JPWO2018055718A1 - Edge heater control device - Google Patents

Abstract

The edge heater control device (3) includes a first temperature distribution prediction unit (33), a second temperature distribution prediction unit (34), and a supply energy calculation unit (32). The first temperature distribution prediction unit (33) is a temperature distribution in the width direction (first temperature distribution) of the rolled material (1) on the outlet side of the edge heater based on a temporary value indicating the electric energy supplied to the edge heater (23). Predict. The second temperature distribution prediction unit (34) predicts the width direction temperature distribution (second temperature distribution) of the rolled material (1) on the exit side of the rolling stand (24) based on the first temperature distribution. The supply energy calculation unit (32) includes an edge heater (23) that is necessary for satisfying the temperature condition regarding the width direction end of the second temperature distribution before the rolled material (1) reaches the edge heater (23). ) Is calculated to indicate the electric energy to be supplied.

Description

  The present invention relates to an edge heater control device for an edge heater that heats the widthwise end of a rolled material.

  In a rolling line, in particular, a hot rolling line, an edge heater is used to heat a width direction end (plate width direction end) of a rolled material. The temperature at the end in the width direction tends to decrease, and the metal material such as strength and ductility decreases when the temperature decreases. The purpose of heating the end portion in the width direction by the edge heater is to obtain a uniform material over the entire plate width direction of the rolled material. In addition, with materials such as stainless steel, cracks may occur at the width direction end due to a decrease in temperature at the width direction end, which may impair rolling stability or cause the product to become defective. In order to prevent this, the rolled material is heated and heated by an edge heater.

  Japanese Patent Application Laid-Open No. 2015-147216 (Patent Document 1) is a patent document that describes accurate calculation of the temperature distribution in the sheet width direction of a rolled material using a difference method in hot rolling. Patent Document 1 discloses a temperature distribution prediction device that approximately calculates a temperature distribution in the width direction based on a temperature calculation value at a central portion of the plate width.

Japanese Unexamined Patent Publication No. 2015-147216

  The temperature at the end in the width direction of the rolled material is likely to be lower than that at the center in the width direction, and the material is likely to deteriorate. In order to improve it, an edge heater is installed in the rolling line. However, the heating control with the conventional edge heater is only for heating the rolled material with electric power determined by trial and error, and the temperature at the end in the width direction of the rolled material on the rolling stand exit side, which has a large effect on the material. The decrease could not be sufficiently suppressed.

  The present invention has been made to solve the above-described problems, and is necessary for satisfying the temperature condition of the end in the width direction of the rolled material on the exit side of the rolling stand before the rolled material reaches the edge heater. Another object of the present invention is to provide an edge heater control device capable of determining the electrical energy to be supplied to the edge heater.

In order to achieve the above object, the present invention is provided with at least one edge heater that heats the widthwise end of the rolled material by receiving the supply of electrical energy according to the indicated value, and at the downstream side of the edge heater. An edge heater control device for a rolling line having a rolling stand,
A first temperature distribution prediction unit for predicting a width direction temperature distribution (first temperature distribution) of the rolled material on the outlet side of the edge heater, based on a temporary value indicating electric energy supplied to the edge heater;
A second temperature distribution prediction unit that predicts a width direction temperature distribution (second temperature distribution) of the rolled material on the rolling stand exit side based on the first temperature distribution;
Before the rolled material reaches the edge heater, the instruction value indicating the electric energy to be supplied to the edge heater, which is necessary for satisfying the temperature condition regarding the end in the width direction of the second temperature distribution, is calculated. And a supply energy calculation unit.

  According to the present invention, before the rolled material reaches the edge heater, it is possible to determine the electrical energy to be supplied to the edge heater, which is necessary to satisfy the temperature condition of the width direction end of the rolled material on the rolling stand exit side. . Therefore, according to this invention, the fall of the material in the rolling stand exit side can be suppressed.

1 is a schematic diagram showing a system configuration of a rolling line according to Embodiment 1. FIG. 3 is a functional block diagram of an edge heater control device 3 according to Embodiment 1. FIG. It is a flowchart of the routine which the 1st supply energy calculation part 32 and the 2nd temperature distribution prediction part 34 perform. It is a flowchart of the routine which the 1st supply energy calculation part 32 and the 1st temperature distribution prediction part 33 perform. 1 is a cross-sectional view showing a cross section perpendicular to the longitudinal direction of a rolled material 1. It is a graph which shows an example which calculated the temperature of the rolling material 1 in the 2nd temperature distribution estimation part 34. FIG. It shows how the mesh is cut for analysis by the finite element method. It is a figure which shows an example of the edge heater temperature calculation simple model. 6 is a functional block diagram of an edge heater control device 3 according to Embodiment 2. FIG. 7 is a flowchart of a routine executed by the edge heater control device 3 according to the second embodiment. It is a graph for demonstrating an example of the relationship between the electrical energy supplied to the edge heater 23, and the temperature of the width direction edge part of 2nd temperature distribution. It is a graph for demonstrating an example of the relationship between the electrical energy supplied to the edge heater 23, and the temperature of the width direction edge part of 2nd temperature distribution. It is a graph for demonstrating the other example of the relationship between the electrical energy supplied to the edge heater 23, and the temperature change of the edge part of the width direction. 6 is a functional block diagram of an edge heater control device 3 according to Embodiment 3. FIG. 10 is a flowchart of a routine executed by the edge heater control device 3 according to the third embodiment. It is a block diagram which shows the hardware structural example of the processing circuit which the edge heater control apparatus 3 which concerns on each embodiment has.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted.

