JP4335860B2 - Winding temperature control device and control method - Google Patents

Description

  The present invention relates to a winding temperature control device for a hot rolling line and a control method thereof, and more particularly to a winding temperature control device and a control method thereof suitable for matching the winding temperature to a target temperature by simple calculation.

  As a conventional method for performing the coiling temperature control, for example, Patent Document 1 discloses a control method for setting a cooling pattern based on information on a rolled material, corresponding to the speed pattern of the rolled material obtained in advance before the start of cooling. Is disclosed. Patent Document 2 discloses a winding temperature control method in which a rolling material cooling apparatus is divided in the longitudinal direction, and this is used as a material cooling unit to predict a temperature for each unit and to match the predicted temperature with a target temperature. Is described. Also, the coiling temperature control device can reduce the influence of disturbance by taking the temperature change of the rolled material and the inlet side temperature change of the transfer table and determining the amount of cooling water in real time and operating the valve accordingly. It is shown.

JP-A-8-66713 JP 2000-167615 A

  However, these methods are not considered to efficiently select an appropriate pattern from among a huge number of combinations of cooling patterns, and therefore there is a problem that requires a large amount of calculation time to determine the cooling pattern. there were. In addition, since the focus is on optimizing the operation of the valve for the coiling temperature control, there is a problem that a certain valve repeatedly opens and closes in time series.

  Further, the rolling speed of the rolled material is generally low when the mill is discharged, rapidly increases after the start of downcoiler winding, and decreases again immediately before the coil exits the mill. In Patent Document 1, good control can be performed in a steady portion where the speed is constant, but in the transient state portion where the speed changes, the speed pattern and the winding temperature pattern do not directly correspond to each other, so the cooling pattern is changed corresponding to the speed pattern. This method has a problem that the accuracy of the coiling temperature control is lowered.

  Moreover, in the control method described in Patent Document 2, since the division unit for predicting the temperature of the rolled material depends on the size of the cooling device, there is a problem that the division becomes coarser than the value required for accuracy. .

  Therefore, the problem to be solved by the present invention is to provide a method for efficiently selecting an appropriate cooling pattern for accurately controlling the coiling temperature from among a huge number of cooling patterns. This is to reduce the calculation time for calculating. Another object is to generate a cooling pattern in which the valve does not repeat opening and closing in time series.

  In order to solve the above-mentioned problems, the present invention is a steel plate before being rolled up by a downcoiler after the steel plate rolled by a hot rolling mill is cooled by a cooling device provided on the outlet side of the hot rolling mill. In the winding temperature control device for controlling the temperature of the steel sheet to a predetermined target temperature, a cooling header priority table storing a priority relationship of the opening order of a number of cooling headers provided in the cooling device, and winding of the steel plate After associating the sheet temperature estimation model for estimating the temperature and the header pattern which is a combination of opening and closing of the cooling header with the control code generated using the information in the priority table, the target winding temperature and the steel sheet Preset control that estimates the coiling temperature using the plate temperature estimation model from the information about the speed, and calculates and outputs a control code for realizing the target coiling temperature using the estimation result And the step, characterized in that it is configured to include a header pattern conversion means for outputting a control code said preset means has outputted to the conversion to the cooling device in the header pattern.

  The control code has a maximum value (or minimum value) when all headers are open, and a minimum value (or maximum value) when all headers are closed. The estimated value is associated with a monotonously decreasing (or increasing).

  The preset control means calculates and outputs the control code in association with each part in the longitudinal direction of the steel sheet, and the header pattern conversion means recognizes the part in the longitudinal direction of the steel sheet directly under each header. The control code corresponding to the part is extracted, converted into a header pattern, and output to the cooling device.

  The preset control means checks the increase / decrease of the control code in the longitudinal direction of the steel plate, and if the control code of a certain part is larger or smaller than the control code of the front and rear, the control code matches the control code of the front or rear Thus, there is provided a smoothing means for correcting the control code so that the change in the control code in the longitudinal direction of the steel sheet becomes a unimodal function.

