JPH037726B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling furnace temperature setting and movement speed in a heating furnace.

[Conventional technology]

A typical conventional heating furnace temperature control method is a control method based on the difference between the target extraction temperature of the material to be heated and the extraction temperature estimated by a simple model formula from the furnace temperature of each area in the furnace and the furnace time. and JP-A-56-75527
There is a method of controlling according to a predetermined temperature increase pattern (heat pattern control) as disclosed in No.

[Problems to be Solved by the Invention] The problems mentioned by the first party are that there is a large variation in the baking state when extracting the heated material, that is, the extraction temperature, and that the temperature at each position in the furnace and the heated material vary widely. The temperature distribution in the thickness direction and longitudinal direction within the material is unknown. This is a simple model formula, and the temperature of the heated material is used for both quality assurance during extraction, furnace temperature control, and movement speed control of the heated material in the furnace, so one point is the representative value. Furthermore, the calculation accuracy of the extraction temperature calculation result value of the material to be heated is also not good because it is a simple model formula.

In the second party heat pattern control method described above,
In addition to the former problem, since the temperature is controlled by the difference from the target temperature at each position in the furnace according to a predetermined temperature increase pattern, it also impedes productivity in the rolling process following the continuous heating furnace and causes problems for the heated material. There is a problem that the rolling pitch lacks stability.

Also, as shown in the example of temperature increase pattern control in Figure 1,
If the time in the furnace is extended due to trouble in the rolling process while the material to be heated is being heated, not only will the previous temperature increase pattern control be meaningless, but the fuel loss required to raise the temperature of the material will also be large. It is.

The present invention aims to solve these conventional problems.

[Means for Solving the Problem 1] One of the features of the first invention of the present application is that the material to be heated in the furnace is divided into a plurality of sections in the thickness direction and the longitudinal direction, and each section is divided at a predetermined period. Calculate the temperature at the current position, calculate the average temperature or minimum temperature of each temperature category each time as a representative value, and calculate the calculated extraction temperature and target extraction by substituting the representative value into a predetermined simple model formula. The present invention provides a heating furnace control method that sequentially controls the furnace temperature and/or moving speed of the remaining furnace area based on the deviation from the temperature.

The target extraction temperature for each of the above-mentioned materials to be heated is the representative temperature in each temperature range in the thickness direction and longitudinal direction of the material to be heated, that is, the average temperature or the minimum temperature required according to the rolling equipment specifications or the minimum temperature necessary for metallurgical heat treatment. The temperature is determined by whichever is higher. In addition, the actual temperature required to guarantee the quality of the heated material is measured at least in the thickness direction and in order to understand the uneven heat pattern caused by skid marks, the placement of the heated material in the furnace, the burner placement position, etc. During movement in the furnace for each temperature section in the longitudinal direction,
This requires sequential calculation at each predetermined position.

In addition, each time the actual temperature is calculated, the average temperature or minimum temperature during extraction, including the amount of temperature rise in the remaining furnace area, is predicted by using a representative value, that is, the average, of the temperature from among a plurality of simple model formulas prepared in advance. The temperature or the minimum temperature is selected as a parameter, and the furnace temperature and heated material movement speed are controlled based on this equation. Therefore, the calculated actual temperature for guaranteeing the quality of the material to be heated is calculated for each section in the thickness direction and the longitudinal direction.

[Effect 1] The accuracy of controlling the furnace temperature and/or moving speed improves as the temperature approaches the extraction end, and calculation processing becomes possible in a short time, resulting in a significant reduction in computer capacity.

