JP2013123734A - Method and device for controlling hot finishing temperature - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide technology capable of improving accuracy of the control of the hot finishing temperature during finish rolling.SOLUTION: A target cooling amount that makes plate temperature at a finish rolling machine outlet side to be target temperature at the outlet side of finishing roll is calculated using temperature model that is preliminarily set from inlet side actual temperature that is temperature of a plate at a finish rolling machine inlet side, and a cooling amount at a cooling device is controlled to the target cooling amount. The temperature drop amount of the plate from the finish rolling machine inlet side to the finish rolling machine outlet side is calculated as a calculated temperature drop amount when cooling is executed with the target cooling amount using the inlet side temperature and the temperature model. The actual temperature drop amount of the plate from the finish rolling machine inlet side to the finish rolling machine outlet side is calculated as an actual temperature drop amount from the inlet side actual temperature to the finish rolling machine outlet side. In addition, the ratio of the actual temperature drop amount to the calculated temperature drop amount is obtained as a learned value and the target cooling amount is corrected by the learned value.

Description

  The present invention uses a cooling device provided between finishing mills in a production facility for hot-rolled metal sheets such as hot-rolled steel sheets so that the sheet temperature on the exit side of the finish rolling mill becomes the finish target temperature on the finish side. The present invention relates to a technology for hot finishing temperature control for temperature control.

In hot finish rolling equipment, the plate is cooled by a cooling device (cooling water spray, etc.) during hot finish rolling, and the temperature of the finish mill exit side is controlled to the finish target temperature. .
In this hot finishing delivery side temperature control, the slab is heated in a heating furnace and rolled with a roughing mill to form a rough bar. Sometimes the target cooling amount is calculated from the actual temperature on the inlet side and the finish target temperature on the inlet side, and the discharge and stop of the cooling device are controlled so that the target cooling amount is reached. The temperature is adjusted so as to be the finishing target temperature (Patent Documents 1 and 2). In this temperature control, the finish side target temperature is converted into the inlet side target temperature using a preset temperature model. That is, the target cooling amount is obtained using a temperature model.

JP 2007-210009 A JP 10-94814 A

In the temperature control during the hot finish rolling, since the target cooling amount is obtained using a temperature model, the accuracy of the temperature model directly affects the control result of the temperature control. For this reason, it is important whether or not the influence of air cooling, water cooling, roll contact, roll contact, roll friction, and plastic heat generation, which are disturbance terms for the temperature model, is accurately reflected in the temperature model.
However, the air cooling, water cooling, roll contact, roll friction, and plastic heat generation conditions that are determined in advance for each material temperature / thickness category are applied to the temperature model according to each control target for each 1 m of coarse bar (cut plate). As a result, the control accuracy may be lowered, for example, the plate thickness may deviate from different material temperatures in the same category.
The present invention has been made paying attention to the above points, and aims to provide a technique capable of improving the accuracy of hot finishing temperature control during finish rolling.

  In order to solve the above-described problems, the present invention provides a cooling device discharge timing and use at the time of entering the finishing mill so that the variation in the actual value of the sheet temperature on the exit side of the finishing mill is within a preset range. The disturbance term in the temperature model of the temperature control used when determining the number (target cooling amount) is learned, and the learning result is reflected in the target cooling amount in the next material and the own material. .

That is, in the invention described in claim 1 of the present invention, during finish rolling of a hot-rolled metal plate at a preset finish rolling speed, the above-mentioned plate is cooled by a cooling device, so that the finish rolling mill at the delivery side. A hot finishing temperature control method for controlling a plate temperature to a preset finishing delivery target temperature, using a preset temperature model based on the entry actual temperature which is the temperature of the plate at the finishing mill entry side. In the hot finishing temperature control method for calculating the target cooling amount to make the plate temperature at the finishing rolling mill delivery side the finishing delivery target temperature, and controlling the cooling amount in the cooling device to the target cooling amount,
Calculate the temperature drop of the plate from the finishing mill entry side to the finishing mill exit side when cooling is performed with the above target cooling amount using the above entry side actual temperature and the above temperature model. As
From the above-mentioned actual temperature on the entry side and the actual temperature of the plate on the finish mill exit side, the actual temperature drop amount of the plate from the finish mill entrance side to the finish mill exit side is calculated as the actual temperature drop amount,
The ratio of the actual temperature drop amount to the calculated temperature drop amount is obtained as a learning value,
According to the learning value, the target cooling amount for a plate different from the plate for which the learning value is obtained is corrected.

Next, the invention described in claim 2 is characterized in that the target cooling amount is corrected by correcting the output value of the temperature model based on the learning value of the configuration described in claim 1. .
Next, in the invention described in claim 3, with respect to the configuration described in claim 1 or 2, the finish-side target temperature is set to the entrance-side target temperature on the finish rolling mill entry side using the temperature model. In the hot finishing temperature control method for calculating the target cooling amount of the cooling device from the difference between the converted input target temperature and the input actual temperature,
The correction by the learning value is performed by correcting the input target temperature converted by the learning value.

Next, in the invention described in claim 4, the hot-rolled metal plate to be finish-rolled is divided into a plurality of plate sections on a preset basis with respect to the configuration described in any one of claims 1 to 3. Classification is performed, the learning value is stored for each plate section, and the learning value of the plate section corresponding to the plate to be finish-rolled is used to perform correction based on the learning value.
Next, the invention described in claim 5 reflects the learned value obtained in the configuration described in claim 4 in the temperature control of the portion of the plate from which the learned value is obtained that has not been finished and rolled. It is characterized by that.

Next, in the invention described in claim 6, during the finish rolling of the hot-rolled metal plate at a preset finish rolling speed, the plate is cooled by a cooling device so that the plate temperature at the exit side of the finish rolling mill is set in advance. It is a hot finishing temperature control device that controls to the set finishing delivery target temperature, and finish rolling using a preset temperature model based on the entry actual temperature that is the temperature of the plate on the finishing mill entry side A target cooling amount calculation unit that calculates a target cooling amount that makes the plate temperature on the machine exit side the target temperature on the finishing side, and a target cooling amount calculated by the target cooling amount calculation unit as a control amount in the cooling device. In the hot finishing temperature control device comprising a cooling amount adjusting unit for controlling the cooling amount,
Using the actual temperature on the entry side and the temperature model, the amount of temperature drop of the plate from the finish mill entry side to the finish mill exit side when cooling is performed with the target cooling amount by the cooling device. A calculated temperature drop amount calculation unit for calculating as a calculated temperature drop amount;
The actual temperature calculated from the actual temperature of the above entry side and the actual temperature of the sheet at the finisher's outlet side as the actual temperature drop from the actual finisher's entry side to the finisher's exit side. A descent amount calculation unit;
A learning value calculation unit for obtaining, as a learning value, a ratio of the actual temperature drop amount calculated by the actual temperature drop amount calculation unit to the calculated temperature drop amount calculated by the calculated temperature drop amount calculation unit;
A cooling amount correction unit that corrects the target cooling amount calculated using the temperature model with the learning value obtained by the learning value calculation unit.

Next, in the invention described in claim 7, in the configuration described in claim 6, the target cooling amount calculation unit uses the temperature model to input the finishing target temperature on the input side of the finishing mill. The target cooling amount of the cooling device is calculated from the difference between the converted input target temperature and the input actual temperature,
The cooling amount correction unit corrects the target cooling amount by correcting the input target temperature converted by the learning value.

Next, in the invention described in claim 8, the hot-rolled metal plate to be finish-rolled is classified into a plurality of plate sections on a preset basis for the configuration described in claim 6 or claim 7, A table generation unit that stores the learning value for each board section,
The cooling amount correction unit refers to the table generation unit, and performs correction by the learning value using the learning value of the plate section corresponding to the plate to be finish-rolled.
Next, in the invention described in claim 9, with respect to the configuration described in claim 8, the obtained learning value is reflected in the temperature control of the part that has not yet been finish-rolled on the plate from which the learning value was obtained. It is characterized by that.

  According to the present invention, the target cooling amount obtained from the output value of the temperature model is corrected by the learning value obtained from the calculated value and the actual value, so that the accuracy of the target cooling amount is improved. It is possible to reduce the variation in the actual value of the plate temperature on the side.

It is a schematic block diagram of the hot finishing equipment which concerns on embodiment based on this invention. It is a figure which shows the example of the finish rolling speed pattern which concerns on embodiment based on this invention. It is a figure explaining the structure of a cooling control controller. It is a figure explaining the process of the target cooling amount calculating part. It is a figure which shows the example of the table content of the learning value of one board division. It is a figure explaining the process of the cooling amount correction | amendment part. It is a figure which shows the relationship between the entrance side target temperature and performance temperature of the hot finishing rolling mill in an Example, Comprising: (a) is before learning, (b) has shown the state after learning. It is a figure which shows the discharge / stop pattern in the cooling device in an Example, Comprising: (a) is before learning, (b) has shown the state after learning. It is a figure which shows the relationship between the target temperature and actual temperature of the hot finishing rolling mill delivery side in an Example, Comprising: (a) is before learning, (b) has shown the state after learning.

Next, embodiments of the present invention will be described with reference to the drawings.
"Constitution"
(Equipment configuration)
As shown in FIG. 1, the finish rolling mill 1 of the present embodiment includes seven stands F <b> 1 to F <b> 7, and a cooling device 2 is disposed between the stands F <b> 1 to F <b> 7. The cooling device 2 is composed of a cooling water spray device, for example, and can spray cooling water toward the surface of the hot-rolled metal plate 6. In addition, air cooling will be performed in the location which does not spray cooling water. In the present embodiment, as an example of the arrangement of the cooling device 2, as shown in FIG. 1, one of the seven stands F1 to F7 is located in front of the F5, F6, and F7 stands (2e, 2f, and 2g in FIG. 1). , F1 and F4 stand (2a and 2d in FIG. 1), F2 and F3 stand (3b and 2c in FIG. 1), a total of 13 cooling devices are illustrated. In FIG. 1, only the cooling device existing above the plate 6 is illustrated, but actually, the cooling device is similarly disposed below the plate 6, and the plate 6 is viewed from both above and below the plate 6. The cooling can be performed.

An entry side thermometer 3 is installed on the entry side of the finish rolling mill 1 and an exit side thermometer 4 is installed on the exit side of the finish rolling mill 1. It is used to measure actual temperatures on the entry and exit sides.
In addition, on the upstream side of the finish rolling mill 1, a rough rolling mill for rolling the heated slab is disposed, and between the exit side of the rough rolling mill and the entrance side of the finish rolling mill 1, A bar heater BH and an edge heater EH for compensating for a temperature drop of the plate 6 are arranged to compensate for the temperature of the plate from rough rolling to the start of finish rolling. In FIG. 1, symbol R5 illustrates the final stand of the rough rolling mill. Moreover, the 2nd thermometer is arrange | positioned at the delivery side of a rough rolling mill, and it can measure the temperature of the board 6 which is rough-rolled and conveyed to the finishing mill 1.
Further, a pinch roll (not shown) and a winder (not shown) for changing the direction of the plate 6 are arranged on the downstream side of the finish rolling mill 1, and the finish-rolled plate 6 is sequentially wound up by the winder. It is configured to wind up with.

(Rolling control)
The finish rolling control controller 11 controls the reduction amount in each stand F1 to F7 to each target reduction amount corresponding to the plate thickness on the finishing mill entry side, the target plate thickness on the delivery side of the rolling mill, and the finish rolling speed.
The finish rolling speed pattern used as a reference for transporting the plate 6 during finish rolling is preset to a speed pattern that can be rolled with high efficiency based on the specifications of the rolling equipment for each plate 6. Yes.

The finish rolling speed pattern in the present embodiment is set as shown in FIG. That is, the finish rolling speed is gradually increased at the first acceleration until the end of the plate 6 after finish rolling is wound around the winder and a stable tension is generated between the winder and the finish mill 1. When the winding is started, the finish rolling speed is increased at a second acceleration larger than the first acceleration, and the maximum finishing rolling speed (finishing) at the upper limit of equipment determined from the specifications of the rolling mill is increased. Accelerate to maximum speed). Thereafter, rolling is performed at the maximum finish rolling speed until the transition to the tail end side rolling of the plate 6, but when it reaches the tail end side of the plate 6, the finish rolling speed is gradually reduced at the first deceleration. The finish rolling speed pattern shown in FIG. 2 is an example. However, based on such an idea, various finish rolling speed patterns are preset for each piece of equipment. The finish rolling speed is indicated by the speed at the seventh stand F7.
In the finish rolling control, the reduction control is performed on the cut plate units obtained by virtually dividing the plate 6 into predetermined units along the longitudinal direction.

(Control section for hot finish delivery temperature control)
Next, temperature control (cooling control) during finish rolling will be described. This temperature control is a temperature control in which cooling is performed using the cooling device 22 during finish rolling so that the temperature at the finish rolling mill delivery side becomes the finish delivery target temperature. This temperature control is performed for each cut plate unit in which the plate 6 is virtually divided into predetermined units along the longitudinal direction. This hot finish delivery side temperature control is performed by the cooling controller 10.
As shown in FIG. 1, the cooling controller 10 functionally includes a cooling amount setting adjustment unit 10A and a target cooling amount calculation unit 10B.

As shown in FIG. 3, the cooling amount setting adjustment unit 10A includes a temperature tracking unit 10Aa and a spray cooling control unit 10Ab.
The temperature tracking unit 10Aa tracks the position of the cut plate in the finish rolling mill 1 for each cut plate. For example, each cut plate position is estimated by the finish rolling speed. The temperature tracking unit 10Aa outputs tracking information to the spray cooling control unit 10Ab.
The spray cooling control unit 10Ab determines the discharge pattern of the cooling water of the cooling device 2 for setting the target cooling amount for each cutting plate based on the target cooling amount for each cutting plate output by the target cooling amount calculation unit 10B. To do. Then, while referring to the tracking information of each cut plate from the temperature tracking unit 10Aa, the discharge of each cooling device 2 is controlled to adjust the cooling amount to each cut plate to the target cooling amount.

The target cooling amount calculation unit 10 </ b> B is a control unit that calculates a target cooling amount for each cut plate with respect to the target plate 6. As shown in FIG. 2, the target cooling amount calculation unit 10B includes an entry side target temperature calculation unit 10Ba, a target cooling amount calculation unit 10Bb, a calculated temperature drop amount calculation unit 10Bc, an actual temperature drop amount calculation unit 10Bd, and a learning value calculation. Unit 10Be, table generation unit 10Bf, and cooling amount correction unit 10Bg.
The said entrance side target temperature calculation part 10Ba calculates a target cooling amount based on the flowchart shown in FIG. That is, the entry side target temperature calculation unit 10Ba acquires the finish rolling speed of the target cut plate based on the finish rolling speed pattern preset for the target plate 6 in step S10.

Next, in step S20, using the above-described finish rolling speed and a preset temperature model, the finish rolling mill is entered when there is no cooling by the cooling device 2 in step S20. Calculate the temperature drop from the side to the finish mill exit side.
Next, in step S30, the learning value P _n ^* for correction is acquired from the cooling amount correction unit 10Bg, and the temperature drop amount obtained in step S20 is corrected, specifically, the temperature drop amount is corrected for learning. Multiply by the value P _n ^* .

In step S40, the calculated target temperature is calculated by adding the calculated temperature drop amount to the finishing target temperature. That is, the finish side target temperature is converted into the inlet side target temperature.
The following equation (1) is an equation representing the processing of step S30 and step S40.
Input side target temperature = Finishing side target temperature + Calculated temperature drop x Learning value P _n ^*
... (1)
The initial value of the learning value is 1, but when a later-described cooling amount correction unit 10Bg calculates the learning value, the learning value P _n ^* is applied.

  Here, the temperature model for calculating the amount of temperature drop during finish rolling is based on the effects of air cooling, water cooling, roll contact, roll friction, plastic heat generation determined by material temperature and plate thickness. A temperature model of heat transfer with respect to the temperature effect of the above-described temperature may be adopted. In this specification, the temperature drop amount and the temperature influence amount are used synonymously. When the temperature drop amount is a negative value, the temperature rise amount is indicated. Generally, a temperature drop occurs from the entrance side to the exit side of the finishing mill.

