JP5261963B2 - Method and apparatus for controlling plate temperature of heating furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely perform ignition/extinguish operation in a joining position of a front material and a rear material. <P>SOLUTION: Total fuel flowing amount to be set in a heating furnace is calculated based on a producing information containing the targeted value of the outlet plate temperature and the pre-detected actual value and also, the plate temperature from the present time to the future is estimated from the plate thickness, plate width and plate passing-through velocity from the present time to the future and then, the future producing plate temperature of the rear plate as the plate material for heating to the next of the front material during presently passing through a heating furnace, and the fuel flowing rate necessary to the rear material from the targeted plate temperature, are pre-calculated. When the platy material is heated with the calculated fuel flowing rate, it is judged that the ignition/extinguish operation is needed or not, and in the case of needing the ignition/extinguish operation, at the time when the joining position of the front material and the rear material is passed through the heating zone , the ignition/extinguish operation is preformed. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a plate temperature control method and apparatus for a heating furnace, and more particularly to a technique suitable for use in performing plate temperature control of a heating furnace used for annealing a steel plate or a thin steel strip.

  Conventionally, the plate temperature control in the heating furnace uses the plate temperature at the outlet of the heating furnace, which is called "exit plate temperature", as a controlled variable, and manipulates the flow rate of fuel such as coke gas (COG) to be supplied to the heating furnace. Done as a quantity.

  Usually, the heating furnace is divided into multiple heating zones ("heating zones") along the steel sheet transport path to facilitate control and save fuel flow. Has been. In the heating zone, the fuel flow rate and temperature can be controlled almost independently of other heating zones. In the following description, this heating zone may be simply referred to as a zone.

  In such a continuous annealing treatment facility, it is important to control the temperature of the steel plate, which is referred to as “plate temperature”, in order to ensure the quality of the steel plate after treatment and to avoid operational troubles such as a heat buckle. Plate temperature control in the heating furnace is an important issue.

  In the continuous annealing treatment facility, different types of steel sheets with different widths called “sheet widths” and “thicknesses” are joined together using an automatic welding mechanism. A technique called “set change” is employed. At the joint between different types of steel plates that appear as a result of changing the set, the plate width, thickness, etc., which are parameters of the heating furnace plate temperature control, change stepwise, and the steel plate referred to as “plate feed speed” In the situation where the transport speed reaches several tens to several hundreds of meters per minute, a considerably high degree of control is required.

FIG. 7 shows a conventional typical plate temperature control apparatus for controlling such a multi-zone heating furnace as an example of a 4-zone heating furnace.
As shown in FIG. 7, the optimum plate temperature control unit 32 receives the state of the heating furnace 31 and the plate temperature as “actual values” from the heating furnace state detection unit 33 and the plate thermometer 34 respectively, and changes the set. Parameters such as the target plate temperature, plate width, plate thickness, and plate feed speed accompanying the above are received as production information.

  Then, the total fuel flow rate Q to be set in the heating furnace is calculated as a manipulated variable according to a predetermined algorithm, and this is used to calculate the flow rate for each zone with a predetermined algorithm such as a specific ratio distribution. Set to 36.

  The instrumentation controller 36 adjusts the opening degree of the valves Ba to Bd of the fuel supply pipe 37 provided for each zone while balancing the air, so that the set flow rate matches the actual value. So that it is controlled.

  In order to perform such control, the operator has performed ignition and extinguishing operations for each of the four zones A to D based on experience and intuition. There is a problem that it is necessary and the workload of the operator is not reduced.

  In order to solve such a problem, for example, Patent Document 1 proposes a method of automatically allocating the total fuel flow rate to each zone without operator intervention.

JP-A-6-10058 JP 61-190026 JP

  In the case of the “plate furnace heating temperature control method” described in Patent Document 1, the fuel flow rate required for the rear material was not foreseen. For this reason, the ignition / extinguishing operation of the heating zone cannot be limited to the joint between the front and rear materials, and depending on the situation of the instrumentation controller 36, the fuel supply pipe 37, etc., the air-fuel ratio control is unstable or incomplete. Due to unexpected effects such as combustion, it was difficult to secure the surface properties and materials of the plate.

  In view of the above-described problems, an object of the present invention is to ensure that an ignition / extinguishing operation is reliably performed at a joint portion between a front material and a rear material.

