JPH09316545A - Method for controlling strip temperature in continuous annealing furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a strip temp. control method of a continuous annealing furnace, by which the strips having different strip thickness, strip width, target strip temp. at the outlet of the heating furnace or priority of the strip temp., are joined and continuously inserted into the heating furnace to execute the annealing treatment. SOLUTION: At the time of changing a prescribed control cycle and velocity V at the center line, the strip temp. TS at the outlet of the heating furnace is continuously predicted from the present over to the future. Fuel flow rate optimizing a prescribed evaluating function with the deviation between a target strip temp. TSR at the outlet of the heating furnace and a predicted strip temp. at the outlet of the heating furnace and a variating quantity of the fuel flow rate in the heating furnace, is calculated to control the strip temp. TS at the outlet of the heating furnace. Then, in the case the priority PRT between the strip temps at the front and the rear parts differs, in order to execute the control seriously taking the strip temp. at the priority side, the strip temp. evaluating range N2 evaluating the deviation between the target strip temp. TSR at the outlet of the heating furnace and the predicted strip temp. at the outlet of the heating furnace over the future, is varied according to the priority PRT of the strip temp.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to continuous annealing in which strips having different sheet thickness, sheet width, heating furnace outlet target sheet temperature or sheet temperature priority are joined and continuously inserted into a heating furnace for annealing treatment. The present invention relates to a plate temperature control method for a furnace.

[0002]

2. Description of the Related Art In a continuous annealing furnace in which continuously fed strips are continuously inserted into a heating furnace for annealing, it is extremely difficult to control the strip temperature of the strip at the outlet of the heating furnace. This is an important issue, and when the plate thickness and the target furnace temperature at the heating furnace outlet change before and after the joint, the deviation from the target plate temperature at the heating furnace outlet is biased to either the front or rear material. It is basically controlled to reduce both of them, and in this respect, various forms of plate temperature control have been performed in the past as well.

However, when there is a difference in material and grade between the front material and the rear material, even if the same material temperature deviation occurs, for example, the material temperature deviation on the front material side has few quality problems, but the rear material There is a case in which the plate temperature deviation on the side becomes a serious problem, and it is difficult to deal with the plate temperature control method alone.

Therefore, Japanese Patent Laid-Open No. 2-163325 discloses
JP-A-3-277723 and JP-A-4-32332
Japanese Patent No. 5 discloses a plate temperature control method in which the set value of the speed and the furnace temperature, which are manipulated variables, are changed at appropriate timings according to various conditions such as the plate temperature priority.

[0005]

However, even the plate temperature control method described in the above-mentioned Japanese Patent Laid-Open Publication still has the following problems to be solved. That is, the above-mentioned plate temperature control method is, first, by the coil information such as the plate thickness of the rear material, the plate width, the target plate temperature, and the operation information such as the center line speed in the front material and the actual furnace temperature value. The center line speed of the rear material is selected from the table values prepared in advance.
Next, given the selected center line speed of the rear material, the furnace temperature setting value of the rear material is also determined in advance.

[0006] Then, according to various operating conditions such as prior material priority and after material priority, the timing for changing the center line speed of the after material and the furnace temperature set value is calculated and the setting is changed. The control method relies heavily on preset calculations.

However, in such a control method based on the preset calculation, the central line speed and the furnace temperature, which are the manipulated variables, are only set according to the table values and the values defined by the preset model, and the joint portion Feedback control cannot be performed until a certain period of time has passed after passing through the heating furnace outlet (preset period). That is, once the operation amount is set by the preset calculation, the table value is inappropriate during that period,
Even if an error in the preset model itself or a control error due to a disturbance such as plate thickness or speed occurs, the correction cannot be corrected, and the plate temperature only changes with the control error generated until the end of the preset period. Therefore, for example, even if the plate temperature changes for some reason, the operation amount cannot be changed,
As a result, defects such as heat buckles occur in the strip, which may cause operational troubles in the continuous annealing furnace.