Embodiment 1 FIG.
<System configuration of rolling line>
FIG. 1 is a schematic diagram showing a system configuration of a rolling line according to the first embodiment. In FIG. 1, a rolled material 1 is thinly extended while being processed in a rolling line 2, and the width is also controlled to a desired value. For ease of explanation, it is assumed that the rolling line 2 is a hot rolling line for steel. The rolling line 2 includes a heating furnace 21, a rough rolling mill 22, an edge heater 23, a finishing rolling mill 24, a cooling table 25, and a winder 26 as main facilities.

  When the rolled material 1 leaves the heating furnace 21, it is a lump of iron formed into a rectangular parallelepiped shape called a slab having a thickness of 250 mm, a width of 800 to 2000 mm, and a length of 5 to 10 m, for example. The slab is heated in the heating furnace 21 and extracted from the heating furnace 21 at about 1200 ° C. The rough rolling mill 22 is often composed of one to three units, and performs multiple pass rolling in the forward direction (from upstream to downstream) and in the reverse direction (from downstream to upstream). A device for adjusting the width called an edger may be attached to the roughing mill 22.

  The edge heater 23 is installed between the rough rolling mill 22 and the finish rolling mill 24 and is an apparatus for heating the width direction end of the rolled material 1. Note that a crop shear that cuts off the leading end of the rolled material, a scale breaker that removes an oxide film formed on the surface of the rolled material with high-pressure water, a bar heater that heats the entire width direction, and the like are provided between the roughing mill 22 and the finishing mill 24. Sometimes installed.

  The finish rolling mill 24 provided downstream of the edge heater 23 includes a plurality of rolling stands, performs unidirectional rolling from upstream to downstream, and determines the final quality related to the size of the rolled material 1 such as the plate thickness and the plate width. . The temperature of the rolled material 1 is about 900 ° C. on the exit side of the finish rolling mill 24. The rolling stand includes devices such as a rolling roll and a support roll. The rolled material 1 is rolled by the upper and lower rolling rolls. At this time, the heat of the rolled material 1 is removed by a rolling roll or cooling water sprayed directly onto the rolled material 1. At the end in the width direction, the area that comes into contact with water and air is larger than that at the center in the width direction, so heat easily escapes and the temperature tends to decrease.

  The cooling table 25 pours water into the rolled material 1 to lower the temperature. The temperature before being wound into a coil by the winder 26 is 200 ° C. when it is low, such as special steel, and around 600 ° C. when it is ordinary steel.

  The edge heater 23 is connected to the edge heater control device 3. The edge heater control device 3 is connected to an edge heater inlet side thermometer 27 provided between the rough rolling mill 22 and the edge heater 23 and the host computer 5.

<Edge Heater Control Device According to Embodiment 1>
The overall outline of the edge heater control device 3 according to the first embodiment will be described with reference to FIG. FIG. 2 is a functional block diagram of the edge heater control device 3 according to the first embodiment.

  The edge heater control device 3 according to Embodiment 1 includes a data acquisition unit 31, a first supply energy calculation unit 32, a first temperature distribution prediction unit 33, and a second temperature distribution prediction unit 34.

  The data acquisition unit 31 receives various data relating to the rolled material 1 from the host computer 5 (steel type / thickness / conveying speed of the rolled material 1, control amount of the finishing mill 24, rolled material 1 on the final rolling stand exit side of the finishing mill 24). Temperature condition at the end in the width direction). Further, the data acquisition unit 31 acquires the initial temperature of the rolled material 1 on the entry side of the edge heater 23 from the edge heater entry side thermometer 27.

  The first temperature distribution prediction unit 33 is based on a temporary value indicating the electric energy supplied to the edge heater 23, and the temperature distribution in the width direction of the rolled material 1 on the outlet side of the edge heater (hereinafter referred to as "first temperature distribution"). Predict.

  The second temperature distribution prediction unit 34 predicts the temperature distribution in the width direction of the rolled material 1 (hereinafter referred to as “second temperature distribution”) on the exit side of the final rolling stand of the finish rolling mill 24 based on the first temperature distribution. To do.

  The edge heater control device 3 indicates the electrical energy to be supplied to the edge heater 23 that is necessary for satisfying the temperature condition regarding the width direction end portion of the second temperature distribution before the rolled material 1 reaches the edge heater 23. The indicated value is calculated.

  The purpose of the system according to the first embodiment is to set the target temperature at the width direction end of the width direction temperature distribution of the rolled material 1 on the final rolling stand exit side of the finish rolling mill 24, that is, the width direction end of the second temperature distribution. When the target temperature is given as a temperature condition, an instruction value indicating electric energy to be supplied to the edge heater 23 necessary to achieve the target temperature is obtained.

  In order to realize this object, the first supply energy calculation unit 32 according to the first embodiment executes the following processes (1) to (3) before the rolled material 1 reaches the edge heater 23. .

(1) The 1st supply energy calculation part 32 acquires the target temperature in the width direction edge part of 2nd temperature distribution as temperature conditions mentioned above. This target temperature is given from the host computer 5 via the data acquisition unit 31. Moreover, in order to obtain a uniform material over all the plate | board width directions of the rolling material 1, the temperature close | similar to the center part of the width direction of 2nd temperature distribution is set to target temperature. The target temperature may be set for one point at the end in the width direction or may be set for a plurality of points. It may also be a representative value.

(2) Next, the first supply energy calculation unit 32 uses the second temperature distribution prediction unit 34 so that the temperature at the end in the width direction of the second temperature distribution satisfies the target temperature acquired in (1). The first temperature distribution necessary for the calculation is calculated.