The plate temperature control method for a heating furnace according to the present invention controls the ignition / extinguishing operation of a heating furnace composed of a plurality of heating zones capable of individually controlling the fuel flow rate, thereby allowing the outlet of the plate-like body to be carried out of the heating furnace. A method for controlling the plate temperature, which includes the actual value detection step for detecting the state value of the heating furnace and the outlet plate temperature as the actual value, and the production including the target value of the outlet plate temperature detected in the actual value detection step. The fuel flow calculation process for calculating the total fuel flow to be set in the heating furnace based on the information and the detected actual value, the transition of the plate temperature, the furnace temperature, the fuel flow from the past to the present, and the present to the future Predicting the future plate temperature of the rear material, which is a plate-like body that heats the current heating furnace next to the front material in the current plate, predicting the current and future plate temperature from the plate thickness, width, and plate speed. And the flow rate of fuel required for the rear material from the target plate temperature A material fuel flow rate calculation step after that calculated in advance, the flow distribution step of performing flow distribution including ignition and extinguishing of each heating zone by allocating the total fuel flow rate calculated by the fuel flow rate calculation step into a plurality of heating zones And determining whether or not the ignition / extinguishing operation is necessary when heating the plate-like body at the fuel flow rate calculated by the rear material fuel flow rate calculating step. An ignition / extinguishment pre-determination step for performing ignition / extinguishment when a portion where the front material and the rear material are joined passes through the heating zone.

The plate temperature control device for a heating furnace according to the present invention controls the ignition / extinguishing operation of a heating furnace composed of a plurality of heating zones capable of individually controlling the fuel flow rate, thereby allowing the outlet of the plate-like body to be carried out of the heating furnace. A device for controlling the plate temperature, including production value detection means for detecting the state value of the heating furnace and the outlet plate temperature as actual values, and production including a target value of the outlet plate temperature detected by the actual value detection means Fuel flow calculation means for calculating the total fuel flow to be set in the heating furnace based on the information and the detected actual value, transition of plate temperature, furnace temperature, fuel flow from past to present, and from present to future Predicting the future plate temperature of the rear material, which is a plate-like body that heats the current heating furnace next to the front material in the current plate, predicting the current and future plate temperature from the plate thickness, width, and plate speed. And the flow rate of fuel required for the rear material from the target plate temperature A material fuel flow rate calculating means after the pre-calculated, the flow distribution means for performing flow distribution including ignition and extinguishing of each heating zone by allocating the total fuel flow rate calculated by the fuel flow rate calculating means into a plurality of heating zones And determining whether or not the ignition / extinguishing operation is necessary when heating the plate-like body at the fuel flow rate calculated by the rear material fuel flow rate calculating means. Ignition / fire extinguishing pre-determining means for igniting / extinguishing when a portion joining the front material and the rear material passes through the heating zone.

The computer program of the present invention controls the outlet plate temperature of the plate-like body carried out of the heating furnace by controlling the ignition / extinguishing operation of the heating furnace including a plurality of heating zones capable of individually controlling the fuel flow rate. A computer program for causing a computer to execute the process, the actual value detecting step for detecting the state value and the outlet plate temperature of the heating furnace as the actual value, and the target value of the outlet plate temperature detected in the actual value detecting step. A fuel flow rate calculation step for calculating the total fuel flow rate to be set in the heating furnace based on the production information including the detected actual value, transition of plate temperature, furnace temperature, fuel flow rate from past to present, Predicting the future plate temperature, which is the plate-like body that is heated next to the front material in the current heating furnace through the plate temperature, predicting the plate temperature from the present to the future based on the plate thickness, plate width, and plate passing speed in the future And the warm, the fuel flow rate calculation step material after advance calculate the fuel flow rate needed by the rear material from the target plate temperature Prefecture, to allocate the total fuel flow rate calculated by the fuel flow rate calculation step into a plurality of heating zones Has a flow distribution step for distributing the flow including ignition and extinguishing of each heating zone, and when the plate-like body is heated with the fuel flow rate calculated by the rear material fuel flow rate calculation step, the ignition / extinguishing operation is performed. Ignition / extinguishing prior to deciding whether or not it is necessary and, if ignition / extinguishing operation is required, igniting / extinguishing when the part joining the front and rear materials passes through the heating zone The determination step is caused to be executed by a computer.