[Means for Solving the Problem 2] Next, the feature of the second invention of the present application is that the material to be heated in the furnace is divided into a plurality of parts in the thickness direction and the longitudinal direction, and The temperature at the current position is calculated for each division, the average temperature or minimum temperature of each division temperature is calculated as a representative value, and the calculated mature temperature is obtained by substituting the representative value into a predetermined simple model formula. The temperature and the calculated extraction temperature are determined, and the deviation between the former and the target ripening temperature at the start of ripening before extraction of the material to be heated is determined, while the deviation between the latter and the target extraction temperature is determined. The furnace temperature and/or movement speed of the remaining furnace area are controlled based on the larger of these deviations, and the representative value of the average temperature or minimum temperature is determined as the target ripening temperature and target temperature at the time of starting ripening. After reaching both of the extraction temperatures, the moving speed of the remaining furnace area is calculated based on the deviation between the extraction temperature calculated based on the representative temperature and the target extraction temperature and the integrated value of the rolling time of the material to be heated located downstream. This is a heating furnace control method that sequentially controls the

The feature here is that when the material to be heated is metallurgically heat treated and requires maintenance of ripening temperature, the calculated extraction temperature can be predicted in the same way as above, and at the same time, the calculated temperature at the start of ripening can also be calculated using a simple model formula. The control is performed based on the larger deviation between these calculated temperatures and each target value.
However, the temperature prediction at the start of ripening is based on the condition that the representative value of the average temperature or minimum temperature at the current position of the material to be heated, which is calculated sequentially, satisfies both the target ripening temperature and the target extraction temperature at the time of the start of ripening. Nothing will be done after that.

[Effect]

Extraction necessary to guarantee the quality of heated materials that require ripening (i.e., solid solution, precipitation of special elements, or heat treatment necessary to maintain these, or ripening heat treatment to reduce uneven heat within the material, etc.) Since the actual temperature is calculated for each section in the thickness direction and longitudinal direction, quality is reliably guaranteed, and the control becomes more accurate as it approaches the extraction end, and calculation processing can be performed in a short time. Machine usage capacity is significantly reduced. Furthermore, compared to conventional heat pattern control, this method does not impede the productivity and stability of the rolling process that follows the continuous heating furnace.

Embodiments of the present invention will be described below with reference to the drawings.

〔Example〕

FIG. 2 is a block diagram showing the configuration of one typical device implementing the control of the present invention. First, to explain the symbols in the figure, A is the heating furnace charging signal generator for the material to be heated, and B is the rolling conditions (rolling schedule) for the material to be heated.
Setting section, C is heating condition setting section for heated material, D is in-furnace position calculation section for heated material, E is furnace status data scanning section such as furnace temperature, F is in-furnace heating condition forming part of this control. Control data group for each heated material and time-series furnace conditions, G is extraction signal generator for heated material, H is fixed period signal generator, I is calculated actual temperature at each position of each heated material in the furnace A calculation section, J is a calculation section for the remaining furnace time of the material to be heated, and K is a section that checks the temperature at the time of extraction and the temperature at the start of aging of the material to be heated, and controls the furnace temperature setting and movement speed in a predetermined aging region. Control calculation unit, L is a moving speed control device for the heated material in the furnace, M is an in-furnace conveyance equipment for the heated material, and an extractor equipment for the heated material, N is a furnace temperature setting control device, O is the furnace temperature Adjustment equipment, 1 is a heating material charging signal, 2 is a heating material charging signal via setting section B, 3 is movement of the rolling condition data group calculated and set in setting section B, 4 is setting section C 5 is the movement of the heating condition data group calculated and set by the setting part D. 6 is the movement of the data such as furnace temperature scanned by the furnace condition data scanning part E. 7 8 is data movement for the calculation unit I to process the calculated actual temperature at each position in the furnace of the heated material; 8 is data movement for the calculation unit J to calculate the remaining time in the furnace for each heated material; 9 10 is the data movement of the moving speed of the heated material in the furnace set by the calculation unit K, 11 is the extraction timing signal generated from the device G, and 12 is the data generated from the signal source H. 13 is the signal 11 and signal 1 that have passed through the calculation unit I.
2 and 14 are signals 11 and 1 that have passed through the calculation section J.
2, and signals 15 and 15 are signals 11 and 12 that have passed through calculation section K.
16 is a timing signal that notifies the controller L when the calculation of the processor K is completed; 17 is a signal that causes the controller L to actually drive the heated material conveyance and extraction equipment M in the furnace; 18 19 shows a timing signal to notify the control device N when the calculation of the calculation unit K is completed, and 19 shows a signal by which the control device N drives the instrumentation equipment O that actually adjusts the furnace temperature.