(3) Thereafter, the first supply energy calculation unit 32 should supply the edge heater 23 necessary for satisfying the first temperature distribution calculated in (2) using the first temperature distribution prediction unit 33. An indication value indicating electric energy is calculated.

  At this time, the second temperature distribution prediction unit 34 generally calculates the temperature of the rolled material 1 from the upstream side toward the downstream side. When performing highly accurate temperature calculation, the rolling material 1 is divided | segmented into a small part using a difference method etc., and the heat | fever in / out of the part is described by numerical formula. When this method is used, in (2), it is impossible to calculate the first temperature distribution from the second temperature distribution, that is, the temperature distribution from the downstream side to the upstream side at once. If a simple temperature model is used, it may be possible to calculate from the downstream side to the upstream side at once, but the accuracy of the temperature model cannot often be maintained.

<Flow of processing for calculating target distribution of first temperature distribution>
Therefore, the first supply energy calculation unit 32 performs the following iterative calculation to calculate a target distribution of the temperature direction temperature distribution (first temperature distribution) of the rolled material 1 on the outlet side of the edge heater. With reference to FIG. 3, the process (2) will be described.

  FIG. 3 is a flowchart of a routine executed by the first supply energy calculation unit 32 and the second temperature distribution prediction unit 34. This routine is executed before the rolled material 1 reaches the edge heater 23.

  In the routine shown in FIG. 3, first, in step S100, the first supply energy calculation unit 32 sets a temporary target distribution of the first temperature distribution.

  Next, in step S110, the second temperature distribution prediction unit 34 uses the thickness direction temperature model 36 to be described later based on the temporary target distribution set in step S100, and the rolling material 1 on the exit side of the finish rolling mill. The width direction temperature distribution (second temperature distribution) is calculated.

  Next, in step S120, the first supply energy calculation unit 32 determines whether or not the temperature at the end in the width direction of the second temperature distribution is within the target temperature range with respect to the second temperature distribution calculated in step S110. To do. The target temperature range is a temperature range in which an error range (± α) is added to the target temperature at the end in the width direction of the second temperature distribution acquired in (1) above.

  When the determination condition in step S120 is not satisfied, the process returns to step S100, and the first supply energy calculation unit 32 slightly changes the temporary target distribution of the first temperature distribution in an appropriate direction. Specifically, when the temperature at the end in the width direction of the second temperature distribution calculated in step S110 is lower than the target temperature range, the next value of the temporary target distribution is set higher than the previous value. On the other hand, when the temperature is higher than the target temperature range, the next value of the temporary target distribution is set lower than the previous value. The temporary target distribution is repeatedly updated until the determination process of step S120 is established.

  If the determination condition in step S120 is satisfied, the process proceeds to step S130. In step S <b> 130, the first supply energy calculation unit 32 determines the temporary target distribution as the target distribution of the first temperature distribution. Thereafter, the routine shown in FIG. 4 is executed.

<Flow of processing to calculate electrical energy to be supplied to edge heater>
Similarly to the above (2), in the calculation of the above (3), it is not possible to calculate the electric energy to be supplied to the edge heater 23 from the target distribution of the first temperature distribution at a stretch from the downstream side to the upstream side. Is possible. Therefore, the first supply energy calculation unit 32 calculates the electrical energy to be supplied to the edge heater 23 by performing the following repeated calculation. With reference to FIG. 4, the process (3) will be described.

  FIG. 4 is a flowchart of a routine executed by the first supply energy calculation unit 32 and the first temperature distribution prediction unit 33. This routine is executed after the execution of the routine shown in FIG. 3 and before the rolled material 1 reaches the edge heater 23.

  In the routine shown in FIG. 4, first, in step S <b> 140, the first supply energy calculation unit 32 sets a temporary value indicating the electric energy to be supplied to the edge heater 23.

  Next, in step S150, the first temperature distribution prediction unit 33 calculates the first temperature distribution using the edge heater temperature calculation simple model 35 described later based on the temporary value set in step S140.

  Next, in step S160, the first supply energy calculation unit 32 determines whether or not the first temperature distribution calculated in step S150 matches or sufficiently approaches the target distribution of the first temperature distribution determined in (2) above. Determine whether. For example, it is determined whether or not the calculated temperature at the end portion in the width direction of the first temperature distribution is within the target temperature range at the end portion in the width direction in the target distribution of the first temperature distribution. The target temperature range is a temperature range in which an error range (± β) is added to the temperature at the end in the width direction of the target distribution of the first temperature distribution.

  When the determination condition in step S160 is not satisfied, the process returns to step S140, and the first supply energy calculation unit 32 slightly changes the temporary value indicating the electric energy to be supplied to the edge heater 23 in an appropriate direction. Specifically, when the temperature at the end in the width direction of the first temperature distribution calculated in step S150 is lower than the target temperature range, the next value of the temporary value is set higher than the previous value. On the other hand, when the temperature is higher than the target temperature range, the next value of the temporary value is set lower than the previous value. The provisional value is repeatedly updated until the determination process of step S160 is established.

  If the determination condition in step S160 is satisfied, the process proceeds to step S170. In step S <b> 170, the first supply energy calculation unit 32 determines the provisional value as an instruction value indicating the electric energy to be supplied to the edge heater 23.

  Thereafter, the edge heater control device 3 transmits an instruction value to the edge heater 23, and the edge heater 23 receives the supply of electrical energy corresponding to the instruction value and heats the end in the width direction of the rolled material 1.

  Note that the instruction value indicating the electric energy supplied to the edge heater 23 may be a voltage value, a current value, or the like in addition to the power value, and is matched to the input of the edge heater 23.

