JPS5959837A - Controlling method of heating furnace - Google Patents

Abstract

PURPOSE:To assure actual temps. for all of respective segments and to avert the hindrance of productivity and stability in the rolling stage following to a furnace by segmenting the thickness and longitudinal directions of the material to be heated in the furnace respectively to plural segments, and controlling the furnace in accordance with the differences between the average values, etc. of the temps. in the respective segments and a target extraction temp. CONSTITUTION:A setting section C for the heating conditions of a material to be heated (material) determines the temp. drop on a rolling line and the permissible deviated heat value of the material in the rolling schedule of a setting section B for rolling conditions and determines the average value or min. temp. of a target extraction temp. An arithmetic section I for actual temp. calculates the temp. up to each position in the furnace of each material in the furnace and the current values of the temp. in the plural segments in the longitudinal direction by using a control data group F. An arithmetic section J for residence time in the furnace calculates the remaining residence time of each material in the furnace with signals 13 and 15. An arithmetic section K for controlling the moving speed of the material estimates whether the material attains the target extraction temp. within the residence time in the furnace or not from the signals 13, 14 and controls successively the moving speed of the material and/or the furnace temp. if said temp. is not attained.

Description

[Detailed description of the invention] The present invention relates to a control method in a heating furnace.

Conventional control methods are based on the difference between the extracted temperature of the material to be heated and the extraction temperature estimated by a simple formula from the furnace temperatures of the four zones inside the furnace and the furnace time, or according to a predetermined temperature increase pattern. This method is typified by the method (pattern control to Hee 1).

The problem with the above-mentioned former method is that the baked state when the material to be heated is extracted, the temperature at each neck in the furnace, and the temperature distribution in the thickness direction and longitudinal force direction are unknown.

This is because 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 using a simple formula, and also for extraction of the heated material. The calculation accuracy of the temperature actual value is also not good because it is a simple formula.

In the P1-pattern control method of the latter method mentioned above, production in the rolling process following the continuous heating furnace is controlled by the difference from the target temperature at each position in the furnace according to a predetermined temperature increase pattern. There are problems in that the rolling pitch of the heated material is poor and the rolling pitch of the heated material is unstable.

Furthermore, as shown in the example of temperature increase pattern control in Fig. 1, if the furnace time is extended due to trouble in the rolling process during the temperature rise of the material to be heated, the temperature increase pattern control up to that point is Not only is this pointless, but the fuel loss required to raise the temperature of the heated material is also large.

Mizumoto Akiban "The aim is to solve the conventional problems such as lateral. One of the features of this is that the material to be heated in the furnace can be heated in multiple directions, both in the thickness direction and in the longitudinal direction. The temperature at the current position is calculated for each division σ at a predetermined period, and the furnace temperature and/or The present invention provides a heating furnace control method for sequentially controlling the degree of transition.

In the present invention, the target extraction temperature of each heated material is the average temperature of each section temperature in the thickness direction and longitudinal direction of the heated material, or the minimum temperature required for rolling at the lowest temperature, and the minimum temperature necessary for metallurgical heat treatment. Whichever is higher temperature. In addition, the actual temperature that guarantees the quality of the heated material is skid marks and the placement of the heated material in the furnace.

In order to understand the uneven heat pattern due to the burner arrangement position, etc., the temperature of each section of the material to be heated in at least the thickness direction and the longitudinal direction is sequentially heated to 81 W at a predetermined position during movement in the furnace.

In addition, each time the actual temperature is calculated, the average temperature or minimum temperature at the time of extraction including the amount of temperature increase in the remaining furnace area is predicted by calculating the average temperature or the minimum temperature of the actual temperature from among a plurality of simple formulas prepared in advance. Temperature is selected as a parameter, and furnace temperature control and heated material movement speed control are performed based on this equation. For this reason, the actual extraction temperature that guarantees the quality of the heated material is guaranteed for all sections in the thickness direction and longitudinal direction, and the accuracy is improved as the temperature and movement speed of the furnace temperature and moving speed are increased. Another advantage of the present invention is that it enables calculation processing in a short time and achieves a significant reduction in Wl computer capacity.