Note that the signals 13 to 19 are all the signals 11 and 12 generated from the signal generator G and the signal source H.
The timing will be determined accordingly.

Next, we will explain the main functions of each component in Figure 2.
The rolling condition setting section B is a section that calculates the rolling schedule and rolling time of the material to be heated (material to be rolled), and as shown in the conceptual diagram of FIG.
Calculate the rolling schedule for the subsequent rolling process.
In the rough zones VSB and R ₁ to _{R 4} of the rolling process, the number of rolling passes of each rolling mill, the thickness at each position, moving speed, rolling speed, and descaling selection are determined.
Determine the rough rolling pitch. Also, finishing zone F ₁ ~
In F ₇ , the rolling speed pattern of the heated material (rolled material HS), the load distribution of each rolling mill, and the required idle time at the finishing front are determined, and the finishing rolling pitch is determined. In the coiler zone DC, the operating time of the winder and the cooling time of the heated material are determined, and the coiler pitch is determined.

These rolling conditions are used when the setting section C, which determines the heating conditions for the material to be heated, calculates the rolling line temperature drop, and when the calculation section J calculates the remaining furnace time. The logic used by this rolling condition setting section B is the same logic as the calculation model for each setting when performing actual rolling, and this improves the prediction accuracy and also allows the rolling condition setting section B to predict the baking state of the heated material during the rolling process. It facilitates yield forward control and temperature learning (feedback to heating control) from the rough rear surface temperature RT ₄ and the finished rear surface temperature FT ₇ .

The heating condition setting unit C for the material to be heated determines the temperature drop on the rolling line (see Fig. C ₂ , C ₃ )
The representative value of the target extraction temperature, that is, the average value or the minimum temperature is determined by C ₆ from the allowable eccentric heat value of the material to be heated.

In addition, for materials to be heated that require mature heat treatment by metallurgical heat treatment, the minimum temperature of the target extraction temperature is determined at _C5 in Figure 4 as the temperature necessary for heat treatment.
For C ₆ , the higher temperature between the temperature of C ₅ and the temperature via C ₃ is set as the lowest temperature of the target extraction temperature.

On the other hand, when the permissible heat deviation range of the above-mentioned material to be heated is narrow (such as skid mark) or when ripening is required for metallurgical heat treatment, the ripening start point before extraction, the target ripening temperature and the time until extraction. Also set.

Note that FIG. 4 illustrates the processing flow of the setting section C in FIG. 2. Note that the material to be heated that requires mature heat treatment by metallurgical heat treatment is Al-
Products containing special elements such as K steel and Nb-containing steel,
There are also those that cause precipitation, and those that diffuse components that do not require intervention in the steel billet.

The calculated actual temperature setting unit I in Fig. 2 uses the control data group F to calculate the current value of the temperature of each heated material in the furnace to each position in the furnace in multiple sections in the thickness direction and longitudinal direction. It is something to do. The calculation formula used here uses a two-dimensional differential model to time-divisionally calculate the temperature increase within the time period during which activation is repeated by the signal 11 or signal 12.

What is shown in Fig. 5 is an example of the calculation result temperature setting section I, which divides the heated material into 5 sections in the thickness direction and 5 sections in the longitudinal direction, and calculates the temperature at each section (5 x 5) points. ing. Furthermore, the reason why the divisions shown in the figure exist in two groups (the east side of the furnace and the west side of the furnace in the figure) is because the temperature distribution in the furnace width direction was considered.

The one shown in FIG. 6 is used when calculating the temperature of the heated material using the two-dimensional differential decomposition model. The furnace atmosphere temperature is 1Hz, 2Hz, 3Hz and
The temperature at each location in the furnace is estimated from the furnace temperature distribution curve based on the values measured by the furnace temperature detectors installed above and below each SZ zone.