<Thick width direction temperature model>
Next, the thickness direction temperature model 36 will be described with reference to FIG. As shown in FIG. 2, the second temperature distribution prediction unit 34 performs a temperature calculation in cooperation with the thickness direction temperature model 36.

  FIG. 5 is a cross-sectional view showing a cross section perpendicular to the longitudinal direction of the rolled material 1. The thickness-width direction temperature model 36 uses a difference method in which the temperature distribution in the thickness direction and the width direction of the cross section perpendicular to the longitudinal direction of the rolled material 1 is taken into account the heat conduction inside the material and the heat transfer between the material surface and the outside. Model. As shown in FIG. 5, the cross section is divided into a plurality of rectangular elements. Black points in FIG. 5 indicate points at which temperatures are calculated by a difference method, and are referred to as nodes. The heat conduction between the nodes and the heat transfer between the nodes and the outside world (air or water) are described by the following mathematical formulas, and the temperature change is calculated based on these equations.

  The heat conduction mentioned above represents the movement of heat inside the steel plate, and is represented by the formula (1).

  Equation (1) is also used to describe heat transfer between the rolling roll and the rolled material 1.

  The heat transfer described above represents heat transfer between the steel plate and the outside, and includes heat transfer by radiation, heat transfer by air-cooled convection, and heat transfer by water-cooled convection.

  Heat transfer by radiation is expressed by equation (2). Hereinafter, when the heat flow is negative, it indicates that heat is taken from the node.

  Heat transfer by air-cooled convection is expressed by equation (3).

  Heat transfer by water-cooled convection is expressed by equation (4).

  Factors that affect the temperature of the rolled material 1 include processing heat generated when processed by the upper and lower rolling rolls, and heat generated by friction between the rolling roll and the rolled material, so these factors should also be considered. is there.

All heat flows are described for one node, and node No. Calculate the temperature change ΔT _i of _i .

  The second temperature distribution prediction unit 34 repeats the above-described heat flow calculation and temperature calculation using the heat flow from the edge heater 23 to the exit side of the finishing mill 24.

  FIG. 6 is a graph showing an example in which the temperature of the rolled material 1 is calculated by the second temperature distribution prediction unit 34. The temperature change of the rolling material 1 from the thermometer FET which is downstream from the edge heater 23 and which is on the entry side of the finishing mill 24 to the thermometer FDT on the exit side of the finishing mill 24 is shown. The edge heater 23 heats the edge in the width direction, and the temperature of the edge in the width direction rises at the position of the FET. Even at the FDT position, the temperature drop at the end in the width direction is suppressed as compared with the case where the edge heater 23 is not heated.

<Simple model for edge heater temperature calculation>
Next, the edge heater temperature calculation simplified model 35 will be described with reference to FIGS. As shown in FIG. 2, the first temperature distribution prediction unit 33 cooperates with the edge heater temperature calculation simplified model 35 to obtain various data and edges related to the rolled material 1 acquired from the host computer 5 and the edge heater entry side thermometer 27. Based on the electrical energy supplied to the heater 23, the temperature distribution in the width direction (first temperature distribution) of the rolled material 1 on the edge heater outlet side is calculated.

  The edge heater 23 heats the rolled material 1 by induction heating. When a current flows through the width direction end of the rolled material 1 under the influence of the magnetic field generated by the edge heater 23, the rolled material 1 generates heat. For this reason, for the modeling, it is necessary to analyze the magnetic field generated by the edge heater 23 and the heat generated by the current flowing through the rolled material 1 under the influence of the magnetic field. In general, the finite element method is applied to the electromagnetic field analysis and the heat conduction analysis, but the analysis takes a very long time. FIG. 7 shows a state where the mesh is cut for analysis by the finite element method. In order to shorten the analysis time, it is necessary to express the results of electromagnetic field analysis and heat conduction analysis by the finite element method (detailed model constructed offline) as a simplified model and use it for online control etc. is there.

  FIG. 8 is a diagram illustrating an example of the edge heater temperature calculation simplified model 35. FIG. 8 is a simplified version of the analysis result of FIG. 7. For example, when an arbitrary electric power is applied to the edge heater 23, the temperature rise at the end in the width direction according to the initial temperature and thickness of the rolled material 1. Represents quantity. FIG. 8 shows a relationship in which the temperature rise at the end in the width direction increases as the thickness of the rolled material 1 decreases, and the temperature increase at the end in the width direction increases as the initial temperature of the rolled material 1 decreases. . Actually, the steel type of the rolled material 1, the conveyance speed, and the like must be taken into consideration as parameters, so that all parameters of the simple model cannot be represented by a three-dimensional graph. The edge heater temperature calculation simplified model 35 can be represented by a model combining several two dimensions (planes).

  Specifically, the edge heater temperature calculation simple model 35 includes input parameters including the electric energy supplied to the edge heater 23, the initial temperature of the rolled material 1 on the inlet side of the edge heater, the plate thickness, the steel type, and the conveyance speed, and the edge heater. 23 is a model in which the output parameter indicating the amount of temperature rise of the rolled material 1 heated to 23 is associated. This model is a simple model defined by, for example, a mathematical expression or a map. By preparing a simple model in advance and using it for online calculation, the calculation time during control can be greatly reduced.

<Effect>
As described above, according to the edge heater control device 3 according to the first embodiment, before the rolled material reaches the edge heater, the target of the end in the width direction of the rolled material 1 on the exit side of the finish rolling mill 24. The electrical energy to be supplied to the edge heater necessary to meet the temperature can be determined. Since the temperature of the end portion in the width direction of the rolled material 1 can be appropriately controlled on the exit side of the finish rolling mill 24 that greatly affects the material, it is possible to suppress deterioration of the material.