  According to the present invention, the total fuel flow rate to be set in the heating furnace is calculated based on the production information including the target value of the outlet plate temperature and the detected actual value, and the plate thickness and plate width from the present to the future are calculated. The future plate temperature of the rear material, which is a plate-like body that is heated next to the front material in the current heating furnace through the current heating furnace, and the target plate The fuel flow rate required for the rear material is calculated in advance from the temperature, and it is determined whether or not the ignition / fire-extinguishing operation is necessary when heating the plate-like body at the calculated fuel flow rate. Is required to ignite and extinguish when the part that joins the front and rear materials passes through the heating zone, so the ignition and fire extinguishing operation is performed at the joint between the front and rear materials. Can be ensured. This makes it possible to prevent unexpected effects such as instability of air-fuel ratio control and incomplete combustion that are likely to occur during ignition and extinguishing operations in parts shipped as products. And material securing can be performed reliably.

(First embodiment)
Next, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a block diagram illustrating an embodiment of the present invention and illustrating an example of a plate temperature control device for a heating furnace.
In FIG. 1, 1 is a strip specification setting device, 2 is a strip tracking device, 3 is a heating furnace state detector, 4 is a heating furnace outlet plate temperature prediction controller, 5 is a fuel flow controller, and 6 is a rear material fuel flow prediction. , 7 is a point extinction predetermination device, 8 is a speed detector, 9 is a set replacement detector, 10 is a heating furnace, and 11 is a plate thermometer. Reference numeral 100 denotes a steel plate heated in the heating furnace 10 of the present embodiment.

  The strip tracking device 2 includes a detection signal P1 from the set change (welding point) detector 9, a central line speed V detected by the speed detector 8, and a distance from the installation location of the set change detector 9 to the heating furnace outlet ( Based on the line length), the strip length z (joint position) from the furnace exit to the next joint is always determined based on the strip length from the furnace exit to the next joint, It outputs to the heating furnace outlet plate temperature prediction controller 4 and the rear material fuel flow rate predictor 6. In addition, the strip tracking device 2 outputs an activation signal P2 to the strip specification setting device 1 at the passage timing of the heating furnace outlet of the joint. As shown in FIG. 1, the strip specification setting device 1 is activated by an activation signal P2 from the strip tracking device 2, and after being passed through the heating furnace, the previous material passing through the heating furnace first, and then being inserted into the heating furnace. The strip specifications (plate thickness, plate width, furnace outlet target plate temperature) of each material are output. The heating furnace state detector 3 detects, as the state of the heating furnace 10, the flow rate of fuel supplied to each of the heating zones A to D and the plate temperature when the strip 100 exits the heating furnace 10 from the plate thermometer 11. Furthermore, the furnace temperature and the point-extinguishing state are also detected as “actual values” of the heating furnace 10.

Hereinafter, further details of the present invention will be described with reference to embodiments.
The heating furnace 10 of the present embodiment is composed of four zones A, B, C, D divided along the conveying path of the steel plate 100, and a flow control valve provided for each zone in the middle of the fuel supply pipe. By adjusting the opening of Ba, Bb, Bc, and Bd (including completely closing), the fuel flow rate distributed to each zone can be individually controlled.

  The furnace state detector 3 inputs the temperature in each zone from the thermometers provided in each of the four zones A, B, C, and D, and takes a weighted average value of the temperature for the zone during ignition. Through this process, the state value of the entire heating furnace is detected, and the point fire extinguishing state of each zone is also detected, and this is output to the heating furnace outlet plate temperature prediction controller 4 and a later material fuel flow rate predictor 6 described later.

  The heating furnace outlet plate temperature prediction controller 4 receives the state value of the heating furnace 10 output from the heating furnace state detector 3 and the plate temperature output from the plate thermometer 11 as the actual value, and the replacement of the set, etc. Information such as target plate temperature, plate width, plate thickness, and plate feed speed is received by the action of the strip specification setting device 1 and the tracking device 2, and the total fuel flow rate Q to be set in the heating furnace 10 is calculated according to a predetermined algorithm. And it outputs to the fuel flow controller 5 as an operation amount.

  That is, the heating furnace outlet plate temperature prediction controller 4 of the present embodiment predicts a plate-like body carried out from the heating furnace 10 based on production information and operation results, that is, a “plate temperature prediction model for predicting the outlet plate temperature of the strip 100. And a control program that performs closed-loop control so that they coincide with the target plate temperature.