Note that this example is a two-dimensional model of the thickness in the longitudinal direction, but when calculating the width direction of the heated material, a three-dimensional model is used that takes into account the distance between the heated materials that exist before and after the heated material. etc. are possible.

The remaining furnace time calculation section J in FIG.
3, the rolling time of the materials to be heated located downstream of each material to be heated in the control data group F is integrated, and this is taken as the remaining time in the furnace of each material to be heated.

Also, in the timing signal activated by the signal 15 from the calculation unit K for furnace temperature setting and heated material movement speed control, as above, the integrated value of the rolling time of the heated material located downstream from each heated material Furthermore, the calculation unit K adds the heating neck allowance determined for the movement speed control, and determines the remaining furnace time.

FIG. 7 shows the function of the calculating section J in FIG. 2 as an example. For example, in FIG. Furnace time is the sum of rolling times for downstream materials.

Further, the remaining furnace time of the material for the second time (when activated by the above signal 15) is the integrated value of the rolling time of the downstream materials and the heating neck allowances α ₁ to α ₅ between the downstream materials.

It should be noted that the above-mentioned "heating neck allowance" will be explained in the function of the calculation section K below.

The calculation unit K for the furnace temperature setting control and the movement speed control of the heated material shown in FIG. Based on the determined representative value (average temperature or minimum temperature) and the remaining furnace time, it is estimated using a plurality of simple model equations whether the extraction target temperature will be reached within the furnace time.

This calculation section performs the calculation twice in the same way as the calculation section J described above, and in the first calculation (when activated from signal 13 via J), a simple calculation is performed based on the representative value of the calculated actual temperature at the current position. As a result of calculation using the model formula, when the extraction target temperature is reached within the remaining furnace time, it is sufficient to leave the furnace temperature setting and moving speed of the material to be heated located downstream as is; When the extraction target temperature is not reached within the furnace time, the remaining furnace time of the heated material is determined and the rolling time of the heated materials located downstream of the heated material is equally extended. This is used as a "heating neck allowance" to control the moving speed of the material to be heated in the furnace.

In the second calculation (when started from signal 15 via J), the aforementioned calculation section J calculates the "heating net cost".
Select a furnace temperature setting that will exactly reach the extraction target temperature within the furnace operating time. Therefore, if the target temperature is reached within the remaining furnace time, the movement speed control value of the heated material and the set value of the furnace temperature are determined in the first calculation, and conversely, if the target temperature is not reached, 1
The second calculation determines the moving speed control value of the material to be heated, and the second calculation determines the set value of the furnace temperature. However, when the furnace temperature setting value is lower than the calculated actual temperature of the heated material, the heating zone where the heated material is present or the heating zone is adjusted so that the calculated actual temperature or the latest temperature of the heated material is reached. Set the furnace temperature of other heating zones that will affect it.

FIG. 8 is a diagram schematically showing the relationship between the calculation units I and K in FIG. 2, and the two-dimensional differential decomposition model in FIG. The multiple regression model is one of the simple models, and the calculation part K
It shows. Now, to explain the material to be heated (hereinafter referred to as material) as an example, the material is currently in the furnace at 2 Hz.
The temperature located at is calculated using a two-dimensional difference resolution model, using the temperatures at multiple division points in the thickness direction and longitudinal direction as actual calculation values.

Next, a multiple regression model using the current actual calculated temperature as a parameter is used to calculate the temperature to be raised during the remaining furnace operation, and it is checked whether the target extraction temperature is reached. However, if the target extraction temperature is the lowest temperature of each class within the material, the current actual temperature also uses the lowest temperature of each class as a parameter, and the multiple regression equation also uses the formula for estimating the lowest temperature from among multiple formulas. select.