  In the present invention, the steel sheet rolled by the hot rolling mill is cooled by a cooling device provided on the outlet side of the hot rolling mill, and the temperature of the steel sheet before being rolled up by the downcoiler is set to a predetermined value. In the winding temperature control method for controlling to the target temperature, priority is given to the opening order of the cooling header provided in the cooling device, and the control code corresponding to the header pattern that is a combination of opening and closing the cooling header is assigned the priority. Using the control code and the information about the speed of the steel plate, the coil temperature estimation model is used to estimate the coiling temperature of the steel plate, and the control code for realizing the target coiling temperature using the estimation result is obtained. The control code is converted into a header pattern and output to the cooling device.

  According to the present invention, in the winding cooling process in hot rolling, the temperature can be controlled with high accuracy in the longitudinal direction of the steel sheet by simple calculation. Further, it is possible to generate a cooling pattern in which the cooling valve does not repeat turning on and off in time series.

  As shown in FIG. 1, the best mode for carrying out the winding temperature control device of the present invention is that the winding temperature control device 100 inputs the target winding temperature, the speed pattern of the steel plate, and the priority order of the cooling device. Information. Then, model-based preset means 111 that calculates a control code corresponding to the command value of the cooling device that achieves a desired coiling temperature using the plate temperature estimation model, and cooling that suppresses unnecessary changes in the command value of the cooling device The apparatus has command value smoothing means 112. Furthermore, it includes header pattern conversion means 130 for converting the control code into the output pattern of the cooling device.

  Thereby, in the winding control of the steel plate after hot rolling, a highly accurate winding temperature can be obtained at any part in the longitudinal direction of the steel plate. As a result, the composition quality of the steel plate can be improved, and at the same time, a steel plate shape close to flatness can be obtained.

  FIG. 1 shows a configuration of a winding temperature control device and a controlled object according to Embodiment 1 of the present invention. The winding temperature control apparatus 100 receives various signals from the control target 150 and outputs control signals to the control target 150.

  First, the configuration of the control target 150 will be described. The control object 150 in this embodiment is a coiling temperature control line for hot rolling, and the steel sheet 151 having a temperature of 900 ° C. to 1000 ° C. rolled by the mill 157 of the rolling unit 152 is cooled by the winding cooling unit 153. Take up with a downcoiler 154. The winding cooling unit 153 is provided with an upper cooling device 158 that cools water from the upper side of the steel plate 151 and a lower cooling device 159 that cools water from the lower side of the steel plate 151. Each cooling device includes a plurality of banks 159 in which a certain number of cooling headers 160 that discharge water are combined.

  In this embodiment, a case where the operation command for each cooling header 160 is open or closed will be described as an example. The mill outlet thermometer 155 measures the temperature of the steel sheet immediately after being rolled by the rolling unit 152, and the winding thermometer 156 measures the temperature immediately before winding by the downcoiler 154. The purpose of the winding temperature control is to make the temperature measured by the winding thermometer 156 coincide with the target temperature. The target temperature may be constant at each part in the coil longitudinal direction, or a different value may be set according to each part.

  Next, the configuration of the winding temperature control device 100 will be shown. The winding temperature control apparatus 100 includes preset control means 110 that calculates a control code corresponding to the opening / closing pattern of each cooling header 160 before the steel plate 155 is cooled by the winding cooling unit 153. In addition, when the steel plate 155 is cooled by the winding cooling unit 153, a dynamic control means 120 is provided that takes in the results such as the measured temperature of the winding thermometer 156 in real time and changes the control code. In addition, header pattern conversion means 130 for converting the control code into the opening / closing pattern of each cooling header 160 is provided. A set of opening / closing patterns of each cooling header 160 is hereinafter referred to as a header pattern.

  The preset control means 110 includes a model-based preset means 111 that takes in information from the target winding temperature table 114, the speed pattern table 115, and the cooling header priority order table 116, and calculates a header pattern by calculation using the plate temperature estimation model 117. Have. A cooling device command value smoothing means 112 is provided for smoothing the temporal output of the header pattern with respect to the calculation result of the model-based preset means 111.

  The dynamic control unit 120 includes a winding temperature deviation correction unit 121 that uses the detected temperature from the winding thermometer 156 to correct a deviation between the temperature and the target temperature. In addition, a mill outlet temperature deviation correction unit 122 is used to correct a deviation between the detected temperature from the mill outlet thermometer 155 and the mill outlet temperature assumed during the preset control calculation. Further, speed deviation correcting means 123 is provided for calculating the speed of the steel plate 151 from the rotation speed of the mill 157 and the downcoiler 154 and correcting the deviation between the calculated result and the steel plate speed assumed at the time of the preset control calculation.