Next, the second feature of the present invention is that the material to be heated in the furnace is divided into a plurality of sections in the thickness direction and longitudinal force direction, and the temperature at the current position is calculated for each section at a predetermined period. In each case, find the difference between the average temperature or minimum temperature of each classification temperature and one point target temperature at the start of ripening before extraction of the material to be heated, and also find the difference from the target extraction temperature, and calculate these 4.
The furnace temperature and/or moving speed of the remaining furnace area is controlled based on the larger difference, and after the average temperature or minimum temperature reaches both the ripening start point and the start target temperature, the average temperature or minimum temperature is This heating furnace control method sequentially controls the furnace temperature and moving speed of the remaining furnace area based on the difference between the temperature and the target extraction temperature.

The feature here is that when the material to be heated is a material to be subjected to metallurgical heat treatment, the average temperature or minimum temperature during extraction is
At the same time, the average temperature or minimum temperature at one point at the start of ripening is controlled by a simple formula based on the larger difference from each of these 11 standard values. However, the prediction of the temperature at the start of aging is as follows:
After the actual average temperature or minimum temperature of the material to be heated, which is calculated sequentially, satisfies both the ripening start point and the target start temperature, the heating is not performed. For this reason, extraction guarantees the quality of heated materials that require ripening (i.e., solid solution of special elements, precipitation, or heat treatment necessary to maintain this property, or ripening heat treatment to reduce material uneven heat, etc.). The actual temperature is ensured in all sections in the thickness direction and longitudinal direction, and the control is also more accurate as it approaches the extraction end, and a computer is used to perform short-time calculation processing. The advantages of the present invention are that the number of jaws used is significantly reduced, and that the productivity and stability of the rolling process following the continuous heating furnace are not impaired at all compared to the conventional P1-pattern control. It is.

Hereinafter, ten embodiments of the present invention will be described with reference to the drawings.

Friend Journey - νW FIG. 2 is a block diagram without showing the structure of a device implementing the control of the present invention. To first explain the symbols in the figure, A is a heating furnace charging signal generator for the heated material, B is a rolling condition (rolling schedule) setting section for the heated material, C is a heating condition setting section for the heated material, 1 ] is a calculation unit for the position of the heated material in the furnace, IΣ is a furnace condition data scanning unit such as humidity in the furnace, F is a group of control data such as each heated material in the furnace and the time-series furnace condition, which constitutes this control, G is the extraction signal generator for the heated material, ■1 is the extraction signal generator for the heated material, ■ is the actual temperature calculation unit at each position of each heated material in the furnace, and J is the remaining temperature of the heated material in the furnace. A time calculation unit (1) is a calculation unit that checks the temperature of the material to be heated at the time of extraction and the temperature at the start of ripening, sets the furnace temperature in a predetermined ripening range, and controls the movement speed.

■, Controls the moving speed of heated objects 4 and 4 in the furnace'! A direct.

M is the furnace conveyance equipment for the heated material 1] and the extraction equipment for the heated material, 1\1 is the furnace temperature setting control device, 0 is the furnace temperature adjustment equipment, 1 is the heated material t)i charging signal, 2 3 is the movement of the rolling condition data group calculated and set by the setting part B. 4 is the movement of the heating condition data part calculated and set by the setting part C. , 5 is the transfer of the heating condition data group calculated and set by the setting section, 6 is the transfer of data such as furnace temperature scanned by the furnace condition data scanning section 1Σ, and 7 is the actual results of the heated material at each position in the furnace. 8 is data movement for the calculation part J to calculate the remaining furnace time R1 of each material to be heated; 9 is data movement used by the calculation part I; lO is the calculation section■
(Data movement of the moving speed of the heated object H in the furnace set in !1 is the extraction timing signal generated from the device iT, G, 12 is the periodic evening/rming signal generated from the signal source ■1, 13 Signal 11 and signal 114 are signals 11 and 15 that have passed through calculation unit J. 15 is signal 11 and signal 12 that have passed through calculation unit J. signals, 16 is a timing signal that notifies the control device 1 when the calculation of the calculation unit 1 is completed; 1 and 7 are signals by which the control device 1 actually drives the heated material conveyance and extraction equipment M of the furnace; 18 indicates that the calculation of the calculation unit 1 has been completed and the control device N is informed [
The timing of the change (FI, 19 is the signal by which the control unit @N drives the a1 unit @O that actually adjusts the furnace temperature) is not shown.