<Modification>
By the way, in the system of Embodiment 1 mentioned above, although the edge heater entrance side thermometer 27 is installed, the edge heater entrance side thermometer 27 may not be installed. When the edge heater inlet side thermometer 27 is not installed, the edge heater inlet side temperature can be predicted using the predicted temperature value of the rolled material 1 calculated for the control of the rough rolling mill 22. The initial temperature of the rolled material 1 on the entry side of the edge heater 23 described above is substituted with this predicted temperature. This point is the same in the following embodiments.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIGS. The system of this embodiment can be realized by causing the edge heater control device 3 to execute a routine of FIG. 10 described later in the configuration shown in FIGS. 1 and 9.

  In the first embodiment described above, it is assumed that the target temperature at the end in the width direction of the width direction temperature distribution (second temperature distribution) of the rolled material 1 on the exit side of the finish rolling mill 24 is given as the temperature condition. . However, the target temperature is not necessarily given to all rolled materials 1. For example, although the target temperature is given in the rolling of high-grade steel sheets, it may not be given in ordinary steel. Therefore, in the second embodiment, when the target temperature is not given, a command value indicating the electric energy supplied to the edge heater 23 is determined so that the energy consumed by the edge heater 23 is used efficiently.

<Edge Heater Control Device According to Embodiment 2>
The overall outline of the edge heater control device 3 according to the second embodiment will be described with reference to FIG. FIG. 9 is a functional block diagram of the edge heater control device 3 according to the second embodiment.

  The edge heater control device 3 according to the second embodiment includes a second supply energy calculation unit in addition to the data acquisition unit 31, the first temperature distribution prediction unit 33, and the second temperature distribution prediction unit 34 described in the first embodiment. 37, a heating mode selector 38, a first heating mode calculator 39, and a second heating mode calculator 40.

  The second supply energy calculation unit 37 uses the first temperature distribution prediction unit 33 and the second temperature distribution prediction unit 34 to provide a temporary value indicating the electric energy supplied to the edge heater 23 and a second value corresponding to the temporary value. The relationship with the predicted temperature at the end in the width direction of the temperature distribution is calculated. Furthermore, the second supply energy calculation unit 37 uses the provisional value calculated by the first heating mode calculation unit 39 or the second heating mode calculation unit 40 as an instruction value indicating the electric energy to be supplied to the edge heater 23.

  Hereinafter, the temporary value indicating the electric energy supplied to the edge heater 23 is also simply referred to as “temporary value”, and the predicted temperature at the end in the width direction of the second temperature distribution corresponding to the temporary value is also simply referred to as “predicted temperature”. .

  The heating mode selection unit 38 selects one of the first heating mode and the second heating mode based on the data including the steel type acquired by the data acquisition unit 31.

  When the first heating mode is selected, the first heating mode calculation unit 39 calculates a temporary value that maximizes the predicted temperature based on the relationship calculated by the second supply energy calculation unit 37.

  When the second heating mode is selected, the second heating mode calculation unit 40 calculates the temperature increase rate of the predicted temperature according to the increase in the temporary value based on the relationship calculated by the second supply energy calculation unit 37. A provisional value that is equal to or greater than a predetermined positive value and has the maximum predicted temperature is calculated.

<Processing Flow in Embodiment 2>
With reference to FIGS. 10 to 13, a description will be given of processing in consideration of energy efficiency performed by the edge heater control device 3 according to the second embodiment when the target temperature of the second rolling distribution is not given.

  FIG. 10 is a flowchart of a routine executed by the edge heater control device 3 according to the second embodiment. This routine is executed before the rolled material 1 reaches the edge heater 23.

  In the routine shown in FIG. 10, first, in step S200, the data acquisition unit 31 performs various data relating to the rolled material 1 (the steel type / thickness / conveying speed of the rolled material 1, the control amount of the finishing mill 24, the width of the second temperature distribution). Temperature conditions at the direction end, initial temperature of the rolled material 1 on the edge heater entrance side, and the like) are acquired.

  Next, in step S <b> 205, the second supply energy calculation unit 37 determines N temporary values (N> 2) of electrical energy supplied to the edge heater 23. In the second embodiment, the second supply energy calculation unit 37 uses the first temperature distribution prediction unit 33 and the second temperature distribution prediction unit 34 to calculate the second temperature distribution according to the temporary value of electric energy. Is repeated N times (steps S210 to S225).

  In step S210, the second supply energy calculation unit 37 increments the counter i (initial value 0) of the number of repetitions. A temporary value indicating the i-th electrical energy is set.

  In step S <b> 215, the second supply energy calculation unit 37 uses the first temperature distribution prediction unit 33 to predict the first temperature distribution based on the temporary value indicating the i-th electrical energy.

  In step S220, the second supply energy calculation unit 37 uses the second temperature distribution prediction unit 34 to predict the second temperature distribution based on the first temperature distribution.

  In step S225, the second supply energy calculation unit 37 determines whether or not the counter i is greater than or equal to N. If the counter i is less than N, the process returns to step S210. If the counter i is greater than or equal to N, the process proceeds to step S230.

  In step S230, the second supply energy calculation unit 37 calculates the relationship between the N temporary values and the predicted temperature at the end in the width direction of the second temperature distribution corresponding to each temporary value. Specifically, an orthogonal coordinate system having a horizontal axis (X axis) as a temporary value indicating the electric energy supplied to the edge heater 23 and a vertical axis (Y axis) as a predicted temperature at the end in the width direction of the second temperature distribution. The points represented by the combination of the provisional value and the predicted temperature are plotted.