  FIG. 2 shows the configuration of the target winding temperature table 114. The example in which the target temperature is stratified corresponding to the type (steel type) of the steel plate is shown. The preset control means 110 determines the steel type of the corresponding coil, and extracts the corresponding target temperature from the target winding temperature table 114.

  FIG. 3 shows the configuration of the speed pattern table 115. The initial speed is the speed from when the tip of the steel plate 151 is paid out from the mill 157 to the coiled by the downcoiler 154 with respect to the steel type, plate thickness, and plate width. After that, the steady speed after sudden acceleration, the speed until the rear end of the steel plate 151 is suddenly decelerated just before being fed out of the mill 157, and the speed until it is taken up by the downcoiler 154 is the final speed, and each speed is stratified. ing.

  The preset control means 110 determines a steel type, a plate thickness, and a plate width of the corresponding coil, and extracts a corresponding speed pattern from the speed pattern table 115. For example, when the steel type is SUS304, the plate thickness is 3.0 to 4.0 mm, and the plate width is 1200 mm, the initial speed is 150 mpm, the steady speed is 150 mpm, and the final speed is 150 mpm.

  FIG. 4 shows the configuration of the cooling header priority table 115. Hereinafter, a case where the total number of headers is 100 will be described as an example. Fig. 4 shows the priority order of 1 to 100 for the opening order of 100 headers. The cooling headers that are preferentially opened for steel grade, sheet thickness, and header classification (upper header or lower header). The order is stored.

  The priority order is determined in consideration of cooling efficiency, allowable temperature difference between the surface and the inside, and the like. For example, when the steel plate 151 is thin, a temperature difference hardly occurs between the surface and the inside, so that the header close to the exit side of the mill 157 where the temperature of the steel plate 151 is high is preferentially opened in consideration of cooling efficiency. When the steel plate 151 is thick, priority is given so that the open headers are not continuous as much as possible for the purpose of suppressing the temperature difference between the surface and the interior within the allowable range by utilizing recuperation by air cooling. By mixing water cooling and air cooling, the temperature difference between the surface and the inside of the steel plate 151 is suppressed at the expense of some cooling efficiency.

  The cooling headers are controlled to be opened as many as the target winding temperature can be achieved. The bulk and cooling headers are numbered in order of proximity to the mill 157, for example (1, 1) represents the first cooling first cooling header.

  In FIG. 4, when the steel type is SUS304, the plate thickness is 2.0 to 3.0 mm, and the cooling header section is the upper header, (1, 1), (1, 2), (1, 3), (1, 4) , (1, 5), (2, 1),..., (20, 4), (20, 5). That is, since it is a thin plate, it is preferentially opened in order from the header on the outlet side of the mill 157 in consideration of cooling efficiency. When the steel type is SUS304, the plate thickness is 5.0 to 6.0 mm, and the cooling header section is the upper header, (1, 1), (1, 4), (2, 1), (2, 4), ( 3, 1), (3, 4),..., (20, 3), (20, 5), in that order. That is, since the steel plate 151 is slightly thick, priority is given so that open headers do not continue.

  In this embodiment, the priority order of the upper header and the lower header is the same, but different priority orders can be given.

  The header pattern is expressed by a corresponding control code. FIG. 5 shows the correspondence between the control code output by the preset control means 110 and the cooling header opening / closing pattern. Control code 0 is fully open and 100 is fully closed. Hereinafter, the header open / close pattern in which only the priority 1 cooling header is open is set as 1, the header open / close pattern in which the two cooling headers of priority 1 and 2 are open is set as the control code, and so on.

  The preset control means 110 outputs a control code corresponding to such a cooling header opening / closing pattern to the smoothing means 112. That is, the control code with all the cooling headers open is set to 0, and the control code with all the cooling headers closed is set to 100 (100 is the total number of cooling headers above or below). If the steel type is SUS304, the plate thickness is 2.0 to 3.0 mm, and the cooling header section is the upper header, the control code is determined according to the priority order of the header. For example, a state in which only (1, 1) is opened is the control code 99, and a state in which (1, 1) (1, 2) is opened is the control code 98, (1, 1) (1, 2), (1, 3 ) Is set as a control code 97. In this manner, hereinafter, control codes are assigned to the header release pattern up to 0 which is a control code in a state where all headers are open.