Here, the plate temperature prediction model represents a dynamic relationship between the furnace outlet plate temperature and the furnace temperature, the fuel flow rate, the plate thickness, the plate width, and the speed. It has a temperature prediction model (for example, a model described in Patent Document 2).

  The fuel flow controller 5 includes a fuel distribution table that defines fuel flow distribution rules, a portion that includes a processor that performs fuel flow distribution with reference to the fuel distribution table, and a fuel distribution table via the processor. And an input / output unit for changing the contents.

  The processor of the fuel flow controller 5 refers to the fuel distribution table based on the total fuel flow received from the heating furnace outlet plate temperature prediction controller 4 and distributes the fuel flow to each of the zones A, B, C, and D. And the opening degree of the flow control valves Ba, Bb, Bc, Bd provided for each zone is adjusted. For example, the total fuel flow rate Q output from the heating furnace outlet plate temperature prediction controller 4 is distributed to each of the four zones A, B, C, and D. The processor portion of the fuel flow controller 5 can be realized by software running on an electronic computer together with software for realizing the heating furnace outlet plate temperature prediction controller 4.

FIG. 5 is a conceptual diagram for explaining a fuel flow rate distribution method by the fuel flow rate controller 5 shown in FIG. 1. The horizontal axis indicates the total fuel flow rate Q (total COG), and the vertical axis indicates the number of ignition zones. ing.
Then, there are threshold values q11, q21, q31 for igniting according to an increase in the total fuel flow rate Q, and threshold values q12, q22, q32 for extinguishing a fire according to a decrease in the total fuel flow rate.

  Now, assuming that each zone has a small ignition fire that can ignore the calorific value, setting the fuel flow allocated to a certain zone to a finite value will put that zone in the ignition state. On the contrary, setting the fuel flow rate distributed to a certain zone to zero means that the zone is put into a fire extinguishing state. For a heating furnace that does not have such a kind of fire, it may be performed in cooperation with the distribution of fuel flow and the control of ignition / extinguishing. Accordingly, it is assumed that the distribution of the fuel flow rate by the fuel flow rate controller 5 serves as both ignition and extinguishing control in each zone.

  First, it is assumed that the total fuel flow rate Q increases monotonously from zero. If the total fuel flow rate Q is larger than zero and smaller than the minimum threshold value q11 at the time of increase, that is, 0 <Q <q11 (≦ MAX flow rate only in the D zone), this total fuel flow rate Q is all in the final stage. Allocated only to zone D. That is, the number of ignition zones is “1”, and the remaining three zones A, B, and C hold the fire extinguishing state.

  When the total fuel flow rate Q further increases and exceeds the minimum threshold value q11 at the time of increase, the zone C is ignited and the total fuel flow rate is distributed to the two subsequent ignition zones D and C. When the total fuel flow rate Q further increases and exceeds an intermediate threshold value q21 (MAX flow rate after adding 3Z and 4Z), the zone B is newly ignited, and the total fuel flow rate Q becomes 3 pieces. It is distributed to the ignition zones D, C, B. When the total fuel flow rate Q further increases and exceeds the maximum threshold value q31 (MAX flow rate after adding 2Z, 3Z and 4Z), the foremost zone A is newly ignited and the total fuel flow rate is increased. Q is distributed to the four ignition zones D, C, B, A. Regarding the fuel distribution to each zone during ignition, the larger the flow rate distribution ratio, the larger the fuel flow rate at the subsequent stage, that is, the larger value is distributed in the order of zones D, C, B, and A. Is done.

  It is assumed that the total fuel flow rate Q starts to decrease monotonously from the above-mentioned all zone ignition state to zero. Even if the total fuel flow rate Q decreases and becomes smaller than the maximum threshold value q31 at the time of increase, the four zones still maintain the ignition state. Only when the total fuel flow rate Q further decreases and becomes smaller than the maximum threshold value q32 at the time of reduction, the distribution amount of the fuel flow rate to the zone A in the foremost stage becomes zero, and this shifts to the fire extinguishing state. That is, the ignition zone becomes the subsequent three zones B, C, and D, and the number of ignition zones decreases from “4” to “3”.

