation step a learning point determination step of determining, as a learning point for the heat transfer coefficient, a length direction position ahead of a length direction position at which the value of the standard deviation continuously becomes equal to or less than a predetermined threshold value, and in the learning point determination step and a learning step of calculating, for each material class, a learning coefficient to be reflected in the learning term of the physical model formula using the temperature of the hot-rolled material at the determined learning point.

A method for controlling the cooling of a rolled material according to the present invention uses the heat transfer coefficient of the hot-rolled material determined by a physical model formula in the process of cooling the hot-rolled material by the cooling equipment and winding it by the coiler. A cooling control device for rolling material that calculates the setting value of cooling equipment for controlling the temperature of the material to a predetermined coiling temperature and controls the cooling equipment using the calculated setting value, For multiple hot-rolled materials, using the actual value of the temperature distribution in the length direction of the hot-rolled material on the delivery side of the cooling equipment, calculate the temperature difference with the adjacent actual value, and calculate the same length direction The standard deviation of the temperature difference is calculated for each position in the length direction using the temperature difference data of the positions as a population, and the front of the length direction position where the calculated standard deviation value is continuously below a predetermined threshold value A learning point determining unit that determines a longitudinal position as a learning point of the heat transfer coefficient, and a learning term of the physical model formula using the temperature of the hot-rolled material at the learning point determined by the learning point determining unit and a learning processing unit that calculates a learning coefficient to be reflected in each material classification.

According to the cooling control method and the cooling control device for a rolled material according to the present invention, the coiling temperature of the rolled material can be controlled with high accuracy.

FIG. 1 is a schematic diagram showing the configuration of a hot rolling line to which a cooling control device for a rolled strip according to an embodiment of the present invention is applied. FIG. 2 is a block diagram showing the configuration of a cooling control device for rolled material, which is an embodiment of the present invention. FIG. 3 is a flow chart showing the flow of learning point determination processing, which is an embodiment of the present invention. FIG. 4 is a diagram for explaining the processing of steps S1 to S3 shown in FIG. FIG. 5 is a diagram for explaining the process of step S4 shown in FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A cooling control device for a rolled material, which is an embodiment of the present invention, will be described below with reference to the drawings.

[Configuration of hot rolling line]
First, with reference to FIG. 1, the configuration of a hot rolling line to which a cooling control device for a rolled strip according to an embodiment of the present invention is applied will be described. However, the hot rolling line to which the cooling control device for rolled material according to one embodiment of the present invention is applied is not limited to the configuration shown in FIG.

FIG. 1 is a schematic diagram showing the configuration of a hot rolling line to which a cooling control device for a rolled strip according to an embodiment of the present invention is applied. As shown in FIG. 1, in a hot rolling line 1 to which a cooling control device for rolled material according to an embodiment of the present invention is applied, a steel strip 3 cast by a continuous casting machine 2 is heated in a heating furnace 4. , rolled to a thickness of several millimeters by a roughing mill 5 and a finishing mill 6 , cooled in a runout cooling facility 7 , and wound into a coil by a coiler 8 .

[Configuration of cooling control device for rolled material]
Next, with reference to FIG. 2, the configuration of a cooling control device for rolled material, which is an embodiment of the present invention, will be described.

FIG. 2 is a block diagram showing the configuration of a cooling control device for rolled material, which is an embodiment of the present invention. A rolled material cooling control device, which is an embodiment of the present invention, is composed of a general-purpose information processing device such as a work station and a personal computer, and controls a runout cooling facility 7 to wind a steel strip 3 by a coiler 8. is controlled to a predetermined winding temperature. As shown in FIG. 2, a rolled material cooling control device 10 (hereinafter abbreviated as cooling control device 10), which is an embodiment of the present invention, includes an input unit 11, an output unit 12, a storage unit 13, and a processing unit 14. It has

The input unit 11 is configured by input devices such as a keyboard, mouse pointer, touch panel, and various switches, and outputs input signals corresponding to operation inputs to the processing unit 14 . The output unit 12 is configured by a display device such as an LCD, an EL display, a CRT display, etc., and displays various information according to display signals output from the processing unit 14 . Note that the output unit 12 may be configured to include an output device such as a printer or a speaker as appropriate.