Another problem common to the above-mentioned conventional plate temperature control methods is that the central line speed is adopted as the manipulated variable, which is a serious problem in reality. . This is because the central line speed depends on the strip threading conditions on the line entry side and the line exit side and various other events. That is, the setting of the central line speed is effective when the line operating condition from the entrance side to the exit side is very stable, but in reality, the central line speed is different depending on changes in the operating condition. Since it often varies depending on the factor, it cannot be said that the setting of the central line speed is appropriate as the operation end of the plate temperature control.

The present invention has been made to solve the above-mentioned problems in the prior art, and the fuel flow rate of the heating furnace is manipulated at a predetermined control period or when the central line speed is changed to change the heating furnace outlet plate. Controlling the temperature, plate thickness, plate width,
At the joints of strips with different heating furnace outlet target plate temperatures, this can be suppressed without causing a control error due to a preset method, and there is a difference in the priority of the plate temperature before and after the joints. Even if it exists, it aims at providing the plate temperature control method of the continuous annealing furnace which can implement exact plate temperature control.

[0010]

According to the present invention, there is provided a semiconductor device comprising:
The plate temperature control method of the continuous annealing furnace described, plate thickness, plate width, heating furnace outlet target plate temperature, at least one of the plate temperature priority is joined strips different, annealing is continuously inserted into the heating furnace. In the continuous annealing furnace to perform, when the predetermined control cycle and the central line speed is changed, the heating furnace outlet plate temperature from the present to the future is continuously predicted, and the heating furnace outlet target plate temperature and the heating furnace outlet predicted plate temperature are By calculating the fuel flow rate that optimizes a predetermined evaluation function based on the deviation and the fluctuation amount of the heating furnace fuel flow rate,
A method for controlling the plate temperature of a continuous annealing furnace for controlling the plate temperature of the heating furnace outlet, wherein when the plate temperature priorities are different before and after the joining portion of the strip, a control that emphasizes the plate temperature on the priority side is performed. Therefore, the plate temperature evaluation range for evaluating the deviation between the heating furnace outlet target plate temperature and the heating furnace outlet predicted plate temperature in the future is changed according to the plate temperature priority.

In the plate temperature control method for a continuous annealing furnace according to claim 1, the strip joint portion is always tracked, and first, the strip plate thickness and plate width at the heating furnace outlet, the heating furnace outlet target plate temperature, and the plate. Determine future prospective values for warm priority. Then, with respect to the plate temperature priorities before and after the joining portion of the strip, it is determined whether or not the front material priorities, the rear material priorities, or the front and rear materials have the same plate temperature priorities by comparing these.

Next, the heating furnace outlet plate temperature from the present to the future is continuously predicted. For such prediction of the heating furnace outlet plate temperature, a known plate temperature prediction model (for example, Japanese Patent Laid-Open No. 61-1) is used.
(Described in Japanese Patent No. 90026) may be used. Specifically, the plate thickness of the determined strip, each predictive value of the plate width, the furnace temperature of the heating furnace, the fuel flow rate, the plate thickness at the heating furnace outlet, the plate width, each actual value of the central line speed,
Sampling is performed at a predetermined control cycle and change in the center line speed, and the sampled temperature is input to the plate temperature prediction model. With these, when changing the predetermined control cycle and central line speed,
It is always possible to easily calculate the predictive plate temperature at the furnace outlet from the present to the future.

Further, the parameters in the plate temperature prediction model may be calculated by utilizing a known estimation method such as a fixed trace method or a recursive least squares method with a forgetting factor, and a parameter estimator (for example, Japanese Patent Laid-Open Publication No. No. 61-190026) is added and activated at a predetermined cycle, so that good accuracy can be maintained even with respect to changes over time in operation and equipment conditions.