The timing of all of the signals 13 to 19 is determined by the signal 11 and the signal 2 generated by the signal generator G and the signal source II.

Next, the main functions of each component in FIG. 2 will be explained.

The rolling condition setting unit 13 is a part that calculates the rolling schedule and rolling time of the heated material (rolled material),
As shown in the conceptual diagram of FIG. 3, a rolling schedule for the rolling process following the heating furnace Fcθ is calculated.

In R1 to R1 (4) of the rough zone VSB of the rolling process, the number of rolling passes of each rolling mill, the thickness at each position, the moving speed, the rolling speed, and the descaling selection are determined, and the rough rolling pitch is determined. In zone 1 Ir t~F7, the material to be heated (
The rolling speed pattern of the material to be rolled (HS), the load distribution of each rolling mill, and the required idle time at the finishing front are determined, and the rolling pitch is determined. coiler zone dc
Now, 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 is used when the remaining furnace time is 1itlt'X.

Note that the logic used by this rolling condition setting section 13 is the same logic as each setting calculation model when performing actual rolling, which improves prediction accuracy and feeds the baked state of the heated material to the rolling process. Forward and mating surface temperature RT, L, (J: , -L: Rear surface temperature FT7
This makes temperature learning (feedback to heating control) easier.

The heating condition setting section C of the heating condition t1 sets the temperature of the material to be heated, that is, the finished product in accordance with the requirements for the rolled product, This is to determine the sieving heat value of the material to be heated, and determine the average value or minimum temperature of the target extraction temperature.

In addition, for materials to be heated that require metallurgical heat treatment, the lowest target extraction temperature;
The lowest temperature for drift extraction, CB and Zu in Figure 4.

・How, -1--i! +! When the allowable heat deviation range of the product to be heated is narrow (skinned marks, etc.) or when ripening is required in metallurgical heat treatment (L), the target temperature for the starting point of ripening before extraction and the time until extraction. Also set.

FIG. 4 illustrates the processing flow of the setting section C in FIG. 2. The materials to be heated that require the above-mentioned metallurgical heat treatment include those in which special elements are dissolved or precipitated, such as Al-Ktfi and Nb-containing steel, and components in steel slabs that do not require intervention. There are things that spread it.

The actual temperature calculation 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 up to the furnace floor position in the thickness direction and the longitudinal direction. It is something to do. The so-called calculation formula used here is to time-divisionally calculate the temperature increase within the time period during which activation is repeated by the Shinkatsu 11 or the Shinkan 12 using a two-dimensional differential decomposition model.

What is shown in Fig. 5 is an example of the above-mentioned actual temperature calculation 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. There is. Also, the reason why the divisions shown in the same figure exist on the Ito side and the four side sides in figures lr and c is because we considered the hot water temperature distribution in the furnace width direction inside the furnace.

The one shown in FIG. 6 is used when calculating the temperature of the heated material using the above two-dimensional model. Furnace 1j surrounding air temperature is 6th
+l+Z, 2Hz, 3117. in the figure. and S2 each I
The temperature at each position in the furnace estimated from the furnace temperature distribution curve from the value measured by the furnace temperature detector installed below -L of F is used.