The storage unit 13 is composed of a flash memory that can be updated and recorded, a hard disk that is built in or connected via a data communication terminal, an information recording medium such as a memory card, and a read/write device for the same. can be used. In the storage unit 13, a computer program for operating the cooling control device 10 and realizing various functions of the cooling control device 10, data used during execution of the computer program, and the like are stored in advance or processed. is stored temporarily each time. The storage unit 13 also stores a performance database (performance DB) 131 and a learning coefficient database (learning coefficient DB) 132 .

The performance DB 131 is a database in which operation data of the steel strip 3 obtained in past operations are registered and accumulated. The operation data includes the steel type, thickness, and width of the steel strip 3 supplied to the runout cooling equipment 7, the temperature distribution in the length direction at the entrance and exit sides of the runout cooling equipment 7, the target winding temperature, the runout cooling equipment Actual values such as the set value of 7 are included. The learning coefficient DB 132 stores learning coefficients for each material category of the steel strip 3 . The material category includes the steel type, thickness, width, target coiling temperature, and the like of the steel strip 3 .

The processing unit 14 is configured by an arithmetic processing device such as a CPU, and uses input signals input from the input unit 11, computer programs and data stored in the storage unit 13, etc., to control each unit that configures the cooling control device 10. It controls the operation of the cooling control device 10 by giving instructions to and transferring data to. The processing unit 14 also functions as a learning point determination unit 141, a learning processing unit 142, and a cooling setting unit 143 by executing computer programs.

The learning point determination unit 141 executes a learning point determination process, which will be described later, so that the position in the length direction of the steel strip 3 ( learning points), and outputs information about the determined learning points to the learning processing unit 142 .

The learning processing unit 142 uses the temperature of the steel strip 3 at the learning point determined by the learning point determination unit 141 to determine the learning coefficient to be reflected in the learning term of the physical model formula for calculating the heat transfer coefficient of the steel strip 3. It is calculated for each material category of band 3. Then, the learning processing unit 142 stores the calculated learning coefficient DB 132 .

The cooling setting unit 143 reads the learning coefficient corresponding to the material classification of the steel strip 3 to be processed from the learning coefficient DB 132, and uses the read learning coefficient to determine the heat transfer coefficient of the steel strip 3 to be processed by a physical model formula. Calculate Then, the cooling setting unit 143 uses the calculated heat transfer coefficient to calculate the setting value of the runout cooling equipment 7 for controlling the temperature of the steel strip 3 to the target coiling temperature, and uses the calculated setting value. to control the runout cooling facility 7.

In the cooling control device 10 having such a configuration, the learning point determination unit 141 performs the following learning point determination process to predict the heat transfer coefficient of the steel strip 3 and the coiling temperature of the steel strip 3. Improve the control accuracy of The operation of the learning point determination unit 141 when executing the learning point determination process will be described below with reference to FIGS. 3 to 5. FIG.

[Learning point determination processing]
FIG. 3 is a flow chart showing the flow of learning point determination processing, which is an embodiment of the present invention. The flowchart shown in FIG. 3 starts at the timing when the rolling process of the steel strip 3 in the hot rolling line 1 is completed and the operation data of the steel strip 3 is stored in the performance DB 131, and the learning point determination process is the process of step S1. proceed to

In the process of step S1, the learning point determination unit 141 determines the actual temperature distribution of the steel strip 3 in the length direction (for example, every 1 m) on the delivery side of the runout cooling equipment 7 from the newly stored operation data of the steel strip 3. A value is read out from the performance DB 131 . Then, the learning point determination unit 141 uses the read actual values to determine the temperature difference Δθna (n=1, 2 . . . , k−1) (k =Longitudinal position of steel strip 3 (number of actual values), a =identifier of steel strip 3 (material a)) are calculated. Thereby, the processing of step S1 is completed, and the learning point determination processing proceeds to the processing of step S2.

In the process of step S2, the learning point determination unit 141 determines the actual value of the temperature distribution in the length direction on the outlet side of the runout cooling equipment 7 for the steel strip 3 in the same material classification as the steel strip 3 in the process of step S1. is read from the performance DB 131 . Then, the learning point determination unit 141 calculates temperature differences Δθnb, Δθnc, Δθnd, and Δθne for each steel strip 3 (materials b to e) in the same manner as in step S1, as shown in FIG. 4(b). . Note that the data of these temperature differences may be stored in the performance DB 131 in advance, and the process of step S2 may be omitted. Also, the number of steel strips 3 for which the temperature difference is calculated is desirably the most recent several in the material category. As a result, the process of step S2 is completed, and the learning point determination process proceeds to the process of step S3.