  Hereinafter, similarly, even if the total fuel flow rate Q further decreases and becomes smaller than the intermediate threshold value q21 at the time of increase, the subsequent three heating zones B, C, and D still maintain the ignition state. Only when it becomes smaller than the intermediate threshold value q22 at the time of decrease, the distribution amount for the heating zone B becomes zero, and the heating zone B shifts to a fire extinguishing state.

  That is, the number of ignition zones decreases from “3” to “2”. Even if the total fuel flow rate Q further decreases and becomes smaller than the minimum threshold value q11 at the time of increase, the subsequent two zones D and C still maintain the ignition state, but this is lower than the minimum threshold value q12 at the time of decrease. Only when it becomes smaller, the distribution amount for zone C becomes zero, and this shifts to the fire extinguishing state.

  That is, the ignition zone is only the last zone D, and the number of ignition zones decreases from “2” to “1”. When the total fuel flow rate Q further decreases to zero, the last zone D is also extinguished and the operation of the entire heating furnace is stopped.

  That is, for the heating zone once shifted to the ignition state, the ignition state is maintained as it is even if the total fuel flow rate is slightly reduced compared to this transition time. In addition, the heating zone once shifted to the fire extinguishing state is maintained in the fire extinguishing state as it is even if the total fuel flow rate is slightly increased as compared to this transition. By setting such refractory areas related to state transitions, frequent point-extinguishing operations can be avoided, incomplete combustion due to unstable furnace plate temperature control and air-fuel ratio control, and on-off valves Reduce the consumption of equipment as much as possible.

  In addition, when the person in charge of operation of this system needs to change the fuel distribution table in the fuel flow controller 5, the fuel distribution table is rewritten via a processor from a rewriting means (not shown) to redistribute the fuel. The rules can be changed at any time. As a result, in addition to the latter-stage high load distribution, any distribution rule such as all-zone equal load, first-stage high load, etc. can be realized.

  In the plate temperature control device of the heating furnace performing such fuel flow control, in the present embodiment, while performing the heating control of the steel plate 100 passing through the current heating furnace 10, the plate temperature from the past to the present, Based on the transition of the furnace temperature and fuel flow rate, and the sheet thickness, sheet width, and threading speed from now to the future, The predicted future plate temperature and its target plate temperature (target value) are predicted. The fuel flow rate required for the rear material (rear material fuel flow rate) is calculated in advance from the predicted future plate temperature of the rear material and the target plate temperature.

First, the relationship between “evaluation function and fuel flow calculation” performed in the present embodiment will be described with reference to the control characteristic diagram of FIG.
In FIG. 3, (a) shows the characteristic regarding plate temperature, (b) shows plate | board thickness and conveyance speed, (c) has shown transition of fuel flow volume.
As shown in FIG. 3C, the fuel flow rate has increased from the past to the present. FIG. 3 (c) shows a state where the fuel flow rate increases stepwise because the fuel flow rate is sampled every predetermined time.

  When it is detected that the plate thickness changes as shown in FIG. 3B, as shown in FIG. 3C, the “required fuel flow rate necessary for heating the rear member to the target plate temperature r”. (2) is calculated. This “required fuel flow rate” is performed using “Equation 3” described later. Then, the calculated “required fuel flow rate” is used in the prior determination of the point fire extinguishing performed by the point extinguishing prior determination device 7.

  By the way, when the current flow rate is immediately changed to the “required fuel flow rate” (2) necessary for heating the rear material to the target plate temperature r, the temperature of the front material currently being heated is represented by a characteristic curve f ′. Too high. Therefore, in the present embodiment, the necessary fuel flow rate (1) (= current flow rate) for optimizing the plate temperature deviations at both the rear end of the front member and the front end of the rear member using “Equation 2” described later. + ΔU (t)) is calculated and switched to it.

  By doing in this way, with respect to the plate temperature predicted value (indicated by the dotted line in FIG. 3A) when the fuel flow rate is not controlled before the plate thickness changes, the “characteristic curve f” is obtained. As shown, the plate temperature deviation can be dispersed at the joint between the front material and the rear material, and the deviation from the target plate temperature can be reduced for both the front material and the rear material.

Next, an example of a control procedure performed by the heating furnace plate temperature control apparatus of the present embodiment will be described with reference to the flowchart of FIG.
When the control process is started, first, in step S201, control is performed so that the measured value of the plate thermometer 11 disposed at the outlet of the heating furnace 10 becomes a preset target plate temperature. The plate temperature prediction for this is carried out by the “plate temperature prediction model” using the following “Equation 1” in the heating furnace outlet plate temperature prediction controller 4.

