JP5000361B2 - Method, apparatus, and computer program for controlling plate temperature in continuous processing line - Google Patents

Description

  The present invention relates to a plate temperature control technique in a continuous processing line such as a continuous hot dip galvanizing line.

  In general, in a continuous processing line, a strip drawn from a coil wound on a payoff reel (POR) on the line entry side is passed through various facilities on the line in order, and after all processing is completed, tension is applied. Wind up with reel (TR). For example, in a continuous hot dip galvanizing line, a cooling zone, plating equipment, etc. are installed on the line, and strips pass continuously through all these equipment. Although the strip length of each coil is finite, the end of the next coil is welded to the end of the next coil so that the strip is processed continuously on the line. On the exit side, when the winding of one coil is completed, the vicinity of the end of the strip is cut, and the strip following the cutting point is wound as another coil.

  In the case of no change in the plate passing condition (normal time) in the patent document 1 or the like, the applicant of the present application performs feedback calculation based on the deviation between the target plate temperature and the actual plate temperature, controls the blower rotation speed, and performs welding. A plate temperature cooling control method has been proposed in which a feedforward calculation is performed by a plate temperature control model based on a steady solution to control the number of rotations of the blower at the time of passing a point, changing the plate speed, or changing the target plate temperature.

JP 2005-220432 A

  Rather than lowering the steel sheet temperature to the target temperature using only the cooling blower, the temperature control is achieved by lowering the steel sheet temperature below the target temperature once with the cooling blower and then heating it to the target temperature with the induction heater. It becomes easier to do. Thus, there is no proposal for improving the control accuracy of the plate temperature in the continuous processing line including the cooling zone for cooling the steel plate by the blower and the induction heater for heating the steel plate after the cooling zone.

  The present invention improves plate temperature control accuracy in a continuous processing line including a cooling zone that continuously cools a plurality of steel plates by a blower, and an induction heater that heats the steel plates at a later stage of the cooling zone. For the purpose.

The plate temperature control method of the present invention is a plate temperature control method in a continuous processing line comprising a cooling zone that continuously cools a plurality of steel plates by a blower, and an induction heater that heats the steel plate at a subsequent stage of the cooling zone. In this case, it is determined whether or not any of the coil width, thickness, and induction heater outlet side target plate temperature is changed, and any of the coil width, plate thickness, and induction heater outlet side target plate temperature is determined. When it is determined that there is such a change, the calculation procedure for calculating the induction heater inlet side plate temperature in the steel plate before the change of any one of the plate width of the coil, the plate thickness, and the induction heater outlet side target plate temperature , plate width of the coil, plate thickness, and a calculation procedure for calculating the induction heater inlet side target metal temperature in the steel sheet after any changes induction heater exit side target metal temperature before A procedure for outputting the induction heater input side target plate temperature calculated by the calculation procedure as a command value to the induction heater, the induction heater input side plate temperature calculated by the calculation procedure, and the induction heater calculated by the calculation procedure A procedure for obtaining and outputting a rotational speed command value of the blower based on the inlet side target plate temperature is performed.
The plate temperature control device of the present invention is a plate temperature control device in a continuous processing line comprising a cooling zone that continuously cools a plurality of steel plates by a blower, and an induction heater that heats the steel plate at a subsequent stage of the cooling zone. And determining means for determining whether or not any of the coil width, plate thickness, and induction heater outlet side target plate temperature has been changed, and the coil width, plate thickness, and induction heater outlet side target plate of the coil If it is determined that there are any changes in temperature, the plate width of the coil, the plate thickness, and operation for calculating the induction heater entrance side temperature in the steel sheet prior to any changes of the induction heater exit side target plate temperature means and, in the coil plate width, thickness, and if it is determined that there are any changes of the induction heater exit side target metal temperature of the coil plate width, thickness, and inductor Calculating means for calculating an induction heater inlet side target metal temperature in Deployment heater exit side target plate steel sheet after any changes temperature, the induction heater inlet side target plate temperature calculated by said calculating means to said induction heater Based on the output means for outputting as a command value, the induction heater inlet side plate temperature calculated by the calculator, and the induction heater inlet side target plate temperature calculated by the calculator, the rotational speed command value of the blower is calculated. Output means for obtaining and outputting.
A computer program according to the present invention is for controlling a plate temperature in a continuous processing line including a cooling zone that continuously cools a plurality of steel plates by a blower, and an induction heater that heats the steel plates at a later stage of the cooling zone. A computer program for determining whether or not any of the coil width, thickness, and induction heater outlet side target plate temperature has been changed, and determining the coil width, thickness, and induction heater outlet side target plate temperature of the coil. When it is determined that there is any change, the calculation processing for calculating the induction heater inlet side plate temperature in the steel plate before the change of any one of the coil width, plate thickness, and induction heater outlet side target plate temperature When the plate width of the coil, thickness, and induction heater exit side target plate temperature either induction heater in steel sheet after change A calculation process for calculating the side target plate temperature, a process for outputting the induction heater input side target plate temperature calculated by the calculation process as a command value to the induction heater, and an induction heater input side plate calculated by the calculation process The computer is caused to execute a process of obtaining and outputting a rotation speed command value of the blower based on the temperature and the induction heater input side target plate temperature calculated by the calculation process.