  FIG. 6 shows an algorithm executed by the model-based preset means 111. Based on the values fetched from the speed pattern table 115 in S6-1, an acceleration start position for shifting from the initial speed to the steady speed and a deceleration start position for shifting from the steady speed to the final speed are calculated. Then, the speed pattern from the start of payout of the steel plate 151 by the mill 157 to the completion of winding by the downcoiler 154 is calculated. The acceleration start position Saccp and the acceleration completion position Saccq can be calculated by the following equations 1 to 4, respectively, as the deceleration start position Sdccp and the deceleration completion position Sdccq.

Lmd: distance from the mill 157 to the downcoiler 154.

Where Sstart: initial speed of the steel plate 151, Smid: steady speed of the steel plate 151, Saccrate: acceleration rate from the initial speed of the steel plate 151 to the steady speed.

However, Lstrip: the length of the steel plate 151, Send: the final speed of the steel plate 151, Sdccrate: the deceleration rate from the steady speed to the final speed of the steel plate 151, Lmargin: the bottom of the steel plate 151, how long before the deceleration completes Margin indicating

According to the calculated speed pattern, the time change of the header pattern that realizes the target winding temperature is calculated by calculation using the plate temperature estimation model 117 in S6-2 and later. In this embodiment, an example in which a header pattern is calculated according to a linear inverse interpolation method is shown.

  In S6-2, for each part of the steel plate 151, two control codes nL and nH that sandwich the control code of the solution are defined. Here, since a solution exists between the fully open and fully closed cooling headers, nL = 0 and nH = 100 are uniformly set. Here, as the control code increases, the number of cooling headers that are simply open decreases. Therefore, when n1 <n2, Tc1 <Tc2 holds for the winding temperatures Tc1, Tc2 corresponding to these header patterns.

  In step S6-3, the average of nL and nH is n0. In S6-4, a winding temperature Tc0 corresponding to the control code n0 is calculated. In S6-4, the temperature estimation calculation according to the plate temperature estimation model 117 is continuously calculated for each part in the longitudinal direction of the steel plate 150 from the mill discharge to the downcoiler winding to estimate the winding temperature. In S6-5, the sign of the estimated winding temperature Tc0 with respect to the target winding temperature Ttarget is determined. If Tc0> Ttarget, there is a solution between n0 and nL, so n0 is newly set to nH. Conversely, when Tc0 <Ttarget, there is a solution between n0 and nH, so n0 is newly set to nL. In S6-6, the end condition of the algorithm is determined. If not satisfied, the execution of S6-3 to S6-5 is repeated.

  Completion of the algorithm is completed by repeating a predetermined number of times of S5-3 to S5-5, the deviation between the coiling temperature estimated value Tc and the target coiling temperature Ttarget is less than a certain value, n0 matches either nH or nL, Etc. may be determined under the condition.

  The control code can be increased by setting the control code with all cooling headers closed to 0 (minimum value) and the control code with all cooling headers open to 100 (maximum value). Accordingly, the estimated value of the coiling temperature may be associated so as to increase monotonously.

  FIG. 7 shows details of the temperature estimation calculation corresponding to S6-4. As the temperature estimation calculation, an example of a so-called forward difference method in which the steel plate 151 is divided in the longitudinal direction and the thickness direction and the calculation is performed by advancing the time by a constant increment Δ is shown.

  The calculation time is updated in S7-1, and the plate speed Vt at the corresponding time is calculated from the speed pattern generated in S6-1 of FIG. In S7-2, the mill payout length is calculated using the calculated plate speed. The payout length Ln is the length of the steel sheet that is discharged from the mill after rolling, and can be calculated by Equation 5. However, Ln-1 is the payout length of the previous time.

In S7-3, the completion of the operation is determined. When the mill payout length Ln is larger than the sum of the total length of the steel plate 151 and the distance between the mill 157 and the downcoiler 154, all the winding temperature prediction calculations corresponding to one coil are completed, and the calculation is completed.