  Next, the process proceeds to step S202, and the fuel flow rate necessary to make the “heating furnace outlet plate temperature y” a predetermined temperature is calculated. The calculation of the fuel flow rate is performed by using the evaluation function shown in the following “Equation 2” in the heating furnace outlet plate temperature prediction controller 4.

  Next, in step S203, it is determined whether or not the joint portion of the steel plate 100 is approaching. It is detected by the strip tracking device 2 that the joining portion of the steel plate 100 is approaching. If the result of determination in step S203 is that the joint is not approaching, control returns to step S201 to perform the control described above.

  On the other hand, if the result of determination in step S203 is that the joint is approaching, processing proceeds to step S204. In step S204, the plate temperature of the rear material is predicted.

  Next, proceeding to step S205, the “difference between the predicted plate temperature of the rear member and the target plate temperature” is evaluated, and the fuel flow rate required for the rear member is calculated. This evaluation is performed by the rear material fuel flow predictor 6, and in this embodiment, the evaluation function shown in the following “Equation 3” is used.

  Here, the difference between the fuel flow rate calculated by “Equation 2” and the fuel flow rate calculated by “Equation 3” will be described. The fuel flow rate calculated by “Equation 2” is a fuel flow rate necessary for the steel plate 100 in the plate to reach a predetermined plate temperature at the outlet of the heating furnace 10. Specifically, as shown in FIG. 4 (a), in a section from t + d (dead time) to t + N2 (plate temperature prediction window), a portion where the target plate temperature and the predicted plate temperature are different (a broken line is attached). ) (U), and ΔU (t) (amount of change in the fuel flow rate) shown in FIG. 4B is calculated so that they are minimized.

On the other hand, in the case of “Equation 3”, the total fuel flow rate required for the rear material is predicted and evaluated in advance. In other words, in “t + N ₁ ′” to “t + N ₂ ′” in FIG. 4, the area of the portion where the target plate temperature deviates from the predicted plate temperature (the blacked-out portion) is evaluated, and these are minimized. It is used to calculate the fuel flow rate. (In the example of FIG. 4, N1 ′ and N2 ′ are smaller than N2, but may be larger than N2)

  Next, the process proceeds to step S206, and as shown in FIG. 5, the ignition / extinguishment hysteresis in consideration of the fuels “min” and “max” in the heating zones A to D is referred to. Ignition / fire extinguishing hysteresis is realized by making the threshold value for starting the ignition operation different from the threshold value for starting the fire extinguishing operation.

  Next, it progresses to step S207 and it is judged whether ignition / extinguishing is performed in a welding point. This determination is made by the point fire extinguishing pre-determination unit 7. As a result of the determination by the point fire extinguishing predeterminer 7, if it is necessary to perform ignition / extinguishing at the welding point, the process proceeds to step S208, and ignition or extinguishing is performed at the welding point between the front and rear materials. Thereafter, the process proceeds to step S209. On the other hand, as a result of the determination in step S207, if it is determined that it is not necessary to perform ignition / extinguishing, the process jumps to step S208 and proceeds directly to step S209.

  In step S209, it is determined whether or not to end the heating process of the strip 100. As a result of the determination, if the heating is not finished, the process returns to step S201 and the above-described process is repeated. When the process is to be ended, an “end” process is executed.

(Example)
Next, an embodiment will be described with reference to the characteristic diagram of FIG.
In the case of this example, the case where the plate thickness is increased to “1.3 times” at the junction between the front material and the rear material, and the target plate temperature is increased is shown. In FIG. 6, SP: set point, PV: process value, NOF: Non oxygen furnace (non-oxidizing furnace) are shown.

  In the case of this example, it is predicted that the plate thickness of the rear material will be “1.3 times”, so as shown by “(1)” in FIG. (From around "15:37" before the joining part), the total fuel flow rate has begun to increase. Further, as the total fuel flow rate is increased, as shown by “(2)” in FIG. “2 zones” are ignited.