According to the present invention, in a continuous processing line including a cooling zone that continuously cools a plurality of steel plates by a blower, and an induction heater that heats the steel plates at a subsequent stage of the cooling zone , It is possible to improve the control accuracy of the plate temperature including when changing either the thickness or the target plate temperature on the outlet side of the induction heater .

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 shows a partial configuration of a continuous hot dip galvanizing line as an example of an embodiment to which the present invention can be applied. On the line, a cooling zone 101 that cools the steel plate 100 by the cooling blower 102, an induction heater (IH) 103 that heats the steel plate 100 at the subsequent stage of the cooling zone 101, and a steel plate 100 that is plated at the subsequent stage of the IH 103 are not shown. A plating facility is installed.

  As shown in FIG. 2, after the plate temperature of the steel plate 100 is once lowered from the target temperature T in the cooling zone 101, it is heated to the target temperature T by the IH 103. This is because the IH 103 is superior in temperature control responsiveness, follow-up performance, and the like as compared with temperature control by a heat release process in the cooling zone 101 (cooling blower 102), and temperature management is easy. Especially in the continuous hot dip galvanizing line, the plate temperature before plating has a great influence on the quality, and it is required to strictly control the plate temperature. Therefore, after the plate temperature of the steel plate 100 is once lowered from the target temperature T, The effect of the method of heating to the target temperature T with IH103 is great.

  As shown in FIG. 1, plate thermometers 104 and 105 are arranged on the inlet side of the cooling zone 101 and on the outlet side of the IH 103.

  In FIG. 3, the structure of the plate temperature control apparatus 10 contained in the process computer which controls the continuous hot-dip galvanizing line of this embodiment is shown. The plate temperature control device 10 includes a feed forward (FF) control unit 11, a feedback (FB) control unit 12, an IH input side target plate temperature calculation unit 13, and an IH input side plate temperature estimation calculation unit 14.

  Substrate result information such as the blower actual revolution, IH actual power, and IH outlet actual plate temperature is externally input to the plate temperature control device 10. Also, tracking information such as coil welding point position and line speed, and schedule information such as IH outlet side target plate temperature (pre-plating target temperature), material plate thickness, and material plate width are input.

  As will be described in detail later, the plate temperature control device 10 performs arithmetic processing based on the input information described above, and outputs the blower rotation speed and the IH input side target plate temperature as lower order command values.

  The plate temperature is controlled by an IH controller (not shown) that receives the IH input target plate temperature obtained by the plate temperature control device 10, the IH output side target plate temperature included in the schedule information, and the IH output obtained by the plate thermometer 105. Based on the actual side plate temperature or the like, the value of the current flowing through the electromagnetic induction coil of the IH 103 is controlled.

  The plate temperature is controlled by the process computer changing the blower rotational speed. The process computer normally uses the IH input side target plate temperature calculated by the IH input side target plate temperature calculation unit 13 of the plate temperature control device 10 and the IH input side plate temperature estimation calculation unit 14 of the plate temperature control device 10. The blower rotational speed is controlled by feedback control based on the deviation from the estimated IH inlet side plate temperature. On the other hand, when the plate passing condition is changed (coil change, IH outlet side target plate temperature change), the plate temperature control device 10 recalculates the IH inlet side target plate temperature, and the feedforward control performs the blower rotation speed. To control.

  FIG. 4 is a flowchart for explaining the processing operation by the plate temperature control device 10. The plate temperature control device 10 determines whether or not the plate passing conditions (coil change, IH outlet side target plate temperature change) are changed (step S101), and depending on the result, the processing of steps S102 to S106, or Steps S107 to S109 are performed.