  FIG. 11 is a graph for explaining an example of the relationship between the electrical energy supplied to the edge heater 23 and the temperature at the end in the width direction of the second temperature distribution. In the example shown in FIG. 11, calculation is performed at 6 points (N = 6), and numbers 1 to 6 are assigned to the plotted points. The electric energy supplied to the edge heater at the calculation point j (1 to 6) is represented by Ej. As shown in FIG. 11, the relationship between the electrical energy supplied to the edge heater 23 (temporary value) and the temperature at the end of the second temperature distribution in the width direction (predicted temperature) increases as the temporary value increases. Is represented by a curved line (as an example, an upwardly convex curve).

  Returning to FIG. In step S235, the heating mode selection unit 38 selects one of the first heating mode and the second heating mode based on the data including the steel type. When the first heating mode is selected, the process proceeds to step S240, and when the second heating mode is selected, the process proceeds to step S245.

  In step S240, the first heating mode calculation unit 39 calculates a provisional value at which the predicted temperature is maximum based on the relationship calculated in step S230. Thereafter, in step S250, the second supply energy calculation unit 37 determines the provisional value of the electric energy calculated in step S240 as an instruction value indicating the electric energy to be supplied to the edge heater 23.

  In the example shown in FIG. 11, among the calculation results, the temperature condition at which the temperature at the end in the width direction on the exit side of the finishing mill is highest, that is, the temperature condition at point 5 is adopted. At this time, the value indicating the electric energy in FIG. 11 is E5. According to the first heating mode, electrical energy with high energy efficiency can be selected, and the temperature at the end in the width direction on the exit side of the finishing mill can be maintained high.

  Returning to FIG. In step S245, based on the relationship calculated in step S230, the second heating mode calculation unit 40 has a temperature increase rate of the predicted temperature corresponding to the increase in the temporary value equal to or higher than a predetermined positive value, To calculate a provisional value at which the predicted temperature is maximized. Thereafter, in step S250, the second supply energy calculation unit 37 determines the temporary value of the electric energy calculated in step S245 as an instruction value indicating the electric energy to be supplied to the edge heater 23.

  With reference to FIG. 12, the process of the 2nd heating mode in step S250 is demonstrated concretely. The energy efficiency of the edge heater 23 is defined as the temperature rise at the end in the width direction on the exit side of the finishing mill per unit energy supplied by the edge heater. In FIG. 12, the slope at each calculation point when connecting each calculation point becomes the energy efficiency of the edge heater 23, and the energy efficiency decreases in the order of points 2, 3, 4, and 5. In this case, the slope at the calculation point 2 is the largest and the efficiency is good, but the temperature rise is not sufficient. Therefore, the electrical energy at the point where the energy efficiency of the edge heater 23 is equal to or higher than a certain value and the temperature at the end in the width direction on the exit side of the finishing mill is highest is supplied to the edge heater 23. This constant value is influenced by the number of rolling mills positioned downstream of the edge heater 23 and the presence or absence of a water cooling device for the steel sheet, and is a numerical value that should be determined for each plant.

  11 and 12, the number of calculation points can be determined according to the ability of the computer. That is, if the number of calculation points is large, the computer load increases, so the number of points is set so as not to impair the calculation accuracy. When there are several calculation points as shown in FIG. 6, each point is approximated by connecting the points with straight lines or higher-order curves and interpolating the values between the points as in the above example. It is possible to obtain energy continuously in addition to the energy of the individual.

  The reason for the upwardly convex curve as shown in FIGS. 11 and 12 is that when the rolled material 1 is heated and the temperature rises, the effects of heat radiation and air / water cooling heat transfer are increased, and it may be easy to cool. Because. This is based on the aforementioned equations (2) to (4). According to the equations (2) to (4), the heat flow deprived from the rolled material 1 becomes large when the difference between the temperature of the rolled material 1 and the temperature around the rolled material 1 is large. In particular, the heat transfer by radiation represented by the formula (2) includes a difference between the fourth power of the temperature of the rolled material 1 and the fourth power of the temperature around the rolled material, so that in a region where the temperature of the rolled material 1 is high, Radiation heat dissipation is greater than the effect of air-cooled convection. That is, when the temperature of the rolled material 1 is increased, the effect of heat removal due to radiation increases, and the temperature of the rolled material 1 may decrease even when more energy is applied from the edge heater 23. Of course, the curve does not always have an upwardly convex curve, but at least becomes a curve where the temperature rise becomes dull as the temperature rises.

  In addition, if there are restrictions such as the upper limit temperature (temperature upper limit value) and the lower limit temperature (temperature lower limit value) on the temperature at the end in the width direction on the exit side of the finishing mill, the edge heater is within the limits. The electric energy supplied to 23 is stopped.

  Specifically, when the first heating mode is selected, in step S240, the first heating mode calculation unit 39 sets a plurality of predicted temperatures that are the upper limit temperatures based on the relationship calculated in step S230. The minimum provisional value is calculated among the provisional values. In addition, when the second heating mode is selected, the first heating mode calculation unit 39 has a predetermined rate of temperature increase corresponding to the increase in the temporary value based on the relationship calculated in step S230. A provisional value that is greater than or equal to the positive value and includes the predicted temperature between the upper limit temperature and the lower limit temperature is calculated.

  FIG. 13 is a graph for explaining another example of the relationship between the electrical energy supplied to the edge heater 23 and the temperature change at the end in the width direction. In FIG. 13, when the first heating mode is selected, the horizontal coordinate of the point that does not exceed the upper limit is E4 and E6, but the energy to be supplied is small, and the point where E4 is the horizontal coordinate is selected. The electrical energy indicated by the provisional value is supplied to the edge heater. In FIG. 13, when the second heating mode is selected, energy that falls within the set upper and lower limit values is supplied to the edge heater.

<Effect>
As described above, according to the edge heater control device 3 according to the second embodiment, the temperature rise at the end in the width direction of the rolling material 1 on the exit side of the finish rolling mill is the optimum energy consumed by the edge heater 23. Can be controlled by point.

Embodiment 3 FIG.
Next, Embodiment 3 will be described with reference to FIGS. The system of this embodiment can be realized by causing the edge heater control device 3 to execute the routine of FIG. 15 described later in the configuration shown in FIGS.

  In the first embodiment, the case where the target temperature at the end in the width direction of the second temperature distribution is given as the temperature condition has been described. On the other hand, in the second embodiment, the case where the target temperature is not given has been described. In the third embodiment, the object is to select and execute the processing of the first embodiment and the processing of the second embodiment according to the presence or absence of the target temperature.

<Edge Heater Control Device According to Embodiment 3>
FIG. 14 is a functional block diagram of the edge heater control device 3 according to the third embodiment. The edge heater control device 3 according to the third embodiment includes the data acquisition unit 31, the first temperature distribution prediction unit 33, the second temperature distribution prediction unit 34 described in the first embodiment, and the first described in the second embodiment. 2 In addition to the supply energy calculation unit 37, the heating mode selection unit 38, the first heating mode calculation unit 39, and the second heating mode calculation unit 40, a rolling mode selection unit 41 is provided.

  The rolling mode selection unit 41 selects the first rolling mode when the target temperature at the end in the width direction of the second temperature distribution is given as the temperature condition, and the second rolling when the target temperature is not given. Select a mode. When the first rolling mode is selected, the first supply energy calculation unit 32 described in the first embodiment calculates an instruction value indicating the electric energy to be supplied to the edge heater 23. Further, when the second rolling mode is selected, the provisional value calculated by the first heating mode calculation unit 39 or the second heating mode calculation unit 40 by the second supply energy calculation unit 37 described in the second embodiment. The value is an instruction value indicating the electric energy to be supplied to the edge heater 23.

<Processing Flow in Embodiment 3>
FIG. 15 is a flowchart of a routine executed by the edge heater control device 3 according to the third embodiment. This routine is executed before the rolled material 1 reaches the edge heater 23.

  In the routine shown in FIG. 10, first, in step S300, the data acquisition unit 31 performs various data related to the rolled material 1 (the steel type / thickness / conveying speed of the rolled material 1, the control amount of the finishing mill 24, the width of the second temperature distribution). Temperature conditions at the direction end, initial temperature of the rolled material 1 on the edge heater entrance side, and the like) are acquired.

  Next, in step S310, the rolling mode selection unit 41 selects a rolling mode. When the target temperature at the end in the width direction of the second temperature distribution is given as the temperature condition, the first rolling mode is selected. Moreover, when the target temperature is not given, the second rolling mode is selected. The target temperature is set according to the steel type of the rolled material 1. For example, the target temperature is often not set for ordinary steel.

  When the first mode is selected, in step S320, the first supply energy calculation unit 32 described in the first embodiment calculates an instruction value indicating the electric energy to be supplied to the edge heater 23. Since the description of the processing contents is the same as that of the first embodiment, a description thereof will be omitted.

  When the second mode is selected, in step S330, the second heating energy calculation unit 37 described in the second embodiment calculates the first heating mode calculation unit 39 or the second heating mode calculation unit 40. The provisional value is set as an instruction value indicating the electric energy to be supplied to the edge heater 23. Since the description of the processing contents is the same as that in the second embodiment, a description thereof will be omitted.

<Effect>
As described above, according to the edge heater control device 3 according to the third embodiment, the processing of the first embodiment and the second embodiment are performed according to the presence or absence of the target temperature at the end in the width direction of the second temperature distribution. Can be selected and executed. Thereby, the edge heater 23 can be optimally operated from the viewpoint of control performance and energy consumption.

  Note that the scope of application of the present invention is not limited to the objects described in the above embodiments.

<Hardware configuration example>
FIG. 16 is a block diagram illustrating a hardware configuration example of a processing circuit included in the edge heater control device 3 according to each embodiment. Each part of the edge heater control device 3 shown in FIG. 2, FIG. 9, and FIG. 14 shows a part of the functions of the control device, and each function is realized by a processing circuit. For example, the processing circuit includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, an input / output interface 104, a system bus 105, an input device 106, a display device 107, a storage 108, and The computer includes a communication device 109.

  The CPU 101 is a processing device that executes various types of arithmetic processing using programs and data stored in the ROM 102 and the RAM 103. The ROM 102 is a read-only storage device that stores a basic program, an environment file, and the like for causing a computer to realize each function. A RAM 103 is a main storage device that stores a program executed by the CPU 101 and data necessary for the execution of each program, and can be read and written at high speed. The input / output interface 104 is a device that mediates connections between various hardware and the system bus 105. A system bus 105 is an information transmission path shared by the CPU 101, ROM 102, RAM 103, and input / output interface 104.

  The input / output interface 104 is connected to hardware such as an input device 106, a display device 107, a storage 108, and a communication device 109. The input device 106 is a device that processes input from a user. The display device 107 is a device that displays the system status and the like. The storage 108 is a large-capacity auxiliary storage device that stores programs and data, and is, for example, a hard disk device or a nonvolatile semiconductor memory. The communication device 109 is a device capable of data communication with an external device (the host computer 5, the edge heater inlet side thermometer 27) by wire or wireless.

DESCRIPTION OF SYMBOLS 1 Rolled material 2 Rolling line 3 Edge heater control apparatus 5 Host computer 21 Heating furnace 22 Rough rolling mill 23 Edge heater 24 Finishing rolling mill 25 Cooling table 26 Winding machine 27 Edge heater inlet side thermometer 31 Data acquisition part 32 1st supply Energy calculator 33 First temperature distribution predictor 34 Second temperature distribution predictor 35 Edge heater temperature calculation simplified model 36 Thickness direction temperature model 37 Second supply energy calculator 38 Heating mode selector 39 First heating mode calculator 40 Second heating mode calculation unit 41 Rolling mode selection unit 101 CPU
102 ROM
103 RAM
104 I / O interface 105 System bus 106 Input device 107 Display device 108 Storage 109 Communication device

Claims (6)

An edge heater for a rolling line, comprising an edge heater that heats the widthwise end of the rolled material upon receiving electric energy in accordance with the indicated value, and at least one rolling stand provided downstream of the edge heater A control device,
A first temperature distribution prediction unit for predicting a width direction temperature distribution (first temperature distribution) of the rolled material on the outlet side of the edge heater, based on a temporary value indicating electric energy supplied to the edge heater;
A second temperature distribution prediction unit that predicts a width direction temperature distribution (second temperature distribution) of the rolled material on the rolling stand exit side based on the first temperature distribution;
Before the rolled material reaches the edge heater, the instruction value indicating the electric energy to be supplied to the edge heater, which is necessary for satisfying the temperature condition regarding the end in the width direction of the second temperature distribution, is calculated. A supply energy calculation unit;
An edge heater control device comprising: The first temperature distribution prediction unit is heated by the edge heater and input parameters including electric energy supplied to the edge heater, an initial temperature of the rolled material on the inlet side of the edge heater, a sheet thickness, a steel type, and a conveyance speed. Predicting the first temperature distribution using a simple model for calculating the edge heater temperature associated with an output parameter indicating the temperature rise of the rolled material,
The second temperature distribution prediction unit uses a difference method in consideration of the heat distribution in the thickness direction and the width direction of the cross section perpendicular to the longitudinal direction of the rolled material in consideration of the heat conduction inside the material and the heat transfer between the material surface and the outside. Predicting the second temperature distribution based on the first temperature distribution using a thickness direction temperature model determined by
The edge heater control device according to claim 1. The supply energy calculation unit
When the temperature condition is the target temperature at the end in the width direction of the second temperature distribution, the temperature at the end in the width direction of the second temperature distribution is set to the target temperature using the second temperature distribution prediction unit. The first temperature distribution necessary for satisfying is calculated, and then the first temperature distribution predicting unit is used to supply electricity to the edge heater necessary for satisfying the calculated first temperature distribution. A first supply energy calculation unit for calculating the indicated value indicating energy;
The edge heater control device according to claim 1, further comprising: The supply energy calculation unit
Using the first temperature distribution prediction unit and the second temperature distribution prediction unit, a temporary value indicating the electric energy supplied to the edge heater, and a width direction end portion of the second temperature distribution corresponding to the temporary value A second supply energy calculation unit for calculating a relationship with the predicted temperature;
A heating mode selector that selects one of the first heating mode and the second heating mode;
When the first heating mode is selected, based on the relationship, a first heating mode calculation unit that calculates a temporary value at which the predicted temperature is maximized;
When the second heating mode is selected, based on the relationship, the temperature increase rate of the predicted temperature according to the increase in the temporary value is equal to or higher than a predetermined positive value, and the predicted temperature is the maximum among them. A second heating mode calculator that calculates a provisional value,
The second supply energy calculation unit further sets the temporary value calculated by the first heating mode calculation unit or the second heating mode calculation unit as the instruction value indicating the electric energy to be supplied to the edge heater. ,
The edge heater control device according to claim 1 or 2. The temperature condition includes an upper limit temperature and a lower limit temperature of a width direction end of the rolled material on the rolling stand exit side,
When the first heating mode is selected, the first heating mode calculation unit calculates a minimum provisional value among a plurality of provisional values at which the predicted temperature becomes the upper limit temperature based on the relationship,
The second heating mode calculation unit, when the second heating mode is selected, based on the relationship, the temperature increase rate of the predicted temperature according to the increase of the temporary value is a predetermined positive value or more, and Calculating a provisional value where the predicted temperature is included between the upper limit temperature and the lower limit temperature;
The edge heater control device according to claim 4. The supply energy calculation unit
Using the first temperature distribution prediction unit and the second temperature distribution prediction unit, a temporary value indicating the electric energy supplied to the edge heater, and a width direction end portion of the second temperature distribution corresponding to the temporary value A second supply energy calculation unit for calculating a relationship with the predicted temperature;
A heating mode selector that selects one of the first heating mode and the second heating mode;
When the first heating mode is selected, based on the relationship, a first heating mode calculation unit that calculates a temporary value at which the predicted temperature is maximized;
When the second heating mode is selected, based on the relationship, the temperature increase rate of the predicted temperature according to the increase in the temporary value is equal to or higher than a predetermined positive value, and the predicted temperature is the maximum among them. A second heating mode calculation unit for calculating a provisional value,
A rolling mode selection unit that selects the first rolling mode when the target temperature is given as the temperature condition, and that selects the second rolling mode when the target temperature is not given,
The first supply energy calculation unit calculates the instruction value indicating the electric energy to be supplied to the edge heater when the first rolling mode is selected,
The second supply energy calculation unit supplies the provisional value calculated by the first heating mode calculation unit or the second heating mode calculation unit to the edge heater when the second rolling mode is selected. The indicated value indicating the electrical energy to be
The edge heater control device according to claim 3.

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