  If the calculation has not been completed, the temperature tracking of the steel sheet is performed in S7-4. In other words, the process of moving the temperature distribution of the steel sheet by a distance corresponding to the position of the steel sheet at the previous time is known from the relationship between Ln and Ln-1 after the time has elapsed by Δ. Do. In S7-5, an estimated value of the steel sheet temperature on the outlet side of the mill is set to the steel sheet 151 discharged from the mill during Δ. In S7-6, it is determined whether each part is water-cooled or air-cooled from information on opening / closing of the header corresponding to each part of the steel plate 151. In the case of water cooling, the heat transfer coefficient is calculated according to, for example, Equation 6 in S7-7.

Where, ω: water density, Tw: water temperature, D: nozzle diameter, pl: nozzle pitch in the line direction, pc: nozzle pitch in the line and perpendicular direction, Tsu: surface temperature of the steel plate 151.

  Equation 6 is a heat transfer coefficient in the case of so-called laminar cooling. There are various other water cooling methods such as spray cooling, and several heat transfer coefficient calculation formulas are known. On the other hand, in the case of air cooling, the heat transfer coefficient is calculated according to Equation 7, for example.

Where σ: Stefan Boltzmann constant (= 4.88), ε: emissivity, Ta: air temperature (° C.), Tsu: surface temperature of steel plate 151.

  Equations 6 and 7 are calculated for the front and back of the steel plate 151, respectively. In S7-9, the temperature of each part of the steel plate 151 is calculated by adding or subtracting the movement of the amount of heat between Δ based on the temperature before Δ has elapsed. If the heat transfer in the thickness direction of the steel plate 151 is ignored, each part in the longitudinal direction of the steel plate 151 can be calculated as in Expression 8.

Where Tn: current plate temperature, Tn-1: plate temperature before Δ, ht: heat transfer coefficient on the steel plate surface, hb: heat transfer coefficient on the back surface of the steel plate, ρ: density of the steel plate, C: specific heat of the steel plate, B : Steel plate thickness.

  Further, when it is necessary to consider the heat conduction in the thickness direction of the steel plate 151, it can be calculated by solving a well-known heat equation. The thermal equation is expressed by Equation 9, and methods for calculating the difference with a computer are published in various documents.

Where λ: thermal conductivity, T: material temperature.

  Then, S6-6 to S7-9 are repeated until the calculation is completed in the entire area of the steel plate 151 in the line from the mill 157 to the downcoiler 154 in S7-10. Further, S7-1 to S7-9 are repeated until it is determined in S7-3 that the calculation is finished.

  FIG. 8 shows an example of a change in the control code given to each part of the steel plate 151 in S6-3 due to the optimization process of FIG. In the first process, the process is performed on the same initial value (nL = 0, nH = 100) in each part. Therefore, as shown in the first process in FIG. In the second processing, the control code to be applied differs depending on whether the prediction result of the coiling temperature Tc0 of each part of the steel plate 151 is larger or smaller than Ttarget with respect to the control code 50. In this embodiment, the portions close to the front and rear ends of the steel plate 151 where the steel plate speed is low are updated to control codes in the direction of closing the header, and the central portion of the steel plate 151 where the steel plate speed is high opens the header. An example of updating to a direction control code is shown.

  Specifically, as shown in the second processing of FIG. 8, the leading end and the trailing end are updated to nL = 50 and nH = 100 in S6-5 of the first processing. The average has been updated to 75. On the other hand, as a result of updating the central portion to nL = 0 and nH = 50 in S6-5 of the first processing, the control code is updated to 25. In this manner, the control codes are sequentially updated by repeating S6-3 to 6-6 in FIG.

  FIG. 9 shows an example of the control code finally output by the preset control means 110. In the example in the figure, the steel plate 151 is divided into meshes in units of 1 m corresponding to the distance from the tip, and control codes are assigned corresponding to the meshes. Since the cooling device includes the upper cooling device 158 and the lower cooling device 159 corresponding to the front and back of the steel plate, the control code is output separately corresponding to the upper header and the lower header. In the figure, for the longitudinal direction of the steel plate 151, the control code for the upper header 1m from the tip is 95, the control code for the lower header is 95, and the control code for the upper header is 14 between 500m and 501m, the control code for the lower header Also shows that it is 14.