Furthermore, the selection of the formula is considered depending on whether the material is present in the furnace at 2Hz, 3Hz, or SZ, and the calculation accuracy improves as it approaches the extraction end.

Note that for materials that require ripening of the material to be heated, the target temperature of the ripening starting point is set in the same manner as above. However, in this case, the time remaining in the furnace minus the ripening time is the time in the furnace.

In addition, after the material passes the ripening start point, the time from the ripening start point to extraction is checked and the movement speed of the material is controlled, and the target ripening temperature and ripening time at the ripening start point are also checked. After the time when the temperature is satisfied, only the target extraction temperature is checked and controlled.

To explain in more detail based on the example of FIG. 8, if the current material position is , the material exists at 2 Hz, so the extraction temperature is estimated using a multiple regression equation for 2 Hz.

T _E xt＝Tsz・[1−εxp［−{αs ₁・＜lnTsz/
(Tsz−Ts _E )>+αs ₂・δTs/h+αs ₃ }]]…A Ts _E =T ₃ z・[1−εxp[−{α ₃₁・<lnT ₃ z/
(T ₃ z−T _3E )>+α ₃₂・δT ₃ /h+α ₃₃ }]]…B T _3E =T ₂ z・[1−εxp[−{α ₂₁・<lnT ₂ z/
(T ₂ z−T _2E )＞＋α ₂₂・δT ₂ /h＋α ₂₃ }]...C Tsz: SZ furnace zone temperature set value T ₃ z: 3Hz 〃 T ₂ z: 2Hz 〃 δTs: Material temperature Remaining in-furnace time of SZ δT ₃ : Remaining in-furnace time of 3Z of material δT ₂ : Remaining in-furnace time of 2Z of material T _2E : Current temperature of material determined by two-dimensional differential decomposition model αs ₁ ~ αs ₃ : Heavy Constant value of regression equation α ₃₁ - _{α 33} : Constant value of multiple regression equation α ₂₁ - _{α 23} : Constant value of multiple regression equation h: Thickness of heated material T _E xt: Estimated value of extraction temperature of heated material Above constant The numerical value is changed depending on whether the extraction temperature determined by T _E xt is the average temperature or the minimum temperature, and a different multiple regression equation is used.

Therefore, the types of calculation formulas are the same. Further, T _2E is the average value when the target extraction temperature is the average temperature, and is the minimum temperature when the target extraction temperature is the lowest temperature.

Next, when the material is located in the material, the extraction temperature is estimated using a 3 Hz multiple regression equation.

T _E xt＝Tsz・[1−αxp［−{εs ₁・＜lnTsz/
(Tsz−Ts _E )＞＋αs ₂・δTs／h＋αs ₃ }]]...D Ts _E xt＝T ₃ z・[1−εxp[−{α ₃₁・＜lnT ₃ z
/(T ₃ z−T _3E )＞＋α ₃₂・δT ₃ /h＋α ₃₃ }]]...E T _3E : Current temperature of the material determined by the two-dimensional difference model Each symbol is the same as above. However, T _3E is the material The current temperature is the average temperature or minimum temperature.

Next, when the material is located in the material, multiple regression for SZ is used to estimate the extraction temperature.

T _E xt＝Tsz・[1−εxp［−{αs ₁・＜lnTsz/
(Tsz−Ts _E )>+αs ₂・δTs/h+αs ₃ }]]...F Ts _E : Current temperature of the material determined by the two-dimensional differential resolution model Each symbol is the same as in equations A, B, and C above. However, Ts _E is the current temperature of the material and is the average or minimum temperature.

As described above, the multiple regression equation is used in a modified manner as the material progresses through the furnace. However, the type of the equation is the same for each equation, and the calculation is done by simply selecting the constant value of the equation, so that it becomes a different regression equation. The calculation accuracy using the above regression equation is as follows: compared to the two-dimensional difference equation, the accuracy of the 2Hz multiple regression equation is σ = 6℃, the accuracy of the 3Hz multiple regression equation is σ = 3℃, and the accuracy of the SZ multiple regression equation is σ = 1℃. I was able to get it.