Note that this example is a two-dimensional model in the longitudinal direction of the thickness, but when calculating the width direction of the heated material, a three-dimensional model that takes into account the distance between the heated materials that exist before and after the heated material is used. I can't even think of using it.

The remaining furnace time calculating section J in FIG. The rolling time of the heated material located further downstream ffl￥f
, (7. Remaining furnace time of each material to be heated.

In addition, at the timing activated by the signal 15 from the calculation unit for furnace temperature setting and heated material movement speed control, -] As in the second point, the rolling time of the heated material 14 located downstream from each heated material is further increased. The calculation unit 1 adds the determined heating neck to the moving speed control and determines the remaining furnace time.

FIG. 7 shows an example of the function of the calculation unit j in FIG. 2. For example, in FIG. ) remaining furnace time is downstream material! 1. Accumulate the rolling times from ■ to ■.

Also, the second time of material ■ (when activated by the above signal 15)
The remaining furnace time is the rolling time of the downstream materials ■~■ and the heating neck cost Cs between each downstream material! It becomes the integrated value of ~ and 5.

Note that "Heating neck formation" in Section 2 will be explained in the following function of the calculation section.

The calculating section for furnace temperature setting and moving speed control of heated materials shown in FIG. From the above-mentioned remaining furnace time (average temperature and minimum temperature) and the remaining furnace time, it is estimated using a plurality of simple formulas whether the extraction target temperature will be reached within the furnace time.

This;1;L calculation section performs calculation twice in the same way as the above-mentioned calculation section J, and once 1.4 (started from signal 13 via J), the extraction target temperature is reached within the remaining furnace time. If not, the time remaining in the furnace 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 to control the moving speed of the heated material in the furnace.

The second time (when activated from signal 15 via J), the calculation section J selects a furnace temperature setting that will exactly reach the extraction target temperature within the furnace operating time, taking into account "1 heating neck allowance". Therefore, the first calculation determines the moving speed control value of the heated book 4, and the second calculation determines the set value of the furnace temperature. however,
If the furnace temperature set value is below the lower limit of the actual temperature by -(n of the material to be heated), the material to be heated is such that it reaches the calculated actual temperature of A or the most recent temperature. Set the furnace temperature of the heating zone or other heating zones that can influence the heating zone.

The relationship between the calculation units 1 and 1 in Figure 2 is expressed as U1%' in Figure 8. , the calculation unit 1 is shown, and the multiple regression model in the figure indicates the calculation unit. Now, to explain the heated material fl (hereinafter referred to as material) ■ as an example, the material (
The temperature at which Wataru (Wataru) is currently located at 2 tTZ in the furnace is calculated using a two-dimensional difference resolution model, using the temperatures at multiple points in the thickness direction and longitudinal direction as actual values.

Next, a multiple regression model using the current actual calculated temperature as a parameter is used to calculate the temperature that will rise during the remaining furnace operation.

1) Check whether the standard extraction temperature is reached.

However, if the target extraction temperature is the lowest temperature for each category of raw meat, use the minimum temperature of each category as a parameter and the single regression formula or the formula for estimating the lowest temperature among multiple formulas. Choose from more.

Furthermore, the formula is selected depending on how far the IJ size exists in 21-IZ, 311Z, or SZ in the furnace, and the calculation accuracy improves as it approaches the extraction end.

In addition, for monthly yields in which the material to be heated requires ripening, the target temperature of the ripening starting point is carried out in the same manner as described in ``-''. 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. Furthermore, after the ripening start point and the heating time are satisfied, Only the target extraction temperature mentioned above is checked and controlled.

To explain in more detail based on the example in Figure 8, if the current material position is material ■, there are 17 materials at 2 Hz, so the extraction temperature is estimated using a multiple regression equation for 2 Hz. do.