  In FIG. 9, the control codes of the upper header and the lower header corresponding to the same part of the steel plate 151 are the same, but different control codes can be set.

  FIG. 10 shows the processing result of the smoothing means 112. The smoothing means 112 performs a process of smoothing the opening and closing of the cooling header on the output of the model-based preset means 111. The control code output by the model-based preset means 111 is smaller in the section of the steel plate parts 3m to 4m than in the front and rear parts. In this case, a control command is output so that a part of the cooling headers open and close instantaneously as the part passes through.

  After the smoothing process by the smoothing means 112, by smoothing the control code 12 to 14, the change of the control code for the steel plate portion becomes monotonous, and the problem before smoothing is solved.

  Generating a command to open and close the cooling header in a short cycle does not actually make sense because of a response delay in the cooling header. Therefore, such a smoothing process is performed to smooth the cooling header command in the time direction. Smoothing can be realized by a simple process in which each control code is compared with the preceding and following control codes, and when both are large or small, the control codes are matched with the preceding or following control codes.

  The control code output by the preset control means 110 is corrected by the dynamic control means 120 in real time while the steel plate 151 is actually cooled. The dynamic control unit 120 includes a winding temperature deviation correcting unit 121 that corrects a deviation between the detected temperature from the winding thermometer 156 and the target temperature. Further, a mill outlet temperature deviation correction unit 122 is provided that corrects a deviation between the detected temperature from the mill outlet thermometer 155 and the mill outlet temperature assumed at the time of preset control calculation. Furthermore, speed deviation correcting means 123 is provided for calculating the speed of the steel plate 151 from the rotational speed of the mill 157 and the downcoiler 154 and correcting the deviation between the calculated result and the steel plate speed assumed at the time of preset control calculation. The sum of these correction amounts is converted into a change amount of the control code and output as a correction amount of the dynamic control means 120. The calculation of the correction amount can be realized by applying PI control or the like. The control code output by the preset control means 110 is corrected according to the output correction amount.

  FIG. 11 shows an example of the correction result when the dynamic control means 120 corrects the control code output by the preset control means 110. The control code of the steel plate portions 5m to 6m is corrected from 12 to 14.

  FIG. 12 shows an algorithm executed by the header pattern conversion means 130. In S11-1, a distance Lh from the tip of the steel plate 151 passing directly under the cooling header is calculated. Usually, the control device 100 has such distance information for use for various purposes.

  In S11-2, it is determined whether or not Lh is smaller than 0. If it is smaller, the steel plate 151 has not reached the corresponding cooling header, so the process is terminated and the process proceeds to S11-6. If it is larger, since the steel plate 151 has reached the corresponding cooling header, a control code corresponding to the distance Lh is extracted in S11-3. That is, Lh and the steel plate part of FIG. 9 are collated, and the upper header control code and the lower header control code corresponding to Lh are extracted.

  In S11-4, the cooling header open / close pattern is extracted from the control code. That is, using the correspondence between the control code and the cooling header open / close pattern in FIG. In S11-5, using the information stored in the cooling header priority table 115, the cooling header to be specifically opened is specified, and finally the opening / closing of the corresponding cooling header is determined. In S11-6, it is determined whether or not the calculation for all the cooling headers has been completed. If the calculation has not been completed, the processes of S11-1 to S11-5 are repeated until the calculation is completed.

  In the present embodiment, the case where the number of cooling headers is 100 at the top and bottom has been described as an example. In the present embodiment, the smoothing means 112 is provided, but a configuration in which it is omitted is also conceivable.

  In the present embodiment, a case where a plant manufacturer remotely performs tuning of a water cooling model or an air cooling model as a service using the Internet will be described. FIG. 13 shows the overall configuration of the system of this embodiment.

  The manufacturer uses the network to record the winding temperature taken by the control device 100 from the control target 150, the header pattern related to this, the actual data such as the speed of the steel plate 151, the mill exit side temperature, and the primary information such as the plate thickness and width. 1211, the server 1210, and the network 1203 are imported into the server 1204 of the company. Then, it is stored in the tuning database 1205.

  The manufacturer 1202 has a model tuning means 1206, and performs correction calculation of hr, hw, and λ described in the first embodiment using the data stored in the tuning database 1205 in accordance with a request from the steel company 1201. The calculation result is transmitted to the steel company 1201. Various methods are known for the correction calculation, as shown in an example in “Structure and Learning Method of Adjusting Neural Network that Performs Model Tuning with High Accuracy (The Institute of Electrical Engineers of Japan D, April, 1995 issue)”. ing. The value of model tuning may be associated with the number of tunings, or may be a result reward associated with a control result improved as a result of tuning.

  The present invention shown in the first and second embodiments can be widely applied to cooling control of a hot rolling line.

The block diagram which showed one Example of the control system of this invention. Explanatory drawing which showed the structure of the target winding temperature table. Explanatory drawing which showed the structure of the speed pattern table. Explanatory drawing which showed the structure of the cooling header priority order table. Explanatory drawing which shows the correspondence table of a cooling header opening / closing pattern and a control code. The flowchart which shows the process of a model based preset means. The flowchart which shows the detailed process of coiling temperature prediction calculation. Explanatory drawing which shows an example of the change of the control code by the optimization process of FIG. Explanatory drawing of the corresponding | compatible table of a steel plate site | part and a control code. Explanatory drawing of a smoothing process. Explanatory drawing of the correction process by a dynamic control means. The flowchart which shows the process of a header pattern conversion means. The block diagram of the system which carries out the remote service of tuning of a control model.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 ... Control apparatus, 111 ... Model based preset means, 112 ... Smoothing means, 114 ... Target winding temperature table, 115 ... Speed pattern table, 116 ... Cooling header priority table, 117 ... Plate temperature estimation model, 120 ... Dynamic control Means 130: Header pattern conversion means 150 ... Control object 153 ... Winding cooling unit 1205 ... Tuning database 1206 ... Model tuning means

Claims (12)

Winding temperature control that cools the steel sheet rolled by the hot rolling mill with a cooling device provided on the outlet side of the hot rolling mill and controls the temperature of the steel sheet before being wound by the downcoiler to a predetermined target temperature. In the device
A cooling header priority table storing a priority relationship of an opening order of a plurality of cooling headers provided in the cooling device;
A plate temperature estimation model for estimating the coiling temperature of the steel plate;
The header pattern, which is a combination of the opening and closing of the cooling header, is associated with the control code generated using the information of the cooling header priority table, and then given control code given to obtain a solution , hot estimates on the delivery side of the rolling mill of a steel sheet temperature, and information whether et related to the velocity of the steel sheet, the sheet temperature using the estimated model estimates the winding temperature of the steel sheet, coiling the estimated temperature target winding that this estimated Preset control means for obtaining and outputting a control code as a solution for realizing the target winding temperature by updating the given control code so as to approach the temperature;
A winding temperature control device comprising: header pattern conversion means for converting a control code output from the preset control means into a header pattern and outputting the header code to the cooling device.   The control code has a maximum value when all headers are open, and a minimum value when all headers are closed, and the estimated value of the coiling temperature decreases monotonously as the control code increases. The winding temperature control device according to claim 1, wherein the winding temperature control device is attached.   The control code has a minimum value when all headers are open and a maximum value when all headers are closed, and the estimated value of the coiling temperature increases monotonically as the control code increases. The winding temperature control device according to claim 1, wherein the winding temperature control device is attached. The control code has a maximum value when all headers are open, and a minimum value when all headers are closed, and the estimated value of the coiling temperature decreases monotonously as the control code increases. Attached,
The preset control means sets the maximum value and the minimum value of the control code as the first control code and the second control code, respectively, and sets the average value of the first control code and the second control code as the third control code. The winding temperature is estimated with a header pattern corresponding to the third control code using the calculated third control code as the given control code, and the estimation result is larger than the target winding temperature. In this case, the third control code is changed to the second control code. Conversely, when the estimation result is smaller than the target winding temperature, the third control code is changed to the first control code. third calculation for updating the control code, coiling temperature control device according to claim 1, wherein a repeated until satisfying the predetermined computation termination condition. The control code has a minimum value when all headers are open and a maximum value when all headers are closed, and the estimated value of the coiling temperature increases monotonically as the control code increases. Attached,
The preset control means sets the maximum value and the minimum value of the control code as the first control code and the second control code, respectively, and sets the average value of the first control code and the second control code as the third control code. The winding temperature is estimated with a header pattern corresponding to the third control code using the calculated third control code as the given control code, and the estimation result is larger than the target winding temperature. In this case, the third control code is changed to the first control code. Conversely, when the estimation result is smaller than the target winding temperature, the third control code is changed to the second control code. third calculation for updating the control code, coiling temperature control device according to claim 1, wherein a repeated until satisfying the predetermined computation termination condition.   The preset control means calculates and outputs the control code in association with each part in the longitudinal direction of the steel sheet, and the header pattern conversion means recognizes the part in the longitudinal direction of the steel sheet directly under each header. The winding temperature control device according to any one of claims 1 to 3, wherein a control code corresponding to the part is extracted, converted into a header pattern, and output to a cooling device. The preset control means, when the value of the control code for each part in the longitudinal direction of the steel sheet is larger or smaller than the preceding and following parts, the process of matching the control code with the front or rear control code It is characterized by comprising smoothing means for correcting the control code so that the change in the control code in the longitudinal direction of the steel sheet is a function of unimodality from repetition to winding of the steel sheet by repeating over the entire length of the steel sheet. coiling temperature control device according to any one of claims 1 to 6. A steel sheet rolled by a hot rolling mill is cooled by a cooling device provided on the outlet side of the hot rolling mill, and the temperature of the steel sheet before the steel sheet is wound by the downcoiler is controlled to a predetermined target temperature. In the temperature control method,
The preset control means associates a header pattern, which is a combination of opening and closing of the cooling header provided in the cooling device, with a control code generated using information in a table storing the priority order of the cooling header, and then solves the problem. given control code given to determine the estimated value of the steel sheet temperature of the hot rolling mill exit side, and information whether et related to the velocity of the steel sheet, the coiling temperature of the steel sheet by using the metal temperature estimation model , And update the given control code so that the estimated coiling estimated temperature approaches the target coiling temperature to obtain and output a control code that is a solution for realizing the target coiling temperature, A winding temperature control method, wherein the control code is converted into a header pattern and output to the cooling device. The control code has a maximum value when all headers are open, and a minimum value when all headers are closed, and the estimated value of the coiling temperature decreases monotonously as the control code increases. Attached,
The maximum value and the minimum value of the control code are set as a first control code and a second control code, respectively, and an average value of the first control code and the second control code is calculated as a third control code. Taking the calculated third control code as the given control code, the winding temperature is estimated with a header pattern corresponding to the third control code. If the estimation result is smaller than the target coiling temperature, the third control code is changed to the first control code and the third control code is changed to the second control code. The winding temperature control method according to claim 8, wherein the operation for updating the code is repeated until a predetermined calculation end condition is satisfied. The control code has a maximum value when all headers are open, and a minimum value when all headers are closed, and the estimated value of the coiling temperature decreases monotonously as the control code increases. Attached,
The maximum value and the minimum value of the control code are set as a first control code and a second control code, respectively, and an average value of the first control code and the second control code is calculated as a third control code. Taking the calculated third control code as the given control code, the winding temperature is estimated with a header pattern corresponding to the third control code. If the estimation result is smaller than the target coiling temperature, the third control code is changed to the second control code and the third control code is changed to the first control code. The winding temperature control method according to claim 8, wherein the operation for updating is repeated until a predetermined calculation end condition is satisfied.   The preset control means divides the steel plate into meshes in the longitudinal direction, calculates the control code in association with each mesh, recognizes the mesh directly under each header, and extracts the control code corresponding to the mesh. The coiling temperature control method according to any one of claims 8 to 10, wherein this is converted into a header pattern and output to a cooling device.   When the value of the control code for each part in the longitudinal direction of the steel sheet is larger or smaller than the preceding and following parts, the process of matching the control code with the front or rear control code is repeated for the entire length of the steel sheet. The coiling temperature according to any one of claims 8 to 11, wherein the control code is finely adjusted so that the control code in the longitudinal direction of the steel sheet changes to a single peak from the discharging and winding of the steel sheet. Control method.

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