JP2017071815A - Furnace temperature setting method and furnace temperature setting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a furnace temperature setting method and a furnace temperature setting device, in which in a continuous type heating furnace, by more appropriately setting an intermediate target steel slab temperature and an intermediate target soaking temperature, while satisfying restrictions on an extraction target steel slab temperature and an extraction target soaking temperature, an operation where a used amount of fuel is suppressed can be performed.SOLUTION: A furnace temperature setting method for setting a furnace temperature of each of burning zones in a continuous type heating furnace, includes the steps of: calculating an output side target steel slab temperature and an output side target soaking temperature of each of the burning zones by assuming that each of the burning zones is operated at a maximum furnace temperature while going way back in order from the soaking zone of predetermined one steel slab, calculating a furnace temperature of each of the burning zones satisfying restrictions of the output side target steel slab temperature and the output side target soaking temperature calculated of the respective steel slabs; and calculating a final furnace temperature of each of the burning zones based on the furnace temperature of the respective burning zones calculated about at least one steel slab present in the respective burning zones.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a furnace temperature setting method and a furnace temperature setting apparatus for a continuous heating furnace used for hot rolling of a metal material.

  For example, in the hot rolling of a metal material such as a steel slab, the metal material is heated in a heating furnace in order to easily perform the plastic rolling process in the uppermost stream of the process. For example, in the field of the steel industry, a continuous heating furnace having a plurality of furnace zones (combustion zones) such as a pre-tropical zone, a heating zone, and a soaking zone is generally used as a heating furnace. The billet is charged from the pretropical entry side, heated by passing through the pretropical zone, the heating zone, and the soaking zone in order, and extracted from the soaking zone.

  The heating in the continuous heating furnace is performed in the subsequent rolling of the steel slab in order to secure a temperature for realizing characteristics required for the product such as surface quality and dimensional accuracy. Therefore, in a continuous heating furnace, it is very important to heat the steel slab to an appropriate temperature.

  Therefore, in general, in a continuous heating furnace, the drive is controlled so that the center temperature or average temperature (extracted steel slab temperature) of the steel slab during extraction exceeds the preset target steel slab temperature. ing. Here, as the “center” of the “center temperature”, depending on operation management requirements, for example, the center in the thickness direction of the steel slab, the center in the length direction, or the center in the width direction, or a combination thereof (for example, The center of the thickness direction and the width direction) is used. The extraction target billet temperature is set in consideration of the characteristics required for the above-described products in addition to the purpose of easily rolling. Similarly, in the continuous heating furnace, the drive is controlled so that the temperature difference (extraction soaking degree) between the center and the surface of the slab at the time of extraction satisfies the preset soaking target soaking degree. There are many things.

  On the other hand, in the heating operation, most of the running cost is occupied by the cost of fuel. Therefore, the continuous heating furnace is required to operate such that the extracted steel slab temperature and the extraction soaking degree satisfy the constraints of the extraction target steel slab temperature and the extraction target soaking degree, respectively, and suppress the fuel consumption as much as possible.

  In recent years, computer management has progressed for the operation of a continuous heating furnace, and various methods for realizing the above operation by automatic control in the continuous heating furnace have been proposed.

  For example, Patent Document 1 discloses a method for obtaining the optimum furnace temperature of each combustion zone in a continuous heating furnace according to the following procedure. That is, in the technique described in Patent Document 1, first, the extracted steel slab temperature, the extracted averaged temperature when the operation is performed in the current operation state, and when the operation is performed by perturbing the furnace temperature of each combustion zone. By calculating the heat degree and the fuel flow rate, and dividing the difference by the furnace temperature perturbation amount, the influence coefficient of the furnace temperature change amount of each combustion zone on the extracted steel slab temperature, the extraction soaking degree, and the fuel flow rate is derived. Next, by calculating the sum of the product of the influence coefficient and the furnace temperature change amount, the extracted slab temperature, the extracted soaking degree, and the fuel flow rate are predicted in a linear form. Then, by solving the linear programming problem such that the fuel flow rate predicted in a linear form is minimized while the extracted slab temperature and the extracted soaking degree satisfy the constraints of the extraction target slab temperature and the extracting target soaking degree, respectively, Find the optimum furnace temperature for each combustion zone.

  However, in the method described in Patent Document 1, when considering the influence coefficient of the furnace temperature change amount of each combustion zone with respect to the extraction target billet temperature and the extraction target soaking degree, the combustion zone located relatively upstream from the extraction side. For, the linearization error is very large. Therefore, when operating according to the furnace temperature of each combustion zone determined using the method described in Patent Document 1, for example, the furnace temperature of the combustion zone located on the front stage side such as the pre-tropical zone may not be appropriate, There is a concern that the extracted slab temperature and the extracted soaking degree cannot achieve the target extracted slab temperature and the extracting target soaking degree.

  As a solution to this, there is a method of setting an intermediate target billet temperature and an intermediate target soaking degree at each combustion zone outlet side or at any other intermediate point. If this method is used, for example, the linearization error of the influence coefficient of the amount of change in the temperature of the pretropical furnace with respect to the temperature of the outgoing target slab in the pretropical zone or the target temperature of the outgoing side can be reduced. Therefore, by performing operation at the furnace temperature for each combustion zone determined by the method, the outlet side slab temperature and the outlet side slab temperature in each combustion zone are set to each combustion zone. Therefore, it is considered that the final extracted slab temperature and the extracted soaking temperature can also achieve the extracted target slab temperature and the extracting target soaking degree.

  As a method for setting the intermediate target billet temperature and the intermediate target soaking degree, for example, methods described in Non-Patent Document 1 and Patent Document 2 are known.

  For example, in Non-Patent Document 1, in addition to the extraction target billet temperature and the extraction target soaking degree, the intermediate target billet temperature and the intermediate target soaking degree at any intermediate point such as each combustion zone exit side are set. Using the same method as in No. 1, the extracted steel slab temperature, extracted soaking degree, intermediate slab temperature and intermediate soaking temperature values when the furnace temperature of each combustion zone is changed are predicted in a linear format, and these values are extracted. Linear design that minimizes the sum of products of furnace temperature and weighting factor for each combustion zone while satisfying the constraints of target slab temperature, extraction target soaking degree, intermediate target slab temperature, and intermediate target soaking degree. A method for obtaining the optimum furnace temperature of each combustion zone by solving the problem is disclosed.

  Further, in Patent Document 2, an intermediate target slab temperature is set on each combustion zone outlet side, and the difference between the intermediate slab temperature and the intermediate target slab temperature when operating at the current furnace temperature, By finding the appropriate furnace temperature in each combustion slab in the combustion zone where the slabs exist by fuzzy inference using control rules that are configured according to conditions such as the remaining furnace time, steel grade, and slab dimensions A method for obtaining the optimum furnace temperature in each final combustion zone is disclosed.

JP 59-159939 A JP-A-4-17621

Kita Kazuaki and three others, "Development of automatic combustion control model for continuous heating furnace for slab for thick plate", IEEJ Study Group materials. MID, Metal Industry Research Society, Institute of Electrical Engineers, October 2, 2009, 2009 (14), p. 1-6

  However, in the methods described in Non-Patent Document 1 and Patent Document 2, the method for setting the intermediate target billet temperature and the intermediate target soaking degree is not necessarily appropriate from the viewpoint of reducing the amount of fuel used.

  For example, Non-Patent Document 1 describes that the intermediate target billet temperature and the intermediate target soaking degree are set so as to coincide with the temperature increase image of the operator. Specifically, for example, performance data at the time of operation by a skilled operator is collected for a predetermined period, and the average value of the slab temperature at the intermediate point in the period and the average value of the soaking degree at the intermediate point in the period, Methods such as setting the intermediate target billet temperature and the intermediate target soaking degree are conceivable. However, in the method of setting the intermediate target slab temperature and the intermediate target soaking degree based on the experience of the operator as described above, the set intermediate target slab temperature and the intermediate target soaking degree are optimal from the viewpoint of reducing the fuel consumption. There is no guarantee that this is true. Even if the operation is performed so that the intermediate slab temperature and the intermediate soaking temperature satisfy the constraints of the intermediate target slab temperature and the intermediate target soaking temperature set based on the experience of the operator, the extracted slab temperature and There is no theoretical support that the extraction soaking degree satisfies the extraction target billet temperature and the extraction target soaking degree constraint.

  Patent Document 2 does not describe any specific method for setting the target billet temperature on the combustion band exit side.

  Therefore, the present invention has been made in view of the above problems, and the object of the present invention is to set the intermediate target billet temperature and the intermediate target soaking degree more appropriately in the continuous heating furnace. A new and improved continuous heating furnace temperature setting method and furnace temperature capable of performing an operation with reduced fuel consumption while satisfying the constraints of the extraction target billet temperature and the extraction target soaking degree It is to provide a setting device.

In order to solve the above problems, according to an aspect of the present invention, there is provided a furnace temperature setting method for setting a furnace temperature of each combustion zone in a continuous heating furnace having N (N ≧ 2) combustion zones. The combustion zone where the billet being calculated is the combustion zone [i] (N> i ≧ 1), and the extraction target billet temperature and the extraction target soaking degree when the billet is extracted are: In the case where they are given as θ _aim [N] and Δθ _aim [N], respectively, the outlet side target billet temperature θ _aim [j] and the outlet side target average of the combustion zone [j] (N ≧ j> i) When it is assumed that the combustion zone [j] is operated at the maximum furnace temperature T _fmax [j] due to equipment restrictions or operation restrictions based on the heat degree Δθ _aim [j], the combustion zone [j exit side slab temperature] θ [j] and the exit-side soaking degree [Delta] [theta] [j] is the exit-side target steel strip temperature theta _{ai m} [j] and the outlet side slab temperature θ [of the combustion zone [j-1] immediately preceding the combustion zone [j] of the steel slab such that the outlet side temperature uniformity Δθ _aim [j]. j-1] and the outgoing side soaking degree Δθ [j-1], and the calculated outgoing side billet temperature θ [j-1] and the outgoing side soaking degree Δθ [j-1] are used as the combustion zone. By repeating the process of [j-1] with the _delivery target billet temperature θ _aim [j-1] and the _delivery target temperature uniformity Δθ _aim [j-1] from j = N to j = i + 1, the combustion zone is an intermediate target value [i] after the exit side target steel strip temperature theta _aim of the combustion zone _{[i], ···, θ aim} [N-1] and exit-side target soaking degree [Delta] [theta] _aim [i ], ..., and an intermediate target value calculation step of calculating a Δθ _{aim [N-1],} the furnace temperature of each combustion zone that satisfies the constraints of the calculated the intermediate target value using An optimum furnace temperature calculating step for calculating the optimum furnace temperature of each combustion zone for each billet, and the calculated optimum furnace temperature for each billet for at least one billet existing in each combustion zone. Based on the above, an optimum furnace temperature editing step for setting the furnace temperature of each combustion zone is provided.

  Further, in the furnace temperature setting method, in the intermediate target value calculation step, the influence coefficients α and β that the change amount of the furnace temperature has on the billet temperature and the soaking degree are expressed by the following equations (101) and (103). The θ [j−1] and the Δθ [j−1] may be obtained by the following mathematical formulas (105) and (107) using the influence coefficients α and β.

Here, in the above formulas (101) to (107),
θ ₀ ′ [k]: The combustion zone [i] is operated at the current furnace temperature T _ftmp [i], and the combustion zone after the combustion zone [i + 1] is the maximum furnace temperature due to equipment restrictions or operation restrictions. T _fmax [i + 1],..., T _fmax [N] on the assumption that the operation is performed, the predicted exit slab temperature of each combustion zone Δθ ₀ ′ [k]: the combustion zone [i] is used as the current furnace It is _assumed that the operation is performed at the temperature T _ftmp [i], and the combustion zones after the combustion zone [i + 1] are operated at the maximum furnace temperature T _fmax [i + 1], ..., T _fmax [N]. Predicted soaking degree of combustion zone θ ₁ ′ [k]: It is assumed that the furnace temperature in combustion zone [k] is operated at a value perturbed by furnace temperature ΔT _f [k] from the furnace temperature T _fmax [k]. when the combustion zone [k] of the exit-side prediction billet temperature [Delta] [theta] ₁ '[k]: furnace temperature in the combustion zone [k] When it is assumed that operating in the furnace temperature T _{fmax [k]} from the furnace temperature ΔT f _[k] by a value obtained by perturbing an exit side prediction soaking of the combustion zone [k].

  In the furnace temperature setting method, in the optimum furnace temperature calculation step, the furnace temperature of each combustion zone that satisfies the restriction of the intermediate target value may be set as the optimum furnace temperature of each combustion zone for each steel slab. .

Further, in the furnace temperature setting method, in the optimum furnace temperature calculation step, the furnace temperature of each combustion zone that satisfies the restriction of the intermediate target value is set to T _fopt0 [i], ..., T _fopt0 [N]. When the optimum furnace temperature of each combustion zone for each steel slab is T _fopt [i],..., T _fopt [N], the optimum furnace temperature T _fopt [i] is _expressed by the following equation (109). The optimum furnace temperature T _fopt [i + 1],..., T _fopt [N] is calculated as _follows : T _fopt [i + 1] = T _fopt0 [i + 1], ..., T _fopt [N] = T _fopt0 [N ] May be calculated.

Here, in the above formula (109),
T _ftmp [i]: current furnace temperature in the combustion zone [i] S ₁ : in a two-dimensional plane with time on the horizontal axis and furnace temperature on the vertical axis, at the current time of the combustion zone [i] If you change the setting of the furnace temperature from the current furnace temperature _{T ftmp} [i] to _{T fopt0} [i], the combustion zone [i] of the furnace temperature is a time delay no _{T ftmp [i] T fopt0 [} i] from Of the difference between the furnace temperature T _ftmp [i] of the combustion zone [i] and the time from the current time until the billet exits the combustion zone [i] Value S ₂ : In a two-dimensional plane with time on the horizontal axis and furnace temperature on the vertical axis, the setting of the furnace temperature of the combustion zone [i] at the current time from the current furnace temperature T _ftmp [i] to T _When it is changed to _opt0 [i], the furnace temperature of the combustion zone [i] follows. The difference between the furnace temperature of the combustion zone [i] and T _ftmp [i] when assuming that the time is changed from T _ftmp [i] to T _fopt0 [i] with a delay of time t _flw [i], It is an integral value with respect to the time from the time until the steel slab leaves the combustion zone [i].

  Further, in the furnace temperature setting method, in the intermediate target value calculation step and the optimum furnace temperature calculation step, out of a plurality of steel slabs existing in the continuous heating furnace, for each combustion zone, until the extraction. The intermediate target value and the furnace temperature of each combustion zone are calculated only for the neck material having the largest rate of increase in billet temperature with respect to the remaining furnace time, and each of the neck materials is calculated in the optimum furnace temperature editing step. The furnace temperature of the combustion zone corresponding to each of the neck materials calculated for may be set as the final furnace temperature of each combustion zone.

In order to solve the above problems, according to another aspect of the present invention, a furnace temperature setting for setting the furnace temperature of each combustion zone in a continuous heating furnace having N (N ≧ 2) combustion zones. A device,
The combustion zone where the billet being calculated is located is the combustion zone [i] (N> i ≧ 1), and the extraction target billet temperature and the extraction target soaking degree when the billet is extracted, When given as θ _aim [N] and Δθ _aim [N], the target steel slab temperature θ _aim [j] and the target heat uniformity Δθ in the combustion zone [j] (N ≧ j> i) Based on _aim [j], when it is assumed that the combustion zone [j] is operated at the maximum furnace temperature T _fmax [j] due to equipment constraints or operation constraints, The steel, such that the outgoing side slab temperature θ [j] and the outgoing side soaking degree Δθ [j] are the outgoing side target steel slab temperature θ _aim [j] and the outgoing side target soaking degree Δθ _aim [j]. Outlet side slab temperature θ [j-1] and exit side average of the combustion zone [j-1] immediately preceding the combustion zone [j] of the piece The degree of heat Δθ [j-1] is calculated, and the calculated outlet side slab temperature θ [j-1] and the outlet side soaking degree Δθ [j-1] are output to the outlet side of the combustion zone [j-1]. By repeating the process of setting the target billet temperature θ _aim [j−1] and the outlet side target temperature uniformity Δθ _aim [j−1] from j = N to j = i + 1, the combustion zone that is the intermediate target value [I] Outgoing target billet temperature θ _aim [i],..., Θ _aim [N−1] and outgoing target soaking degree Δθ _aim [i] _,. Using the intermediate target value calculation unit for calculating [N-1] and the furnace temperature of each combustion zone that satisfies the restriction of the calculated intermediate target value, the optimum furnace temperature of each combustion zone for each steel slab is determined. Optimum furnace temperature calculation part to be calculated, and the calculated optimum furnace temperature for each billet for at least one billet existing in each combustion zone. There is provided a furnace temperature setting device including an optimum furnace temperature editing unit that sets the final furnace temperature of each combustion zone.

  As described above, according to the present invention, in a continuous heating furnace, it is possible to perform an operation in which the amount of fuel used is further suppressed while satisfying the restrictions on the extraction target billet temperature and the extraction target soaking degree.

It is a figure showing an example of 1 composition of a system concerning a 1st embodiment of the present invention. It is a functional block diagram which shows an example of a function structure of the optimal furnace temperature calculation part for every steel piece shown in FIG. It is a flowchart which shows an example of the process sequence of the furnace temperature setting method which concerns on 1st Embodiment. It is a flowchart which shows an example of the process sequence of the calculation method of the intermediate target value performed by step S105 shown in FIG. It is a flowchart which shows the process sequence in the specific example of the calculation method of the intermediate | middle target value performed by step S105 shown in FIG. It is a graph which shows the time change of furnace temperature in the case of changing the furnace temperature of combustion zone [i] from the current furnace temperature _Tftmp [i] to furnace temperature _Tfopt0 [i]. It is a flowchart which shows an example of the process sequence in the optimal furnace temperature calculation step which concerns on 2nd Embodiment. It is a block diagram which shows an example of the hardware constitutions of the furnace temperature setting apparatus which concerns on 1st and 2nd embodiment. It is a figure which shows the structure of the system used for the numerical experiment. It is a graph which shows the change of the furnace temperature in 1 heating zone. It is a graph which shows the change of the furnace temperature in 2 heating zones. It is a graph which shows the change of the furnace temperature in a soaking zone. It is the graph which compared the average value of the furnace temperature of 1 heating zone shown in FIG. 10, and the average value of the furnace temperature of 2 heating zones shown in FIG. It is a graph which shows the relationship between extraction steel slab temperature and extraction target steel slab temperature. It is a graph which shows the relationship between extraction soaking degree and extraction target soaking degree. It is a graph which shows the fuel usage-amount in an Example and a comparative example. It is a graph which shows the change of the furnace temperature in the combustion zone in which the steel piece made into the calculation object exists in a comparative example. It is a graph which shows the change of the furnace temperature in the combustion zone in which the steel piece made into the calculation object exists in an Example (1st Embodiment). It is a graph which shows the change of the furnace temperature in the combustion zone in which the steel piece made into the calculation object exists in an Example (2nd Embodiment). It is a graph which shows the change of the billet temperature in a heating furnace in a comparative example. It is a graph which shows the change of the billet temperature in a heating furnace in an Example (1st Embodiment). It is a graph which shows the change of the billet temperature in a heating furnace in an Example (2nd Embodiment). It is a graph which shows the required calorie | heat amount in the heating operation in a comparative example, an Example (1st Embodiment), and an Example (2nd Embodiment).

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

(1. First embodiment)
(1-1. System configuration)
With reference to FIG. 1, a configuration example of a system according to the first embodiment of the present invention will be described. FIG. 1 is a diagram illustrating a configuration example of a system according to the first embodiment of the present invention.

  Referring to FIG. 1, a system 1 according to the first embodiment includes a heating furnace 10 and a furnace temperature setting device 20. In the system 1, the optimum furnace temperature of the heating furnace 10 is calculated by the furnace temperature setting device 20 such that the amount of fuel used is further suppressed while satisfying the restrictions on the extraction target billet temperature and the extraction target soaking degree. Then, the furnace temperature of the heating furnace 10 is controlled according to the optimum furnace temperature calculated by the furnace temperature setting device 20.

(Heating furnace 10)
FIG. 1 shows a cross-sectional view of the heating furnace 10 cut along a cross section parallel to the furnace length direction (left and right direction on the paper surface). Referring to FIG. 1, the heating furnace 10 conveys the steel piece S in the furnace length direction in the furnace body 110, a plurality of burners 120 installed in the furnace body 110 along the furnace length direction, and the furnace body 110. It mainly includes a skid 130, a plurality of thermometers 140 installed in the furnace body 110 along the furnace length direction, and a burner control unit 150 that controls the combustion amount of the burner 120.

  A plurality of burners 120 are installed in the furnace body 110 along the furnace length direction. The burner control unit 150 controls the combustion amount of the burner 120 by giving the burner 120 an instruction value of the fuel flow rate that realizes the optimum furnace temperature calculated by the furnace temperature setting device 20. In FIG. 1, for simplicity, only one burner 120 is illustrated as being controlled by the burner control unit 150, but in reality, all the burners 120 installed in the furnace body 110 are illustrated. The burner control unit 150 can control the combustion amount of

  The skid 130 is configured by a skid beam extending in the furnace length direction being supported by a plurality of skid posts extending in the furnace height direction (up and down direction on the paper surface). A plurality of skids 130 are installed in the furnace width direction (perpendicular to the paper surface), and the steel piece S placed on the skid 130 is moved in the furnace length direction by moving back and forth in the furnace length direction while moving up and down in the furnace height direction. Transport to.

  A plurality of thermometers 140 are installed in the furnace body 110 along the furnace length direction, and measure the furnace temperature at a predetermined sampling period. Information about the furnace temperature measurement value by the thermometer 140 is provided to the furnace temperature setting device 20 as one of the heating furnace information. In FIG. 1, for the sake of simplicity, only the furnace temperature measurement value by one thermometer 140 is illustrated as being provided to the furnace temperature setting device 20 as the heating furnace information. The furnace temperature measured values by all the thermometers 140 installed in the body 110 can be provided to the furnace temperature setting device 20 as heating furnace information.

  Although illustration is omitted, in addition to the thermometer 140, the furnace body 110 may be provided with various measuring devices for measuring various conditions in the furnace (for example, the pressure in the furnace). Measurement values obtained by these measuring instruments can also be provided to the furnace temperature setting device 20 as one piece of heating furnace information.

  In the heating furnace 10, the steel slab S is conveyed in the furnace length direction by the skid 130 in a state where the burner 120 is cooked at a predetermined combustion amount by the burner control unit 150, so that the steel slab S is Heated. The slab S is charged into the furnace body 110 from an inlet provided on the furnace wall at one end (charging side) in the furnace length direction of the furnace body 110 so that the furnace width direction is the longitudinal direction. Is done. And the steel piece S is conveyed by the skid 130, and is extracted from the extraction port provided in the furnace wall of the other side (extraction side) edge part in the furnace length direction of the furnace body 110. FIG.

  As illustrated, a plurality of steel pieces S can be sequentially inserted into the heating furnace 10. The interior of the furnace body 110 is divided into a plurality of sections (combustion zones) in the furnace length direction. In the illustrated example, the heating furnace 10 has a pre-tropical zone, a 1 heating zone, a 2 heating zone, and a soaking zone as combustion zones. The steel slab S is heated so that the desired steel slab temperature and the desired soaking degree are obtained when the steel slab S sequentially passes through the pre-tropical zone, the first heating zone, the second heating zone, and the soaking zone.

  Although not shown, the heating furnace 10 is further provided with a control device that controls the heating state of the steel slab S by controlling the operation of the heating furnace 10. The burner control unit 150 described above may be a function included in the control device. The control device controls the operation of each component of the heating furnace 10 such as the burner 120 and the skid 130, for example, the furnace temperature, the conveying speed of the steel slab S, the pressure in the furnace, the amount of air in the furnace, etc. The steel piece S is heated. In addition, since the function of the said control apparatus may be the same as the function which the control apparatus of a general continuous heating furnace has, the detailed description is abbreviate | omitted here.

  In addition, the structure of the heating furnace 10 shown in FIG. 1 is an example to the last, and in 1st Embodiment, the hardware structure of the heating furnace 10 is not limited, The heating furnace which is a control object has at least two combustion zones ( Any heating furnace may be used as long as it has a pre-tropical zone, at least one of one or a plurality of heating zones, and a soaking zone, and may be any type of heating furnace. For example, in the illustrated example, the heating furnace 10 having two heating zones is used, but the heating furnace to be controlled may be a heating furnace having only one heating zone. In the illustrated example, the heating furnace 10 is a so-called walking beam type heating furnace to which the skid 130 is applied as a transfer device, but the heating furnace to be controlled is a heating to which another transfer device is applied. It may be a furnace. In addition, as another example of the configuration of the heating furnace 10 that can be controlled in the first embodiment, it is described in, for example, “Japan Industrial Furnace Association,“ New Edition Industrial Furnace Handbook ”, Part II Section 2.3”. The structure of the various heating furnaces which can be mentioned can be mentioned.

(Furnace temperature setting device 20)
The furnace temperature setting device 20 includes a billet temperature calculation unit 210, an optimum furnace temperature calculation unit 220 for each billet, and an optimum furnace temperature editing unit 230 as functions thereof. Each function of the furnace temperature setting device 20 is realized by a processor constituting the furnace temperature setting device 20 operating according to a predetermined program. In the furnace temperature setting device 20, a billet temperature calculation unit 210, a billet optimum furnace temperature calculation unit 220, and an optimum furnace temperature editing unit 230 are assigned to each function at a predetermined cycle (for example, 3 to 5 (min)). By repeatedly executing the calculated processing, the optimum furnace temperature is repeatedly calculated in this cycle.

(Slab temperature calculator 210)
The slab temperature calculation unit 210 calculates the current slab temperature of one slab S as a calculation target based on the slab information and the heating furnace information. Here, the billet information is information related to the billet S such as the extraction target billet temperature, the extraction target soaking degree, and the position of each billet S in the furnace. In addition, the billet information may include various pieces of information about the billet S generally required for operation of the continuous heating furnace, such as the size of each billet S and the steel type of each billet S.

  The heating furnace information is information related to the heating furnace 10 such as the current furnace temperature and the current fuel flow rate provided to each burner 120 (that is, the current combustion amount of each burner 120). In addition, the heating furnace information may include various types of information about the heating furnace that are generally required for operation of the continuous heating furnace, such as the furnace pressure and the amount of air in the furnace.

  Since the billet information and the heating furnace information can be used for the control of the heating furnace 10, for example, it is stored in the control device of the heating furnace 10 described above, and the billet temperature calculation unit 210 and the steel from the control device. Each piece is provided to the optimum furnace temperature calculation unit 220. Or about the information (for example, furnace temperature, furnace pressure, etc.) obtained by actually measuring among billet information and furnace information, for example, each measuring instrument (thermometer 140) provided in the furnace 10 is used. , A pressure gauge, etc.) may be directly provided from the measuring device to the billet temperature calculation unit 210 and the optimum billet temperature calculation unit 220 for each billet. In FIG. 1, typically, a state in which a furnace temperature measurement value by the thermometer 140 is provided to the billet temperature calculation unit 210 and the optimum billet temperature calculation unit 220 for each billet as heating furnace information is schematically illustrated. However, as described above, the heating furnace information may include various types of information related to the heating furnace in addition to the furnace temperature.

  Specifically, the billet temperature calculation unit 210 calculates the billet temperature of the billet S calculated by itself in the previous step, the current furnace temperature measured by the thermometer 140, and the billing steel. Based on the current in-furnace position of the piece S, the current billet temperature of the billet S to be calculated can be calculated. Here, the information about the billet temperature of the billet S and the current in-furnace position is included in the billet information. Information about the furnace temperature is included in the heating furnace information. In addition, the calculation method of the billet temperature by the billet temperature calculation unit 210 is not limited, and the calculation method is generally used as a billet temperature calculation method such as a heat transfer calculation or an approximate calculation by a difference method or an implicit method. Since various methods used in the above are applicable, a description of a specific method for calculating the billet temperature by the billet temperature calculation unit 210 is omitted here.

  The billet temperature calculation unit 210 calculates the billet temperature for each billet S present in the furnace. And the billet temperature calculation part 210 provides the information about the billet temperature of each billet S to the optimal furnace temperature calculation part 220 for every billet with other billet information.

(Optical furnace temperature calculation unit 220 for each steel piece)
The optimum furnace temperature calculation unit 220 for each billet calculates the optimum furnace temperature of each combustion zone for one billet S as a calculation object based on the billet information and the heating furnace information. Here, the optimum furnace temperature of each combustion zone for the slab S is that the extracted slab temperature and the extracted soaking degree of the slab S satisfy the constraints of the extracted target slab temperature and the extracting target soaking degree, It is the furnace temperature of each combustion zone where the amount of fuel used from the current position in the furnace to the extraction port is further suppressed. In addition, the function of the optimum furnace temperature calculation unit 220 for each slab will be described in detail later (1-2. Functional configuration of the optimum furnace temperature calculation unit 220 for each slab).

  The optimum furnace temperature calculation unit 220 for each billet calculates the optimum furnace temperature of each combustion zone for each billet S present in the furnace. Then, the optimum furnace temperature calculation unit 220 for each billet provides the optimum furnace temperature editing unit 230 with information relating to the calculated optimum furnace temperature of each combustion zone for each billet S.

(Optimum furnace temperature editor 230)
The optimum furnace temperature editing unit 230 edits the optimum furnace temperature of each combustion zone for each steel piece S calculated by the optimum furnace temperature calculation unit 220 for each steel piece, and sets the final optimum furnace temperature for each combustion zone. To do. The method for setting the final optimum furnace temperature of each combustion zone by the optimum furnace temperature editing unit 230 is not limited, and various commonly used methods may be used as the setting method. For example, the optimum furnace temperature editing unit 230 sets the maximum value or average value of the optimum furnace temperature of the combustion zone for each steel slab S present in each combustion zone as the final optimum furnace temperature of each combustion zone. Can do. Further, for example, the optimum furnace temperature editing unit 230 sets the optimum furnace temperature of the combustion zone for the steel slab S located in the place closest to the extraction side of each combustion zone, respectively, for the final optimum furnace of each combustion zone. It can be warm.

  The configuration example of the system 1 according to the first embodiment has been described above with reference to FIG. In the embodiment described above, the slab temperature calculation unit 210 and the optimum slab temperature calculation unit 220 for each slab each calculate the slab temperature and the optimum furnace temperature of each combustion zone for each slab S present in the furnace. The case where the optimum furnace temperature editing unit 230 calculates and calculates the optimum furnace temperature of each combustion zone by editing the optimum furnace temperature of each combustion zone for each steel slab S has been described. One embodiment is not limited to such an example. For example, from among a plurality of steel slabs S present in the furnace, the neck material that is considered to be the most difficult to satisfy the constraints of the extraction steel slab temperature and the extraction target soaking temperature at present, the extraction steel slab temperature and the extraction soaking temperature. For each neck material, the slab temperature calculation unit 210 and the slab optimum furnace temperature calculation unit 220 may calculate the slab temperature and the optimum furnace temperature for each combustion zone. In this case, the optimum furnace temperature editing unit 230 can set the optimum furnace temperature of the combustion zone corresponding to each neck material calculated for each neck material as the final optimum furnace temperature of each combustion zone. .

  As a method for selecting the neck material, various methods that can be generally assumed can be used. As an example, ((extraction target slab temperature) − (current slab temperature)) / (remaining furnace time until extraction) is calculated for each slab, and the slab S having the largest value is the neck material. May be considered. Since this value represents the rate of increase in billet temperature with respect to the remaining furnace time until extraction, the larger the value, the less likely it is to satisfy the constraints on the extraction target billet temperature and the extraction target soaking degree. Because.

  Here, the configuration illustrated in FIG. 1 is merely an example of the system 1 according to the first embodiment, and the specific configuration of the system 1 is not limited to such an example. For example, the system 1 may be provided with a storage device that stores various information used by the furnace temperature setting device 20 such as billet information and heating furnace information. In this case, the billet temperature calculation unit 210 and the billet optimum furnace temperature calculation unit 220 can acquire billet information and furnace information by accessing the storage device.

  Moreover, each function with which the furnace temperature setting apparatus 20 is provided may not be performed in one apparatus, and may be performed by cooperation of a several apparatus. For example, one device having only one of the functions of the billet temperature calculating unit 210, the optimum furnace temperature calculating unit 220 for each billet, and the optimum furnace temperature editing unit 230 communicates with other devices having other functions. The function equivalent to the furnace temperature setting apparatus 20 shown in figure may be implement | achieved by connecting so that it is possible. In addition, the system 1 can take any configuration that can be generally assumed.

  Further, a computer program for realizing each function of the furnace temperature setting device 20 shown in FIG. 1, particularly each function of the optimum steel piece temperature calculating unit 220 shown in FIG. Can be implemented. In addition, a computer-readable recording medium storing such a computer program can be provided. The recording medium is, for example, a magnetic disk, an optical disk, a magneto-optical disk, or a flash memory. Further, the above computer program may be distributed via a network, for example, without using a recording medium.

(1-2. Functional Configuration of Optimum Furnace Temperature Calculation Unit 220 for each Billet)
(1-2-1. Overall configuration)
With reference to FIG. 2, the function of the optimum furnace temperature calculation unit 220 for each billet will be described in detail. FIG. 2 is a functional block diagram showing an example of a functional configuration of the steel piece optimum furnace temperature calculation unit 220 shown in FIG.

  Referring to FIG. 2, the optimum furnace temperature calculation unit 220 for each billet includes, as its function, a data acquisition unit 221, an intermediate target value calculation unit 222, an optimum furnace temperature calculation unit 223 for each combustion zone, and an optimum furnace temperature output. Part 224.

  When the intermediate target value calculation unit 222 calculates the outlet side billet temperature (intermediate target billet temperature) of each combustion zone and the outlet side target temperature uniformity (intermediate target temperature uniformity) of each combustion zone, the data acquisition unit 221 Steel bill information and furnace information to be used for the acquisition. In the following description, the intermediate target slab temperature and the intermediate target soaking degree are collectively referred to as an intermediate target value. The data acquisition unit 221 acquires billet information including information on the current billet temperature from the billet temperature calculation unit 210. Moreover, the data acquisition part 221 acquires the heating furnace information containing the information about the present furnace temperature from measuring devices, such as the thermometer 140 installed in the control apparatus of the heating furnace 10, or a heating furnace. The data acquisition unit 221 provides the acquired billet information and furnace information to the intermediate target value calculation unit 222.

  The intermediate target value calculation unit 222 calculates an intermediate target value (that is, an intermediate target billet temperature and an intermediate target soaking degree) for one billet S to be calculated based on the billet information and the heating furnace information. . The intermediate target value calculation unit 222 determines that the extracted slab temperature and the extracted soaking degree of the slab S to be calculated satisfy the constraints of the extracted target slab temperature and the extracted target soaking degree, An intermediate target value is calculated so that the amount of fuel used from the position to the extraction port can be further suppressed. The intermediate target value calculation unit 222 provides information about the calculated intermediate target value to the optimum furnace temperature calculation unit 223 for each combustion zone. The method of calculating the intermediate target value by the intermediate target value calculation unit 222 will be described in detail later (1-2-2. Method of calculating the intermediate target value).

  The optimum furnace temperature calculation unit 223 for each combustion zone calculates the furnace temperature of each combustion zone based on the intermediate target values (intermediate target billet temperature and intermediate target soaking degree) calculated by the intermediate target value calculation unit 222. Specifically, the optimum furnace temperature calculation unit 223 for each combustion zone calculates, by the intermediate target value calculation unit 222, the outlet side slab temperature and the outgoing side soaking degree of each combustion zone of one steel slab S to be calculated. The furnace temperature of each combustion zone is calculated so as to satisfy the constraints of the intermediate target values (intermediate target slab temperature and intermediate target soaking degree). The calculation method of the furnace temperature of each combustion zone by the optimum furnace temperature calculation unit 223 for each combustion zone is not limited, and in the first embodiment, as the calculation method, an intermediate target billet temperature and an intermediate target soaking degree are given. In this case, various methods generally used as a method for calculating the furnace temperature in each combustion zone may be used. For example, the optimum furnace temperature calculation unit 223 for each combustion zone can calculate the furnace temperature of each combustion zone using the method described in Non-Patent Document 1 and Patent Document 2. The optimum furnace temperature calculation unit 223 for each combustion zone provides the information about the calculated furnace temperature of each combustion zone to the optimum furnace temperature output unit 224.

  As described above, the intermediate target value calculation unit 222 allows the extracted slab temperature and the extracted soaking degree of the slab S to be calculated to satisfy the constraints of the extracted target slab temperature and the extracted target soaking degree, An intermediate target value is calculated so that the amount of fuel used for S from the current position in the furnace to the extraction port is further suppressed. Therefore, the furnace temperature of each combustion zone obtained by the optimum furnace temperature calculation unit 223 for each combustion zone so as to satisfy the restriction of the intermediate target value can correspond to the optimum furnace temperature of each combustion zone.

  The optimum furnace temperature output unit 224 uses the information about the furnace temperature of each combustion zone obtained as a result of the calculation by the optimum furnace temperature calculation unit 223 for each combustion zone as the optimum furnace temperature of each combustion zone for each slab S. 1 to the optimum furnace temperature editing unit 230 shown in FIG.

  The optimum furnace temperature calculation unit 220 for each steel piece, that is, the data acquisition unit 221, the intermediate target value calculation unit 222, the optimum furnace temperature calculation unit 223 for each combustion zone, and the optimum furnace temperature output unit 224 are each a steel piece present in the furnace. Each process described above with respect to S is performed, and information on the optimum furnace temperature of each combustion zone for each steel slab S is output to the optimum furnace temperature editing unit 230. However, as described above, when obtaining the optimum furnace temperature of each combustion zone only for the neck material, the data acquisition unit 221, the intermediate target value calculation unit 222, the optimum furnace temperature calculation unit 223 for each combustion zone, and the optimum furnace temperature output The unit 224 only needs to execute the processes described above for only the neck material.

(1-2-2. Method for calculating intermediate target value)
A method for calculating the intermediate target value in the intermediate target value calculation unit 222 shown in FIG. 2 will be described in detail. In the following description, θ is the steel slab temperature, Δθ is the soaking degree, T _f is the furnace temperature, the numbers in square brackets [] are the combustion zones (1: pre-tropical zone, ..., N: soaking zone, i: calculation) It represents a combustion zone (N> i ≧ 1) in which the target steel slab S exists.

In the first embodiment, the intermediate target value calculation unit 222 repeats the procedure shown in the following (rule) from j = N to j = i + 1, so that the steel slab S is the steel slab S to be calculated. Outgoing target slab temperature θ _aim [i],..., Θ _aim [N−1] and outgoing target soaking degree Δθ _aim [i], in each combustion zone after the current combustion zone [i], ..., Δθ _aim [N−1] is obtained. The outgoing target billet temperature θ _aim [N] and the outgoing target soaking degree Δθ _aim [N] are the extraction target billet temperature and the extracting target soaking degree, respectively, and are given as billet information.

(rule)
The combustion zone [j] is subjected to equipment restrictions or operation based on the _delivery target slab temperature θ _aim [j] and the _delivery target thermal uniformity Δθ _aim [j] of the combustion zone [j] (N ≧ j> i). When it is assumed that the operation is performed at the maximum furnace temperature T _fmax [j] on the constraint, the outlet side slab temperature θ [j] and the outgoing side soaking degree Δθ [j] of the combustion zone [j] of the slab S are the above θ _aim [j] and the above-mentioned Δθ _aim [j] The outlet side slab temperature θ [j-1] and the outgoing side soaking degree Δθ of the combustion zone [j-1] immediately preceding the slab S [J-1] is calculated, and these values are calculated based on the outlet side target slab temperature θ _aim [j-1] and the outlet side target temperature uniformity Δθ _aim [j−] of the combustion zone [j-1] of the _immediately preceding stage. 1].

  The specific method for calculating the exit side slab temperature θ [j-1] and the exit side soaking degree Δθ [j-1] of the combustion zone [j-1] of the slab S is not limited, and various A method may be used. In the first embodiment, for example, as described in the following (1-2-3. Specific example of calculation method of intermediate target value), the influence of the change amount of the furnace temperature on the billet temperature and the soaking degree A method of expressing the coefficient in a linear format and calculating the outlet side slab temperature θ [j-1] and the outlet side temperature uniformity Δθ [j-1] of the combustion zone [j-1] using the influence coefficient is preferable. Can be used. However, the first embodiment is not limited to such an example. For example, the influence coefficient that the amount of change in the furnace temperature has on the slab temperature and the soaking degree is analytically obtained using various nonlinear theoretical models. The exit side slab temperature θ [j-1] and the exit side temperature uniformity Δθ [j-1] of the combustion zone [j-1] may be calculated using the influence coefficient. Alternatively, for example, by performing heat transfer calculation (heat transfer simulation) using a finite element method, the outlet side slab temperature θ [j-1] and the outgoing side temperature uniformity Δθ [j in the combustion zone [j-1]. −1] may be calculated.

  As described above, according to the first embodiment, assuming that the soaking zone [N] is operated at the maximum furnace temperature, the outlet side target billet temperature in the combustion zone [N-1] in the immediately preceding stage is assumed. And the outgoing target soaking degree is calculated. Further, assuming that the combustion zone [N-1] immediately preceding the soaking zone [N] is operated at the maximum furnace temperature, the outlet side target slab temperature in the combustion zone [N-2] immediately before that and The outgoing target soaking degree is calculated. By repeating the above calculation, the outlet side target slab temperature and the outlet side target temperature uniformity in each combustion zone up to the combustion zone [i] where the billet S to be calculated is currently located are calculated. Then, each combustion zone satisfying the constraints on the outlet side target slab temperature and the outlet side target temperature uniformity in each combustion zone calculated in this way by the optimum furnace temperature calculation section 223 for each combustion zone shown in FIG. Is calculated as the optimum furnace temperature.

  Here, as described above, for example, the method of obtaining the furnace temperature of each combustion zone in consideration of only the extraction target billet temperature and the extraction target soaking degree as exemplified in Patent Document 1, the pre-tropical zone, etc. There is a possibility that an appropriate furnace temperature cannot be set for the combustion zone before the tropical zone. In order to solve this, as in Non-Patent Document 1 and Patent Document 2, for example, intermediate target slab temperature and intermediate target soaking degree are set at intermediate points (for example, the exit side of each combustion zone), and these intermediate target steels are set. Although methods have been proposed to determine the furnace temperature of each combustion zone using the piece temperature and the intermediate target soaking degree, these methods have sufficient methodology for setting the intermediate target billet temperature and the intermediate target soaking degree. It cannot be said that it has been established.

  On the other hand, in the first embodiment, the intermediate target value calculating unit 222 sets the outlet side target slab temperature and the outlet side target temperature uniformity of each combustion zone as the intermediate target slab temperature and the intermediate target temperature uniformity. It becomes possible to set more appropriately. In general, in the operation of a continuous heating furnace, when the furnace temperature necessary to achieve the extraction target billet temperature and the extraction target soaking degree is secured, the furnace in the preceding combustion zone such as the pretropical zone is used. It is known that the unit fuel consumption is better if the so-called front-stage low-load rear-stage high-load operation, in which the temperature is relatively low and the furnace temperature in the subsequent combustion zone, such as soaking in the tropical zone, is relatively high, is performed. (For example, refer to JP 2007-308777 A and JP 2006-274421 A). As described above, according to the first embodiment, assuming that each combustion zone is operated at the maximum furnace temperature while going back in order from the soaking zone, the outlet side target slab temperature and the outlet side target average of each combustion zone are assumed. Since the heat degree is calculated, the furnace temperature is increased toward the extraction side (ie, the soaking area) by performing the operation according to the furnace temperature set based on the delivery target billet temperature and the delivery target temperature uniformity. As a result, a low-load and high-load operation is realized. That is, according to the first embodiment, it is possible to set the intermediate target slab temperature and the intermediate target soaking degree so that the fuel consumption rate is improved.

  Further, in the first embodiment, the extraction target billet temperature, the extraction target soaking degree, and the maximum furnace temperature due to equipment constraints or operation constraints (that is, the maximum possible furnace that can be realistically realized). Temperature), the outlet side slab temperature and the outgoing target soaking degree of each combustion zone are calculated, so the slab temperature and soaking degree of the slab S at the time of extraction are the extracted target slab temperature and extraction. It can be numerically guaranteed that the target soaking degree is satisfied.

  Thus, according to the first embodiment, the intermediate target slab temperature and the intermediate target soaking degree are set so as to further suppress the fuel consumption while satisfying the restrictions on the extraction target slab temperature and the extraction target soaking degree. Is done. Then, the final furnace temperature of each combustion zone is set based on the intermediate target billet temperature and the intermediate target soaking degree. Therefore, it becomes possible to set the furnace temperature of each combustion zone so as to further suppress the fuel consumption while satisfying the restrictions on the extraction target billet temperature and the extraction target soaking degree.

(1-2-3. Specific example of calculation method of intermediate target value)
As a specific example of the calculation method of the intermediate target value by the intermediate target value calculation unit 222 described above, the influence coefficient that the change amount of the furnace temperature has on the billet temperature and the soaking degree is represented by a linear form, and the influence coefficient is used. The method of calculating the outlet side slab temperature θ [j-1] and the outlet side soaking degree Δθ [j-1] of the combustion zone [j-1] will be described in detail.

In the method, the intermediate target value calculation unit 222 first operates the combustion zone [i] where the steel slab S exists at the current furnace temperature T _ftmp [i], and _installs the combustion zones after the combustion zone [i + 1]. , T _fmax [N], assuming that the maximum furnace temperature T _fmax [i + 1],..., T _fmax [N] due to constraints or operation constraints is assumed, the predicted exit slab temperature θ ₀ ′ [i] of each combustion zone _{, ···, θ 0 '[N} ] and the exit-side prediction soaking degree _{Δθ 0' [i], ···} , to calculate the Δθ ₀ '[N]. For example, the intermediate target value calculation unit 222 includes T _ftmp [i], T _fmax [i + 1],..., T _fmax [N] obtained from the heating furnace information and the current calculated by the billet temperature calculation unit 210. billets temperature theta and [i], using, by performing heat transfer calculations, the delivery side prediction billet temperature _{θ 0 '[i], ···} , θ 0' [N] and the exit-side prediction Hitoshi Heat degrees Δθ ₀ ′ [i],..., Δθ ₀ ′ [N] can be calculated.

Next, the intermediate target value calculation unit 222 perturbs only the furnace temperature in the combustion zone [k] (N ≧ k> i) by the above-described T _fmax [k] to ΔT _f [k], and sets the other combustion zones. _Assuming that the furnace temperature is _operated as T _ftmp [i], T _fmax [i + 1],..., T _fmax [N], the predicted predicted slab temperature θ ₁ in the combustion zone [k]. '[K] and the predicted outgoing heat uniformity Δθ ₁ ' [k] are calculated by, for example, the same heat transfer calculation.

Next, the intermediate target value calculation part 222 calculates | requires influence coefficient (alpha), (beta) with respect to the steel piece temperature and the soaking | uniform-heating degree of the furnace temperature change amount in combustion zone [k] according to following formula (1), (2). Since the furnace temperature T _fmax [i + 1],..., T _fmax [N] is the maximum furnace temperature due to equipment restrictions or operation restrictions, the perturbation ΔT _f [k] given is basically negative. However, since the value of the perturbation ΔT _f [k] is very small, the influence coefficients α and β are values that do not depend on the positive / negative direction of the perturbation.

  The intermediate target value calculation unit 222 repeats the above calculation up to k = i + 1,..., N, and α [i + 1],..., Α [N], β [i + 1],. N].

Then, the intermediate target value calculation unit 222 uses the calculated influence coefficients α and β, and the outlet side billet temperature θ [j−1] and the outlet side in the combustion zone [j−1] described in the above (rule). The soaking degree Δθ [j−1] is obtained according to the following mathematical formulas (3) and (4), and these values are calculated based on the outlet side target slab temperature θ _aim [j−1] and the outlet temperature in the combustion zone [j−1]. The side target soaking degree Δθ _aim [j−1].

  Heretofore, an example of a method for calculating the intermediate target value by the intermediate target value calculation unit 222 has been described.

(1-3. Furnace temperature setting method)
(1-3-1. Overall processing)
With reference to FIG. 3, the process sequence of the furnace temperature setting method which concerns on 1st Embodiment is demonstrated. FIG. 3 is a flowchart showing an example of a processing procedure of the furnace temperature setting method according to the first embodiment. Each process shown in FIG. 3 corresponds to each process executed by the furnace temperature setting device 20 shown in FIG.

  Referring to FIG. 3, in the furnace temperature setting method according to the first embodiment, first, the current billet temperature of one billet S to be calculated is calculated based on billet information and heating furnace information. (Step S101: Billet temperature calculation step). Specifically, for example, the billet temperature of the billet S as the calculation target calculated by itself in the previous step, the current furnace temperature measured by the thermometer 140, and the current furnace of the billet S as the calculation target Based on the internal position or the like, the current billet temperature of the billet S to be calculated can be calculated using heat transfer calculation or the like. However, the method for calculating the billet temperature in step S101 is not limited to such an example, and various methods that can be generally used for calculating the billet temperature may be used in step S101. Note that the processing shown in step S101 corresponds to the processing executed by the billet temperature calculation unit 210 shown in FIG.

  The processes shown in the following steps S103 to S109 correspond to the processes executed by the optimum steel piece temperature calculating unit 220 shown in FIG.

  When the billet temperature of the billet S is calculated in step S101, the billet information including the billet temperature of the billet S and the heating furnace information is acquired (step S103: data acquisition step). ). Note that the process shown in step S103 corresponds to the process executed by the data acquisition unit 221 shown in FIG.

  Next, based on the billet information and the furnace information, an intermediate target value (that is, an intermediate target billet temperature and an intermediate target soaking degree) for one billet S that is a calculation target is calculated (step S105: Intermediate target value calculation step). In the process shown in step S105, the extracted slab temperature and the extracted soaking degree of the billet S to be calculated satisfy the constraints of the extracted target slab temperature and the extracted target soaking degree, and the slab S is located in the current position in the furnace. The intermediate target value is calculated so that the amount of fuel used from the start to the extraction port can be further suppressed. The details of the intermediate target value calculation method executed in step S105 will be described later in (1-3-2. Intermediate target value calculation method). Note that the processing shown in step S105 corresponds to the processing executed by the intermediate target value calculation unit 222 shown in FIG.

  Next, the optimum furnace temperature of each combustion zone is calculated based on the intermediate target value (intermediate target billet temperature and intermediate target soaking degree) calculated in step S105 (step S107: optimal furnace temperature calculation step). More specifically, in step S107, the intermediate side value (intermediate target slab temperature and intermediate target value) in which the outgoing side slab temperature and the outgoing temperature uniformity of each combustion zone of one steel slab S to be calculated are calculated in step S105. The furnace temperature of each combustion zone that satisfies the constraint of the intermediate target heat uniformity is calculated as the optimum furnace temperature of each combustion zone. For example, in step S107, the furnace temperature of each combustion zone is calculated using the methods described in Non-Patent Document 1 and Patent Document 2. When the intermediate slab temperature and the intermediate soaking degree of the slab S satisfy the restriction of the intermediate target value calculated in step S105, the extracted slab temperature and the extracted soaking degree of the slab S are consequently extracted. The constraints on the target billet temperature and the extraction target soaking degree will be satisfied. Note that the process shown in step S107 corresponds to the process executed by the optimum furnace temperature calculation unit 223 for each combustion zone shown in FIG.

  Next, the information regarding the optimum furnace temperature of each combustion zone about each steel piece S calculated in step S107 is output (step S109: optimum furnace temperature output step). Note that the process shown in step S109 corresponds to the process executed by the optimum furnace temperature output unit 224 shown in FIG.

  In the furnace temperature setting method according to the first embodiment, the processes shown in steps S103 to S109 described above are calculated for all the steel pieces S existing in the furnace.

  Once the optimum furnace temperature of each combustion zone is calculated for each billet S, the optimum furnace temperature of each combustion zone for each billet S is then edited, and the final optimum furnace temperature for each combustion zone is set. (Step S111: Optimal furnace temperature editing step). For example, in step S111, the maximum value or average value of the optimum furnace temperature of the combustion zone for each steel piece S present in each combustion zone may be set as the final optimum furnace temperature of each combustion zone. However, the method for obtaining the final optimum furnace temperature of each combustion zone in step S111 is not limited to such an example, and various commonly used methods may be used in step S111. For example, the optimum furnace temperature of the combustion zone with respect to the steel piece S located in the place closest to the extraction side of each combustion zone may be set as the final optimum furnace temperature of each combustion zone. Note that the process shown in step S111 corresponds to the process executed by the optimum furnace temperature editing unit 230 shown in FIG.

  The processing procedure of the optimum furnace temperature setting method according to the first embodiment has been described above with reference to FIG. When a neck material is selected from the steel slab S for each combustion zone and the optimum furnace temperature of each combustion zone is calculated only for the neck material, the processing shown in steps S103 to S109 is performed for the neck. It may be done only on the material. In this case, in the process shown in step S111, the optimum furnace temperature of the combustion zone corresponding to each neck material calculated for each neck material can be made the final optimum furnace temperature of each combustion zone.

(1-3-2. Method for calculating intermediate target value)
With reference to FIG. 4, the intermediate target value calculation method executed in step S105 shown in FIG. 3 will be described in detail. FIG. 4 is a flowchart showing an example of the processing procedure of the intermediate target value calculation method executed in step S105 shown in FIG.

Referring to FIG. 4, in the method of calculating the intermediate target value according to the first embodiment, first, j = N (N ≧ j> i), and the outlet side target slab temperature θ _aim [ The extracted target billet temperature θ _aim [N] and the extracted target temperature uniformity Δθ _aim [N] are set as j] and the _delivery target temperature uniformity Δθ _aim [j] (step S201).

Next, assuming that the combustion zone [j] is operated at the maximum furnace temperature T _fmax [j] due to equipment constraints or operation constraints, the outlet side billet temperature θ [j] of the combustion zone [j] of the billet S ] and the exit-side soaking degree [Delta] [theta] [j] is such that the theta _aim [j] and the [Delta] [theta] _aim [j], the delivery side slab of one of the steel strip S preceding the combustion zone [j-1] The temperature θ [j-1] and the outgoing side temperature uniformity Δθ [j-1] are calculated, and these values are calculated as the outgoing target billet temperature θ _aim [j-1] and the outgoing temperature of the combustion zone [j-1]. The side target soaking degree Δθ _aim [j−1] is set (step S203).

  In step S203, a specific method for calculating the outgoing side slab temperature θ [j-1] and the outgoing side temperature uniformity Δθ [j-1] of the combustion zone [j-1] of the slab S is as follows. Without being limited, various methods may be used. In the first embodiment, for example, the influence that the amount of change in the furnace temperature has on the billet temperature and the degree of soaking, as described below (1-3-3. Specific example of calculation method of intermediate target value). A method of expressing the coefficient in a linear format and calculating the outlet side slab temperature θ [j-1] and the outlet side temperature uniformity Δθ [j-1] of the combustion zone [j-1] using the influence coefficient is preferable. Can be used. However, the first embodiment is not limited to such an example. For example, the influence coefficient that the amount of change in the furnace temperature has on the slab temperature and the soaking degree is analytically obtained using various nonlinear theoretical models. The exit side slab temperature θ [j-1] and the exit side temperature uniformity Δθ [j-1] of the combustion zone [j-1] may be calculated using the influence coefficient. Alternatively, for example, by performing heat transfer calculation using the finite element method, the outlet side slab temperature θ [j-1] and the outgoing side temperature uniformity Δθ [j-1] of the combustion zone [j-1] are calculated. May be.

When the outgoing side target slab temperature θ _aim [j−1] and the outgoing side target heat uniformity Δθ _aim [j−1] of the combustion zone [j−1] are obtained in step S203, j = i + 1. Whether or not the obtained outlet side slab temperature θ _aim [j−1] and the outgoing side target temperature uniformity Δθ _aim [j−1] are the combustions in which the billet S to be calculated is currently located It is determined whether it is for the band [i] (step S205).

  When j = i + 1 is not true, the result of calculation retroactively from the soaking zone [N] results in the target slab temperature in the combustion zone [i] where the billet S to be calculated is currently located, This means that the calculation has not yet been performed up to the delivery target temperature uniformity. Accordingly, when it is determined in step S205 that j = i + 1 is not satisfied, j is decremented (step S207), and the process returns to step S203. Similarly, the outlet side target slab temperature and the outlet side target temperature uniformity are obtained for the previous combustion zone.

When j = i + 1, as a result of calculating retroactively from the soaking zone [N], the target steel slab temperature in the combustion zone [i] where the billet S to be calculated is currently located It means that the calculation has been performed up to the delivery target temperature uniformity. Therefore, if it is determined in step S205 that j = i + 1, the exit side of each combustion zone from the combustion zone [i], which is the calculation result, to the combustion zone [N-1] that is one stage before the soaking zone. Outputs the target billet temperature and the outgoing target temperature uniformity (θ _aim [i],..., Θ _aim [N−1], Δθ _aim [i],..., Δθ _aim [N−1]). (Step S209), a series of calculations is terminated.

  In the first embodiment, the series of processes shown in FIG. 4 described above is executed for all the steel slabs S present in the furnace, and the outlet side target slab temperature of each combustion zone for each steel slab S And the output side target temperature uniformity is output. However, as described above, when calculating the optimum furnace temperature of each combustion zone only for the neck material, the series of processes shown in FIG. 4 described above may be performed only for the neck material.

  The processing procedure of the intermediate target value calculation method according to the first embodiment has been described above with reference to FIG. Note that the processing procedure shown in FIG. 4 corresponds to the calculation method described in (1-2-2. Intermediate target value calculation method) expressed as a specific processing procedure.

(1-3-3. Specific example of calculation method of intermediate target value)
As a specific example of the calculation method of the intermediate target value in step S105 shown in FIG. 3 described above, referring to FIG. 5, the influence coefficient that the furnace temperature change amount has on the billet temperature and the degree of soaking is expressed in a linear form. And a method for calculating the outlet side slab temperature θ [j-1] and the outlet side temperature uniformity Δθ [j-1] of the combustion zone [j-1] using the influence coefficient will be described in detail. FIG. 5 is a flowchart showing a processing procedure in a specific example of the intermediate target value calculation method executed in step S105 shown in FIG.

  Referring to FIG. 5, in the calculation method of the intermediate target value according to this specific example, first, in steps S301 to S304, the influence coefficients α and β that the change amount of the furnace temperature has on the billet temperature and the degree of soaking are as follows. Calculated.

Specifically, first, the combustion zone [i] in which the slab S is present is operated at the current furnace temperature T _ftmp [i], and the combustion zone after the combustion zone [i + 1] is on equipment constraints or operation constraints. maximum furnace temperature _{T fmax [i + 1],} ···, on the assumption that operating in _{T fmax} [N], the delivery side prediction billet temperature theta ₀ in each combustion zone '[i], ···, θ 0 '[N] and the predicted outgoing heat uniformity Δθ ₀ ' [i],..., Δθ ₀ '[N] are calculated (step S301). For example, T _ftmp [i], T _fmax [i + 1],..., T _fmax [N] can be acquired as the heating furnace information. Further, the current billet temperature θ [i] is calculated by the processing in step S101 shown in FIG. Therefore, in step S301, by using these values, by performing the heat transfer calculations, the delivery side prediction billet temperature _{θ 0 '[i], ···} , θ 0' [N] and the exit-side prediction soaking degree Δθ ₀ ′ [i],..., Δθ ₀ ′ [N] can be calculated.

Next, k = i + 1 (N ≧ k> i) is set (step S302). And it is assumed that only the furnace temperature of the combustion zone [k] is operated by the value perturbed by ΔT _f [k] from T _fmax [k] described above, the predicted outgoing slab temperature of the combustion zone [k] θ ₁ ′ [k] and the predicted outgoing heat uniformity Δθ ₁ ′ [k] are calculated, for example, by heat transfer calculation similar to step S301 (step S303).

Next, using the calculated predicted outgoing side slab temperature θ ₀ ′ [k], θ ₁ ′ [k], and predicted outgoing side temperature uniformity Δθ ₀ ′ [k], Δθ ₁ ′ [k], From Equations (1) and (2), the influence coefficients α and β of the furnace temperature change amount on the billet temperature and the soaking degree in the combustion zone [k] are calculated (step S304).

  Next, it is determined whether or not k = N (step S305). If k = N is not satisfied, k is incremented (step S306), and the process returns to step S303. That is, the influence coefficients α and β are similarly calculated for the next combustion zone. As a result, the processes shown in step S303 and step S304 are repeated until k = i + 1,..., N, and α [i + 1],..., Α [N], β [i + 1],. , Β [N].

The subsequent processes in steps S307 to S315 correspond to the processes in steps S201 to S209 shown in FIG. However, in the processing procedure shown in FIG. 5, the processing in step S309 corresponding to step S203 (the outlet side target billet temperature θ _aim [j−1] and the outlet side target heat uniformity Δθ _aim [ j-1] is more specific.

Specifically, first, j = N (N ≧ j> i), and extraction is performed as an outlet side target slab temperature θ _aim [j] and an outlet side target temperature uniformity Δθ _aim [j] of the combustion zone [j]. The target billet temperature θ _aim [N] and the extraction target soaking degree Δθ _aim [N] are set (step S307).

Next, assuming that the combustion zone [j] operates at the maximum possible furnace temperature T _fmax [j], the outlet side slab temperature θ [j] and the outgoing side average of the combustion zone [j] of the slab S Outlet slab temperature θ [j− in the combustion zone [j−1] immediately preceding the slab S such that the heat degree Δθ [j] becomes the above θ _aim [j] and the above Δθ _aim [j]. 1] and the outgoing side temperature uniformity Δθ [j−1] are calculated using the above formulas (3) and (4), and these values are calculated as the outgoing side target billet temperature θ of the combustion zone [j-1]. _aim [j-1] and the outgoing target heat equalization degree Δθ _aim [j-1] (step S309).

Next, whether or not j = i + 1, that is, the obtained billet slab temperature θ _aim [j-1] and the billet target temperature uniformity Δθ _aim [j-1] are _bills to be calculated It is determined whether S is for the combustion zone [i] in which it is currently located (step S311).

  If it is determined in step S311 that j = i + 1 is not satisfied, j is decremented (step S313), and the process returns to step S309. Similarly, the outlet side target slab temperature and the outlet side target temperature uniformity are obtained for the previous combustion zone.

If it is determined in step S311 that j = i + 1, the outgoing target steel of each combustion zone from the combustion zone [i], which is the calculation result, to the combustion zone [N-1] one stage before the soaking zone. One-side temperature and outlet-side target temperature uniformity (θ _aim [i],..., Θ _aim [N−1], Δθ _aim [i],..., Δθ _aim [N−1]) are output (step S315), a series of calculations is terminated.

  In the first embodiment, the series of processes shown in FIG. 5 described above is performed on all the steel slabs S existing in the furnace, and the outlet side target slab temperature of each combustion zone for each steel slab S And the output side target temperature uniformity is output. However, as described above, when calculating the optimum furnace temperature of each combustion zone only for the neck material, the series of processes shown in FIG. 5 described above may be performed only for the neck material.

  The specific example of the processing procedure of the intermediate target value calculation method according to the first embodiment has been described above with reference to FIG. Note that the processing procedure shown in FIG. 5 corresponds to the calculation method described in (1-2-3. Specific example of calculation method of intermediate target value) described above as a specific processing procedure.

(2. Second Embodiment)
A second embodiment of the present invention will be described. In the first embodiment described above, the furnace temperature of each combustion zone that satisfies the constraints of the intermediate target value (intermediate target slab temperature and intermediate target soaking degree) is set to, for example, the non-patent document 1 or the patent document 2. The furnace temperature was used as it was as the optimum furnace temperature for each combustion zone. Here, in the methods described in Non-Patent Document 1 and Patent Document 2, both satisfy the restriction of the intermediate target value on the assumption that the actual furnace temperature immediately matches the set furnace temperature. The furnace temperature for each combustion zone is calculated. However, in the actual heating furnace 10, it takes a predetermined time (follow-up time) from instructing the change of the furnace temperature until the furnace temperature is changed to the set value. Therefore, when the furnace temperature calculated by the method described in Non-Patent Document 1 or Patent Document 2 is used as a set value as it is, the furnace temperature in each combustion zone of the heating furnace 10 is controlled, the follow-up time is set. Since there is a difference between the actual furnace temperature and the set furnace temperature, there is a possibility that the slab temperature and the soaking degree of the slab S cannot be controlled to desired values (that is, the intermediate target slab temperature and the intermediate target soaking degree). There is.

  Such a tendency is considered to be remarkable when the remaining in-furnace time of the steel slab S (the in-furnace time of the steel slab S until it is extracted from the location where it is present) is short. This is because, when the remaining furnace time of the steel slab S is short, the difference in the furnace temperature corresponding to the follow-up time has a greater effect on the steel slab temperature and the degree of soaking.

  Therefore, in the second embodiment, after calculating the furnace temperature of each combustion zone that satisfies the constraint of the intermediate target value, the furnace temperature is corrected in consideration of the follow-up time, and the corrected furnace The temperature is regarded as the optimum furnace temperature. By performing the heating furnace operation using the optimum furnace temperature thus obtained, even the steel slab S having a short remaining furnace time as described above, the slab temperature and the degree of soaking can be more accurately determined. It becomes possible to control.

  Hereinafter, the second embodiment will be described in detail. The second embodiment is different from the first embodiment described above in terms of the function of the optimum furnace temperature calculation unit 223 for each combustion zone shown in FIG. 2 and step S107 (optimum furnace temperature calculation step) shown in FIG. This corresponds to a change in the content of the process. Since other matters are the same as those in the first embodiment, in the following explanation of the second embodiment, explanations of items that are the same as those in the first embodiment are omitted, and the first embodiment is omitted. Only matters that differ from the above will be explained.

(2-1. Function of optimum furnace temperature calculation unit 223 for each combustion zone)
The function of the optimum furnace temperature calculation unit 223 for each combustion zone in the second embodiment will be described. In the second embodiment, the optimum furnace temperature calculation unit 223 for each combustion zone first uses a method similar to that in the first embodiment (for example, the method described in Non-Patent Document 1 or Patent Document 2). The intermediate slab temperature calculated by the intermediate target value calculator 222 (intermediate target slab temperature and intermediate target slab temperature) is calculated by the intermediate target value calculator 222. Calculate the furnace temperature of each combustion zone that satisfies the constraint of (heat level). The furnace temperature of each combustion zone calculated in this way is _defined as T _fopt0 [i],..., T _fopt0 [N].

Here, T _fopt0 [i],..., T _fopt0 [N] does not take into account the follow-up time described above. Therefore, in the second embodiment, the optimum furnace temperature calculation unit 223 for each combustion zone corrects the furnace temperature T _opt0 [i] in consideration of the follow-up time according to the following procedure.

Note that the optimum furnace temperature calculation unit 223 for each combustion zone does not perform correction processing such as the furnace temperature T _fopt0 [i] for T _fopt0 [i + 1],..., T _fopt0 [N]. Since it takes a sufficiently long time for the steel piece S to reach the combustion zone [i + 1],..., The combustion zone [N], the combustion zone [i + 1],. For the furnace temperature T _fopt0 [i + 1],..., T _fopt0 [N] of [N], the slab S is in the combustion zone [i + 1] _,. ], The furnace temperature can be changed to T _fopt0 [i + 1],..., T _fopt0 [N].

Specifically, the optimum furnace temperature calculation unit 223 for each combustion zone changes the furnace temperature when the furnace temperature of the combustion zone [i] is changed from the current furnace temperature T _ftmp [i] to the furnace temperature T _fopt0 [i]. Predict the time change of The time change of the furnace temperature can be expressed as a graph showing the relationship between the time and the furnace temperature, for example, as shown in FIG.

FIG. 6 is a graph showing the change in the furnace temperature over time when the furnace temperature in the combustion zone [i] is changed from the current furnace temperature T _ftmp [i] to the furnace temperature T _opt0 [i]. In FIG. 6, the horizontal axis represents time, the vertical axis represents the furnace temperature, and the combustion zone from the current time t _tmp to the banding time t _out (time when the steel piece S exits the combustion zone [i] where the steel piece S is currently located) [ i] changes in the furnace temperature are plotted. As shown in FIG. 6, the actual furnace temperature coincides with the set furnace temperature T _opt0 [i] with a delay of the follow-up time t _flw [i].

In FIG. 6, the area of the region surrounded by the furnace temperature when the follow-up time is assumed to be zero and the time until the steel piece S leaves the combustion zone [i] is defined as S ₁ [i]. That is, S ₁ [i] is a combustion when it is assumed that the furnace temperature of the combustion zone [i] is changed from the current furnace temperature T _ftmp [i] to the set furnace temperature T _fopt0 [i] without time delay. It is an integral value for the time from the current time t _tmp to the time t _out when the billet leaves the combustion zone [i], of the difference between the furnace temperature of the zone [i] and T _ftmp [i]. In the example illustrated in FIG. 6, S ₁ [i] is a rectangular area represented by a product of (T _opt0 [i] −T _ftmp [i]) and (t _out −t _tmp ). .

On the other hand, in FIG. 6, the area of the region surrounded by the furnace temperature in consideration of the follow-up time t _flw [i] and the time until the steel piece S leaves the combustion zone [i] is represented by S ₂ [i]. And That is, in S ₂ [i], the furnace temperature of the combustion zone [i] is changed from the current furnace temperature T _ftmp [i] to the set furnace temperature T _fopt0 [i] with a delay of the follow-up time t _flw [i]. Of the difference between the furnace temperature of the combustion zone [i] and T _ftmp [i], the integrated value of the time from the current time t _tmp to the time t _out when the billet leaves the combustion zone [i]. It is. In the example shown in FIG. 6, S ₂ [i] is an area of a region represented by a trapezoid surrounded by a graph representing the furnace temperature and the horizontal axis.

The combustion zone each optimum furnace temperature calculating unit 223, by using the area _{S 1} and the area _{S 2,} the following equation (5), tracking time _{t flw} [i] after correction furnace temperature _{T fopt} Considering [I] is obtained.

The furnace corresponding to the follow-up time t _flw [i] in the case where the furnace temperature of the combustion zone [i] is changed from the current furnace temperature T _ftmp [i] to the furnace temperature T _opt0 [i] by the above formula (5). The amount of temperature deviation is corrected.

Further, as described above, the optimum furnace temperature calculation unit 223 for each combustion zone does not perform correction processing such as T _fopt0 [i] for T _fopt0 [i + 1],..., T _fopt0 [N]. _{Let f opt} [i + 1] = T _opt0 [i + 1],..., T _opt [N] = T _opt0 [N].

The optimum furnace temperature calculation unit 223 for each combustion zone uses the T _fopt [i],..., T _fopt [N] obtained in this way as the optimum for each combustion zone for the steel piece S to be calculated. The furnace temperature is provided to the optimum furnace temperature output unit 224 shown in FIG.

  As described above, according to the second embodiment, after the intermediate target value for each combustion zone is obtained, the furnace temperature of each combustion zone that satisfies the restriction of the intermediate target value is calculated. The furnace temperature is calculated in consideration of the follow-up time. Therefore, the slab temperature and the soaking degree of the slab S can be controlled with higher accuracy, and the intermediate target value can be more reliably satisfied.

(2-2. Processing at the optimal furnace temperature calculation step)
With reference to FIG. 7, the process in the optimal furnace temperature calculation step in the second embodiment (the process in step S107 shown in FIG. 3) will be described. FIG. 7 is a flowchart showing an example of a processing procedure in the optimum furnace temperature calculation step according to the second embodiment. 7 may be executed by the optimum furnace temperature calculation unit 223 for each combustion zone.

Referring to FIG. 7, in the process in the optimum furnace temperature calculating step according to the second embodiment, first, θ _aim [i],..., Θ _aim [N], Δθ _aim [i] _,. The furnace temperatures T _opt0 [i],..., T _opt0 [N] of each combustion zone satisfying the constraint of Δθ _aim [N] are calculated (step S401). Here, θ _aim [i],..., Θ _aim [N−1], Δθ _aim [i],..., Δθ _aim [N−1] are 1 from the combustion zone [i]. These are the outlet side target slab temperature and outlet side target temperature uniformity of each combustion zone up to the preceding combustion zone [N-1], and are calculated by a series of processes shown in FIG. 4 or FIG. Further, θ _aim [N] and Δθ _aim [N] are an extraction target billet temperature and an extraction target soaking degree, and are given as billet information in advance. In step S401, the furnace temperature T _fopt0 [i],..., T _fopt0 [N] is calculated by a method that does not consider the follow-up time, such as the methods described in Non-Patent Document 1 and Patent Document 2 above. The

Next, using the calculated furnace temperature _{T fopt0} [i], from the equation (5), taking into account the follow-up time the furnace temperature _{T fopt} [i] is computed (step S403).

Next, for other combustion zones, T _fopt [i + 1] = T _fopt0 [i + 1],..., T _fopt [N] = T _fopt0 [N] (step S405). T _fopt [i],..., T _fopt [N] calculated in step S403 and step S405 is the optimum furnace temperature of each combustion zone.

  The details of the process in the optimum furnace temperature calculation step in the second embodiment have been described above with reference to FIG.

(3. Hardware configuration)
Next, the hardware configuration of the furnace temperature setting device according to the first and second embodiments will be described in detail with reference to FIG. FIG. 8 is a block diagram illustrating an example of a hardware configuration of the furnace temperature setting device according to the first and second embodiments. The hardware configuration shown in FIG. 8 can constitute the furnace temperature setting device 20 shown in FIG.

  Referring to FIG. 8, the furnace temperature setting device 900 mainly includes a CPU 901, a ROM 903, and a RAM 905. The furnace temperature setting device 900 is further connected to the CPU 901, the ROM 903, and the RAM 905 via the bus 907. The input device 909, the output device 911, the storage device 913, the drive 915, the connection port 917, And a communication device 919.

  The CPU 901 functions as an arithmetic processing device and a control device, and controls all or a part of the operation in the furnace temperature setting device 900 according to various programs recorded in the ROM 903, the RAM 905, the storage device 913, or the removable recording medium 921. The ROM 903 stores programs used by the CPU 901, calculation parameters, and the like. The RAM 905 primarily stores programs used by the CPU 901, parameters that change as appropriate during execution of the programs, and the like. These are connected to each other by a bus 907 constituted by an internal bus such as a CPU bus. In the first and second embodiments, the CPU 901 can configure the steel slab temperature calculation unit 210, the optimum steel temperature calculation unit 220 for each steel slab, and the optimum furnace temperature editing unit 230 shown in FIG.

  The input device 909 is an operation unit operated by the user, such as a mouse, a keyboard, a touch panel, a button, a switch, and a lever. The input device 909 may be, for example, remote control means (so-called remote control) using infrared rays or other radio waves, or may be an external connection device 923 such as a PDA corresponding to the operation of the furnace temperature setting device 900. There may be. Furthermore, the input device 909 includes, for example, an input control circuit that generates an input signal based on information input by the user using the above-described operation means and outputs the input signal to the CPU 901. A user of the furnace temperature setting device 900 can input various data and instruct a processing operation to the furnace temperature setting device 900 by operating the input device 909.

  The output device 911 is configured by a device capable of visually or audibly notifying acquired information to the user. Examples of such devices include CRT display devices, liquid crystal display devices, plasma display devices, EL display devices, display devices such as lamps, audio output devices such as speakers and headphones, printer devices, mobile phones, and facsimiles. The output device 911 outputs results obtained by various processes performed by the furnace temperature setting device 900, for example. Specifically, the display device displays the results obtained by various processes performed by the furnace temperature setting device 900 as text or an image. The audio output device converts an audio signal composed of reproduced audio data, acoustic data, and the like into an analog signal and outputs the analog signal.

  The storage device 913 is a data storage device configured as an example of a storage unit of the furnace temperature setting device 900. The storage device 913 includes, for example, a magnetic storage device such as an HDD (Hard Disk Drive), a semiconductor storage device, an optical storage device, or a magneto-optical storage device. The storage device 913 stores programs executed by the CPU 901, various data, various data acquired from the outside, and the like. In the first and second embodiments, the storage device 913 corresponds to a storage device in which the steel piece information and / or the heating furnace information described in (1-1. System Configuration) can be stored.

  The drive 915 is a recording medium reader / writer, and is built in or externally attached to the furnace temperature setting device 900. The furnace temperature setting device 900 can acquire various types of information recorded on the removable recording medium 921 via the drive 915. Further, the furnace temperature setting device 900 can record various information on the removable recording medium 921 via the drive 915. The removable recording medium 921 is various media such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory. For example, the removable recording medium 921 is a CD medium, a DVD medium, a Blu-ray (registered trademark) medium, or the like. Further, the removable recording medium 921 may be a CompactFlash (registered trademark) (CompactFlash: CF), a flash memory, an SD memory card (Secure Digital memory card), or the like. Further, the removable recording medium 921 may be, for example, an IC card (Integrated Circuit card) on which a non-contact type IC chip is mounted, an electronic device, or the like.

  The connection port 917 is a port for directly connecting a device to the furnace temperature setting device 900. Examples of the connection port 917 include a USB (Universal Serial Bus) port, an IEEE 1394 port, a SCSI (Small Computer System Interface) port, and an RS-232C port. By connecting the external connection device 923 to the connection port 917, the furnace temperature setting apparatus 900 acquires various data from the external connection device 923 via the connection port 917, and various data to the external connection device 923. Can be provided.

  The communication device 919 is a communication interface including a communication device for connecting to the communication network 925, for example. The communication device 919 is, for example, a communication card for wired or wireless LAN (Local Area Network), Bluetooth (registered trademark), or WUSB (Wireless USB). The communication device 919 may be a router for optical communication, a router for ADSL (Asymmetric Digital Subscriber Line), or a modem for various communication. The communication device 919 can transmit and receive signals and the like according to a predetermined protocol such as TCP / IP, for example, with the Internet and other communication devices. In addition, the communication network 925 connected to the communication device 919 is configured by a wired or wireless network, and may be, for example, the Internet, a home LAN, infrared communication, radio wave communication, satellite communication, or the like. . The furnace temperature setting device 900 can receive various types of information from an external device connected via the communication network 925 by the communication device 919. Further, the furnace temperature setting device 900 can transmit various kinds of information to an external device connected via the communication network 925 by the communication device 919.

  The example of the hardware configuration of the furnace temperature setting device 900 according to the first and second embodiments has been described above with reference to FIG. Each component described above may be configured using a general-purpose member, or may be configured by hardware specialized for the function of each component. Therefore, the hardware configuration to be used can be changed as appropriate according to the technical level at the time of implementing the first and second embodiments.

  In order to confirm the effect of the present invention, as a first example, when a furnace is operated by setting the furnace temperature of each combustion zone by the furnace temperature setting method according to the first embodiment described above (implementation) Example) and changes in furnace temperature, extracted steel slab temperature, extracted soaking degree, and fuel consumption when the furnace temperature of each combustion zone is set by the conventional method (comparative example) Evaluation was made by numerical experiments. As a comparative example, as an example of a conventional method, based on the method described in Non-Patent Document 1, the average value of the operation results by the operator is referred to and the outlet target slab temperature and the outlet target average of each combustion zone. The method for determining the heat was used.

  The configuration of the system used for the numerical experiment is shown in FIG. FIG. 9 is a diagram illustrating a configuration of a system used in the numerical experiment. Referring to FIG. 9, the system 2 used for the numerical calculation corresponds to a system in which the heating furnace 10 (excluding the burner control unit 150) of the system 1 according to the present embodiment shown in FIG. To do. The heating furnace simulator 30 is a simulator that can simulate the behavior of the heating furnace, and information on the heating furnace (for example, furnace temperature, flow rate of fuel supplied to the burner) acquired during operation and the state of each steel piece (for example, extracted steel piece). Temperature, degree of soaking, etc.) can be obtained by simulation. In the present numerical experiment, “Mitsubishi Electric Technical Report”, 1985, Vol. 59, no. 4, pp. The method described in “24-27” was used. At that time, actual data at the time of actual operation was used as billet information and heating furnace information necessary for the simulation.

The configuration of the system 2 shown in FIG. 9 is for performing a simulation according to the embodiment. In an Example, in the optimal furnace temperature calculation part 220 for each billet, the above (1-2-3. Specific example of calculation method of intermediate target value) and the above (1-3-3. Specific method of calculation of intermediate target value) Example) The furnace temperature is changed when obtaining the target steel slab temperature θ _aim [j−1] and the target target temperature uniformity Δθ _aim [j−1] of the combustion zone [j−1]. The influence coefficients α and β that the amount exerts on the billet temperature and the degree of soaking are represented by a linear form, and using the influence coefficients, the outlet billet temperature θ [j−1] and the outlet billet temperature in the combustion zone [j−1] The intermediate target value was obtained by a method of calculating the side soaking degree Δθ [j−1]. Here, for the pre-tropical zone, the furnace temperature is specified in advance for operational reasons, and therefore the steel slab S located after the first heating zone was used as the calculation target. And the furnace temperature of each combustion zone after 1 heating zone which satisfy | fills the restriction | limiting of the said intermediate | middle target value is calculated for every steel piece S using the method of the said nonpatent literature 1, The furnace temperature is set to steel. The optimum furnace temperature of each combustion zone after one heating zone for each piece S was considered. In the optimum furnace temperature editing unit 230, the maximum value of the optimum furnace temperature for each steel slab S is set as the furnace temperature of each combustion zone after the final one heating zone. At this time, if the calculated furnace temperature of each combustion zone is lower than the minimum furnace temperature of each combustion zone determined due to equipment restrictions or operation restrictions, the minimum furnace temperature is set to the final furnace of each combustion zone. It was warm.

  On the other hand, in the configuration of the system 2 shown in FIG. 9 in the comparative example, in the functional block corresponding to the steel piece optimum furnace temperature calculation unit 220, the intermediate target value is determined with reference to the average value of the operation results by the operator, Using the method described in Non-Patent Document 1, the optimum furnace temperature of each combustion zone after one heating zone for each steel slab S based on the intermediate target value was calculated. In the functional block corresponding to the optimum furnace temperature editing unit 230, the maximum value of the optimum furnace temperature of each combustion zone for each slab S is determined for each combustion zone after the final one heating zone, as in the embodiment. The optimum furnace temperature was set.

  The results of the numerical experiment are shown in FIGS. FIG. 10 is a graph showing changes in the furnace temperature in one heating zone. FIG. 11 is a graph showing changes in the furnace temperature in the two heating zones. FIG. 12 is a graph showing changes in the furnace temperature in the soaking zone. FIG. 13 is a graph comparing the average value of the furnace temperature in one heating zone shown in FIG. 10 with the average value of the furnace temperature in two heating zones shown in FIG. FIG. 14 is a graph showing the relationship between the extracted billet temperature and the extraction target billet temperature. FIG. 15 is a graph showing the relationship between the extracted soaking degree and the extraction target soaking degree. FIG. 16 is a graph showing the amount of fuel used in Examples and Comparative Examples.

  Referring to FIGS. 10 to 13, in this numerical experiment, the soaking zone is implemented in the soaking zone because the furnace temperature is uniquely determined by the condition of the steel slab S existing in the soaking zone. The behavior of the change in the furnace temperature is similar between the example and the comparative example. On the other hand, in the 1st heating zone and the 2nd heating zone, the furnace temperature in the example is lower than that in the comparative example. Further, the furnace temperature decrease from the comparative example to the example is larger in the one heating zone, and it can be confirmed that the furnace temperature is determined so that the operation at the front stage low load and the rear stage high load type is performed. As a result, as shown in FIG. 16, it was confirmed that the fuel consumption was reduced in the example compared to the comparative example.

  On the other hand, referring to FIG. 14, in all the steel slabs S, the extracted steel slab temperature exceeds the extraction target steel slab temperature in both the example and the comparative example. Further, referring to FIG. 15, in all the steel slabs S in both the example and the comparative example, the extraction soaking degree satisfies the extraction target soaking degree.

  Thus, although both the examples and comparative examples can satisfy the constraints due to the extraction target billet temperature and the extraction target soaking degree, it has been found that the examples can suppress the fuel consumption more. .

  Next, as a second example, when the furnace temperature of each combustion zone is set by the furnace temperature setting method according to the first embodiment described above and the heating furnace is operated (Example (first embodiment )), When the furnace is operated by setting the furnace temperature of each combustion zone by the furnace temperature setting method according to the second embodiment described above (Example (second embodiment)), and the conventional When the furnace temperature of each combustion zone was set by the method and the heating furnace was operated (Comparative Example), the change in furnace temperature, the temperature of the extracted steel slab, the degree of soaking, and the required heat amount were evaluated by numerical experiments.

  As a comparative example, as in the first embodiment, based on the method described in Non-Patent Document 1, the average value of the operation results by the operator is referred to and the outlet side target slab temperature and the output temperature of each combustion zone are referred to. The method of determining the side target soaking degree was used.

  In the example (first embodiment), as in the first example, the above (1-2-3. Specific example of calculation method of intermediate target value) and (1-3-3. Intermediate target) are described. The intermediate target value is calculated by the method described in (Specific Example of Value Calculation Method), and the furnace temperature of each combustion zone that satisfies the restriction of the intermediate target value is calculated using the method described in Non-Patent Document 1 above. The furnace temperature was regarded as the optimum furnace temperature for each combustion zone.

  In the example (second embodiment), similarly to the example (first embodiment), (1-2-3. Specific example of calculation method of intermediate target value) and (1-3-3) .. Specific example of calculation method of intermediate target value) The intermediate target value was calculated by the method described in the above. However, in the example (second embodiment), based on the intermediate target value, the above (2-1. Function of the optimum furnace temperature calculation unit 223 for each combustion zone) and the above (2-2. Optimum furnace temperature calculation). The optimum furnace temperature of each combustion zone for each steel slab S was calculated in consideration of the follow-up time using the method described in the step processing.

  The numerical calculation was performed using the system 2 shown in FIG. 9 as in the first embodiment. However, in the example (the second embodiment), the actual furnace temperature follows the first-order lag with respect to the set furnace temperature for the furnace temperature change in each combustion zone. In addition, for the pure evaluation of the effect of the present invention, in the second embodiment, the intermediate target value and the optimum furnace temperature were not obtained for all the steel pieces existing in each combustion zone, but were selected as the neck material. From charging to extraction of one piece of steel was evaluated. In other words, the optimum furnace temperature of each combustion zone obtained for the neck material is directly adopted as the set furnace temperature of each combustion zone, and a heating furnace operation simulation from charging to extraction of the neck material is performed, The change in temperature, the temperature of the extracted steel slab, the degree of soaking of the extraction, and the required heat amount were evaluated.

  The billet information used in the numerical experiment in the second example is shown in Table 1 below. Table 2 below shows the conditions (maximum furnace temperature and minimum furnace temperature that the heating furnace can take) for the heating furnace used in the numerical experiment in the second embodiment.

  Moreover, about the billet temperature used for calculation of an intermediate target value, it computed by the heat transfer calculation by the difference method. Further, the required heat amount was calculated based on the heating furnace heat balance formula described in “Electrical Society Proceedings”, 1996, Vol. 116, No. 12, pp. 1220-1229.

  The results of the numerical experiment are shown in FIGS. FIG. 17 is a graph showing changes in the furnace temperature in the combustion zone where the billet being calculated is present in the comparative example. FIG. 18 is a graph showing changes in the furnace temperature in the combustion zone where the billet being calculated is present in the example (first embodiment). FIG. 19 is a graph showing changes in the furnace temperature in the combustion zone where the billet being the object of calculation exists in the example (second embodiment). FIG. 20 is a graph showing changes in billet temperature in the heating furnace in the comparative example. FIG. 21 is a graph showing changes in billet temperature in the heating furnace in the example (first embodiment). FIG. 22 is a graph showing changes in billet temperature in the heating furnace in the example (second embodiment). FIG. 23 is a graph showing the amount of heat required for the heating operation in the comparative example, example (first embodiment), and example (second embodiment).

  Referring to FIGS. 17 to 19, in the example (first embodiment) and the example (second embodiment), the pre-tropical set furnace temperature is suppressed to be lower than that in the comparative example, and the preload is low. It turns out that the operation of the latter stage high load has been realized. This is because, in the comparative example, the pre-tropical outgoing side billet temperature is set higher than necessary based on the past results, etc., whereas the example (first embodiment) and the example ( This is because in the second embodiment, the minimum value necessary for the extracted billet temperature to satisfy the target value is set as the pre-tropical outgoing billet temperature.

  Further, when attention is paid to the two heating zones and the set temperature in the soaking zone, it can be seen that the example (second embodiment) is slightly higher than the example (first embodiment). In the example (second embodiment), the above formula (ie, the optimum furnace temperature) is set to the above equation (the optimum furnace temperature) so as to compensate for the deviation between the actual furnace temperature and the set furnace temperature during the follow-up time. This is because the correction using 5) is performed.

  Referring to FIGS. 20 to 22, it can be seen that the extraction target billet temperature is achieved in all of the comparative example, the example (first embodiment), and the example (second embodiment). However, in the comparative example and the example (first embodiment), the extraction target soaking degree cannot be achieved. The reason why the comparative example has not achieved the extraction target soaking degree is that it has become difficult to achieve the extraction target soaking degree because priority was given to achieving the outlet extraction target billet temperature of the two heating zones. On the other hand, in the example (first embodiment), the outgoing side target slab temperature and the outgoing side target soaking degree of each combustion zone are set by calculating backward from the extraction target slab temperature and the extracting soaking degree. Problems like the comparative example are improved. However, in the example (first embodiment), since the follow-up time of the furnace temperature is not taken into consideration, the steel slab cannot be heated as intended, and as a result, the target temperature uniformity cannot be satisfied during extraction. ing. On the other hand, in the example (second embodiment), since the follow-up time of the furnace temperature is taken into account by the correction using the above formula (5), both the extraction target billet temperature and the extraction target soaking degree are both set. Satisfactory and more accurate heating furnace operation has been realized.

  Referring to FIG. 23, it can be seen that in the example (first embodiment) and the example (second embodiment), the required heat amount is suppressed to be smaller than that in the comparative example. This is because, in the example (first embodiment) and the example (second embodiment), the operation at the front stage low load and the rear stage high load type can be realized. In the example (second embodiment), the amount of heat required is increased as compared with the example (first embodiment) by performing the correction for the follow-up time using the above formula (5). However, the amount of increase is limited to a slight range, and the required amount of heat can be greatly reduced as compared with the comparative example.

(4. Supplement)
The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

S Steel slab 1, 2 System 10 Heating furnace 20 Furnace temperature setting device 30 Heating furnace simulator 110 Furnace body 120 Burner 130 Skid 140 Thermometer 150 Burner control unit 210 Steel slab temperature calculation unit 220 Optimum furnace temperature calculation unit 221 for each slab Acquisition unit 222 Intermediate target value calculation unit 223 Optimum furnace temperature calculation unit for each combustion zone 224 Optimum furnace temperature output unit 230 Optimum furnace temperature editing unit

Claims (6)

A furnace temperature setting method for setting the furnace temperature of each combustion zone in a continuous heating furnace having N (N ≧ 2) combustion zones,
The combustion zone where the billet being calculated is located is the combustion zone [i] (N> i ≧ 1), and the extraction target billet temperature and the extraction target soaking degree when the billet is extracted, When given as θ _aim [N] and Δθ _aim [N], the target steel slab temperature θ _aim [j] and the target heat uniformity Δθ in the combustion zone [j] (N ≧ j> i) Based on _aim [j], when it is assumed that the combustion zone [j] is operated at the maximum furnace temperature T _fmax [j] due to equipment constraints or operation constraints, The steel slab such that the outgoing side slab temperature θ [j] and the outgoing side soaking degree Δθ [j] become the outgoing side target steel slab temperature θ _aim [j] and the outgoing side soaking degree Δθ _aim [j]. , The outlet side slab temperature θ [j-1] of the combustion zone [j-1] immediately before the combustion zone [j] Δθ [j-1] is calculated, and the calculated outlet side slab temperature θ [j-1] and the outgoing side soaking degree Δθ [j-1] are set as the outgoing side target of the combustion zone [j-1]. By repeatedly performing the billet temperature θ _aim [j−1] and the outlet side target heat uniformity Δθ _aim [j−1] from j = N to j = i + 1, the combustion band [ i] Outgoing target billet temperature θ _aim [i],..., θ _aim [N−1] and outgoing target soaking degree Δθ _aim [i],..., Δθ _aim [ N-1], an intermediate target value calculation step;
Optimum furnace temperature calculation step for calculating the optimum furnace temperature of each combustion zone for each billet using the furnace temperature of each combustion zone that satisfies the calculated constraint of the intermediate target value;
An optimum furnace temperature editing step for setting a furnace temperature for each combustion zone based on the calculated optimum furnace temperature for each billet for at least one billet respectively present in each combustion zone;
Including a furnace temperature setting method. In the intermediate target value calculation step, influence coefficients α and β that the change amount of the furnace temperature has on the slab temperature and the soaking degree are obtained by the following mathematical formulas (101) and (103), and the influence coefficients α and β are calculated as follows. The θ [j−1] and the Δθ [j−1] are obtained by the following mathematical formulas (105) and (107).
The furnace temperature setting method according to claim 1.

Here, in the above formulas (101) to (107),
θ ₀ ′ [k]: The combustion zone [i] is operated at the current furnace temperature T _ftmp [i], and the combustion zone after the combustion zone [i + 1] is the maximum furnace temperature due to equipment restrictions or operation restrictions. T _fmax [i + 1],..., T _fmax [N] on the assumption that the operation is performed, the predicted exit slab temperature of each combustion zone Δθ ₀ ′ [k]: the combustion zone [i] is used as the current furnace It is _assumed that the operation is performed at the temperature T _ftmp [i], and the combustion zones after the combustion zone [i + 1] are operated at the maximum furnace temperature T _fmax [i + 1], ..., T _fmax [N]. Predicted soaking degree of combustion zone θ ₁ ′ [k]: It is assumed that the furnace temperature in combustion zone [k] is operated at a value perturbed by furnace temperature ΔT _f [k] from the furnace temperature T _fmax [k]. when the combustion zone [k] of the exit-side prediction billet temperature [Delta] [theta] ₁ '[k]: furnace temperature in the combustion zone [k] When it is assumed that operating in the furnace temperature T _{fmax [k]} from the furnace temperature ΔT f _[k] by a value obtained by perturbing an exit side prediction soaking of the combustion zone [k]. In the optimum furnace temperature calculation step, the furnace temperature of each combustion zone that satisfies the constraints of the intermediate target value is set as the optimum furnace temperature of each combustion zone for each steel slab,
The furnace temperature setting method according to claim 1 or 2. In the optimum furnace temperature calculation step, the furnace temperature of each combustion zone that satisfies the constraint of the intermediate target value is T _fopt0 [i],..., T _fopt0 [N], and When the optimum furnace temperature is set to T _fopt [i],..., T _fopt [N], the optimum furnace temperature T _opt [i] is calculated by the following equation (109), and the optimum furnace temperature T _opt [ , T _opt [N] is _calculated as T _opt [i + 1] = T _opt0 [i + 1],..., T _opt [N] = T _opt0 [N],
The furnace temperature setting method according to claim 1 or 2.

Here, in the above formula (109),
T _ftmp [i]: current furnace temperature in the combustion zone [i] S ₁ : in a two-dimensional plane with time on the horizontal axis and furnace temperature on the vertical axis, at the current time of the combustion zone [i] If you change the setting of the furnace temperature from the current furnace temperature _{T ftmp} [i] to _{T fopt0} [i], the combustion zone [i] of the furnace temperature is a time delay no _{T ftmp [i] T fopt0 [} i] from Of the difference between the furnace temperature T _ftmp [i] of the combustion zone [i] and the time from the current time until the billet exits the combustion zone [i] Value S ₂ : In a two-dimensional plane with time on the horizontal axis and furnace temperature on the vertical axis, the setting of the furnace temperature of the combustion zone [i] at the current time from the current furnace temperature T _ftmp [i] to T _When it is changed to _opt0 [i], the furnace temperature of the combustion zone [i] follows. The difference between the furnace temperature of the combustion zone [i] and T _ftmp [i] when assuming that the time is changed from T _ftmp [i] to T _fopt0 [i] with a delay of time t _flw [i], It is an integral value with respect to the time from the time until the steel slab leaves the combustion zone [i]. In the intermediate target value calculation step and the optimum furnace temperature calculation step, among the plurality of steel slabs existing in the continuous heating furnace, for each combustion zone, the rise of the slab temperature with respect to the remaining furnace time until extraction Only for the neck material with the largest rate, the intermediate target value and the furnace temperature of each combustion zone are calculated,
In the optimum furnace temperature editing step, the furnace temperature of the combustion zone corresponding to each of the neck materials calculated for each of the neck materials is set as the final furnace temperature of each combustion zone.
The furnace temperature setting method according to any one of claims 1 to 4. A furnace temperature setting device for setting the furnace temperature of each combustion zone in a continuous heating furnace having N (N ≧ 2) combustion zones,
The combustion zone where the billet being calculated is located is the combustion zone [i] (N> i ≧ 1), and the extraction target billet temperature and the extraction target soaking degree when the billet is extracted, When given as θ _aim [N] and Δθ _aim [N], the target steel slab temperature θ _aim [j] and the target heat uniformity Δθ in the combustion zone [j] (N ≧ j> i) Based on _aim [j], when it is assumed that the combustion zone [j] is operated at the maximum furnace temperature T _fmax [j] due to equipment constraints or operation constraints, The steel, such that the outgoing side slab temperature θ [j] and the outgoing side soaking degree Δθ [j] are the outgoing side target steel slab temperature θ _aim [j] and the outgoing side target soaking degree Δθ _aim [j]. Outlet side slab temperature θ [j-1] and exit side average of the combustion zone [j-1] immediately preceding the combustion zone [j] of the piece The degree of heat Δθ [j-1] is calculated, and the calculated outlet side slab temperature θ [j-1] and the outlet side soaking degree Δθ [j-1] are output to the outlet side of the combustion zone [j-1]. By repeating the process of setting the target billet temperature θ _aim [j−1] and the outlet side target temperature uniformity Δθ _aim [j−1] from j = N to j = i + 1, the combustion zone that is the intermediate target value [I] Outgoing target billet temperature θ _aim [i],..., Θ _aim [N−1] and outgoing target soaking degree Δθ _aim [i] _,. An intermediate target value calculation unit for calculating [N-1];
Using the furnace temperature of each combustion zone that satisfies the constraint of the calculated intermediate target value, an optimum furnace temperature calculation unit that calculates the optimum furnace temperature of each combustion zone for each billet,
An optimum furnace temperature editing unit for setting a final furnace temperature of each combustion zone based on the calculated optimum furnace temperature for each of the steel pieces for at least one steel piece respectively present in each combustion zone;
A furnace temperature setting device.

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