1"p xt, ='L"sz-(1-5xp [-(
rj, sx ・<-Q, nTsz/ (1″sz
-'rsg )>+rAs2・eTs/h 4-c4
sa ) ] ) A1,”sE=
'1''3z・['l−εxp[(4+(, unTsz
/ (1'3Z i"3a) >"-62・eTg /
h Juuchi. ) ] ) -----------13', 1
”:+ e =T2 y, ・[+−εxp [(g21
・＜J'-nT2z/ (T2z ``I'2 E)＞
-1-wipe 22・θ', 1. '2 /1tIt tenbi,
23 ) ] ) ------C8T2e:
2σU1 Zheng) The current temperature of the monthly profit obtained using the solution model h: JTI of the heated material] εxl; : Recorded in the estimated extraction temperature of the heated material? The value of it is changed depending on whether the extraction temperature determined by 1'axL; 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, T7a is 1''. When the target extraction temperature is the average temperature, it is the average value, and when the target extraction temperature is the lowest temperature, it is the minimum temperature.

Next, when the material is located in material (2), the extraction temperature is estimated using a 3H2 multiple regression equation.

Tct=Tsz・[1- and XP [-(c4gl・
<, fLnTsz/ (T3 z-'rsg) )+
d, s2 ・aTs/ b + o(Sa ) ] )
D],'sH=Tsz・[1- and XP
[-(17'u 1' GnTa Z/ ("J,
"3 Z i-" a e ) ＞+2・θ'J'3/
hl-n3)]) ------7--E'I"3 g
: Current temperature of monthly interest rate 'I' calculated by two-dimensional difference model
a xt, = ”l'sz・(1-doxp[-(c%,
s!・Qnl'sz/ (Tsz-TgB)>
1ty<s2・aTs/b +dys3)ko) --
−−−−−−−−F゛1゛phase: 2-dimensional The regression equation is now used in a modified form.”
There is C. However, the type of equation is the same for each weapon, and the calculation is done by simply selecting the constant of the equation, which is a different regression equation.
are doing.

The regression equation accuracy of the ``-1 notation is 21 compared to the two-dimensional difference equation.
-(Multiple regression equation for Z small = 6°C, 3 tT The multiple regression equation for Z = 3""c, the multiple regression equation for sz was able to obtain an accuracy of small = 1°C.

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. It is necessary to take measures such as eliminating heat time.

The movement speed control device 1 for the heated material in FIG.

Function to control the drive of the heated material conveying device (walking beam) of the heating furnace and furnace extraction t% of the heated material
(Rafter to Extract 1) control device (M in Figure 1), which controls the rolling bit (of H to be heated) (
Checking the moving time between each rolling process shown in Figure 2),
The arithmetic unit K in FIG. 1 has a function of setting the furnace temperature in accordance with the furnace temperature setting in the furnace interior calculated by 4 (cellar 1 and upcon 1 roll).

According to the present invention, the actual temperature that guarantees the quality of the material to be heated is guaranteed for all sections (thickness direction and longitudinal direction), and also for maturation heat (i.e. solid solution precipitation of special elements) or maintenance of these. It has become possible to guarantee the quality of the necessary materials to be heated in all categories.

Furthermore, the control also improves accuracy as it approaches the extraction end.
It also enables n1 arithmetic processing in a short period of time, allowing 51 arithmetic operations.
'ff Fil 6 no.
L1. mel゛),su,no,ru gefn ′ jF
()) The biggest effect is that the I゛11 pattern control does not impede the productivity and stability of the rolling process following the continuous heating furnace at all, and saves energy in the heating furnace.

The graphs shown in Figures 9 and 10 show the control results compared with the conventional technology (all controls using simple formulas), and both show that highly accurate control is achieved by fT. ing.

[Brief explanation of drawings]

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 that implements the present invention in one embodiment, and FIG. 3 is a block diagram showing the relationship between the hot rolling line and the control contents of the rolling condition setting section B in FIG. 2 in one spell. 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 of the heating condition setting section C in FIG. 2.
on arithmetic. A plan view showing an example of dividing the heated material in the thickness direction and longitudinal direction,
Figure 6 is a schematic diagram showing the relationship between the arrangement of temperature detectors in the heating furnace and the calculation of the furnace atmosphere temperature at each position in the furnace, and Figures 7 and 8 are shown in Figure 2. Part 1. J
FIG. 3 is a block diagram showing the relationship between the position of each heated material, the calculated value, and the calculation timing related to the calculations of FIG. FIG. 9 is a graph showing the relationship between rough finishing temperature and extraction temperature, and FIG. 10 is a graph showing the relationship between extraction temperature and temperature deviation. Δ: Heating furnace charging signal generator for heating month 13: Rolling condition (rolling schedule) setting unit for heated material C: Heating condition setting unit for heated material ■, ): In-furnace position calculation unit for heated material E: Furnace condition data such as internal temperature scanning unit F: Control data group for each heated material in the furnace and time-series furnace condition, etc. that constitutes the control of the present invention G: Extraction signal generator for heated material II: Heated material extraction signal generator ■: Actual temperature calculation unit for each heated material at each position in the furnace J::
Unexamined calculation unit for heating material remaining in the furnace: Checks the temperature of the material to be heated at the time of extraction and the temperature at the start of aging, and sets the furnace temperature in the predetermined aging range and controls the movement speed. Furnace movement speed control device for heated materials M: In-furnace conveyance equipment for heating materials and extractor equipment for heated materials N: Furnace temperature setting control device O: Furnace temperature adjustment equipment L: Heated material charging signal 2: Heated material charging signal via setting section B 3: Setting section I
3 to 4 calculation and movement of the set rolling condition data group 4: Movement of the heating condition data part calculated and set in setting section C 5: 81 calculation in setting section and movement of the set heating condition data group 6: Furnace condition Data scanning unit) Data movement such as the furnace temperature scanned by Σ 7: Actual temperature at each position in the furnace of the heated material Data movement for processing by the calculating unit I 8: Calculating unit J scans each heated material Data movement to reduce the remaining furnace time 9: Calculation unit ■ (Data movement used by lO2 Data movement of the moving speed of the heated material in the furnace set in the calculation unit) l: Generated from device G Extraction timing signal 12:
Periodic timing signal 13 generated from signal source ■]: Signal 11 and signal 1214 via calculation unit ■:
Signal 11 via calculation section J. Signal 12° and signal 15 15: Signal 11 via calculation unit I (repetition signal 12 of signal 12 to calculation unit J) 16: Timing signal that notifies the control device when the calculation of calculation unit I is completed 17: Control device 1. Signal 18 for driving the material to be heated and extraction equipment M in the actual furnace: Timing signal 19 for notifying the control device N when the calculation of the calculation section (■) has finished; 4 for the control device N to adjust the actual furnace temperature. Signal patent applicant for driving equipment O “New 1” Honstetsu Co., Ltd.

Claims (2)

[Claims] (1) The material to be heated in the furnace is divided into multiple sections in the thickness direction and longitudinal force direction, and the temperature at the current position is calculated for each section at a predetermined period, and each time the average temperature or minimum temperature of each section temperature is calculated. A heating furnace control method characterized by sequentially controlling the furnace temperature and/or moving speed of the remaining furnace area based on the difference between humidity and target extraction temperature. (2) The material to be heated in the furnace is divided into multiple sections in the thickness direction and longitudinal force direction, and the temperature at the current position is calculated for each section at a predetermined period, and each time the average temperature or minimum temperature of each section temperature is calculated. Find the difference between the temperature and the target temperature at the start of ripening before extraction of the material to be heated. Also find the difference from the target extraction temperature, and calculate the remaining furnace area based on the larger of these four differences. The temperature and movement speed are controlled, and after the average temperature or minimum temperature reaches both the ripening start point and the start target temperature, the remaining temperature is determined based on the difference between the average temperature or minimum temperature and the target extraction temperature. A method for controlling a heating furnace, characterized by sequentially controlling the furnace temperature and/or moving speed of a furnace zone.