JP2007063641A - Method and apparatus for controlling speed in continuous heat treatment facility, and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To optimize the correlation between the variation of strip temperature and the central speed of the passing strip while keeping the strictness under considering a neck speed schedule based on the restricting conditions. <P>SOLUTION: A speed controlling apparatus is provided with: a neck speed schedule preparing part 2 for preparing the neck speed schedule to the distance, in which the strip 100 is advanced from the present position to x[m], based on the restricting conditions at respective heat treatment furnaces 200, 300, 400; a heating furnace simulator 3 for predicting the responsiveness of the strip temperature at the outlet side of the heating furnace 200 as to the restrictive speed schedules by preparing the speed schedule based on the speed changing timing and the speed changing rate in the plurality of beforehand prepared patterns under considering the upper limit value of the central speed and a bias value to the neck speed schedule based on the neck speed schedule; and a central speed search part 4 for deciding the speed changing timing and the speed changing rate by using an evaluation function containing the responsiveness of the strip temperature at the outlet side of the heating furnace 200 and the speed changing rate, as factors. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a speed control method, apparatus, and computer program for controlling the central speed of a sheet passing plate in continuous heat treatment equipment such as continuous hot dipping equipment and continuous annealing equipment.

  For example, in a metal manufacturing plant such as the steel industry, in a continuous heat treatment facility such as a continuous hot dip plating facility or a continuous annealing facility for a metal strip, a series of operations from the heating furnace entrance side to the alloying furnace exit side or from the heating furnace entrance side When controlling the central speed of the plate through to the heat treatment furnace exit side, it is necessary to determine a restricted speed schedule (referred to as “neck speed schedule” in this specification) based on constraints such as equipment capacity and manufacturing specifications. is there. When there are a plurality of constraint conditions, the minimum speed of the theoretical constraint speed obtained from each constraint condition is extracted as the neck speed schedule so as to satisfy all the constraint conditions.

  If the neck speed schedule is determined, the speed is changed at an appropriate acceleration / deceleration rate based on that schedule. However, if the speed is changed at a fixed acceleration / deceleration rate, the plate temperature will be within the upper and lower limits. May result in instability of the operation.

  At present, guidance level systems such as displaying the neck speed schedule on the screen have been constructed, but the final speed determination is based on the judgment of the operator.

  As a technique for controlling the plate passing speed in the continuous heat treatment equipment, for example, in Patent Document 1, steel that is passed through a continuous annealing furnace by automatically setting the acceleration / deceleration rate of the line speed based on the measured plate temperature. An automatic line speed acceleration / deceleration rate setting system is disclosed in which the line speed of a steel strip is changed at an appropriate acceleration / deceleration rate without causing the strip to go out of plate temperature.

  Further, Patent Document 2 discloses a central speed control of a continuous annealing line in which a step of calculating a constraining speed of a central speed based on restrictions due to furnace load combustion and a heat treatment method and a step of determining an acceleration / deceleration rate are performed. A method is disclosed.

  Further, in Patent Document 3, when the deviation between the estimated plate temperature change amount and the target plate temperature of the strip is out of the allowable range, the furnace temperature control of the heating furnace and the strip passing speed correction control are performed. A plate temperature control method in a continuous annealing furnace performed is disclosed.

JP 2003-226911 A JP-A-6-330182 JP-A-2-258933

  However, the line speed acceleration / deceleration rate automatic setting system disclosed in Patent Document 1 has a problem that the neck speed schedule based on the constraint condition is not considered.

  Further, in the central speed control method of the continuous annealing line disclosed in Patent Document 2, when determining the acceleration / deceleration rate, the limit speed (rate-control line) that does not fluctuate the plate temperature of each heat treatment furnace, which is found from experiments, is used. Since it is based on experiments, there is a problem of lack of strictness.

  Further, in the plate temperature control method disclosed in Patent Document 3, when the deviation between the estimated plate temperature change amount and the target plate temperature of the strip is outside the allowable range, the furnace temperature control of the heating furnace and the strip passage are performed. It is a technique for performing correction control of the plate speed, and is not a technique for determining the optimum operating condition by simultaneously calculating the plate temperature change amount and the speed change rate.

  The present invention has been made in view of the above points, while considering the neck speed schedule based on the constraint conditions, the plate temperature does not deviate from the upper and lower limits, and while maintaining strictness, the plate temperature change amount and The purpose is to determine the best operating conditions as much as possible by calculating the speed change rate at the same time.

The speed control method of the continuous heat treatment equipment according to the present invention is a speed control method for controlling the central speed of the sheet passing in the continuous heat treatment equipment, and the metal strip is currently used based on the constraints in the continuous heat treatment equipment. A neck speed schedule creation procedure for creating a neck speed schedule while traveling a predetermined distance from the base, and a neck speed schedule created by the neck speed schedule creation procedure based on the speed change timing and speed change rate of a plurality of patterns A speed schedule is created based on the simulation procedure for predicting the plate temperature with a simulator simulating a predetermined heat treatment furnace included in the continuous heat treatment facility for each speed schedule, and the results obtained by the simulation procedure are included as elements. Use the evaluation function to Characterized in that it executes the central speed search procedure to determine the change timing and the speed change rate.
Another feature of the speed control method for the continuous heat treatment facility according to the present invention is that the upper limit value of the central speed of the plate and the bias value for the neck speed schedule can be input from the operator. In consideration of the upper limit value of the central speed and the bias value for the neck speed schedule, the speed schedule is created based on the speed change timings and speed change rates of a plurality of patterns prepared in advance.
The speed control device for a continuous heat treatment facility according to the present invention is a speed control device for controlling the central speed of the plate in the continuous heat treatment facility, and the metal strip is currently used based on the constraint conditions in the continuous heat treatment facility. A neck speed schedule creating means for creating a neck speed schedule while traveling a predetermined distance from the base, and a neck speed schedule created by the neck speed schedule creating means based on the speed change timing and speed change rate of a plurality of patterns A speed schedule is created based on the simulation means for predicting the plate temperature by a simulator simulating a predetermined heat treatment furnace included in the continuous heat treatment facility for each speed schedule, and the result obtained by the simulation means is included as an element Use the evaluation function to It has a feature in that a central speed search means for determining the change timing and the speed change rate.
Another feature of the speed control apparatus for continuous heat treatment equipment according to the present invention is that the simulation means further comprises an input means for allowing an operator to input an upper limit value of the central speed of the plate and a bias value for the neck speed schedule. Then, in consideration of the input upper limit value of the central speed and the bias value for the neck speed schedule, the speed schedule is created based on the speed change timings and speed change rates of a plurality of patterns prepared in advance.
The computer program according to the present invention is a computer program for causing a computer to execute a process for controlling the central speed of the sheet passing in the continuous heat treatment equipment, and the metal strip is currently used based on the constraints in the continuous heat treatment equipment. Based on a neck speed schedule creation process for creating a neck speed schedule while traveling for a predetermined distance, and a neck speed schedule created by the neck speed schedule creation process, based on a speed change timing and a speed change rate of a plurality of patterns A speed schedule is created for each speed schedule, and a simulation process for predicting a plate temperature by a simulator simulating a predetermined heat treatment furnace included in the continuous heat treatment facility, and a result obtained by the simulation process are elements. Using an evaluation function including to have features a central speed search process for determining the speed change timing and the speed change rate to the point to be executed by a computer.

  According to the present invention, it is possible to calculate the plate temperature change amount and the speed change rate at the same time while maintaining the strictness by performing the simulation with the simulator simulating the heat treatment furnace while considering the neck speed schedule based on the constraint conditions. The best operating conditions can be determined.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Although only an outline is shown in FIG. 2, it is an example of a continuous heat treatment facility in which a metal strip (strip) 100 such as a steel material is continuously passed through a heating furnace 200, a soaking furnace 300, and an alloying furnace 400.

  In FIG. 1, the structure of the speed control apparatus of the continuous heat processing equipment to which this invention is applied is shown. The speed control apparatus of this embodiment controls the central speed of the threading plate in the continuous heat treatment facility shown in FIG.

  Reference numeral 1 denotes an input unit for the operator to input the upper limit value of the central speed of the plate and the bias value for the neck speed schedule. FIG. 3 shows an operator intervention operation panel as an example of the input unit 1. Here, an arbitrary upper limit [mpm] and an arbitrary bias value in the range of 0 to −100 [mpm] can be input.

  Reference numeral 2 denotes a neck speed schedule creation unit, which creates a neck speed schedule while the strip 100 travels x [m] from the present, based on the constraint conditions in the heat treatment furnaces 200, 300, and 400 of the continuous heat treatment equipment.

  3 is a furnace simulator, based on the neck speed schedule created by the neck speed schedule creation unit 2, considering the upper limit value of the central speed input from the input unit 1 and the bias value for the neck speed schedule. A speed schedule is created based on a plurality of patterns of speed change timings and speed change rates prepared in advance, and the responsiveness of the outlet side plate temperature of the heating furnace 200 is predicted by simulation for each speed schedule.

  Reference numeral 4 denotes a central speed search unit, which determines a speed change timing and a speed change rate that are considered to be optimal, using an evaluation function including the responsiveness of the outlet side plate temperature of the heating furnace 200 and the speed change rate as elements. Based on the determined speed change timing and speed change rate, the speed control of the threading plate in the continuous heat treatment facility is executed.

  Reference numeral 5 denotes a display device that visually displays, for example, a neck speed schedule created by the neck speed schedule creation unit 2 and a plurality of speed schedules created by the furnace simulator 3. Thereby, the improvement of the operation guidance function with respect to an operator is implement | achieved.

  FIG. 4 is a flowchart for explaining the speed control processing operation of the continuous heat treatment facility in the present embodiment.

  First, in step S <b> 1, the neck speed schedule creation unit 2 calculates theoretical constraint speeds in the heating furnace 200, the soaking furnace 300, and the alloying furnace 400.

For example, the theoretically limited speed VC _HF based on the heating capacity in the equipment specifications in the heating furnace 200 is calculated using an appropriate mathematical model f ₁ as shown in the following formula (1).
VC _HF = f ₁ (TPH, ρ, WD, TH, VR) (1)
However, TPH: T / H [ton / hour], ρ: specific gravity [ton / m ³ ], WD: plate width [m], TH: plate thickness [m], VR: speed achievement rate [−].

The theoretically limited speed VC _RSF based on the soaking time in the equipment specifications in the soaking furnace 300 is calculated using an appropriate mathematical model f ₂ as shown in the following formula (2).
VC _RSF = f ₂ (PL _RSF , Tref _RSF ) (2)
However, PL _RSF : soaking furnace path length [m], Tref _RSF : soaking time [sec].

Further, the theoretically constrained speed VC _HO based on the alloying time in the equipment specifications in the alloying furnace 400 is calculated using an appropriate mathematical model f ₃ as shown in the following formula (3).
VC _HO = f ₃ (PL _HO , Tref _HO ) (3)
However, PL _HO : alloying furnace path length [m], Tref _HO : alloying time [sec].

Next, in step S2, the neck speed schedule creation unit 2 strips the current strip based on the theoretically constrained speeds VC _HF , VC _RSF , and VC _HO in the heat treatment furnaces 200, 300, and 400 calculated in step S1. Create a neck speed schedule while 100 progresses x [m].

Specifically, as shown in FIG. 5 (a), the theoretical limitation speed VC _HF at each heat treatment furnace 200, 300, 400, VC _RSF, so as to satisfy all the VC _HO, theoretical constraint velocity VC _HF, VC _RSF , And extract the minimum speed of VC _HO as the neck speed schedule VC _min .

Next, in step S3, the furnace simulator 3 sets the upper limit value of the central speed input from the input unit 1 and the bias value for the neck speed schedule based on the neck speed schedule VC _min created in step S2. In consideration, a speed schedule V is created based on a plurality of patterns of speed change timings and speed change rates prepared in advance, and the responsiveness of the exit side plate temperature of the heating furnace 200 is predicted by simulation for each speed schedule V. .

Specifically, as shown in FIG. 5B, the neck speed schedule VC _min created in step S <b> 2 is lowered by the bias value input from the input unit 1 and input from the input unit 1. Cut the part that exceeds the upper limit (see dotted line in the figure). Then, a plurality of speed schedules V are created based on a plurality of speed change timings and speed change rates prepared in advance. FIG. 5B shows an example of how the speed change rate is changed.

  In the present embodiment, as the response of the outlet side plate temperature of the heating furnace 200 predicted by the heating furnace simulator 3, as shown in FIG. 6, the target plate of the outlet side plate temperature of the heating furnace 200 for each of a plurality of speed schedules V. An error prediction value ΔTS (t) [° C.] for temperature is obtained. The target plate temperature of the outlet side plate temperature of the heating furnace 200 is determined by a process computer (not shown) according to a production schedule.

  FIG. 7 shows an outline of the furnace simulator 3. In the heating furnace simulator 3 of the present embodiment, a radiant tube temperature model 701, a furnace temperature model 702, a hearth roll temperature model 703, a plate temperature model 704, and a furnace wall temperature model 705 represented by the following formulas 1 to 5 are constructed. Then, the heat treatment in the heating furnace 200 is simulated using these mathematical models, and the estimated error value ΔTS (t) [° C.] of the outlet side plate temperature of the heating furnace 200 is obtained for each of the plurality of speed schedules V.

  In the present embodiment, since the plate temperature change of the heating furnace 200 among the heat treatment furnaces 200, 300, and 400 is important in operation, a simulator simulating the heating furnace 200 is constructed. You may make it construct | assemble a simulator about the heat processing furnace 200,300,400.

  FIG. 8 is a diagram for creating a speed schedule V based on a plurality of patterns of speed change timings and speed change rates in step S3, and predicting the responsiveness of the outlet side plate temperature of the heating furnace 200 for each speed schedule V by simulation. It is a flowchart for explaining a processing operation in detail.

  For example, it is assumed that the speed change timing pattern α (i) is prepared from i = 0 to N, and the speed change rate pattern β (j) is prepared from j = 0 to M.

Initially, starting from i = 0 (step S301), a speed change timing pattern α (i) is set (step 302), a speed change rate pattern β (i) of j = 0 is set, and ΣΔ
TS (t) ² is obtained and stored in the database (steps S303 to S305).

  Next, 1 is added to j (step S306), and steps S302 to S305 are repeated until j becomes maximum, that is, j = M (step S307).

  Thereafter, 1 is added to i (step S308), and steps S302 to S308 are repeated until i becomes maximum, i.e., i = N (step S309).

Through the processing described above, a speed schedule V is created based on a plurality of patterns of speed change timing (i = 0 to N) and speed change rate (j = 0 to M), and ΣΔTS (t) for each speed schedule V ² can be obtained.

Next, in step S4, the central speed search unit 4 uses the evaluation function J _s including the responsiveness (error predicted value ΔTS (t)) of the outlet side plate temperature of the heating furnace 200 and the speed change rate as elements, Determine the speed change timing and speed change rate that are considered optimal.

Specifically, ΣΔTS (t) ² calculated in step S3 and the speed change rate V _{ra
Based on te} [mpm / sec] and an appropriate weight w [−], a speed change timing and a speed change rate at which the evaluation function J _s configured by the following equation (4) takes the minimum value are determined.
J _s = ΣΔTS (t) ² + w · (1 / V _rate ) (4)

  Then, the speed control of the threading plate in the continuous heat treatment facility is executed based on the speed change timing and the speed change rate determined in step S4.

  As described above, the correlation between the plate temperature change amount and the central velocity of the plate is maintained while maintaining the rigorousness by performing the simulation with the simulator simulating the heating furnace 200 while considering the neck velocity based on the constraint condition. Optimization can be achieved.

  Note that the speed control apparatus of the above-described embodiment is specifically configured by a computer system or apparatus. Accordingly, a storage medium storing software program codes for realizing the functions described above is supplied to the system or apparatus, and a computer (or CPU or MPU) of the system or apparatus reads and executes the program codes stored in the storage medium. Needless to say, this can be achieved.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code itself and the storage medium storing the program code constitute the present invention. As a storage medium for supplying the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

It is a figure which shows the structure of the central speed control apparatus of the continuous heat processing equipment of this embodiment. It is a figure for demonstrating the outline | summary of the continuous heat processing equipment of this embodiment. It is a figure which shows an operator intervention operation panel. It is a flowchart for demonstrating the processing operation | movement of the speed control of a continuous heat processing equipment. It is a figure which shows the relationship between a travel distance and speed, (a) is a figure which shows a mode that a neck speed schedule is created, (b) is a figure which shows a mode that a speed schedule is created. It is a figure which shows the relationship between time and plate temperature. It is a figure which shows the outline | summary of a heating furnace simulator. It is a flowchart for demonstrating the processing operation | movement for creating the speed schedule based on the speed change timing and speed change rate of several patterns, and predicting the responsiveness of a heating furnace exit side plate temperature by simulation about each speed schedule.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Input part 2 Neck speed schedule preparation part 3 Heating furnace simulator 4 Central speed search part 5 Display apparatus 100 Metal strip 200 Heating furnace 300 Soaking furnace 400 Alloying furnace

Claims (5)

A speed control method for controlling the central speed of the threading plate in a continuous heat treatment facility,
Based on the constraints in the continuous heat treatment facility, a neck speed schedule creation procedure for creating a neck speed schedule while the metal strip travels a predetermined distance from the present time;
Based on the neck speed schedule created by the neck speed schedule creation procedure, a speed schedule is created based on a plurality of speed change timings and speed change rates, and each speed schedule is included in the predetermined heat treatment facility. Simulation procedure for predicting the plate temperature with a simulator simulating the heat treatment furnace of
A speed control method for a continuous heat treatment facility, wherein a central speed search procedure for determining a speed change timing and a speed change rate is executed using an evaluation function including a result obtained by the simulation procedure as an element. The operator can input the upper limit value of the central speed of the plate and the bias value for the neck speed schedule from the operator.
In the simulation procedure, the speed schedule is created based on the speed change timings and speed change rates of a plurality of patterns prepared in advance in consideration of the input upper limit value of the central speed and the bias value for the neck speed schedule. The speed control method for continuous heat treatment equipment according to claim 1, wherein A speed control device for controlling the central speed of the plate in a continuous heat treatment facility,
Neck speed schedule creating means for creating a neck speed schedule while the metal strip travels a predetermined distance from the present, based on the constraints in the continuous heat treatment facility;
Based on the neck speed schedule created by the neck speed schedule creating means, a speed schedule is created based on a plurality of speed change timings and speed change rates, and each speed schedule is included in the continuous heat treatment facility. Simulation means for predicting the plate temperature by a simulator simulating the heat treatment furnace of
A speed control apparatus for continuous heat treatment equipment, comprising: a central speed search means for determining a speed change timing and a speed change rate using an evaluation function including a result obtained by the simulation means as an element. Further comprising an input means by which an operator can input an upper limit value of the central speed of the plate and a bias value for the neck speed schedule,
The simulation means creates a speed schedule based on a plurality of patterns of speed change timings and speed change rates prepared in advance in consideration of the input upper limit value of the central speed and a bias value for the neck speed schedule. The speed control apparatus for a continuous heat treatment facility according to claim 3. There is a computer program for causing a computer to execute a process for controlling the central speed of the plate in a continuous heat treatment facility,
Based on the constraints in the continuous heat treatment facility, a neck speed schedule creation process for creating a neck speed schedule while the metal strip travels a predetermined distance from the present time;
Based on the neck speed schedule created by the neck speed schedule creation process, a speed schedule is created based on a plurality of patterns of speed change timings and speed change rates, and each speed schedule is included in the predetermined heat treatment facility. Simulation processing to predict the plate temperature by a simulator simulating the heat treatment furnace of
A computer program for causing a computer to execute a central speed search process for determining a speed change timing and a speed change rate using an evaluation function including a result obtained by the simulation process as an element.

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