When it is determined in step S101 that there is a change in the sheet passing condition, specifically, the welding point on the front side of the coil having a different sheet passing condition, that is, the processing condition passes through the plate thermometer 104, or the IH outlet target If there is a change in the plate temperature, in step S102, the IH input side plate temperature is calculated by the formula f based on the heat transfer model using the IH output side actual plate temperature and the IH actual power, line speed, material plate thickness, and material plate width. Is calculated. This IH inlet side plate temperature is the temperature in the steel plate before the passage condition is changed on the inlet side of IH 103 (point A in FIG. 1), that is, the plate temperature relating to the current coil. Formula (1) shows an estimated calculation formula for the IH inlet side plate temperature T _{Si — hat} . The material thickness TH, the material width WD, and the like here are values of the current coil at the point A.

  Next, in step S103, the IH inlet side target plate temperature is calculated using the IH outlet side target plate temperature, material plate thickness, material plate width, and line speed, and stored in a memory (not shown). This IH entry side target plate temperature is the temperature applied to the steel plate after the passage condition is changed on the entry side of IH 103 (point A in FIG. 1), that is, the plate temperature related to the next coil. Expressions (2) and (3) show expressions based on the formula g based on the heat transfer model used to derive the IH inlet side target plate temperature as shown below. The material thickness TH, the material width WD, and the like here are values of the next coil to be conveyed to the point A from now on.

Here, when the output power P is P _min (lower limit power) <P <P _max (upper limit power), the change of the IH temperature increase amount α is not performed.

On the other hand, in the case of P <P _min and P> P _max , an inverse calculation of the IH temperature rise α is performed using a value obtained by clamping the output power P to the upper limit power P _max or the lower limit power P _min (formula ( 2), (3)).

And by calculating the following formula, the IH 103 can be stably used with power in a certain range (P _{min to} P _max ). Note that these P _min (lower limit power) and P _max (upper limit power) do not mean the upper and lower limits of the IH 103, but are appropriately set.
IH inlet side target plate temperature = IH outlet side target plate temperature-α

  Next, in step S104, the IH inlet side target plate temperature calculated in step S103 is output as a command value to an IH controller (not shown).

  In steps S105 and S106, FF calculation is performed based on the IH inlet side plate temperature calculated in step S102 and the IH inlet side target plate temperature calculated in step S103, and the blower rotational speed command value is set. Find and output.

  On the other hand, if it is determined in step S101 that there is no change in the sheet passing conditions (normally), in step S107, from the above equation (1), the IH delivery side actual plate temperature, IH actual power, line speed, material plate The IH inlet side plate temperature is calculated using the thickness and the material plate width.

  Next, in steps S108 and S109, based on the IH inlet side plate temperature calculated in step S107 and the IH inlet side target plate temperature calculated in the previous change of the passing plate condition and stored in the memory, FB ( (Feedback) is calculated and a blower rotation speed command value is obtained and output.

  Note that the series of processing in steps S101 to S109 may be executed periodically (for example, every 20 seconds) or in a pattern of preset time intervals. Also, it may be executed when a weld point detector (not shown), which is installed near the plate thermometer 104, for example, includes a light source and a light receiver facing each other with a coil interposed therebetween, is detected. good.

  As described above, since the IH inlet side plate temperature is estimated and calculated, blower rotation speed control can be performed without a plate thermometer, and the control accuracy of the IH outlet side plate temperature can be improved.

  Further, in normal times, the blower rotation speed is controlled by feedback control based on a deviation between the IH input side target plate temperature obtained by the plate temperature control device 10 and the IH input side plate temperature estimated by the plate temperature control device 10. On the other hand, when changing the plate feed conditions (coil change, IH outlet side target plate temperature change), the plate temperature control device 10 recalculates the IH inlet side target plate temperature, and the feedforward control is used to set the blower rotational speed. Since the control is performed, the control accuracy of the plate temperature can be improved not only in normal times but also in the transition period (when the plate passing condition is changed).

  FIG. 5 shows a hardware configuration example of a computer system that can function as the plate temperature control device 10. The computer system includes a CPU 50, an input device 51, a display device 52, and a storage device 53, and each unit is connected via a bus 54. The storage device 53 includes a ROM, a RAM, an HD, and the like, and stores a computer program for controlling the operation as the process computer described above. The function or processing of the plate temperature control device is realized by the CPU 50 executing the computer program. In addition, the plate temperature control apparatus 10 may be comprised by one computer apparatus, and may be comprised by several computer apparatus.

  It goes without saying that the object of the present invention can also be achieved by a computer (or CPU or MPU) executing a computer program that causes a computer to realize the functions of the plate temperature control device. In this case, the computer program itself read from the storage medium and the storage medium storing the computer program constitute the present invention. As a storage medium for supplying the computer program, 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 partial structure of the continuous hot-dip galvanizing line of embodiment. It is a characteristic view which shows an example of the plate | board temperature control in the continuous hot-dip galvanizing line of embodiment. It is a figure which shows the structure of the plate temperature control apparatus in the continuous hot-dip galvanizing line of embodiment. It is a flowchart explaining the processing operation by the plate temperature control apparatus of embodiment. It is a figure which shows the hardware structural example of a computer system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Plate temperature control apparatus 11 Feed forward (FF) control part 12 Feedback (FB) control part 13 IH input side target plate temperature calculation part 14 IH input side plate temperature estimation calculation part 100 Steel plate 101 Cooling zone 102 Cooling blower 103 Induction heater 104 Plate Thermometer 105 Plate thermometer

Claims (4)

A plate temperature control method in a continuous processing line comprising a cooling zone that continuously cools a plurality of steel plates by a blower, and an induction heater that heats the steel plate at a subsequent stage of the cooling zone,
It is determined whether or not any of the coil width, plate thickness, and induction heater outlet side target plate temperature is changed , and any change in the coil width, plate thickness, and induction heater outlet side target plate temperature is changed. If it is determined that there is
Calculation procedure for calculating the induction heater inlet side plate temperature in the steel plate before the change of any one of the coil width, plate thickness, and induction heater outlet side target plate temperature ;
Calculation procedure for calculating the induction heater inlet side target plate temperature in the steel plate after changing any of the coil width, plate thickness, and induction heater outlet side target plate temperature ;
A procedure for outputting the induction heater input side target plate temperature calculated by the calculation procedure as a command value to the induction heater;
Performing a procedure for obtaining and outputting the rotational speed command value of the blower based on the induction heater inlet side plate temperature calculated by the calculation procedure and the induction heater inlet side target plate temperature calculated by the calculation procedure. The plate temperature control method characterized by this. When it is determined that there is no change in the coil width, thickness, and induction heater target temperature on the coil ,
Calculation procedure for calculating the induction heater inlet side plate temperature,
The induction heater inlet side plate temperature calculated by the above calculation procedure and the induction heater inlet side target plate temperature calculated when any of the previous coil width, plate thickness, and induction heater outlet side target plate temperature is changed. The plate temperature control method according to claim 1, wherein a procedure for obtaining and outputting a rotational speed command value of the blower is performed based on the procedure. A plate temperature control device in a continuous processing line comprising a cooling zone that continuously cools a plurality of steel plates by a blower, and an induction heater that heats the steel plates at a later stage of the cooling zone,
A determination means for determining whether or not any of the coil width, the plate thickness, and the induction heater outlet side target plate temperature is changed;
When it is determined that any of the coil width, the plate thickness, and the induction heater outlet side target plate temperature is changed , any of the coil width, the plate thickness, and the induction heater outlet side target plate temperature is determined. calculating means for calculating an induction heater entrance side temperature in Kano before the change of the steel sheet,
When it is determined that any of the coil width, the plate thickness, and the induction heater outlet side target plate temperature is changed , any of the coil width, the plate thickness, and the induction heater outlet side target plate temperature is determined. calculating means for calculating an induction heater inlet side target metal temperature in the steel sheet after Kano change,
An output means for outputting the induction heater input side target plate temperature calculated by the calculation means as a command value to the induction heater;
Output means for obtaining and outputting a rotation speed command value of the blower based on the induction heater inlet side plate temperature calculated by the calculator and the induction heater inlet side target plate temperature calculated by the calculator. A plate temperature control device characterized by that. A computer program for controlling a plate temperature in a continuous processing line comprising a cooling zone for continuously cooling a plurality of steel plates by a blower, and an induction heater for heating the steel plates at a later stage of the cooling zone,
It is determined whether or not any of the coil width, plate thickness, and induction heater outlet side target plate temperature is changed , and any change in the coil width, plate thickness, and induction heater outlet side target plate temperature is changed. If it is determined that there is
Arithmetic processing for calculating the induction heater inlet side plate temperature in the steel plate before changing any of the coil width, plate thickness, and induction heater outlet side target plate temperature ;
Arithmetic processing for calculating the induction heater inlet side target plate temperature in the steel plate after changing any of the coil width, plate thickness, and induction heater outlet side target plate temperature ;
Processing for outputting the induction heater target side plate temperature calculated by the calculation processing as a command value to the induction heater;
Based on the induction heater inlet side plate temperature calculated by the calculation process and the induction heater inlet side target plate temperature calculated by the calculation process, a process for obtaining and outputting the rotation speed command value of the blower to the computer A computer program to be executed.

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