In the process of step S3, the learning point determination unit 141, as shown in FIG. Δθnc, Δθnd, Δθne) are used as a population to calculate the standard deviation σn of each. As a result, the process of step S3 is completed, and the learning point determination process proceeds to the process of step S4.

In the process of step S4, the learning point determination unit 141 determines, as shown in FIG. is determined as the learning point of the heat transfer coefficient of the steel strip 3 in that material class. According to this treatment, the tip of the material that originally had no temperature variation at the tip was adopted as the learning point for the heat transfer coefficient, and the variation was reduced for the material that had variation in the temperature of the tip. Position is taken as the learning point for the heat transfer coefficient. As a result, the variation in the learned value of the heat transfer coefficient is reduced, and the prediction accuracy of the heat transfer coefficient of the steel strip 3 and the control accuracy of the coiling temperature of the steel strip 3 are improved. As a result, the processing of step S4 is completed, and the series of learning point determination processing ends.

As a result of extensive studies, the inventors of the present invention found that the cause of the variation in the temperature of the tip is that water rides on the steel strip due to the poor shape of the tip, and the water rides on the steel strip locally. It was found that the reason for this is that the In addition, the inventors have found that this variation in temperature at the tip portion is reduced when the tip portion of the steel strip winds around the coiler and tension is applied to the steel strip. Therefore, the point between the runout cooling equipment and the coiler at the timing when the tip of the steel strip is wound around the coiler or when the steel strip is tensioned may be used as the learning point for the heat transfer coefficient.

Although the embodiments to which the invention made by the present inventors is applied have been described above, the present invention is not limited by the descriptions and drawings forming a part of the disclosure of the present invention according to the present embodiments. That is, other embodiments, examples, operation techniques, etc. made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

1 Hot Rolling Line 2 Continuous Caster 3 Steel Strip 4 Heating Furnace 5 Rough Rolling Mill 6 Finishing Rolling Mill 7 Runout Cooling Equipment 8 Coiler 10 Cooling Control Device for Rolled Material 11 Input Section 12 Output Section 13 Storage Section 14 Processing Section 131 Achievements Database (Results DB)
132 learning coefficient database (learning coefficient DB)
141 learning point determination unit 142 learning processing unit 143 cooling setting unit

Claims (2)

In the process of cooling the hot-rolled material with the cooling equipment and winding it with the coiler, the temperature of the hot-rolled material is controlled to a predetermined coiling temperature using the heat transfer coefficient of the hot-rolled material determined by the physical model formula. A cooling control method for a rolled material that calculates a set value of a cooling facility for and controls the cooling facility using the calculated set value,
A temperature difference calculation step of calculating the temperature difference between a plurality of hot-rolled materials of the same material class and adjacent actual values using the actual values of the temperature distribution in the length direction of the hot-rolled materials on the delivery side of the cooling equipment. When,
A standard deviation calculating step of calculating the standard deviation of the temperature difference for each position in the length direction, with the data of the temperature difference at the same length direction position calculated in the temperature difference calculating step as a population;
A learning point determination step of determining, as a learning point for the heat transfer coefficient, a lengthwise position ahead of a lengthwise position where the standard deviation value calculated in the standard deviation calculating step is continuously equal to or lower than a predetermined threshold value. When,
a learning step of calculating, for each material classification, a learning coefficient to be reflected in the learning term of the physical model formula using the temperature of the hot-rolled material at the learning point determined in the learning point determination step;
A cooling control method for a rolled material, comprising: In the process of cooling the hot-rolled material with the cooling equipment and winding it with the coiler, the temperature of the hot-rolled material is controlled to a predetermined coiling temperature using the heat transfer coefficient of the hot-rolled material determined by the physical model formula. A cooling control device for a rolled material that calculates a set value of a cooling facility for and controls the cooling facility using the calculated set value,
For multiple hot-rolled materials of the same material class, the temperature difference between the adjacent actual values was calculated using the actual value of the temperature distribution in the length direction of the hot-rolled material on the delivery side of the cooling equipment. The standard deviation of the temperature difference is calculated for each position in the length direction using temperature difference data at the same length direction position as a population, and the length at which the calculated standard deviation value is continuously below a predetermined threshold a learning point determining unit that determines a longitudinal position ahead of the directional position as a learning point for the heat transfer coefficient;
a learning processing unit that calculates, for each material classification, a learning coefficient to be reflected in the learning term of the physical model formula using the temperature of the hot-rolled material at the learning point determined by the learning point determination unit;
A cooling control device for a rolled material, comprising:

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