The above formula is also used when it is necessary to check the maturation time and temperature at the start of maturation of the material, but in this case, the parameter of the remaining furnace time of the material is determined by the maturation time compared to the actual remaining furnace time. It is necessary to take measures such as removing

The movement speed control device L of the heated material in FIG.
This function controls the drive of the heated material conveying device (walking beam) of the heating furnace and the control device (M in Figure 2) of the furnace extractor for the heated material. , checking the rolling pitch of the material to be heated (transfer time between each rolling process shown in Fig. 3), and the calculation section K in Fig. 2.
It has a function (set-up control) to set the furnace temperature according to the furnace temperature settings for each zone in the furnace calculated by the furnace.

The graphs shown in FIGS. 9 and 10 compare the control results of the prior art (all control based on simple model equations) and this embodiment. Figure 9 is a graph of actual values for steel materials in the same lot, with the vertical axis representing the extraction temperature of the steel materials from the heating furnace and the horizontal axis representing the finishing temperature. However, in this example, the temperature was significantly improved to 20°C.

Figure 10 shows hot rolled steel materials in the same lot.
It is a graph of actual values, with the vertical axis representing the yield stress (YP), which is the mechanical test value of the steel material after hot rolling, and the horizontal axis representing the extraction temperature of the steel material from the heating furnace. In the conventional technology, the variation was ±2σ within the range shown between the upper and lower solid lines with diagonal lines, but in the example of the present invention, the variation was within the range between the solid lines, and was improved to less than half. Both indicate that highly accurate control is being performed.

〔Effect of the invention〕

According to the present invention, the calculated actual temperature that guarantees the quality of the material to be heated is guaranteed for each section in the thickness direction and longitudinal direction, and the temperature required for ripening (i.e., solid solution precipitation of special elements) or maintaining these is guaranteed. It has also become possible to reliably guarantee the quality of the heated materials for all categories.

Furthermore, the accuracy of the control improves as it approaches the extraction end, and it also enables calculation processing in a short time, significantly reducing the amount of computer usage, and compared to conventional heat pattern control, the rolling process following a continuous heating furnace is improved. The biggest effect is that it does not impede productivity or stability at all, and that it saves energy in the heating furnace.

[Brief explanation of the drawing]