The temperature model used for temperature control in order to calculate the temperature drop amount (temperature influence amount) of the present embodiment is between the stands (F1 stand to F2 stand, F2 stand to F3 stand, F3 stand to F4 stand, F4 stand). (F5 stand, F5 stand to F6 stand, F6 stand to F7 stand) is expressed by a calculation temperature influence amount expression such as the following expression (2).
Calculated temperature influence amount = Air cooling temperature + Water cooling temperature
+ Roll contact temperature + Roll friction temperature + Plastic heat generation temperature
... (2)
here,
Air cooling temperature = constant x thermal diffusivity ÷ thermal conductivity ÷ plate thickness x time x heat transfer coefficient Water cooling temperature = constant x thermal diffusivity ÷ thermal conductivity ÷ plate thickness x time x water cooling temperature coefficient Roll contact temperature = constant x thermal diffusion Rate ÷ thermal conductivity ÷ plate thickness × time × roll contact temperature coefficient Roll friction temperature = constant × thermal diffusivity ÷ thermal conductivity ÷ plate thickness × time × roll friction temperature coefficient Plastic heating temperature = constant × density × specific heat × load × The amount of distortion.
The thermal diffusivity, thermal conductivity, density, and specific heat in the above formula are constants obtained in advance from experiments and calculations, and individual values are set for each category of material temperature and plate thickness.

The time in the above formula is set based on the rolling speed of the target cut sheet.
Moreover, when converting into the inlet side target temperature by the inlet side target temperature calculation part 10Ba, the calculated temperature influence amount is calculated by setting the water cooling temperature to zero and calculating the calculated temperature influence amount. The amount of temperature drop.
Further, the target cooling amount calculation unit 10Bb is based on the entry side target temperature obtained by the entry side target temperature calculation unit 10Ba and the sheet temperature (actual value) on the finishing rolling mill entry side measured by the entry side thermometer 3. The target cooling temperature of the corresponding cut plate is calculated, and the calculated target cooling amount is output to the cooling amount setting adjustment unit 10A.

Further, the calculated temperature drop amount calculation unit 10Bc inputs the sheet temperature (actual value) on the finishing mill entry side measured by the entry side thermometer 3, and from the finish rolling mill entry side to the finish rolling mill exit side. The amount of temperature drop is calculated using a temperature model. In this case, the calculation is performed in consideration of the cooling in the cooling device 2.
The amount of temperature drop is determined as follows. That is, based on the rolling speed of the target cut sheet and the sheet temperature (actual value) on the finishing mill entry side measured by the entry side thermometer 3, the above temperature model equation is calculated to calculate the temperature influence amount. And the calculated temperature influence amount is taken as the calculated temperature drop amount. Here, the actual temperature of the finishing mill entry side plate may be estimated and used based on the plate temperature actually measured by the thermometer on the coarse rolling mill exit side.

Further, the actual temperature drop amount calculation unit 10Bd inputs the actual input temperature (measured value) and the outgoing temperature (actual value) measured by the input side thermometer 3 and the output side thermometer with respect to the same cut plate portion. To do. And from the difference of the temperature, the actual value of the temperature drop amount from the finishing mill entry side to the finishing mill exit side is calculated as the actual temperature drop amount.
Actual temperature drop = Input actual temperature (actual value)-Outlet temperature (actual value)
... (3)
Further, the learning value calculation unit 10Be inputs the calculated temperature drop amount calculated by the calculated temperature drop amount calculation unit 10Bc and the actual temperature drop amount calculated by the actual temperature drop amount calculation unit 10Bd to the same cut plate portion. Then, the learning value is calculated by the following formula.
Learning value = Actual temperature drop / Calculated temperature drop (4)

The table generation unit 10Bf provides plate sections based on preset criteria, and prepares a table for each plate section. And the said learning value is stored and memorize | stored in the table of the board classification to which the board which calculated the said learning value corresponds. In the present embodiment, the newest learning value and the second newest learning value are stored for each table of each plate section. That is, when a new learning value is obtained, the newest learning value stored in the table is set as the second learning value, and the new learning value is set as the newest learning value.
The plate section table is, for example, a table of material section 110 section × plate thickness section 23 section.

  Here, the learning value may be calculated and stored for all the cut plates of one plate. However, in this embodiment, only a representative point set in advance in one plate is used as the learning value. Store. For example, the representative point is a speed change point of the finishing rolling speed (positions 1 to 5 in FIG. 2). The learning value of the cut plate other than the representative point is obtained from the representative point, for example, by performing linear interpolation. If it does in this way, even if the length of each board differs, it can respond. An example of learning values stored in one table table is shown in FIG.

In the present embodiment, the following five points are obtained as representative points based on the change mode of the finish rolling speed pattern and stored in the table.
The representative point cutting plate is, for example, a cutting plate 1 m from the tip (position 1 in FIG. 2), a cutting plate when changing from the first acceleration to the second acceleration (position 2 in FIG. 2), maximum Cutting plate when switching to the finishing rolling speed (position 3 in FIG. 2), cutting plate when changing from the maximum finishing rolling speed to deceleration (position 4 in FIG. 2), cutting board 2 m before the tail end (FIG. 2) 2 of 5). If these five representative points are known, the learning value can be estimated by linear interpolation since the speed changes linearly during that time.

Cooling amount correction unit 10Bg calculates a learned value P _n ^* for compensation for the plate of interest, and outputs the for calculated correction learned value P _n ^* to the target cooling amount calculating unit 10Bb. The processing of the cooling amount correction unit 10Bg will be described with reference to the flowchart shown in FIG.
In step S100, the cooling amount correction unit 10Bg searches for a learned value in a table of the same plate section as the hot-rolled metal plate to be subjected to finish rolling next.

And when it determines with there being a corresponding learning value in step S110, it transfers to step S110. On the other hand, if it is determined that there is no corresponding learning value, in step S140, the learning value P _n ^* to be corrected for the plate is set to “1” and output to the target cooling amount calculation unit 10Bb.
In step S120, corresponding learning values (learning values for five representative points) are acquired from the table. Then, the learning value P _n ^* for correction at the substitute point is calculated using the acquired learning value of the representative point.
That is, the learning value P _n ^* at the representative point is obtained by subjecting the learning values of the five representative points to smoothing processing according to the following equation (5). p _i is the latest learning value, and p _i−1 is the second new learning value. An example is shown in FIG.
^{_{P n * = p i × α}} + p i-1 × (1-α) ··· (5)
However, n = 1-5

Next, in step S130, the cut plate portion positioned between the representative points is obtained using the learning values P _n ^* of the two representative points positioned before and after the cut plate portion. Specifically, the learning value P ^* of the cut plate portion is calculated by performing linear interpolation according to the position between the two learning values P _n ^* .
The learning value stored in the table is not limited to 5 points. It may be 6 points or more, or 4 points or 3 points.
Here, the weight gain α is set to be smaller than 0.5, and the weight of the old value (second new value) is set to be large. For example, α = 0.3. The learning value stored in the table may be three or more, or may be one, but it is preferable to use two or more to obtain the correction learning value.
And cooling amount correction | amendment part 10Bg outputs the learning value _Pn ^* for correction | amendment corresponding to a corresponding cut plate to the entrance side target temperature calculation part 10Ba. The learning value P _n ^* for correction of all the cut plates of the corresponding plate may be obtained and output in the form of a table.

(Operation other)
In this embodiment, the influence of air cooling, water cooling, roll contact, roll friction, plastic heat generation determined by the material temperature / sheet thickness classification is obtained as a learning value as one influence coefficient term, and the learning value is equal to or higher than the next material. Correct the target cooling amount of the plate.
In this embodiment, the target cooling amount is corrected by multiplying the learning value P _n ^* by the temperature drop amount that is the output value of the temperature model when converting the finishing delivery target temperature to the target entry temperature. ing.
This makes it possible to bring the calculated temperature drop closer to the actual temperature drop, and as a result of improving the accuracy of the temperature model, the plate temperature on the finishing mill exit side can be adjusted to the finishing target temperature more accurately. Is possible.

(Modification)
In the cooling amount correction unit 10Bg, the case is described in which the learned value P _n ^* learned in the past with another plate is reflected on the plate before rolling. Along with the learning value P _n ^* learned with the other plates, the learning value learned for the cut plate portion of the own material that has been finished and rolled is used as the learning value in the bar, and the cutting value of the own material before the finish rolling is obtained. You may use for correction of a board part.
In the present embodiment, the in-bar learning value is calculated using the most recently calculated in-bar learning value and the second newest in-bar learning value. To do.
Learning value between bars = (Lastly calculated learning value within the bar) x β
+ (Second newest learning value in the bar) × (β−1)
... (6)
And the following formula is adopted instead of the above formula (1).
Input side target temperature = Finishing side target temperature
+ Calculated temperature drop amount x Learning value P ^* × (In-bar learning value for correction)

As a result, the accuracy of the output value of the temperature model is further improved by reflecting the learning value of the own material, that is, by performing fine adjustment in the in-bar learning that is short-term learning.
That is, in the present invention, the accuracy of the temperature model is improved by correcting the output value of the temperature model using the learning value P _n ^* which is long-term learning and the in-bar learning which is short-term learning. As a result, temperature control with suppressed temperature deviation becomes possible.

Here, in order to increase the influence of the learning value P ^* , the final learning value may be determined by weighting the following equation.
Final learning value = learning value P ^* × γ + (correction value in bar for correction) × (1-γ)
However, γ is greater than 0.5 and less than 1.
Here, the position of the cut plate for obtaining the in-bar learning value does not need to be matched with the cut plate position for obtaining the learning value P ^* stored in the table for reflection in the next material. Compared to the case where the learning value P ^* is obtained, it is preferable that the interval between the cut plates for obtaining the in-bar learning value is short.

Further, for example, the correction value in the bar for correction may be corrected by the ratio between the finishing rolling speed of the cut sheet for which the learning value in the bar is obtained and the finishing rolling speed of the cut sheet reflecting the learning value in the bar.
Moreover, although a hot-rolled steel plate can be illustrated as a hot-rolled metal plate, the hot-rolled metal plate which can apply this invention is not limited to a hot-rolled steel plate.
Moreover, in the said embodiment, the target cooling amount is correct | amended by reflecting a learning value with respect to the output value of the temperature model at the time of converting into entrance side target temperature. The target cooling amount may be corrected by multiplying the converted input target temperature or target cooling amount itself by the learning value.

FIGS. 7 to 9 show a hot rolled steel sheet made of a low-carbon material with a rolling target value after finishing rolling of 2.35 mm and a width of 1300 mm, a finishing target temperature of 870 ° C., It is a figure which shows one Example of the temperature control before learning in the case where temperature control is implemented, and after learning, Each figure is a finish input side temperature, the discharge / stop pattern of the cooling device 2, and finish output side temperature, respectively It is the figure explaining in the case of before learning and after learning.
FIG. 7A, FIG. 8A, and FIG. 9A are examples when the learning of this embodiment is not applied. On the other hand, FIG. 7B, FIG. 8B, and FIG. 9B are examples when the learning of the present embodiment is applied. As learning, the case where both the learning value by the past material and the learning value of the own material are applied is illustrated.

As can be seen from FIG. 7 (a), FIG. 8 (a), and FIG. 9 (a), accurate temperature influence terms (air cooling, water cooling, roll contact, roll friction, plastic heat generation) are reflected when not learned. Therefore, the discharge of the cooling device 2 is insufficient, and the finish side temperature is greatly deviated. On the other hand, as can be seen from FIGS. 7 (b), 8 (b) and 9 (b), by learning, temperature influence terms (air cooling, water cooling, roll contact, roll friction) for each material temperature and sheet thickness category. Therefore, a good finish side temperature can be realized.
In fact, it was also confirmed that the correctness ratio within the finishing target temperature ± Temp was improved by learning. In this example, Temp was set to 25 ° C.

DESCRIPTION OF SYMBOLS 1 Finishing rolling mill 2 Cooling device 3 Inlet side thermometer 4 Outlet side thermometer 10 Cooling control controller 10A Cooling amount setting adjustment part 10Aa Temperature tracking part 10Ab Spray cooling control part 10B Target cooling amount calculation part 10Ba Inlet side target temperature calculation part 10Bb Target cooling amount calculation unit 10Bc Calculated temperature drop amount calculation unit 10Bd Actual temperature drop amount calculation unit 10Be Learning value calculation unit 10Bf Table generation unit 10Bg Cooling amount correction unit 11 Finish rolling control controller _Pn Learning value (learning to be reflected on the next material) value)

Claims (9)

Heat that controls the plate temperature on the delivery side of the finishing mill to a preset finish side target temperature by cooling the plate with a cooling device during finish rolling of the hot rolled metal plate at a preset finish rolling speed. This is an intermediate finishing temperature control method, which uses the preset temperature model based on the actual temperature at the inlet side of the finishing mill at the inlet side, and uses the preset temperature model to determine the finishing temperature at the finishing mill outlet side. In the hot finish temperature control method for calculating the target cooling amount to be the target temperature on the side, and controlling the cooling amount in the cooling device to the target cooling amount,
Calculate the temperature drop of the plate from the finishing mill entry side to the finishing mill exit side when cooling is performed with the above target cooling amount using the above entry side actual temperature and the above temperature model. As
From the above-mentioned actual temperature on the entry side and the actual temperature of the plate on the finish mill exit side, the actual temperature drop amount of the plate from the finish mill entrance side to the finish mill exit side is calculated as the actual temperature drop amount,
The ratio of the actual temperature drop amount to the calculated temperature drop amount is obtained as a learning value,
A hot finishing temperature control method, wherein the target cooling amount for a plate different from the plate for which the learned value is obtained is corrected by the learned value.   2. The hot finish temperature control method according to claim 1, wherein the target cooling amount is corrected by correcting the output value of the temperature model based on the learned value. The finishing target temperature is converted into the inlet target temperature on the finishing mill entry side using the temperature model, and the target cooling of the cooling device is calculated from the difference between the converted entry target temperature and the entry actual temperature. In the hot finishing temperature control method for determining the quantity,
The hot finish temperature control method according to claim 1 or 2, wherein the correction by the learning value is performed by correcting the input target temperature converted by the learning value.   Hot rolled metal sheets to be finish-rolled are classified into a plurality of sheet sections according to preset criteria, the learning values are stored for each of the sheet sections, and the learned values of the sheet sections corresponding to the sheets to be finish-rolled The hot finish temperature control method according to any one of claims 1 to 3, wherein the correction is performed using the learning value.   5. The hot finishing temperature control method according to claim 4, wherein the obtained learning value is reflected in the temperature control of a portion of the plate from which the learning value is obtained that has not yet been finish-rolled. During hot rolling of a hot-rolled metal sheet at a preset finishing rolling speed, the sheet is cooled by a cooling device to control the sheet temperature at the finishing mill exit side to a preset finishing target temperature. It is a finishing temperature control device, based on the inlet side actual temperature which is the temperature of the plate on the finishing mill entry side, using a preset temperature model, the plate temperature on the finishing mill exit side is set to the above finishing delivery side A target cooling amount calculation unit that calculates a target cooling amount to be a target temperature, and a cooling amount adjustment unit that controls the cooling amount in the cooling device using the target cooling amount calculated by the target cooling amount calculation unit as a control amount, In the hot finishing temperature control device provided,
Using the actual temperature on the entry side and the temperature model, the amount of temperature drop of the plate from the finish mill entry side to the finish mill exit side when cooling is performed with the target cooling amount by the cooling device. A calculated temperature drop amount calculation unit for calculating as a calculated temperature drop amount;
The actual temperature calculated from the actual temperature of the above entry side and the actual temperature of the sheet at the finisher's outlet side as the actual temperature drop from the actual finisher's entry side to the finisher's exit side. A descent amount calculation unit;
A learning value calculation unit for obtaining, as a learning value, a ratio of the actual temperature drop amount calculated by the actual temperature drop amount calculation unit to the calculated temperature drop amount calculated by the calculated temperature drop amount calculation unit;
A hot finishing temperature control apparatus comprising: a cooling amount correction unit that corrects a target cooling amount calculated using the temperature model with the learning value obtained by the learning value calculation unit. The target cooling amount calculation unit converts the finish delivery side target temperature into an entry side target temperature on the finishing mill entry side using the temperature model, and calculates the converted entry side target temperature and the entry side actual temperature. Find the target cooling amount of the cooling device from the difference,
The hot finish temperature control device according to claim 6, wherein the cooling amount correction unit corrects the target cooling amount by correcting the input target temperature converted according to the learning value. The hot-rolled metal sheet to be finish-rolled is classified into a plurality of sheet sections based on preset criteria, and includes a table generation unit that stores the learning value for each sheet section,
The said cooling amount correction | amendment part performs correction | amendment by the said learning value using the learning value of the board classification corresponding to the board to finish-roll with reference to a table production | generation part. Hot finishing temperature control device described in 1. 9. The hot finishing temperature control apparatus according to claim 8, wherein the learned value obtained is reflected in temperature control of a portion of the plate from which the learned value is obtained that has not yet been finish-rolled.

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