After the heating furnace outlet predicted plate temperature is calculated as described above, the heating furnace outlet plate temperature is controlled by operating the fuel flow rate at a predetermined control cycle or when the center line speed is changed. The well-known plate temperature control method described in JP-A-72022 is used. The known plate temperature control method has a predetermined evaluation function based on the deviation between the heating furnace outlet target plate temperature and the heating furnace outlet predicted plate temperature and the amount of fluctuation of the heating furnace fuel flow rate, and a fuel for optimizing this evaluation function. Although it is an excellent control method for sequentially calculating the flow rate, in the present invention, further, in order to realize the accurate plate temperature control according to the plate temperature priority before and after the joining portion of the strip, the heating furnace outlet target in the evaluation function Range of time to evaluate the deviation between the plate temperature and the predicted plate temperature at the furnace exit (hereinafter,
It is called "plate temperature evaluation range". ) Was changed according to the plate temperature priority.

More specifically, first, at the joining portion of the strips where there is no difference in sheet temperature priority between the front material and the rear material, the deviation from the target furnace temperature at the heating furnace outlet is either the front material or the rear material. The plate temperature evaluation range is adjusted so as to become smaller without being biased to one side or the other, and this is set as a reference value.

At the joint portion of the strip in which the front material is prioritized, in order to realize the plate temperature control that emphasizes the latest plate temperature as the front material, rather than the future plate temperature as the rear material, the plate temperature evaluation is performed. Keep the range smaller than the standard value. By this,
At the joint portion of the strip, the plate temperature deviation on the front material side can be made as small as possible.

Further, at the joint portion of the strip in which the rear material is prioritized, in order to realize the plate temperature control which attaches importance to the future plate temperature as the rear material rather than the latest plate temperature as the front material, The evaluation range is set larger than the reference value. As a result, the strip temperature deviation on the rear material side can be made as small as possible at the joint portion of the strip.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Next, referring to the attached drawings, an embodiment in which the present invention is embodied will be described to provide an understanding of the present invention.

FIG. 1 is a block diagram showing the overall construction of a plate temperature control device A for a continuous annealing furnace which can be suitably used in a plate temperature control method for a continuous annealing furnace according to an embodiment of the present invention. FIG. It is a time chart which shows the contents.

Of the signal lines shown in FIG. 1, the solid line shows the data flow, and the dotted line shows the detection pulse or the start signal. The plate temperature control method for a continuous annealing furnace according to the present invention is actually controlled by using a process computer, and FIG. 1 shows the inside in a functionally understandable manner.

As shown in FIG. 1, in the present embodiment, the strip 100 is heated by the heating furnace 10. The heating furnace 10 includes a direct-fired furnace that directly injects a flame onto the strip 100 to heat it, an indirect furnace that indirectly heats with a radiant tube, and the like. However, the plate temperature control method of the continuous annealing furnace according to the present invention is Any of these heating furnaces can be suitably applied.

Referring to FIG. 1, first, the control around the heating furnace 10 will be described. A welding point detector 16 for detecting the joint portion of the strip 100 is arranged in front of the heating furnace 10. The welding point detector 16 detects a joint portion of the strip 100 which is passed through the continuous annealing furnace, and sends the detection signal P1 to a strip tracking device 15 which is an example of strip tracking means described later.

The heating furnace 10 is equipped with a furnace temperature detector 21 for detecting the temperature inside the furnace, and the furnace temperature observed value TF detected by the furnace temperature detector 21 is an example of parameter estimating means described later. It is sent to the parameter estimator 17 and the heating furnace outlet plate temperature prediction controller 19.

The heating furnace 10 is also equipped with a fuel flow rate detector 12 for detecting the flow rate of fuel supplied to the heating furnace 10. The fuel flow rate observation value FL detected by the fuel flow rate detector 12 is It is sent to the fuel flow rate controller 13, which is an example of the flow rate control means, and the heating furnace outlet plate temperature prediction controller 19.

The heating furnace outlet 11 has a heating furnace outlet plate temperature detector 22 for detecting the plate temperature of the strip 100 at this outlet.
Is arranged, and the plate temperature observation value detected by the heating furnace outlet plate temperature detector 22, that is, the heating furnace outlet plate temperature TS
Is sent to the heating furnace outlet plate temperature prediction controller 19 and the parameter estimator 17.

A speed detector 14 for detecting the strip passing speed (center line speed) V of the strip 100 is provided near the heating furnace outlet 11, and the detected center line speed V is , Strip tracking device 15
To the parameter estimator 17 and the heating furnace outlet plate temperature prediction controller 19.

Further, as shown in FIG. 1, a strip specification setting device 20 which is an example of strip specification determining means,
Heating furnace outlet plate temperature prediction controller 19 and parameter estimator 1
7 and a plate temperature priority determination device 18, which is an example of a plate temperature priority determination means described later, and the plate temperature priority determination device 18 is also connected to a heating furnace outlet plate temperature prediction controller 19. Has been done.

The function of each component of the plate temperature controller A of the continuous annealing furnace having the above-mentioned structure will be further described. The controlled object of the present invention is the plate temperature of the strip 100 at the heating furnace outlet 11. That is, the fuel flow rate of the heating furnace 10 for adjusting the plate temperature at the heating furnace outlet 11 to the target value is manipulated.

The fuel flow rate controller 13 regulates the fuel supplied to the heating furnace 10.
For example, a generally used control method such as PID control (proportional integral derivative control) can be preferably used.

The main point of the present invention is that, taking into consideration the plate temperature priorities of the strips 100 before and after the joining portion, the heating furnace outlet plate temperature TS is set to the heating furnace outlet at a predetermined control period and when the central line speed V changes. This is how to set the set value for the fuel flow rate controller 13 in order to exactly match the target plate temperature TSR.

The strip tracking device 15 detects the detection signal P1 from the welding point detector 16, the center line speed V detected by the speed detector 14, and the welding point detector 16.
Based on the distance (line length) from the installation location of the furnace to the heating furnace outlet 11, the strip length Z (joint position) from the heating furnace outlet 11 to the next joint is always obtained to determine the plate temperature priority. Device 18 and heating furnace outlet plate temperature prediction controller 1
Output to 9. Also, the strip tracking device 15
Outputs a start signal P2 to the strip specification setter 20 at the timing when the joint passes through the heating furnace outlet 11.

As shown in FIG. 1, the strip specification setting device 20 is activated by the activation signal P2 from the strip tracking device 15, and the strip specification (plate thickness TH
1, TH2; plate width WD1, WD2; heating furnace outlet target plate temperature TSR1, TSR2, plate temperature priority PRT1, PRT2)
Is output.

Here, the subscript (number) 1 in the strip specifications shown in FIG. 1 is a value relating to the strip 100 passing through the heating furnace outlet 11, and the subscript (number) 2 is relating to the subsequent (future) strip 100. It is a value.

The plate temperature priority determination device 18 compares the plate temperature priorities of the strips 100 before and after the joint, and evaluates the deviation between the heating furnace outlet target plate temperature TSR and the heating furnace outlet predicted plate temperature in the future. The range (plate temperature evaluation range N2) is changed. That is, the plate temperature priority determination device 18 is
Information from the strip specification setter 20 (plate temperature priority PR
Based on (T1, PRT2), conditions such as prior material prioritization, posterior material prioritization, or equal front and rear material temperature priority are determined,
The corresponding plate temperature evaluation range N2 is output to the heating furnace outlet plate temperature prediction controller 19 at a predetermined timing by referring to the information on the joint position Z notified by the strip tracking device 15. After the joint has passed through the heating furnace outlet 11, the number of coils existing in the heating furnace 10 is the same (the same coil), so the plate temperature priority determination device 18 is activated again, and the plate temperature evaluation range N2 is reached. Is returned to a predetermined reference value (a plate temperature evaluation range N2 when the front and rear materials have the same plate temperature priority).

Next, the heating furnace outlet plate temperature prediction controller 19
The heating furnace outlet plate temperature TS is controlled while being predicted, and the central line speed V of the strip 100 and the heating furnace 10 are controlled.
From the furnace temperature detector 21 of the furnace temperature observed value, that is, the heating furnace temperature T
F, fuel flow rate observation value FL from fuel flow rate detector 12, plate temperature observation value from heating furnace outlet plate temperature detector 22, that is, strip 1 at heating furnace outlet plate temperature TS or heating furnace outlet 11
No. 00 plate thickness, each plate width actual value and each future prediction value, and further future heating furnace outlet target plate temperature TSR notified by the strip specification setter 20 described above,
The plate temperature evaluation range N2 from the plate temperature priority determination device 18 is input, and the fuel flow rate set value FLS is calculated. The fuel flow rate observation value FL is detected by a known fuel flow rate detector, and the fuel flow rate controller 13 and the heating furnace outlet plate temperature prediction controller 1 are detected.
9 is output.

Here, the heating furnace outlet plate temperature prediction controller 19
Is a known plate temperature prediction model showing a dynamic relationship between the heating furnace outlet plate temperature TS, the furnace temperature observation value TF, the fuel flow rate observation value FL, and the strip thickness, strip width, and central line speed V of the strip 100 ( For example, it has a model described in Japanese Patent Laid-Open No. 61-190026).

Further, the parameter estimator 17 is, for example,
The parameter estimator described in Japanese Patent Laid-Open No. 61-190026 can be used, is activated at a predetermined cycle, and estimates the parameters in the "plate temperature prediction model" described above based on past results. To do.

Next, a plate temperature control method for the continuous annealing furnace using the plate temperature control device A for the continuous annealing furnace having the above-mentioned structure will be described. In the present invention, the joint portion of the strip 100 is always tracked, and first, the plate thickness, the plate width, and the heating furnace outlet plate temperature T of the strip 100 at the heating furnace outlet 11 are first described.
Each future predictive value of S and the plate temperature priority PRT is determined. Then, with respect to the plate temperature priorities PRT before and after the joining portion, these are compared, and the plate temperature evaluation range N2 according to conditions such as prior material priority, posterior material priority, or equal plate temperature priorities of front and rear materials is preliminarily set. Make a decision.

Here, the plate temperature evaluation range N2 is a time range in which the deviation between the heating furnace outlet target plate temperature TSR and the heating furnace outlet predicted plate temperature is continuously evaluated in the future, and the joining of the strips 100 is performed. Furnace temperature target plate temperature T
A plate temperature evaluation range N2 is set as a reference value so that the deviation from SR is not biased to either the front material or the rear material and becomes smaller, and this is set for the front material and the rear material. Used when there is no difference in. Then, in the joint portion where the front material should be prioritized, in order to realize the plate temperature control that emphasizes the latest plate temperature as the front material, rather than the future plate temperature as the rear material,
The plate temperature evaluation range N2 is set to be smaller than the reference value, and at the joint where the rear material should be prioritized,
The plate temperature evaluation range N2 is set to be larger than the reference value in order to realize the plate temperature control that places importance on the plate temperature in the future as a succeeding material.

Next, the heating furnace outlet plate temperature TS from the present to the future is continuously predicted. In the present embodiment, a known plate temperature prediction model (for example, Japanese Patent Laid-Open No. 60-190026).
It is possible to predict the heating furnace outlet plate temperature TS by using the model described in the publication).

Equation (1) of the plate temperature prediction model shown below
Is the heating furnace outlet plate temperature TS from the past to the time (t-1)
And the actual values of the furnace temperature and the fuel flow rate of the heating furnace 10 and the values of the plate thickness, the plate width, and the speed from the past to time t (actual or predicted value)
And are used to predict the heating furnace outlet plate temperature TS at time t.

[0042]

[Equation 1]

Then, the heating furnace outlet plate temperature prediction controller 19
In order to control the heating furnace outlet plate temperature, is started immediately at a predetermined control cycle and when the central line speed V changes, and the fuel flow rate of the heating furnace 10, which is the manipulated variable, is calculated moment by moment. For this fuel flow rate, for example, the amount of change can be obtained as a value that gives the minimum value of the evaluation function J expressed by the following equation (2).

[0044]

[Equation 2]

Here, the plate temperature evaluation range N2 in this evaluation function J has been previously given by the plate temperature priority determination device 18. Further, the calculation method of Δu that gives the minimum value of the evaluation function J is, for example, a generalized predictive control theory (Generalized Predictive C) which is one method of modern control theory.
Ontrol Theory), this calculation method is described in various documents, and since it does not directly relate to the present invention, its description is omitted.

As described above, in the plate temperature control method for the continuous annealing furnace according to the present embodiment, the strip 100 before and after the joining portion is
The sheet temperature evaluation ranges N2 are determined according to conditions such as the sheet temperature priorities of the front and rear materials, or the front and rear materials having the same sheet temperature priority. Since the feedback control is performed while continuously predicting the heating furnace outlet plate temperature TS at the time of the change of, the correction calculation of this control can be immediately performed even when the disturbance such as the change of the central line speed V occurs. It is possible to avoid the occurrence of a control error based on a preset method, and realize an unprecedented accurate plate temperature control according to the plate temperature priority even when the plate temperature priorities are different before and after the joint. be able to.

[0047]

EXAMPLE FIG. 2 is a time chart showing the operation contents of the plate temperature control method for the continuous annealing furnace according to the embodiment of the present invention described above. Here, the heating furnace 10 of the continuous annealing furnace is a direct furnace.

The contents of this operation are as shown in FIG.
Strip I (plate thickness: 0.875 mm, heating furnace outlet target plate temperature TSR: 700 ° C, plate temperature priority: normal), strip II (plate thickness: 0.725 mm, heating furnace outlet target plate temperature TS
R: 710 ° C., plate temperature priority: high, strip III (plate thickness: 0.820 mm, heating furnace outlet target plate temperature TSR: 71
0 ℃, Plate temperature priority: Normal, Strip IV (plate thickness:
0.685 mm, heating furnace outlet target plate temperature TSR: 710
C., plate temperature priority: normal), and a plate temperature control method when the plates are successively inserted into a continuous annealing furnace.

In controlling the plate temperature of such a continuous annealing furnace,
It is necessary to realize accurate plate temperature control considering the difference in plate temperature priority of each strip.
At the II joint, the back material (strip II) takes precedence, at the strip II and strip III joint, the front material (strip II) takes precedence, and at the strip III and strip IV joint, the front material It is necessary to carry out plate temperature control without giving priority to only one of the following materials.

In the continuous annealing furnace plate temperature control method according to one embodiment of the present invention, as described above, the plate temperature priorities of the strips 100 before and after the joining portion are compared, and the front material priority, the rear material priority, Or the front and back materials have the same plate temperature priority (no priority)
The plate temperature evaluation range N2 is determined according to such conditions, and feedback control is performed while continuously predicting the heating furnace outlet plate temperature TS when the predetermined control cycle and the central line speed V change.

Therefore, first, strip I and strip
At the joining portion of II, since the plate temperature priority of the rear material side (strip II) is high, the plate temperature evaluation range N2 becomes larger than a predetermined reference value, and as shown in FIG. Although the fuel flow rate of the heating furnace 10 is reduced and the heating furnace outlet plate temperature TS at the end portion of the strip I on the front material side is lowered, as shown in FIG. In the strip II on the material side after the plate temperature rises stepwise, the heating furnace outlet plate temperature TS and the heating furnace outlet target plate temperature TSR are as close to each other as possible from the tip portion.

Next, at the joint portion of the strips II and III, since the plate temperature priority on the front material side (strip II) is high, the plate temperature evaluation range N2 becomes smaller than a predetermined reference value, and the temperature shown in FIG. As shown in FIG. 2C, the fuel flow rate of the heating furnace 10 does not change while the strip II is passing through the heating furnace 10. As shown in FIG. In the end part, no plate temperature deviation occurred.

Further, strip III and strip IV
In the joint portion with and, since the plate temperature priorities of the front and rear materials are the same, the plate temperature evaluation range N2 becomes a predetermined reference value, and the fuel flow rate of the heating furnace 10 decreases a little early as shown in FIG. 2 (c). Then, although the heating furnace outlet plate temperature TS at the end portion of the strip III on the front material side becomes slightly lower, as shown in FIG. 2D, the plate thickness becomes thin and the plate temperature rises stepwise. When combined with the leading edge of the strip IV on the rear material side, optimal control is realized in such a manner that the end portion of the front material strip III and the leading edge of the rear material strip IV share the plate temperature deviation. ing.

Although the present invention has been described with reference to one embodiment, the present invention is not limited to the structure described in the above embodiment, but is described in the scope of claims. It also includes other embodiments and modifications within the scope of the matters described.

[0055]

In the plate temperature control method for the continuous annealing furnace according to the first aspect of the present invention, the target plate temperature and the predicted plate temperature at the exit of the heating furnace from the present to the future are natural when the predetermined control cycle or the central line speed is changed. Moreover, since it is continuously incorporated into the control calculation and the feedback control is performed while predicting the future plate temperature, the correction calculation of the control can be immediately performed even when the change of the central line speed V occurs. It is also possible to avoid occurrence of a control error based on the preset method. Moreover, since the plate temperature evaluation range for evaluating the deviation between the heating furnace outlet target plate temperature and the heating furnace outlet predicted plate temperature in the future is changed according to the plate temperature priority,
Even if the plate temperature priorities are different before and after the joint, it is possible to carry out extremely accurate plate temperature control that has not been available in the past.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of a plate temperature control device for a continuous annealing furnace that can be preferably used in a plate temperature control method for a continuous annealing furnace according to an embodiment of the present invention.

FIG. 2 is a time chart showing operation contents of control in the embodiment.

[Explanation of symbols]

A Plate temperature control device for continuous annealing furnace TF Observed temperature of furnace FL Observed value of fuel flow rate TS Heating furnace outlet plate temperature V Passing speed (center line speed) TSR Heating furnace outlet target plate temperature P1 Detection signal Z From heating furnace outlet Strip length to joint position P2 Start signal PRT Plate temperature priority FLS Fuel flow rate set value N2 Plate temperature evaluation range 10 Heating furnace 11 Heating furnace outlet 12 Fuel flow rate detector 13 Fuel flow rate controller 14 Speed detector 15 Strip Tracking device (strip tracking means) 16 Welding point detector 17 Parameter estimator (parameter estimation means) 18 Plate temperature priority determination device 19 Heating furnace outlet plate temperature prediction controller 20 Strip specification setting device 21 Furnace temperature detector 22 Heating furnace Outlet plate temperature detector 100 strip

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Haruhiko Eguchi 1-1 Hibahata-cho, Tobata-ku, Kitakyushu-shi, Fukuoka New Nippon Steel Corporation Yawata Works

Claims (1)

[Claims] 1. A strip having different at least one of plate thickness, plate width, heating furnace outlet target plate temperature, and plate temperature priority is joined,
In a continuous annealing furnace that performs an annealing treatment by continuously inserting it into a heating furnace, when changing a predetermined control cycle and central line speed,
Continuously predict the heating furnace outlet plate temperature from the present to the future, and optimize a predetermined evaluation function based on the deviation between the heating furnace outlet target plate temperature and the heating furnace outlet predicted plate temperature and the fluctuation amount of the heating furnace fuel flow rate. A method of controlling the plate temperature of a continuous annealing furnace, which calculates a fuel flow rate and controls the plate temperature at the outlet of the heating furnace, wherein when the plate temperature priorities are different before and after the joining portion of the strip, the plate on the priority side In order to perform control with an emphasis on temperature,
Plate temperature control of a continuous annealing furnace, characterized in that the plate temperature evaluation range for evaluating the deviation between the heating furnace outlet target plate temperature and the heating furnace outlet predicted plate temperature in the future is changed according to the plate temperature priority. Method.