FIG. 1 is a graph showing an example of conventional temperature increase pattern control. Fig. 2 is a block diagram showing the configuration of a control device implemented in one embodiment representative of the present invention, and Fig. 3 is a block diagram schematically showing the relationship between the hot rolling line and the control contents of the rolling condition setting section B in Fig. 2. 4 is a block diagram showing the processing flow of the heating condition setting section C in FIG. 2, and FIG. 5 is a block diagram showing the processing flow in the heating condition setting section C in FIG. 6 is a block diagram showing the relationship between the arrangement of temperature detectors in the heating furnace and calculation of the furnace atmosphere temperature at each position in the furnace, and FIGS. 7 and 8 are 2 FIG. 3 is a block diagram showing the relationship between the positions of the heated materials, the calculated values, and the calculation timings related to the calculations of the calculation units I, J, and K shown in the figure. Figure 9 is a graph showing the relationship between rough finishing temperature and extraction temperature, comparing the results of the present invention example and the conventional technology. Figure 10 shows the comparison of the results of the present invention example and the conventional technology. It is a graph showing the relationship between extraction temperature and temperature deviation. A: Signal generator for charging the material to be heated into the heating furnace, B:
Rolling conditions (rolling schedule) setting section for the material to be heated, C: Heating condition setting section for the material to be heated, D: In-furnace position calculation section for the material to be heated, E: Furnace condition data scanning section such as furnace temperature, F : A group of control data such as each material to be heated in the furnace and time-series furnace conditions that constitute the control of the present invention,
G: Extraction signal generator for heated materials, H: Periodic signal generator, I: Actual temperature calculation unit at each position of each heated material in the furnace, J: Special calculation for remaining heated materials in the furnace part, K: Checking the temperature at the time of extraction and the temperature at the start of ripening of the material to be heated, setting the furnace temperature in a predetermined ripening range and controlling the movement speed, L: Controlling the movement speed of the material to be heated in the furnace. Device, M: In-furnace conveyance equipment for heated materials and extractor equipment for heated materials, N: Furnace temperature setting control device, O: Furnace temperature adjustment equipment, 1: Heated material charging signal, 2: Setting section Heated material charging signal via B,
3: Movement of the rolling condition data group calculated and set in setting part B, 4: Movement of the heating condition data part calculated and set in setting part C, 5: Movement of the heating condition data group calculated and set in setting part D. , 6: Data movement such as the furnace temperature scanned by the furnace condition data scanning section E, 7: Data movement for processing by the actual temperature calculation section I of the heated material at each position in the furnace, 8: Operation section J is data movement for calculating the remaining time in the furnace of each heated material, 9: Data movement used by calculation section K, 10: Data movement of the in-furnace movement speed of the heated material set by calculation section K, 11: Extraction timing signal generated from device G, 12: Periodic timing signal generated from signal source H, 13: Signal 11 and signal 12 via calculation unit I, 14: Operation unit J
Signal 11, signal 12, and signal 15 via
15: A repeating signal of the signal 11 and signal 12 passed through the calculation unit K to the calculation unit J; 16: A timing signal that notifies the control device L when the calculation of the calculation unit K is completed;
17: A signal from which the control device L drives the material to be heated and the extraction equipment M in the actual furnace, 18: A timing signal that notifies the control device N when the calculation of the calculation unit K is completed, 19: The control device N detects the actual furnace temperature. A signal that drives the instrumentation O that regulates the

Claims (1)

[Claims] 1. Calculate the representative temperature of the material to be heated at the current position in the heating furnace at predetermined intervals, predict the extraction temperature of the material to be heated based on the representative temperature, and calculate the extraction temperature of the material to be heated based on the representative temperature. In a heating furnace control method that sequentially controls the furnace temperature setting of the remaining furnace area and the moving speed of the heated material based on the deviation value from the target extraction temperature and the integrated value of the rolling time of the heated material located downstream, The material to be heated is divided into a plurality of parts in the thickness direction and the longitudinal direction, and the current temperature of the material to be heated at the current position is calculated for each division using a differential model equation, and the current temperature of each division is calculated. 1. A method for controlling a heating furnace, comprising: calculating a representative temperature of a material to be heated based on the representative temperature; and calculating a predicted extraction temperature using a predetermined simple model formula based on the representative temperature. 2 Calculate the representative temperature of the material to be heated at the current position in the heating furnace at every predetermined period, and based on the representative temperature of the material to be heated, predict the ripening temperature at the start of ripening and the extraction temperature at the time of extraction. Then, calculate the deviation value between the calculated ripening temperature and the target ripening temperature and the deviation value between the calculated extraction temperature and the target extraction temperature, and integrate the deviation values of both and the rolling time of the material to be heated located downstream. In the method for controlling a heating furnace equipped with a ripening temperature range that controls the furnace temperature setting and movement speed in the remaining furnace area based on the value, the material to be heated is divided into a plurality of pieces in the thickness direction and the longitudinal direction, Calculate the current temperature of the heated material at the current position using a differential model equation for each section, calculate the representative temperature of the heated material based on the current temperature of each section, and calculate the representative temperature of the heated material based on the current temperature of each section. The calculated ripening temperature and the calculated extraction temperature are calculated using a predetermined simple model formula, and the furnace temperature and movement speed in the remaining furnace area are calculated based on the larger of the two deviation values and the integrated value of the rolling time. or after the representative temperature reaches both the target ripening temperature and the target extraction temperature, the furnace temperature setting and movement speed are controlled based on the deviation value of the extraction temperature and the integrated value of the rolling time. A heating furnace control method characterized by: