Temperature control system and temperature control method for hot rolling line

Abstract

This hot rolling line comprises: a rough rolling mill; a finishing rolling mill; an intermediate device group provided between the rough rolling mill and the finishing rolling mill; a rough outlet side thermometer provided between the rough rolling mill and the intermediate device group; a finishing inlet-side thermometer provided between the finishing rolling mill and the intermediate device group; and a control device. The intermediate device group includes a cooling device which uses cooling water to cool a material-to-be-rolled. The control device includes: a setting calculation device which determines a flow rate setting value of the cooling water in the cooling device; a feed forward control device which executes, on the basis of the flow rate setting value, a feed forward control of the flow rate of the cooling water in the cooling device; and a learning device which calculates learning values on the basis of actual flow rate values of the cooling water in the cooling device and finishing inlet-side temperature values indicating actual temperature values of the material-to-be-rolled measured by the finishing inlet-side thermometer.

Description

[Technical Field]

[0001] The present disclosure relates to a system and method for controlling the temperature of a material being rolled in a hot rolling line (hereinafter also referred to as "rolled material"). [Background technology]

[0002] A hot rolling line generally comprises a roughing mill and a finishing mill. At least one roughing mill is provided in a hot rolling line. The roughing mill performs rough rolling (reverse rolling), which involves feeding the material to be rolled in the forward direction and pulling it back in the reverse direction. In rough rolling, the thickness of the material to be rolled is reduced to a target intermediate bar thickness. At least two finishing mills are provided downstream of the roughing mill. The finishing mills perform finish rolling (tandem rolling) on the material to be rolled. In finish rolling, the thickness of the material to be rolled is reduced to a target coil thickness, which is the target thickness of the product.

[0003] The temperature of the material being rolled during rough rolling is approximately 1000-1150°C. The temperature of the material being rolled drops as it is transported from the roughing mill to the finishing mill. The head and tail of the material being rolled reach the finishing mill at different times. Therefore, the temperature of the material being rolled generally decreases from the head to the tail. When the temperature of the head is approximately 1000-1100°C, the temperature of the tail can be more than 50°C lower than that of the head. This phenomenon is called thermal rundown.

[0004] In the past, in hot rolling lines, there has been no particular control over the temperature of the material to be rolled at the entry side of the finishing rolling mill (hereinafter also referred to as the "finishing entry temperature"). The reason for this is that the temperature of the material to be rolled at the exit side of the finishing rolling mill (hereinafter also referred to as the "finishing exit temperature") is set within a certain range, and the temperature of the material to be rolled extracted from the heating furnace is set to a sufficiently high temperature so that rolling can be carried out stably from the head to the tail.

[0005] However, in recent years, the requirements for the material quality and precision of the rolled material have become stricter, and the finish entry temperature is often controlled. For example, in ferrite rolling, the finish entry temperature is controlled at 900°C or less. Also, in order to control the grain size of the rolled material at the exit of the finishing mill, finish rolling is sometimes performed in the temperature range of 950-1000°C. For rolled materials with sizes that are difficult to roll, such as extremely thin materials, finish rolling is sometimes performed at the highest possible temperature to reduce the rolling load.

[0006] Patent Document 1 can be cited as a conventional technique related to the present disclosure. Patent Document 1 discloses a method for controlling a group of nozzles installed between a roughing mill and a finishing mill. In Patent Document 1, the group of nozzles is arranged in the conveyance direction and width direction of the material to be rolled, and cooling water for the material to be rolled is sprayed from the group of nozzles. In the method of Patent Document 1, the operation of the group of nozzles is controlled so that the temperature drop of the material to be rolled in the width direction is kept within a predetermined range. However, Patent Document 1 does not provide a detailed explanation about the control of the temperature of the material to be rolled in the conveyance direction (i.e., the longitudinal direction).

[0007] Another prior art related to the present disclosure is Patent Document 2. Patent Document 2 discloses a method for controlling a cooling device installed between a roughing mill and a finishing mill. In the method of Patent Document 2, the flow rate of cooling water supplied from the cooling device to control the finishing entry temperature to a target value is calculated using the measurement value of a thermometer installed at the entry side of the cooling device (i.e., the exit side of the roughing mill). However, the behavior of water cooling at high temperatures is extremely complex, as it is affected by factors such as the formation of a boiling film at the interface between the rolled material and the water, water convection, and turbulence. In addition, the cooling characteristics of water cooling, including the heat transfer coefficient, vary depending on the rolling speed, the surface condition of the rolled material, and other factors, making quantitative prediction difficult. Therefore, there is a problem in that a non-negligible difference between the finishing entry temperature and the target value is unavoidable. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 7-24515 [Patent Document 2] Japanese Patent Application Publication No. 2007-50417 Summary of the Invention [Problem to be solved by the invention]

[0009] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a technology that can control the temperature of the rolled material at the inlet side of the finishing mill to a desired temperature in a hot rolling line equipped with a roughing mill and a finishing mill. [Means for solving the problem]

[0010] A first aspect of the present disclosure is a system for controlling the temperature of a material to be rolled in a hot rolling line, which has the following features. The hot rolling line includes a roughing mill that performs reverse rolling, a finishing mill that performs tandem rolling, a group of intermediate devices provided between the roughing mill and the finishing mill, a roughing outlet thermometer provided between the roughing mill and the group of intermediate devices, a finishing inlet thermometer provided between the finishing mill and the group of intermediate devices, and a control device. The intermediate device group includes a cooling device that cools the material to be rolled using cooling water. The control device a setting calculation device for determining a set value of a cooling water flow rate in the cooling device; a feedforward control device that performs feedforward control of the flow rate of the cooling water in the cooling device based on the flow rate set value; a learning device that calculates a learning value based on an actual value of the flow rate of cooling water in the cooling device and an actual value of a finish inlet temperature that indicates an actual value of the temperature of the rolled material measured by the finish inlet thermometer; Includes. The setting calculation device Before a final pass of the reverse rolling is performed on the rolled material, a finish inlet temperature target value indicating a target value of the temperature of the rolled material at the inlet side of the finishing rolling mill is determined; calculating a cooling device outlet temperature target value indicating a target value for the temperature of the rolled material at the outlet of the cooling device so that a finish inlet temperature predicted value indicating a predicted value for the temperature of the rolled material at the inlet of the finishing rolling mill coincides with the finish inlet temperature target value; The flow rate setting value is determined based on the cooling device outlet temperature target value and the learned value. The feedforward control device comprises: determining a target temperature pattern indicating a pattern of target values of the temperature of the rolled material over the entire length of the rolled material at the outlet side of the cooling device; A flow rate reference value of the cooling water in the cooling device is calculated for each point in the longitudinal direction of the rolled material based on the flow rate set value, speed information of the roughing rolling mill, and a rough discharge side temperature actual value indicating the actual value of the temperature of the rolled material measured by the rough discharge side thermometer. The flow rate reference value is calculated so that a cooling device outlet side temperature predicted value indicating a predicted value of the temperature of the rolled material at the outlet side of the cooling device matches the target temperature pattern. The feedforward controller also The feedforward control is performed so that the flow rate of the cooling water in the cooling device when each point of the rolled material reaches a position where it is cooled by the cooling device matches the flow rate reference value calculated for each point of the rolled material. The learning device calculates the learned value based on the difference between the actual finish inlet temperature value and a re-predicted finish inlet temperature value (original: recalculated actual finish inlet temperature value) indicating a re-predicted value of the temperature of the rolled material at the inlet side of the finishing rolling mill. The re-predicted finish inlet temperature value is calculated based on the actual flow rate value, the actual rough outlet temperature value, and the actual speed of the rolled material.

[0011] A second aspect of the present disclosure is a method for controlling the temperature of a material to be rolled in a hot rolling line, which has the following characteristics. The hot rolling line includes a roughing mill that performs reverse rolling, a finishing mill that performs tandem rolling, a group of intermediate devices provided between the roughing mill and the finishing mill, a roughing outlet thermometer provided between the roughing mill and the group of intermediate devices, a finishing inlet thermometer provided between the finishing mill and the group of intermediate devices, and a control device. The intermediate device group includes a cooling device that cools the material to be rolled using cooling water. The method comprises: determining a set point for the cooling water flow rate of the cooling device; performing feedforward control of the flow rate of the cooling water in the cooling device based on the flow rate set value; a step of calculating a learning value based on an actual value of the flow rate of cooling water in the cooling device and an actual value of the finish inlet temperature indicating an actual value of the temperature of the rolled material measured by the finish inlet thermometer; Includes. The step of determining a flow setpoint comprises: determining a finish entry temperature target value indicating a target value of the temperature of the rolled material at the entry side of the finishing rolling mill before a final pass of the reverse rolling is performed on the rolled material; a step of calculating a cooling device outlet temperature target value indicating a target value of the temperature of the rolled material at the outlet of the cooling device so that a finish inlet temperature predicted value indicating a predicted value of the temperature of the rolled material at the inlet of the finishing rolling mill coincides with the finish inlet temperature target value; determining the flow rate setting value based on the cooling device outlet temperature target value and the learned value; Includes. The step of performing feedforward control includes: determining a target temperature pattern that indicates a pattern of target values of the temperature of the rolled material over the entire length of the rolled material at the outlet side of the cooling device; a step of calculating a flow rate reference value of the cooling water in the cooling device for each point in the longitudinal direction of the rolled material based on the flow rate set value, speed information of the roughing rolling mill, and a rough discharge side temperature actual value indicating the actual value of the temperature of the rolled material measured by the rough discharge side thermometer, wherein the flow rate reference value is calculated so that a cooling device outlet side temperature predicted value indicating a predicted value of the temperature of the rolled material at the outlet side of the cooling device matches the target temperature pattern; executing the feedforward control so that the flow rate of the cooling water in the cooling device when each point of the rolled material reaches a position where it is cooled by the cooling device coincides with the flow rate reference value calculated for each point of the rolled material; Includes. The step of calculating the learning value includes: The method includes a step of calculating the learned value based on the difference between the actual finish inlet temperature value and a finish inlet temperature re-prediction value indicating a re-prediction value of the temperature of the rolled material at the inlet side of the finishing rolling mill, wherein the finish inlet temperature re-prediction value is calculated based on the actual flow rate value, the actual rough outlet temperature value, and the actual speed of the rolled material. [Effects of the Invention]

[0012] According to the first and second aspects, a cooling device outlet temperature target value is calculated so that the finish inlet temperature predicted value coincides with the finish inlet temperature target value. Furthermore, a cooling water flow rate setting value in the cooling device is determined based on this cooling device outlet temperature target value and a learned value. Furthermore, a cooling water flow rate reference value in the cooling device is calculated based on this flow rate setting value, speed information of the roughing mill, and an actual roughing outlet temperature value.

[0013] The flow rate reference value is calculated so that the predicted temperature value at the exit of the cooling device matches the target temperature pattern of the rolled material over the entire length of the rolled material at the exit of the cooling device. Once the flow rate reference value is calculated for each point on the rolled material, feedforward control is performed so that the flow rate of the cooling water in the cooling device when each point on the rolled material reaches the position where it is cooled by the cooling device matches these flow rate reference values. This makes it possible to achieve the target temperature pattern, and therefore makes it possible to match the actual finish entry temperature value with the target finish entry temperature value. In addition, according to the first and second aspects, since a learning value is calculated, it is also possible to improve the accuracy of control of the finish entry temperature. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram illustrating a configuration example of a hot rolling line to which a first embodiment is applied. [Figure 2] FIG. 10 is a diagram illustrating a target position set on the outlet side of the cooling device. [Figure 3] FIG. 4 is a diagram illustrating a target value of the temperature of the material to be rolled at a target position. [Figure 4] 10 is a flowchart illustrating the flow of processing performed by a setting calculation device to determine a target value for the temperature of the material to be rolled at a target position. [Figure 5] 10 is a flowchart illustrating the flow of processing performed by a setting calculation device to determine a flow rate setting value. [Figure 6] FIG. 10 is a diagram illustrating a speed pattern. [Figure 7] FIG. 4 is a diagram showing an example of a result of control according to the first embodiment. [Figure 8] FIG. 10 is a diagram showing an example of the results when the target value of the temperature of the material to be rolled at the target position is changed in the longitudinal direction of the material to be rolled and the cooling device 2 is controlled. [Figure 9] FIG. 2 is a diagram illustrating a configuration example of a hot rolling line to which a second embodiment is applied. [Figure 10] FIG. 10 is a diagram illustrating a configuration example of a hot rolling line to which a third embodiment is applied. [Figure 11]FIG. 10 is a diagram illustrating an example of temperature distribution in the width direction of a segment (h). [Figure 12] FIG. 10 is a diagram illustrating a configuration example of a hot rolling line to which a fourth embodiment is applied. [Figure 13] FIG. 10 is a diagram illustrating a configuration example of a hot rolling line to which a fifth embodiment is applied. [Figure 14] FIG. 10 is a diagram illustrating a configuration example of a hot rolling line to which a sixth embodiment is applied. [Figure 15] 10A and 10B are diagrams illustrating an example of winding and unwinding of a material to be rolled by a coil box. [Figure 16] FIG. 13 is a diagram showing an example of a result of control according to the seventh embodiment. [Figure 17] FIG. 13 is a diagram illustrating a configuration example of a hot rolling line to which the ninth embodiment is applied. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that common elements in the drawings are designated by the same reference numerals and redundant description will be omitted.

[0016] 1. First embodiment The first embodiment will be described with reference to FIGS. 1-8.

[0017] 1-1. Example of hot rolling line configuration FIG. 1 is a diagram illustrating an example of the configuration of a hot rolling line to which the first embodiment is applied. The hot rolling line 1 shown in FIG. 1 has a cooling device 2. The cooling device 2 is installed between a roughing mill 3 and a finishing mill 4. The cooling device 2 is an example of the "intermediate device group" of the present disclosure. A table is installed between the roughing mill 3 and the finishing mill 4 to transport the material to be rolled (hereinafter also referred to as "material M") from the exit side of the roughing mill 3 to the entry side of the finishing mill 4.

[0018] The cooling device 2 has, for example, water injection nozzle groups provided corresponding to the width and length directions of the material M, and a valve provided commonly to the water injection nozzle groups. A plurality of water injection nozzle groups are provided, and a valve is provided for each water injection nozzle group. By controlling the opening and closing of the valve, the flow rate of cooling water at the water injection nozzles included in the water injection nozzle group corresponding to this valve is adjusted. The opening and closing of the valve is controlled by a control device 6.

[0019] At least one roughing mill 3 is provided in the hot rolling line 1. The roughing mill 3 performs rough rolling (reverse rolling) on the material M to reduce the thickness of the material M to a target intermediate bar thickness. Typically, the thickness of the material M before rough rolling is 180 mm or more, and the target intermediate bar thickness is 30-65 mm. After rough rolling, the material M is transported to the finishing mill 4. At least two finishing mills 4 are provided in the hot rolling line 1. The finishing mill 4 performs finish rolling (tandem rolling) on the material M to reduce the thickness of the material M to a target coil thickness. The rough rolling by the roughing mill 3 and the finish rolling by the finishing mill 4 are also controlled by the control device 6.

[0020] The hot rolling line 1 is equipped with various measuring instruments. The various measuring instruments include a rough discharge side thermometer 51 and a finish entry side thermometer 52. The rough discharge side thermometer 51 is provided on the exit side of the rough rolling mill 3, and measures the temperature T M Actual value of the rough outlet temperature (hereinafter referred to as "actual value of rough outlet temperature T RD mea " or "Actual temperature T RD mea The finishing entry thermometer 52 is provided on the entry side of the finishing rolling mill 4, and measures the temperature T M The actual value of the finishing inlet temperature (hereinafter referred to as "finishing inlet temperature actual value T FE mea " or "Actual temperature T FE mea The actual temperature T RD mea and T FE meais transmitted to the control device 6.

[0021] The control device 6 is a computer having at least one processor and at least one memory. The control device 6 may be composed of at least two computers. The control device 6 performs various controls in the hot rolling line 1. The various controls include control of the cooling device 2 (i.e., control of opening and closing of valves), control of the roughing mill 3, and control of the finishing mill 4.

[0022] 1-2. Control device configuration example In the first embodiment, the control of the cooling device 2 is considered among various controls by the control device 6. Here, there is a certain distance from the cooling device 2 to the finishing entry side thermometer 52. Therefore, for example, the actual temperature T FE mea Therefore, in the first embodiment, the temperature T from the target position TBD (see FIG. 2) to the installation position FE is used. M The temperature T at the installation position FE is predicted. M (That is, the actual temperature T FE mea ) is the target value (hereinafter referred to as the "finishing inlet temperature target value T FE tar " or "Target temperature T FE tar In the example shown in FIG. 2, the target position TBD is set on the outlet side of the cooling device 2 and upstream of the installation position FE.

[0023] 1, the control device 6 includes a setting calculation device 61, a feedforward (FF) control device 62, and a learning device 63 as a configuration for controlling the cooling device 2. These devices are, for example, functions of the control device 6. Such functions of the control device 6 are realized, for example, by a processor included in the control device 6 executing a predetermined control program read from a memory.

[0024] The setting calculation device 61 performs a "setting calculation" for controlling the cooling device 2. In this setting calculation, the temperature T M The target value of the cooling device outlet temperature T TBD tar " or "Target temperature T TBD tar The operation command IOP includes the conditions and restrictions for using the cooling device 2. Depending on the type and size of the material M, the temperature T M The target value of the finishing inlet temperature (hereinafter referred to as the "finishing inlet temperature target value T FE tar " or "Target temperature T FE tar ") may be included in the operation command IOP. In the setting calculation, the target temperature T TBD tar Based on this, whether or not to cool the material M is determined for each valve of the cooling device 2. In the setting calculation, a flow rate setting value Q of the cooling water in the water injection nozzle corresponding to the valve that performs cooling of the material M is further determined. In the setting calculation, the temperature T M The flow rate-temperature change influence coefficient Inf cnt is calculated. Note that the target temperature T TBD tar An example of a method for determining the flow rate set value Q will be described later.

[0025] The FF control device 62 executes "FF control" of the flow rate of the cooling water in the cooling device 2. In the FF control, the target temperature T TBD tar The pattern (hereinafter referred to as "target temperature pattern T TBD tar(i)"). A cooling water flow rate reference value in the cooling device 2 is calculated for each point of the material M so that the above condition is met. In FF control, the speed of the material M being rolled by the roughing mill 3 is determined based on the rotation speed of the rolls of the roughing mill 3, the reduction amount, etc., and the position of each point of the material M passing through the roughing mill 3 is determined. After the tail end of the material M leaves the roughing mill 3, the speed of the material M is determined based on the speed of the table transporting the material M. In FF control, the response delay of the cooling device 2 is further taken into account, and the cooling water flow rate reference value calculated for each point is changed at the time when each point of the material M reaches a position where it is cooled by cooling water from the cooling device 2. Specific examples of FF control will be described later.

[0026] The learning device 63 calculates the actual temperature T FE mea Based on this, the learned value ΔT TBD ofs This learning value ΔT TBD ofs is used to correct the target value of the temperature of material M(i+1) at the target position TBD in the setting calculation for material M(i+1) to be rolled next to material M(i) currently being rolled in the hot rolling line 1. A specific example of the learning calculation will be described later.

[0027] 1-3.Target temperature T TBD tar Example of a method for determining Figure 3 shows the target temperature T TBD tar 3 is a diagram illustrating the temperature T M The transition of the target temperature T FE tar is usually given as the temperature target value when the tip of the material M passes through the installation position FE. The target temperature T FE tar is determined, for example, according to an operation command IOP. In another example, the target temperature T FE tarThe target temperature T FE tar The determination is made before the final pass of rough rolling is performed on the material M.

[0028] The properties of material M (ductility, hardness, etc.) change at temperature T M For steel types with strict requirements for material properties, the temperature of this material M must be controlled in accordance with the operation command IOP. In this case, the target temperature value given by the operation command IOP is set to the target temperature T FE tar On the other hand, for steel types that do not have strict requirements for material properties, the target temperature T FE tar In addition, there are cases where a production volume is required in the hot rolling line 1, and in this case, it is desirable to perform rolling in as short a time as possible. Therefore, when a temperature target value is not given by the operation command IOP, the speed of the material M being rolled by the finishing mill 4 (i.e., the finishing rolling speed) is increased, so the target temperature T FE tar A low temperature is set.

[0029] However, if the finish rolling speed becomes too high, there is a possibility that the operator will not be able to intervene in time. Also, there is a possibility that the load on the finish rolling mill will reach its upper limit. Therefore, in the first embodiment, the finish rolling speed is set to the maximum speed within the allowable speed range, and the target value of the finish delivery temperature (hereinafter referred to as the "finish delivery temperature target value T FD tar " or "Target temperature T FD tar The final inlet temperature is calculated under the condition that the target temperature T FE tar The "finishing delivery temperature" here is the temperature T M The "finishing entry temperature" is the temperature T at the entry side of the finishing rolling mill 4. M is.

[0030] Target temperature T TBD taris determined, for example, by the following procedure. (a) The initial value of the finishing entry temperature is set to the assumed value of the finishing entry temperature (hereinafter referred to as the assumed temperature T FE asu ") (b) Set the finishing rolling speed to the maximum speed within the allowable speed range. (c) Temperature T at the exit side of the finishing mill 4 from the installation position FE M Calculate the temperature drop up to the measurement position and calculate the predicted value of the finish outlet temperature. (d) When the predicted value of the finishing outlet temperature and the target value are almost the same, the assumed temperature T FE asu the target temperature T FE tar Let's say (e) If there is a difference between the predicted and target values of the finishing outlet temperature, the assumed temperature T FE asu Change

[0031] Steps (a)-(c) and (e) are repeated until step (d) produces a result in which the predicted value and the target value are nearly identical. FE asu The change of can be made based on the magnitude relationship between the predicted value and the target value. For example, if the predicted value is larger than the target value, the difference between the two or the value obtained by multiplying this difference by a gain is used as the assumed temperature T FE asu Subtract from the new assumed temperature T FE asu If the predicted value is smaller than the target value, the difference between the two or the difference multiplied by the gain is used as the assumed temperature T FE asu to obtain the new assumed temperature T FE asu The maximum speed used in step (b) may be determined by the operator or may be set in advance for each steel type and size.

[0032] Figure 3 shows the target temperature T FE tar In addition to the target temperature T TBD tarThe temperature T is maintained between the target position TBD and the installation position FE by air cooling, heat retention, and heating. M This temperature change ΔT TBD-FE is the target temperature T TBD tar Also, the learning value ΔT TBD ofs If has been calculated, this learning value ΔT TBD ofs is the target temperature T TBD tar will be taken into consideration in determining

[0033] Figure 4 shows the target temperature T TBD tar 4 is a flowchart illustrating the flow of processing performed by the setting calculation device 61 to determine the temperature T. In the processing routine shown in FIG. 4, first, the rough outlet temperature and the speed pattern are read (step S11). The rough outlet temperature is calculated based on the actual temperature T RD mea Until the target value of the rough discharge side temperature included in the operation command IOP is acquired, the predicted value of the rough discharge side temperature or the target value of the rough discharge side temperature included in the operation command IOP is used. The speed pattern to be read is a predicted pattern for the speed of the material M passing through the cooling device 2, and the details thereof will be described later.

[0034] Following the processing of step S11, when the material M is transported from the installation position RD to the target position TBD, the temperature T M The predicted value of the cooling device outlet temperature T TBD pre " or "Predicted temperature T TBD pre " is calculated based on the formula (1) (step S12).

[0035]

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[0036] In the process of step S12, the predicted temperature T TBD pre The temperature drop ΔT from the installation position RD to the target position TBD when the cooling device 2 is not used is calculated. TBD rad is calculated based on equation (2).

[0037]

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[0038] Following the processing of step S12, when the material M is transported from the target position TBD to the installation position FE, the temperature T M The predicted value of the finishing inlet temperature (hereinafter referred to as "finishing inlet temperature predicted value T FE pre " or "Predicted temperature T FE pre " is referred to as ". The variable in the second term on the right side of the equation (3) is the same as that in the equation (1).") is calculated based on the equation (3) (step S13).

[0039]

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[0040] Following the processing of step S13, the predicted temperature T calculated in step S13 FE pre and the target temperature T FE tar Difference ΔT FE pre(=T FE pre -T FE tar It is determined whether the predicted temperature T FE pre and target temperature T FE tar is set in advance as a value that is considered to be almost identical (however, tol1≧0). FE pre If it is determined that the difference ΔT is smaller than the threshold value tol1, the processing routine is terminated (i.e., the cooling of the material M by the cooling device 2 is not performed). FE pre If is less than or equal to the threshold tol1, the difference ΔT FE pre If is a negative value (i.e., the predicted temperature T FE pre is the target temperature T FE tar (if lower than

[0041] difference ΔT FE pre If it is determined that the predicted temperature T is equal to or greater than the threshold value tol1, the process of step S15 is performed. FE pre Difference from ΔT FE pre is divided. The value after division (=T FE pre -ΔT FE pre ) is the temperature T at the target position TBD M The assumed value of the cooling device outlet temperature T TBD asu " or "Assumed temperature T TBD asu ").

[0042] Following the processing of step S15, the predicted temperature T FE pre In the process of step S16, the first term on the right side of equation (3) (i.e., T TBD pre ) the assumed temperature T calculated in step S15TBD asu is substituted, and the predicted temperature T FE pre is calculated.

[0043] Following the processing of step S16, the difference ΔT FE pre Absolute value of abs_ΔT FE pre In the process of step S17, it is determined whether the difference ΔT FE pre is the predicted temperature T calculated in step S16 FE pre and the target temperature T FE tar The threshold value tol2 is the difference between the predicted temperature T FE pre and target temperature T FE tar are set in advance as values that are deemed to be almost identical. The threshold value tol2 may be equal to the threshold value tol1.

[0044] Absolute value abs_ΔT FE pre If it is determined that the temperature is smaller than the threshold value tol2, the assumed temperature T TBD asu is the target temperature T TBD tar is set to (step S18).

[0045] On the other hand, the absolute value abs_ΔT FE pre If it is determined that the predicted temperature T is equal to or greater than the threshold value tol2, the process of step S15 is performed again. FE pre From the difference ΔT calculated in step S17 FE pre is divided. The value after division (=T FE pre -ΔT FE pre) is used to perform the processing from step S16 onwards. That is, if a negative determination result is obtained in step S17, the processing from step S15 to S17 is repeated.

[0046] 1-4. Example of how to determine the flow rate setting value Q 5 is a flowchart illustrating the flow of processing performed by the setting calculation device 61 to determine the flow rate setting value Q. In the processing routine shown in FIG. 5, first, the coarse outlet temperature and speed pattern are read (step S21). The processing content of step S21 is the same as that of step S11 described in FIG. 4.

[0047] Following the processing of step S21, the reference flow rate Q of the cooling water at the center of the width direction of the cooling device 2 is cnt std and the reference flow rate Q of the cooling water at the width direction end edg std and are set as the initial values of the flow rate setting value Q (step S22). The initial value Q(x) of the flow rate setting value Q(x) at the center in the width direction with respect to the position x of the material M based on the longitudinal direction is cnt use is expressed by equation (4), and the flow rate setting value Q(x) at the center of the width direction for the same position x is edg use is expressed by equation (5).

[0048]

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[0049]

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[0050] Flow reference value Q cnt std and Q edg std are prepared in advance as parameters for each steel type and size of the material M. Under these initial conditions, the temperature T at the target position TBD when the material M is transported from the installation position RD to the target position TBD isM (i.e., predicted temperature T TBD pre ) is calculated based on equations (6) and (7) (step S23).

[0051]

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[0052]

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[0053] Temperature in the width direction T M The change in the flow rate Q(x) is dominated by the effect of the change in the flow rate at the center of the width direction. cnt use The change in the flow rate of the cooling water at the width direction edge changes the temperature T M In this case, the flow rate setting value Q(x) at the width direction end edg use Using the flow rate setting value Q(x) cnt use In the former case, the flow rate set value Q(x) is expressed by equation (8), and in the latter case, the flow rate set value Q(x) is expressed by equation (9).

[0054]

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[0055]

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[0056] Following the processing of step S23, the flow rate-temperature change influence coefficient Inf cnt is determined (step S24). cnt is the temperature drop ΔT calculated based on equation (2) TBD rad and the temperature drop ΔT calculated based on equation (10) TBD pre and the flow rate reference value Q cnt std The predicted temperature T TBD pre The value calculated in step S23 is used for .

[0057]

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[0058]

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[0059] Following the processing of step S24, the influence coefficient Inf cnt and the predicted temperature T TBD pre and target temperature T TBD tar Difference ΔT TBD and based on the target temperature T TBD tar The flow rate setting value Q(x) of the cooling water at the center of the width direction to achieve this cnt use is determined based on equation (12) (step S25).

[0060]

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[0061] Following the processing of step S25, the flow rate set value Q(x) determined in step S25 is cnt use is the upper limit Q(x) cnt max and the lower bound Q(x) cnt min A limit check is performed using equations (13) and (14) so that the value does not fall below (step S26).

[0062]

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[0063]

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[0064] Following the processing of step S26, the flow rate setting value Q(x) at the width direction end edg use is the flow rate setting value Q(x) cnt use The flow rate setting value Q(x) is corrected in accordance with the change (step S27). edg use The correction is done using equation (15).

[0065]

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[0066] Following the processing of step S27, the flow rate setting value Q(x) determined in step S25 is edg use is the upper limit Q(x) edg max and the lower bound Q(x) edg min A limit check is performed using equations (16) and (17) so that the value does not fall below (step S28).

[0067]

number

[0068]

number

[0069] Following the processing of step S28, the predicted temperature T TBD pre In the process of step S29, the flow rate setting value Q(x) calculated in steps S24-S28 is added to the flow rate setting value Q(x) on the right side of equation (7). cnt use and Q(x) edg use is substituted, and the predicted temperature T TBD pre is calculated.

[0070] Following the processing of step S29, the difference ΔT TBD pre Absolute value of abs_ΔT TBD pre In the process of step S30, it is determined whether the difference ΔT TBD pre is the predicted temperature T calculated in step S29 TBD pre and the target temperature T TBD tar The threshold value tol3 is the difference between the predicted temperature T TBD pre and target temperature T TBD tar are preset as values that are deemed to be almost identical. The threshold value tol3 may be equal to the threshold value tol1 or tol2.

[0071] Absolute value abs_ΔT TBD pre is determined to be smaller than the threshold value tol3, the predicted temperature T TBD pre The flow rate set value Q(x) used in the calculation of is adopted (step S31).

[0072] On the other hand, the absolute value abs_ΔT TBD preIf it is determined that the predicted temperature T is equal to or greater than the threshold value tol3, a limit check of the flow rate setting value Q(x) is performed (step S32). TBD pre and target temperature T TBD tar Two types of judgments are made based on the magnitude relationship between the predicted temperature T TBD pre is the target temperature T TBD tar If it is greater than the predicted temperature T TBD pre It is determined whether the flow rate setpoint Q(x) used in the calculation of the predicted temperature T is an upper limit. TBD pre is the target temperature T TBD tar If it is smaller than the predicted temperature T TBD pre It is determined whether the flow rate setpoint Q(x) used in the calculation is at the lower limit.

[0073] In the first or second case where a positive determination result is obtained in the process of step S32, the process of step S33 is performed. TBD pre is the target temperature T TBD tar and the predicted temperature T TBD pre In the second case, i.e., the predicted temperature T TBD pre is the target temperature T TBD tar and the predicted temperature T TBD pre If the flow rate setpoint Q(x) used in the calculation is a lower limit, then this lower limit is adopted as the flow rate setpoint Q(x).

[0074] If a positive determination result is not obtained in the process of step S32, the process of step S25 is performed again. In other words, if a negative determination result is obtained in step S32, the processes of steps S25 to S32 are performed repeatedly.

[0075] In the processing routine of FIG. 5, an example in which the flow rate reference values are set at the center and end portions in the width direction has been described. However, the cooling device 2 can be further divided in the width direction and flow rate reference values can be set. Even in this case, the initial value Q(x) of the flow rate setting value Q(x) cnt use and correcting the flow rate at each portion in accordance with the change in the flow rate at the center portion in the width direction, the flow rate setting value Q(x) at all portions in the width direction can be determined.

[0076] 1-5.Speed pattern Here, the speed pattern will be explained with reference to FIG. 6. The speed pattern of the material M varies depending on the operation of rough rolling and finish rolling. In the example shown in FIG. 6, the speed of the material M when entering the rough rolling mill 3 (rough entry speed) is v RM thd In order to roll the material M as fast as possible, the speed of the material M during rough rolling (rough rolling speed) is v RM run After rough rolling, the material M is transported as fast as possible, so the speed of the material M during transportation (transport speed) is v trn On the other hand, in the finish rolling, the speed constraints at the inlet side of the finish rolling mill 4 are taken into consideration, so the speed of the material M at the inlet side of the finish rolling mill 4 (finish inlet speed) is increased to the speed v FME Therefore, the range of the speed change at the tip of the material M is different from that at the tail end of the material M. RM thd , v RM run and v trn is, for example, preset and included in the operation command IOP.

[0077] 1-6. Specific examples of FF control In FF control, the flow rate setting value Q and the influence coefficient Inf cnt and the speed pattern of the material M, a target temperature pattern T set over the entire length of the material M is obtained. TBD tarA reference value for the flow rate of the cooling water in the cooling device 2 is calculated for each point on the material M so that (i) is achieved. A common target temperature T TBD tar When this is set, the target temperature T TBD tar (x) is expressed by equation (18). In order to compensate for the temperature drop due to thermal rundown, the target temperature T TBD tar When increasing the temperature T TBD tar When lowering the target temperature T TBD tar (x) is expressed by equation (19).

[0078]

number

[0079]

number

[0080] FF control is performed when the material M reaches the installation position RD after rough rolling and reaches the actual temperature T RD mea The actual temperature T RD mea fluctuates in the longitudinal direction of the material M. Therefore, by appropriately changing the flow rate of the cooling water according to the position x of the material M, the temperature T M This can reduce fluctuations in the

[0081] In order to appropriately change the flow rate of cooling water according to the position x, the material M is virtually divided into a number of segments in the longitudinal direction. Each segment is an example of "each point in the longitudinal direction of the material to be rolled" in this disclosure. The flow rate reference value is determined for each segment. For example, the length of the segment is assumed to be 1 m. In this case, the actual temperature T RD mea The flow reference value is determined using the following formula: In this case, the flow reference value can be determined using the convergence calculation described in the method for determining the flow setpoint Q.

[0082] In the FF control, the position x of the material M and the speed at the position x are also determined based on information such as the rotation speed of the rolls of the roughing mill 3, the reduction amount, and the speed of the conveying table. When a certain segment passes the installation position RD, a flow rate reference value is calculated, and the opening and closing of the valve is controlled so that this flow rate reference value is realized at the timing when this segment reaches a position where it is cooled by cooling water from the cooling device 2. According to this control, the target temperature pattern T set over the entire length of the material M is TBD tar It is possible to achieve (i).

[0083] 1-7.Specific examples of learning calculations In the learning calculation, the learning value ΔT TBD ofs The learning calculation is performed when the material M, which has been cooled by cooling water, reaches the installation position FE and reaches the actual temperature T FE mea The learning calculation is performed at the timing when the actual temperature T TBD mea and T FE mea In addition, the temperature T at the installation position FE M The predicted value of the final inlet temperature (hereinafter referred to as the "predicted value of the final inlet temperature T FE repre " or "Reforedicted temperature T FE repre ") is used. The predicted temperature T FE repre For example, the actual temperature T of the h-th segment (h) from the tip is calculated as TBDmea (h) and T FE mea This is based on (h) and the speed performance of segment (h).

[0084] Re-predicted temperature T FE repre When calculating the temperature drop ΔT when the segment (h) is transported from the installation position RD to the target position TBD, TBD rad (h) is predicted using the speed record of segment (h). FE repre In the calculation, the temperature drop of the segment (h) during the time when the material M is transported from the target position TBD to the installation position FE is calculated using the actual flow rate value of the cooling water in the cooling device 2.

[0085] In the learning calculation, the re-predicted temperature T FE repre and actual temperature T FE mea and the temperature prediction error ΔT FE mea is calculated (Equation 20). Then, the error ΔT FE mea and the learning value ΔT applied to the material M(i-1) rolled in the hot rolling line 1 before the material M(i) currently being rolled. TBD ofs (old) and smoothed. This results in a new learning value ΔT TBD ofs (new) is calculated (Equation 21). TBD ofs (new) is used to correct the target value of the temperature of the material M(i+1) at the target position TBD in the setting calculation for the material M(i+1).

[0086]

number

[0087]

number

[0088] 1-8.Effects According to the first embodiment described above, the actual temperature T FE mea is the target temperature T FE tar In this setting calculation, the target temperature T TBD tar The flow rate setting value Q is determined. After the setting calculation, FF control is performed. In FF control, the target temperature T TBD tar Based on this, the target temperature pattern T TBD tar (i) is set, and this target temperature pattern T TBD tar The flow rate reference value is determined based on the flow rate set value Q etc. so that (i) is achieved. In FF control, the opening and closing of the valve is controlled so that this flow rate reference value is realized. Therefore, the target temperature pattern T TBD tar (i) can be achieved, so the actual temperature T FE mea , the target temperature T FE tar In addition, according to the first embodiment, the learned value ΔT TBD ofs Since the calculation and update are performed, it is possible to improve the accuracy of the control of the finishing inlet temperature.

[0089] 7 is a diagram showing an example of the results of control according to the first embodiment. The upper part of FIG. 7 shows the actual temperature T RD mea and two types of reforecast temperatures T TBD repre The transition of and are plotted. Here, the predicted temperature T TBD repre is the temperature T at the target position TBD M The predicted temperature T TBD repre (use) is calculated based on the actual temperature TTBD mea The re-prediction of the temperature T TBD repre (no use) is calculated based on the actual temperature T TBD mea This was based on the actual speed of material M.

[0090] As can be seen from the top of Figure 7, the actual temperature T RD mea If there is unevenness in the temperature, the predicted temperature T TBD repre On the other hand, when the control according to the first embodiment is performed, the re-predicted temperature T TBD repre (use) is maintained at a nearly constant temperature. Then, as can be seen from the middle of FIG. 7, the actual temperature T FE mea Therefore, the finish rolling can be stabilized compared to when the cooling device 2 is not used (i.e., when air cooling is used).

[0091] Furthermore, when the control according to the first embodiment is performed, the actual temperature T FE mea (use) has a low temperature over the entire length of the material M. Therefore, as shown in the lower part of FIG. 7, it is possible to increase the finish rolling speed FM.

[0092] Generally, in finish rolling, the target temperature T FD tar However, if the cooling device 2 is not used, the actual temperature T FE mea (no use) is high over the entire length of the material M, and the temperature fluctuations are also large. Therefore, in this case, it is necessary to lower the finish rolling speed FM, and it is also necessary to frequently change the finish rolling speed FM to compensate for the temperature fluctuations. In this regard, according to the control of the first embodiment, the actual temperature T FEmea (use) is low over the entire length of the material M, and temperature fluctuations are small. Therefore, the finish rolling speed FM can be increased while the frequency of changes in the finish rolling speed FM can be reduced, making it possible to perform finish rolling more stably.

[0093] Figure 8 shows the target temperature T TBD tar 8 is a diagram showing an example of the results when the cooling device 2 is controlled by changing the target temperature T TBD tar The target temperature pattern T TBD tar (i) is used. Such a target temperature pattern T TBD tar According to the control using (i), the target temperature T TBD tar As a result, the actual temperature T FE mea Since the rolling speed can be kept constant, it becomes possible to perform finish rolling at a substantially constant finish rolling speed.

[0094] 2. Second embodiment The second embodiment will be described with reference to Fig. 9. Note that the description of the configuration and functions common to the previously described embodiments will be omitted as appropriate.

[0095] 2-1. Example of hot rolling line configuration FIG. 9 is a diagram illustrating an example of the configuration of a hot rolling line to which the second embodiment is applied. In the example shown in FIG. 9, a table for transporting material M is installed between a roughing mill 3 and a finishing mill 4. This is the same as described in the first embodiment. In the second embodiment, on this transport table and downstream of the cooling device 2, heat retention devices such as a heat cover 7 and a coil box 8, and a heating device such as an induction heating device 9 are installed. The heat retention devices and the heating devices are also examples of the "intermediate device group" of the present disclosure. For ease of explanation, the heat retention devices and the heating devices will hereinafter also be collectively referred to as "additional devices."

[0096] The heat cover 7 has a mechanism for opening and closing the multiple panels. While the multiple panels are closed, the heat cover 7 accumulates heat from the material M that would otherwise be lost through radiation inside the mechanism, thereby keeping the material M warm. The coil box 8 temporarily winds the material M into a coil, thereby reducing the contact area with the outside air and keeping the material M warm. The coiled material M is then unwound and made into a plate before finish rolling. The heat cover 7 and the coil box 8 can prevent a drop in the temperature of the material M, and maintain the actual temperature T FE mea The induction heating device 9 can make the temperature T M Increases.

[0097] The use or non-use of additional equipment is selected according to the operating conditions. For example, when the overall length of the material M is long, the coil box 8 is used to prevent the roughing mill 3 and the finishing mill 4 from being in tandem via the material M. The coil box 8 is also used when the thickness of the material M is thin. The reason for this is to prevent the temperature drop of the material M due to thermal rundown and to reduce the temperature change ΔT from the head end to the tail end. TBD-FE However, because the outermost and innermost peripheries of the coiled material M are in contact with air, the temperatures of the outermost and innermost peripheries are lower than the temperature of the intermediate portion other than these portions. Therefore, when the coil box 8 is used in combination with the cooling device 2, it is desirable to weaken the cooling of the outermost and innermost peripheries compared to the cooling of the intermediate portion.

[0098] 2-2. Control device configuration example In the second embodiment, the cooling device 2 is controlled in the same manner as in the first embodiment. Therefore, the configuration of the control device 6 in the second embodiment is basically the same as that in the first embodiment. However, in the second embodiment, setting calculations and learning calculations are performed taking into account the additional device.

[0099] 2-3.Example of setting calculation When an additional device is installed in the hot rolling line 1, the speed pattern of the material M changes depending on the operation of the additional device in addition to the operations of the rough rolling and finish rolling. Taking into account the speed constraints imposed by the operation of the additional device, the speed of the material M at the inlet side of the finishing mill 4 (speed v FME ) must be set.

[0100] In the second embodiment, the operation command IOP includes the operation setting of the additional device. In the setting calculation of the second embodiment, the target temperature T TBD tar (That is, the temperature T M The target temperature T TBD tar The method for determining is basically the same as that explained in Fig. 4. However, in the second embodiment, in the process of step S13 in Fig. 4, a temperature drop calculation is performed taking into account the operation settings of the additional device.

[0101] Consider a case where the heat cover 7, coil box 8, and induction heating device 9 shown in FIG. 9 are additional devices. In this case, for each additional device, the temperature T M is calculated taking into account the operation settings of the additional equipment. This calculation is performed by dividing the conveying table into multiple areas AR1-AR5. Area AR1 corresponds to the cooling equipment 2, area AR3 corresponds to the heat cover 7, area AR4 corresponds to the coil box 8, and area AR5 corresponds to the induction heating equipment 9. There is no specific equipment in area AR2.

[0102] The outlet position of area AR1 (i.e., target position TBD) corresponds to the inlet position of area AR2, the outlet position of area AR2 corresponds to the inlet position HCE of area AR3, and the outlet position HCD of area AR3 corresponds to the inlet position of area AR4. Also, the outlet position CBD of area AR4 corresponds to the inlet position of area AR5, and the outlet position of area AR5 coincides with the installation position FE (see Figure 2). The temperature T at the outlet of the additional device M The calculation of the predicted value of is performed based on equations (22)-(25).

[0103]

number

[0104]

number

[0105]

number

[0106]

number

[0107] The variables in equations (22)-(25) are as follows (excluding the variables already mentioned): T HCE pre : Temperature T at position HCE M Predicted value [degC] T HCD pre : Temperature T at position HCD M Predicted value [degC] T CBD pre : Temperature T at position CBD M Predicted value [degC] ht air hc : Air-cooled heat transfer coefficient in area AR3 [W / mm] ht air cb : Air-cooled heat transfer coefficient in area AR4 [W / mm] ht air eh : Air-cooled heat transfer coefficient in area AR5 [W / mm] t hc : Heat cover 7 operating setting [-] t cb : Coil box 8 operation setting [-] t eh : Operation setting of induction heating device 9 [-] dt eh : Temperature increase by induction heating device 9 [degC]

[0108] The processing other than the temperature drop calculation is the same as the processing in the first embodiment.

[0109] 2-4. Learning calculation example In the learning calculation in the second embodiment, the re-predicted temperature T FE repre The calculation is based on the actual temperature T TBD mea (h) and T FE mea (h), the speed record of segment (h), and the operation record of the additional device. FE repre The operating performance of the additional equipment is added to the parameters of the calculation.

[0110] 2-5.Effects According to the second embodiment described above, when the cooling device 2 and the additional device are installed in the hot rolling line 1, it is possible to obtain the same effects as those of the first embodiment.

[0111] 3. Third embodiment The third embodiment will be described with reference to Figures 10 and 11. Note that the description of the configurations and functions common to the previously described embodiments will be omitted as appropriate.

[0112] 3-1. Example of hot rolling line configuration Fig. 10 is a diagram illustrating a configuration example of a hot rolling line to which the third embodiment is applied. In the example shown in Fig. 10, a scan pyrometer 53 is provided near a finish entry thermometer 52. The scan pyrometer 53 is included in various measuring instruments provided in the hot rolling line 1. The scan pyrometer 53 measures, for example, the temperature distribution in the width direction of the material M passing through an installation position FE (see Fig. 2) or its vicinity. The scan pyrometer 53 is an example of a "finish entry temperature distribution meter" in the present disclosure.

[0113] The temperature distribution in the width direction is M The actual value of the temperature at the center of the width direction (hereinafter referred to as the "temperature actual value T cnt_FE mea " or "Center actual temperature T cnt_FE mea ) and the temperature at the end T M The actual value of the temperature at the end of the width direction (hereinafter referred to as the "actual value of the temperature at the end of the width direction T edg_FE mea " or "End point actual temperature T edg_FE mea ") and the actual center temperature T cnt_FE mea and actual end temperature T edg_FE mea is transmitted to the control device 6.

[0114] 3-2. Features of the third embodiment FIG. 11 is a diagram illustrating an example of temperature distribution in the width direction of the segment (h). The horizontal axis of FIG. 11 indicates the width direction of the segment (h). The horizontal axis includes the OS (Operation side) direction and the DS (Drive side) direction. The solid line in FIG. 11 represents the actual value MTD of the temperature distribution. As can be seen from the actual value MTD, the temperature distribution from the center to the end in the OS direction is almost the same as the temperature distribution from the center to the end in the DS direction. However, the temperature T at the end M is the temperature at the center T M This is due to the influence of heat radiation from the side of material M.

[0115] In the first and second embodiments, the temperature T M On the other hand, in the third embodiment, the control was performed by focusing on the temperature T M In addition, the temperature T M The dashed line in FIG. 11 represents the target value TTD of the temperature distribution in the width direction of the material M passing through the installation position FE. The temperature T M The target value of the temperature T M The target value of (hereinafter referred to as "target temperature T cnt_FE tar) and the temperature T at the end position (position MED or MEO). M The target value of (hereinafter referred to as "target temperature T edg_FE tar ") and the difference ΔT edg_FE tar These temperatures T M The difference between the target values (hereinafter also referred to as the "target temperature difference") ΔT edg_FE tar is included in the operation command IOP. The temperature T at the width direction edge M An example of the setting calculation for the control is described below.

[0116] 3-3. Control device configuration example In the third embodiment, the cooling device 2 is controlled in the same manner as in the first embodiment. Therefore, the configuration of the control device 6 in the third embodiment is basically the same as that in the first embodiment. However, in the third embodiment, the temperature T M Setting calculations for the control, learning calculations, and FF control are performed.

[0117] 3-4. Example of learning calculation In the learning calculation in the third embodiment, the temperature correction value ΔT at the width direction end of the material M passing through the installation position FE edg_FE comp is calculated. Temperature correction value ΔT edg_FE comp is the target temperature difference ΔT in the setting calculation for material M(i+1). edg_FE tar This is used to correct the temperature correction value ΔT. edg_FE comp is the target temperature difference ΔT edg_FE tar and the actual temperature difference ΔT edg_FE mea where the actual temperature difference ΔT edg_FE mea is the actual temperature at the center T cnt_FE mea and the actual temperature at the end T edg_FE mea The actual temperature difference ΔT at the width direction end of segment (h) edg_FE meais calculated by equation (26).

[0118]

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[0119]

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[0120] Temperature correction value ΔT for setting calculation of material M(i+1) edg_FE comp (new) is the temperature correction value ΔT applied to material M(i-1) edg_FE comp It is calculated based on equation (28) using (old).

[0121]

number

[0122] Temperature correction value ΔT edg_FE comp When (new) is calculated, the temperature correction value ΔT edg_FE comp However, the actual flow rate Q of the cooling water at the end of the width direction for the position x of the material M is updated. edg act If any of the flow rates reaches the upper or lower limit, the temperature correction value ΔT edg_FE comp (new) will not be updated.

[0123] 3-5.Example of setting calculation In the setting calculation in the third embodiment, the temperature correction value ΔT edg_FE comp Using this, the flow rate setting value Q(x) at the width direction end (i.e., the flow rate setting value Q(x) edg use However, the temperature T M The temperature difference varies depending on the steel type and size, and also varies depending on the heating mode of the material M by the additional device and whether or not the additional device is used. Therefore, in the third embodiment, the temperature T M Reference temperature difference ΔT for factors affecting the temperature difference edg_FE nom It is managed as (Equation 29).

[0124]

number

[0125] Flow rate correction value Q at the width direction end edg comp is the target temperature difference ΔT edg_FE tar and the temperature correction value ΔT edg_FE comp and the reference temperature difference ΔT edg_FE nom and the flow rate-temperature change influence coefficient Inf at the width direction end wdt and is calculated using equation (30) based on

[0126]

number

[0127] The influence coefficient Inf in equation (30) wdt is the temperature T M The influence coefficient Infwdt is the influence coefficient Inf cnt Similarly, it may be calculated using actual values, or may be determined by prior simulation or the like.

[0128] Flow rate setting value Q(x) edg use The change is made by adding the flow correction value Q to the variable in equation (15). edg comp This is done using the following equation (31):

[0129]

number

[0130] Furthermore, the changed flow rate setting value Q(x) edg use For Q(x), the upper bound edg max and the lower bound Q(x) edg min A limit check is performed using (Equations (32) and (33)). This limit check is as described in step S28 of FIG.

[0131]

number

[0132]

number

[0133] 3-6. Example of FF control In the FF control in the first embodiment, a target temperature pattern T is set over the entire length of the material M based on the flow rate setting value Q(x) etc. TBD tarIn order to achieve (i), the flow rate reference value of the cooling water in the cooling device 2 was calculated for each point on the material M. In the FF control in the third embodiment, this flow rate setting value Q(x) is applied to the center of the material M in the width direction, while the flow rate setting value Q(x) edg use By applying this to the width direction end of the material M, the target temperature pattern T TBD tar (i) is set. Then, this target temperature pattern T TBD tar To achieve (i), the flow rate reference value of the cooling water in the cooling device 2 is determined for each segment. The segment (h) is set in the longitudinal direction of the material M. Therefore, for example, if the segment (h) is divided into three in the width direction, it is possible to determine the flow rate reference value for the center in the width direction and the flow rate reference values for the ends in the OS direction and the DS direction.

[0134] Effects According to the third embodiment described above, the flow rate setting value Q is changed at the width direction end. edg_FE mea The target temperature difference ΔT edg_FE tar This allows the actual temperature T FE mea the target temperature T FE tar It is possible to match it with

[0135] 4. Fourth embodiment The fourth embodiment will be described with reference to Fig. 12. Note that the description of the configuration and functions common to the above-described embodiments will be omitted as appropriate.

[0136] 4-1. Example of hot rolling line configuration Fig. 12 is a diagram illustrating a configuration example of a hot rolling line to which the fourth embodiment is applied. In the example shown in Fig. 12, a scan pyrometer 54 is provided near a rough discharge side thermometer 51. The scan pyrometer 54 is included in various measuring instruments provided in the hot rolling line 1. The scan pyrometer 54 measures, for example, the temperature distribution in the width direction of the material M passing through the installation position RD (see Fig. 2) or its vicinity. The scan pyrometer 54 is an example of a "rough discharge side temperature distribution meter" in the present disclosure.

[0137] The temperature distribution in the width direction is M The actual value of the temperature at the center of the width direction (hereinafter referred to as the "temperature actual value T cnt_RD mea " or "Center actual temperature T cnt_RD mea ) and the temperature at the end T M The actual value of the temperature at the end of the width direction (hereinafter referred to as the "actual value of the temperature at the end of the width direction T edg_RD mea " or "End point actual temperature T edg_RD mea ") and the actual center temperature T cnt_RD mea and actual end temperature T edg_RD mea is transmitted to the control device 6.

[0138] 4-2. Features of the fourth embodiment As in the third embodiment, in the fourth embodiment, the temperature T M The difference between the third embodiment and the fourth embodiment is the setting position of the target temperature difference in the width direction. That is, in the former, the target temperature difference (i.e., the target temperature difference ΔT edg_FE tar ) is set, but in the latter case, this target temperature difference is set for the installation position RD. Specifically, in the fourth embodiment, the temperature T M The target value of (hereinafter referred to as "target temperature T cnt_RD tar ) and the temperature T at the end position (position MED or MEO). M The target value of (hereinafter referred to as "target temperature T edg_RDtar ") and the difference ΔT edg_RD tar is set. Target temperature difference ΔT edg_RD tar is included in the Operational Instruction IOP.

[0139] 4-3. Control device configuration example As in the third embodiment, in the fourth embodiment, the temperature T M Setting calculations for the control, learning calculations, and FF control are performed.

[0140] 4-4. Learning calculation example In the learning calculation in the fourth embodiment, the temperature correction value ΔT at the width direction end of the material M passing through the installation position RD edg_RD comp is calculated. Temperature correction value ΔT edg_RD comp is the target temperature difference ΔT in the setting calculation for material M(i+1). edg_RD tar This is used to correct the temperature correction value ΔT. edg_RD comp is the target temperature difference ΔT edg_RD tar and the actual temperature difference ΔT edg_RD mea where the actual temperature difference ΔT edg_RD mea is the actual temperature at the center T cnt_RD mea and the actual temperature at the end T edg_RD mea The actual temperature difference ΔT at the width direction end of segment (h) edg_RD mea is calculated by equation (34).

[0141]

number

[0142] Temperature correction value ΔT for setting calculation of material M(i+1) edg_RD comp (new) is the temperature correction value ΔT applied to material M(i-1) edg_RD comp This calculation is performed using the formula (28) "ΔT edg_FE comp " to "ΔT edg_RD comp This can be explained by reading it as ".

[0143] Temperature correction value ΔT edg_RD comp When (new) is calculated, the temperature correction value ΔT edg_RD comp However, the actual flow rate Q of the cooling water at the end of the width direction for the position x of the material M is updated. edg act If any of the flow rates reaches the upper or lower limit, the temperature correction value ΔT edg_RD comp (new) will not be updated.

[0144] 4-5.Example of setting calculation In the setting calculation in the fourth embodiment, the temperature correction value ΔT edg_RD comp Using this, the flow rate setting value Q(x) at the width direction end (i.e., the flow rate setting value Q(x) edg use ) is changed. The setting calculation in the fourth embodiment is basically the same as that in the third embodiment. However, since there is a difference in the setting position of the target value between these embodiments, the reference temperature difference ΔT edg_RD nom The variables in (29) do not include those related to the additional equipment included as variables in equation (29).

[0145] 4-6. Example of FF control An example of the FF control in the fourth embodiment is the same as that of the FF control in the third embodiment.

[0146] Effects According to the fourth embodiment described above, the flow rate setting value Q is changed at the width direction end. Therefore, when a large temperature difference occurs between the center and end in the width direction of the material M at the entrance side of the roughing mill 3, this temperature difference is adjusted to the target temperature difference ΔT at the installation position RD at the exit side of the roughing mill 3. edg_RD tar It is possible to match it with

[0147] 5. Fifth embodiment The fifth embodiment will be described with reference to Fig. 13. Note that the description of the configurations and functions common to the above-described embodiments will be omitted as appropriate.

[0148] Fig. 13 is a diagram illustrating a configuration example of a hot rolling line to which the fifth embodiment is applied. In the example shown in Fig. 13, an induction heating device 9 is installed between a roughing mill 3 and a finishing mill 4. The configuration example in which the induction heating device 9 is installed is common to the configuration example shown in Fig. 9.

[0149] In the setting calculation of the first embodiment, the predicted temperature T FE pre is the target temperature T FE tar If the temperature is lower than the temperature T M Specifically, the control device 6 (setting calculation device 61) increases the predicted temperature T FE pre is the target temperature T FE tar If it is determined that the actual temperature is lower than the actual temperature T FE mea can be increased, so the actual temperature T FEmea the target temperature T FE tar In this case, since the cooling device 2 is not used, the learning value ΔT TBD ofs will not be updated.

[0150] 6. Sixth embodiment The sixth embodiment will be described with reference to Fig. 14. Note that the description of the configurations and functions common to the previously described embodiments will be omitted as appropriate.

[0151] 14 is a diagram illustrating a configuration example of a hot rolling line to which the sixth embodiment is applied. The example shown in FIG. 14 is basically the same as the configuration example shown in FIG.

[0152] In the setting calculation of the first embodiment, if a positive determination result is obtained in the processing of step S32 in FIG. 5 (first case), the upper limit of the flow rate setting value Q(x) is adopted as the flow rate setting value Q(x). However, adopting the upper limit of the flow rate setting value Q(x) means that the predicted temperature T TBD pre is the target temperature T TBD tar Therefore, if the upper limit of the flow rate setting value Q(x) is adopted, the actual temperature T TBD mea the target temperature T TBD tar It may not be possible to match

[0153] Therefore, in the sixth embodiment, when the flow rate set value Q(x) exceeds the upper limit, the roughing speed is reduced. Specifically, when the upper limit of the flow rate set value Q(x) is adopted as the flow rate set value Q(x), the setting calculation device 61 reduces the roughing speed to a speed v RM run (See Figure 3). The reason for this is generally that the actual temperature T TBD mea Since the temperature at the tip of the material M is the highest, the rough rolling speed is reduced to lower the temperature at this tip, and the actual temperature T TBD meaHowever, if the operating conditions do not permit a change in the rough rolling speed, the rough rolling speed will not be changed.

[0154] In the setting calculation of the sixth embodiment, the velocity v RM run Based on the speed pattern including the rough rolling speed changed to a speed lower than the set position RD, the temperature drop of the material M when the material M is transported from the set position RD to the target position TBD is calculated (Equation (1)). Then, the predicted temperature T TBD pre and target temperature T TBD tar If the difference is less than the allowable value, the temperature drop calculation is terminated. Otherwise, the rough rolling speed is increased to the speed v RM run In order to maintain the stability and operation of the rough rolling as much as possible, the rough entry speed and the conveying speed are not changed. In addition, when the rough rolling speed is changed, the rough rolling speed is changed to a speed lower than the rough entry speed (i.e., speed v RM thd ) after the change, a lower limit is set for the rough rolling speed so that it does not fall below the actual temperature T TBD mea the target temperature T TBD tar It is possible to control it to be close to .

[0155] 7. Seventh embodiment The seventh embodiment will be described with reference to Figures 15 to 17. Note that the description of the configurations and functions common to the previously described embodiments will be omitted as appropriate.

[0156] The seventh embodiment is premised on a configuration example in which a coil box 8 is installed between the roughing mill 3 and the finishing mill 4. An example of a configuration in which a coil box 8 is installed is the configuration example shown in FIG.

[0157] Figure 15 is a diagram illustrating an example of winding and unwinding of material M using a coil box 8. (i)-(iii) of Figure 15 show the change in shape of material M during winding. (iv)-(v) of Figure 15 show the change in shape of material M during unwinding. As can be seen from (i)-(v) of Figure 15, the positions of the leading end MF and the trailing end ME of material M are swapped before and after winding. In addition, the heat retention effect while material M is being wound into a coil differs significantly between the innermost portion MI, the outermost portion MO, and the middle portion MM.

[0158] Therefore, in the seventh embodiment, when the coil box 8 is used, the target temperatures T TBD tar In the setting calculation of the seventh embodiment, first, the temperature drop of the material M when the material M is transported from the installation position RD to the target position TBD is calculated, and the target temperature T TBD tar_MM This target temperature T TBD tar_MM the target temperature T TBD asi Let (Equation (35)).

[0159]

number

[0160] Target temperature T for the outermost MO TBD tar_MO and the target temperature T for the innermost periphery MI TBD tar_MI is the target temperature T TBD asi is determined as follows (Equations (36) and (37)).

[0161]

number

[0162]

number

[0163] Temperature drop amount ΔT MO and ΔT MI can be calculated by the following equations (38) and (39), respectively, taking into account thermal radiation, assuming that the outermost and innermost portions MO and MI are more easily cooled than the middle portion MM because they are in contact with air.

[0164]

number

[0165]

number

[0166] In the FF control of the seventh embodiment, the target temperature T TBD tar Change the pattern of the outermost MO. MO The length of the innermost circumference MI is L MI Then, the position y is y≦L MO In this case, the position y is L MO <y<L bar -L MIIn this case, according to equation (41), the position y is y≧L bar -L MI In the case of TBD tar (i) is set.

[0167]

number

[0168]

number

[0169]

number

[0170] 16 is a diagram showing an example of the results of control according to the seventh embodiment. In the example shown in FIG. 16, a coil box 8 is used. The upper part of FIG. 16 shows the actual temperature T RD mea and two types of reforecast temperatures T TBD repre The transition of and are plotted. The predicted temperature T TBD repre The two types of actual temperatures T FE mea and the two types of actual temperatures T FE mea As can be seen from the comparison with the above, when the coil box 8 is used, the temperature of the middle part MM of the material M becomes constant. This is due to the uniform temperature caused by heat retention and contact heat transfer, and the same phenomenon is observed not only when the control according to the seventh embodiment is performed (use), but also when only air cooling is performed (no use).

[0171] However, the two types of actual temperatures T shown in the lower part of Fig. 16 FE meaAs can be seen from the comparison with the above, when the control according to the seventh embodiment is performed (use), the actual temperature T FE mea This means that the target temperature T TBD tar_MO and T TBD tar_MI is the target temperature T TBD tar_MM This is because the flow rate setting value Q is determined so that it is higher than

[0172] 8. Eighth embodiment An eighth embodiment will be described below, and explanations of configurations and functions common to the previously described embodiments will be omitted as appropriate.

[0173] In the third or fourth embodiment, the flow rate setting value Q(x) at the width direction end edg use After this is set, the flow rate set value Q(x) is calculated using equation (33). edg use A lower limit check was performed on the flow setpoint Q(x). edg use is the lower bound Q(x) edg min If it is less than the flow rate setpoint Q(x), edg use is the lower bound Q(x) edg min However, the flow rate setting value Q(x) edg use is the lower bound Q(x) edg min This means that the actual temperature difference ΔT edg_FE mea is the target temperature difference ΔT edg_FE tar Therefore, the lower bound Q(x) edg min If is adopted, the actual temperature difference ΔT edg_FE mea The target temperature difference ΔT edg_FE tar It may not be possible to match

[0174] Therefore, in the setting calculation of the eighth embodiment, the flow rate setting value Q(x) edg use is the lower bound Q(x) edg min If it is less than the target temperature T TBD tar Reduce the flow rate setting Q(x) edg use is the flow rate setting value Q(x) cnt use This flow rate setting value Q(x) is calculated using cnt use is the target temperature T TBD tar Therefore, the target temperature T TBD tar If we lower the flow rate setting value Q(x), cnt use and Q(x) edg use Therefore, the flow rate setting Q(x) edg use is the lower bound Q(x) edg min It is possible to prevent the value from falling below this.

[0175] In the setting calculation of the eighth embodiment, the target temperature T TBD tar After the change, the temperature drop of the material M when it is transported from the installation position RD to the target position TBD is calculated (Equation (1)). In addition, the flow rate setting value Q(x) cnt use and Q(x) edg use is calculated (Equation (31)), and the flow rate setting value Q(x) edg use A lower limit check is performed for the flow rate setpoint Q(x) (equation (33)). edg use and the lower bound Q(x) edg min If the difference is less than the allowable value, the calculation is terminated. edg_FE mea The target temperature difference ΔT edg_FE tar It is possible to match it with

[0176] 9. Ninth embodiment The ninth embodiment will be described with reference to Fig. 17. Note that the description of the configurations and functions common to the previously described embodiments will be omitted as appropriate.

[0177] If some kind of abnormality occurs in the finishing rolling mill 4, the material M may not be able to be transported to the finishing rolling mill 4. This problem can also occur if some kind of abnormality occurs in equipment downstream of the finishing rolling mill 4. When such an abnormality occurs, the material M needs to be oscillated before the finishing rolling mill 4. In this case, however, a drop in the temperature of the material M is unavoidable. Therefore, in the ninth embodiment, when the control device 6 receives an emergency command IEM notifying the occurrence of an abnormality, the cooling by the cooling device 2 is stopped.

[0178] Length L of material M bar Depending on the material, there is a possibility that a part of the material M may remain at the position of the cooling device 2 due to oscillation before the finishing rolling mill 4. Therefore, especially in the case of the length L bar When oscillating a long length of material M, it is desirable to stop the cooling by the cooling device 2. In order to stop the cooling as quickly as possible, when the control device 6 receives an emergency command IEM, the FF control device 62 immediately sets the flow rate reference value of the cooling device 2 to zero. This makes it possible to stop the cooling by the cooling device 2 and prevent the temperature of the material M from decreasing due to this cooling. [Explanation of symbols]

[0179] 1 hot rolling line, 2 cooling device, 3 roughing mill, 4 finishing mill, 51 roughing outlet thermometer, 52 finishing inlet thermometer, 53, 54 scan pyrometer, 6 control device, 61 setting calculation device, 62 FF control device, 63 learning device, FE, RD installation position, TBD target position, M rolled material, ME tail end, MF front end, MI innermost peripheral part, MM middle part, MO outermost peripheral part, T M Temperature of the rolled material, T FE mea Finishing inlet temperature actual value (actual temperature), T FE tar Finishing entry temperature target value (target temperature), T FEpre Finishing entry temperature prediction value (predicted temperature), T FE repre Finishing inlet temperature re-prediction value (re-prediction temperature), T RD mea Actual rough outlet temperature (actual temperature), T RD tar Rough output side temperature target value (target temperature), T RD pre Predicted temperature of the crude outlet (predicted temperature), T TBD tar Cooling device outlet temperature target value (target temperature), T TBD pre Cooling device outlet temperature forecast value (forecast temperature), T TBD repre Cooling device outlet temperature re-prediction value (re-prediction temperature), T TBD tar_MI The target temperature for the innermost part, T TBD tar_MM Target temperature for the middle section, T TBD tar_MO Target temperature for the outermost periphery, ΔT TBD ofs Learning value, ΔT edg_FE comp Temperature correction value, ΔT edg_FE tar The difference in the target temperature value across the width of the rolled material (target temperature difference), ΔT edg_FE mea Actual temperature difference, Q cnt std Flow reference value, Q edg comp Flow rate correction value, T TBD tar (i) Target temperature pattern