  In this way, by performing ignition / extinguishing in advance when the portion joining the front and rear materials passes through the zone, as indicated by “(3)” in FIG. The “plate temperature deviation” indicated by diagonal lines can be divided between the front and rear materials, and optimal control can be realized. As a result, the plate temperature control accuracy can be remarkably improved, and the work load on the operator can be greatly reduced.

(Another embodiment according to the present invention)
Each means constituting the heating furnace plate temperature control apparatus and each step of the heating furnace plate temperature control method in the embodiment of the present invention described above is executed by a program stored in a RAM or ROM of a computer. Can be realized. This program and a computer-readable recording medium on which the program is recorded are included in the present invention.

  In addition, the present invention can be implemented as a system, apparatus, method, program, storage medium, or the like, and can be applied to a system composed of a plurality of devices. Moreover, you may apply to the apparatus which consists of one apparatus.

  In the present invention, a software program (in the embodiment, a program corresponding to the flowchart shown in FIG. 2) for realizing the functions of the above-described embodiments is directly or remotely supplied to a system or apparatus, and the system Or the case where it is achieved also by the computer of the apparatus reading and executing the supplied program code is included.

  Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. In other words, the present invention includes a computer program itself for realizing the functional processing of the present invention.

  In that case, as long as it has the function of a program, it may be in the form of object code, a program executed by an interpreter, script data supplied to the OS, and the like.

  As a recording medium for supplying the program, for example, floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, MO, CD-ROM, CD-R, CD-RW, magnetic tape, nonvolatile memory card ROM, DVD (DVD-ROM, DVD-R) and the like.

  As another program supply method, a client computer browser is used to connect to an Internet homepage, and the computer program itself of the present invention or a compressed file including an automatic installation function is downloaded from the homepage to a recording medium such as a hard disk. Can also be supplied.

  It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage. That is, a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer is also included in the present invention.

  In addition, the program of the present invention is encrypted, stored in a storage medium such as a CD-ROM, distributed to users, and key information for decryption is downloaded from a homepage via the Internet to users who have cleared predetermined conditions. It is also possible to execute the encrypted program by using the key information and install the program on a computer.

  In addition to the functions of the above-described embodiments being realized by the computer executing the read program, the OS running on the computer based on the instructions of the program is used for the actual processing. The functions of the above-described embodiment can be realized by performing some or all of the processes.

  Furthermore, after the program read from the recording medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion board or The CPU or the like provided in the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

It is a block diagram which shows embodiment of this invention and demonstrates the structural example of the plate temperature control apparatus of a heating furnace. It is a flowchart explaining an example of the control procedure of the plate temperature control method of a heating furnace. It is a characteristic view which shows the relationship between a fuel flow volume and plate | board temperature, (a) shows the characteristic regarding plate | board temperature, (b) shows board thickness and conveyance speed, (c) is a characteristic view which shows transition of fuel flow volume. It is. It is a conceptual diagram for demonstrating how to take the evaluation range of plate temperature. It is a figure explaining the ignition and extinguishing hysteresis which considered the fuel "min" and "max" of four heating zones. It is a characteristic view showing an example of control performed when the plate thickness is increased to “1.3 times” and the target plate temperature is increased. It is a block diagram which shows the structural example of the plate temperature control apparatus of the conventional heating furnace.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Strip specification setting device 2 Strip tracking device 3 Reheating furnace state detector 4 Reheating furnace outlet plate temperature prediction controller 5 Fuel flow controller 6 Rear material fuel flow predictor 7 Point-fire extinction predetermination device 8 Speed detector 9 10 Heating furnace 11 Plate thermometer 100 Steel plate

Claims (7)

A method of controlling the outlet plate temperature of a plate-like body carried out of a heating furnace by controlling ignition / extinguishing operation of a heating furnace composed of a plurality of heating zones capable of individual control of fuel flow,
Actual value detection step of detecting the state value and outlet plate temperature of the heating furnace as actual values;
Production information including a target value of the outlet plate temperature detected in the actual value detection step, and a fuel flow rate calculation step for calculating a total fuel flow rate to be set in the heating furnace based on the detected actual value;
Predicting the plate temperature from the present to the future based on the transition of the plate temperature, furnace temperature, fuel flow rate from the past to the present, and the plate thickness, plate width, and plate feed speed from the present to the future. A rear material fuel flow rate calculating step for calculating in advance a fuel flow rate required for the rear material from the predicted future plate temperature of the rear material which is a plate-like body to be heated next to the front material, and the target plate temperature;
A flow distribution step of performing flow distribution including ignition and extinguishing of each heating zone by distributing the total fuel flow calculated by the fuel flow calculation step to a plurality of heating zones ;
When heating the plate-like body with the fuel flow rate calculated in the rear material fuel flow rate calculating step, it is determined whether or not the ignition / extinguishing operation is necessary. A method for controlling the plate temperature of a heating furnace, comprising: an ignition / fire extinguishing pre-determination step for performing ignition / extinguishing when a portion where the rear material and the rear material are joined passes through the heating zone. In the rear material fuel flow rate calculating step, the following equation:

The temperature control method for a heating furnace according to claim 1, wherein the total fuel flow rate required to heat the rear member to a predetermined temperature is calculated using an evaluation function.   The flow rate distribution step of performing flow rate distribution including ignition and extinguishing of each heating zone by allocating the total fuel flow rate calculated by the fuel flow rate calculation step to the plurality of heating zones. 3. A method for controlling the plate temperature of the heating furnace according to 2. A device for controlling the outlet plate temperature of the plate-like body carried out of the heating furnace by controlling the ignition / extinguishing operation of the heating furnace comprising a plurality of heating zones capable of individual control of the fuel flow rate,
Actual value detection means for detecting the heating furnace state value and outlet plate temperature as actual values;
Production information including a target value of the outlet plate temperature detected by the actual value detecting means, and a fuel flow rate calculating means for calculating a total fuel flow rate to be set in the heating furnace based on the detected actual value;
Predicting the plate temperature from the present to the future based on the transition of the plate temperature, furnace temperature, fuel flow rate from the past to the present, and the plate thickness, plate width, and plate feed speed from the present to the future. A rear material fuel flow rate calculating means for calculating in advance a fuel flow rate required for the rear material from the predicted future plate temperature of the rear material which is a plate-like body to be heated next to the front material, and the target plate temperature;
Flow distribution means for performing flow distribution including ignition and extinguishing of each heating zone by distributing the total fuel flow calculated by the fuel flow calculation means to a plurality of heating zones ;
When heating the plate-like body at the fuel flow rate calculated by the rear material fuel flow rate calculation means, it is determined whether the ignition / extinguishing operation is necessary. A plate temperature control device for a heating furnace, comprising: an ignition / extinguishment pre-determination means that performs ignition / extinguishment when a portion joining the rear material and the rear material passes through the heating zone. In the rear material fuel flow rate calculating means, the following equation:

5. The plate temperature control device for a heating furnace according to claim 4, wherein a total fuel flow rate required to heat the rear member to a predetermined temperature is calculated by using as an evaluation function.   The flow distribution means for performing flow distribution including ignition and extinguishing of each heating zone by allocating the total fuel flow calculated by the fuel flow calculation means to the plurality of heating zones. 5. A plate temperature control device for a heating furnace as described in 5. A computer that causes the computer to execute a step of controlling the outlet plate temperature of the plate-like body carried out of the heating furnace by controlling the ignition / extinguishing operation of the heating furnace including a plurality of heating zones capable of individually controlling the fuel flow rate. A program,
Actual value detection step of detecting the state value and outlet plate temperature of the heating furnace as actual values;
Production information including a target value of the outlet plate temperature detected in the actual value detection step, and a fuel flow rate calculation step for calculating a total fuel flow rate to be set in the heating furnace based on the detected actual value;
Predicting the plate temperature from the present to the future based on the transition of the plate temperature, furnace temperature, fuel flow rate from the past to the present, and the plate thickness, plate width, and plate feed speed from the present to the future. A rear material fuel flow rate calculating step for calculating in advance a fuel flow rate required for the rear material from the predicted future plate temperature of the rear material which is a plate-like body to be heated next to the front material, and the target plate temperature;
A flow distribution step of performing flow distribution including ignition and extinguishing of each heating zone by distributing the total fuel flow calculated by the fuel flow calculation step to a plurality of heating zones ;
When heating the plate-like body with the fuel flow rate calculated in the rear material fuel flow rate calculating step, it is determined whether or not the ignition / extinguishing operation is necessary. A computer program for causing a computer to execute an ignition / extinguishment predetermination step for performing ignition / extinguishment when a portion where the rear material and the rear material are joined passes through the heating zone.

Images