Claims

1. A system for controlling the temperature of a material to be rolled in a hot rolling line, the system comprising: a roughing mill that performs reverse rolling; a finishing mill that performs tandem rolling; a group of intermediate devices provided between the roughing mill and the finishing mill; a roughing outlet thermometer provided between the roughing mill and the group of intermediate devices; a finishing inlet thermometer provided between the finishing mill and the group of intermediate devices; and a control device, The intermediate device group includes a cooling device that cools the rolled material using cooling water, The control device a setting calculation device for determining a set value of a cooling water flow rate in the cooling device; a feedforward control device that performs feedforward control of the flow rate of the cooling water in the cooling device based on the flow rate set value; a learning device that calculates a learning value based on an actual value of the flow rate of cooling water in the cooling device and an actual value of a finish inlet temperature that indicates an actual value of the temperature of the rolled material measured by the finish inlet thermometer; Including, The setting calculation device Before a final pass of the reverse rolling is performed on the rolled material, a finish inlet temperature target value indicating a target value of the temperature of the rolled material at the inlet side of the finishing rolling mill is determined; calculating a cooling device outlet temperature target value indicating a target value for the temperature of the rolled material at the outlet of the cooling device so that a finish inlet temperature predicted value indicating a predicted value for the temperature of the rolled material at the inlet of the finishing rolling mill coincides with the finish inlet temperature target value; determining the flow rate setting value based on the cooling device outlet temperature target value and the learned value; The feedforward control device comprises: determining a target temperature pattern indicating a pattern of target values of the temperature of the rolled material over the entire length of the rolled material at the outlet side of the cooling device; calculating a flow rate reference value of the cooling water in the cooling device for each point in the longitudinal direction of the rolled material based on the flow rate set value, speed information of the roughing rolling mill, and a rough discharge side temperature actual value indicating an actual value of the temperature of the rolled material measured by the rough discharge side thermometer; the flow rate reference value is calculated so that a cooling device outlet temperature prediction value, which indicates a predicted value of the temperature of the rolled material at the outlet of the cooling device, matches the target temperature pattern; executing the feedforward control so that the flow rate of the cooling water in the cooling device when each point of the rolled material reaches a position where it is cooled by the cooling device coincides with the flow rate reference value calculated for each point of the rolled material; the learning device calculates the learned value based on a difference between the actual finish entry temperature value and a re-predicted finish entry temperature value indicating a re-predicted value of the temperature of the rolled material at the entry side of the finishing rolling mill; The finish inlet temperature re-prediction value is calculated based on the flow rate actual value, the rough outlet temperature actual value, and the speed actual value of the material to be rolled. A temperature control system for a hot rolling line.

2. 10. The temperature control system of claim 1, The intermediate device group further includes a heat retention device that maintains the temperature of the rolled material and a heating device that heats the rolled material, The setting calculation device further comprises: Calculating the cooling device outlet temperature target value based on the operation setting values of the heat retention device and the heating device; The learning device further The final inlet temperature re-prediction value is calculated based on the actual flow rate value, the actual rough outlet temperature value, the actual speed of the material to be rolled, and the operational results of the heat retention device and the heating device. A temperature control system for a hot rolling line.

3. 3. The temperature control system according to claim 1 or 2, a finish entry temperature distribution meter that is provided between the finishing rolling mill and the intermediate device group and that measures a temperature distribution in the width direction of the rolled material, The learning device further calculate a temperature correction value indicating a correction value for the temperature of the end portion relative to the temperature of the central portion on the delivery side of the roughing mill based on the difference between a target value difference indicating the difference between a target value of the temperature of the rolled material at the central portion in the width direction and that at the end portion in the width direction, and an actual value difference indicating the difference between an actual value of the temperature of the rolled material at the central portion in the width direction and that at the end portion in the width direction, calculated based on the temperature distribution; The setting calculation device further comprises: determining a flow rate correction value indicating a correction value of the flow rate of the cooling water in the cooling device at the end portion using the target value difference and the temperature correction value; determining a flow rate setting value at the end portion based on the cooling device outlet temperature target value, the flow rate setting value determined based on the learned value, and the flow rate correction value; The feedforward control device further comprises: A feedforward control of the flow rate of the cooling water at the end portion is performed based on a flow rate set value at the end portion. A temperature control system for a hot rolling line.

4. 3. The temperature control system according to claim 1 or 2, a rough delivery-side temperature distribution meter that is provided between the roughing rolling mill and the intermediate device group and that measures a temperature distribution in the width direction of the rolled material; The learning device further calculate a temperature correction value indicating a correction value for the temperature of the end portion relative to the temperature of the central portion on the delivery side of the roughing mill based on the difference between a target value difference indicating the difference between a target value of the temperature of the rolled material at the central portion in the width direction and that at the end portion in the width direction, and an actual value difference indicating the difference between an actual value of the temperature of the rolled material at the central portion in the width direction and that at the end portion in the width direction, calculated based on the temperature distribution; The setting calculation device further comprises: determining a flow rate correction value indicating a correction value of the flow rate of the cooling water in the cooling device at the end portion using the target value difference and the temperature correction value; determining a flow rate setting value at the end portion based on the cooling device outlet temperature target value, the flow rate setting value determined based on the learned value, and the flow rate correction value; The feedforward control device further comprises: A feedforward control of the flow rate of the cooling water at the end portion is performed based on a flow rate set value at the end portion. A temperature control system for a hot rolling line.

5. 10. The temperature control system of claim 1, The intermediate device group further includes a heating device that heats the rolled material, The setting calculation device further comprises: If the predicted value of the finish inlet temperature is lower than the target value of the finish inlet temperature, an operation command is sent to the heating device. A temperature control system for a hot rolling line.

6. 3. The temperature control system according to claim 1 or 2, The setting calculation device further comprises: When the flow rate setting value used in calculating the predicted finish inlet temperature value exceeds an upper limit, the speed of the material being rolled by the roughing mill is changed to a speed lower than the setting speed. A temperature control system for a hot rolling line.

7. 3. The temperature control system according to claim 1 or 2, The intermediate device group includes a coil box that maintains the temperature of the rolled material, the setting calculation device sets the cooling device outlet temperature target value for each of an innermost portion, an outermost portion, and an intermediate portion of the rolled material wound into a coil shape by the coil box; The flow rate setting value is determined for each of the innermost circumferential portion, the outermost circumferential portion, and the intermediate portion based on the cooling device outlet temperature target value set for each of the innermost circumferential portion, the outermost circumferential portion, and the intermediate portion. A temperature control system for a hot rolling line.

8. 4. The temperature control system of claim 3, The setting calculation device further comprises: When the flow rate setting value at the end in the width direction falls below a lower limit, the cooling device outlet temperature target value is changed to a lower temperature. A temperature control system for a hot rolling line.

9. 3. The temperature control system according to claim 1 or 2, The feedforward control device changes the flow rate reference value to zero based on an emergency command notifying the occurrence of an abnormality in the finishing mill and equipment downstream of the finishing mill. A temperature control system for a hot rolling line.

10. A method for controlling the temperature of a material to be rolled in a hot rolling line including a roughing mill that performs reverse rolling, a finishing mill that performs tandem rolling, a group of intermediate devices provided between the roughing mill and the finishing mill, a roughing outlet thermometer provided between the roughing mill and the group of intermediate devices, and a finishing inlet thermometer provided between the finishing mill and the group of intermediate devices, The intermediate device group includes a cooling device that cools the rolled material using cooling water, determining a set point for the cooling water flow rate of the cooling device; performing feedforward control of the flow rate of the cooling water in the cooling device based on the flow rate set value; a step of calculating a learning value based on an actual value of the flow rate of cooling water in the cooling device and an actual value of the finish inlet temperature indicating an actual value of the temperature of the rolled material measured by the finish inlet thermometer; Including, determining the flow setpoint, determining a finish entry temperature target value indicating a target value of the temperature of the rolled material at the entry side of the finishing rolling mill before a final pass of the reverse rolling is performed on the rolled material; a step of calculating a cooling device outlet temperature target value indicating a target value of the temperature of the rolled material at the outlet of the cooling device so that a finish inlet temperature predicted value indicating a predicted value of the temperature of the rolled material at the inlet of the finishing rolling mill coincides with the finish inlet temperature target value; determining the flow rate setting value based on the cooling device outlet temperature target value and the learned value; Including, the step of performing feedforward control determining a target temperature pattern that indicates a pattern of target values of the temperature of the rolled material over the entire length of the rolled material at the outlet side of the cooling device; a step of calculating a flow rate reference value of the cooling water in the cooling device for each point in the longitudinal direction of the rolled material based on the flow rate set value, speed information of the roughing rolling mill, and a rough discharge side temperature actual value indicating the actual value of the temperature of the rolled material measured by the rough discharge side thermometer, wherein the flow rate reference value is calculated so that a cooling device outlet side temperature predicted value indicating a predicted value of the temperature of the rolled material at the outlet side of the cooling device matches the target temperature pattern; executing the feedforward control so that the flow rate of the cooling water in the cooling device when each point of the rolled material reaches a position where it is cooled by the cooling device coincides with the flow rate reference value calculated for each point of the rolled material; Including, The step of calculating the learned value includes: The method includes a step of calculating the learned value based on a difference between the actual finish inlet temperature value and a re-predicted finish inlet temperature value indicating a re-predicted value of the temperature of the rolled material at the inlet side of the finishing rolling mill, wherein the re-predicted finish inlet temperature value is calculated based on the actual flow rate value, the actual rough outlet temperature value, and the actual speed of the rolled material. A method for controlling the temperature of a hot rolling line.

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