JPS6160250A - Method for controlling cutting with continuous casting installation - Google Patents

Abstract

PURPOSE:To improve yield by feeding back not only the actual cutting length of the own strand but also the actual cutting length of the other strands and controlling collectively the determination of the set cutting length of all the strands. CONSTITUTION:The cutting length for each billet determined by a computer 2 for control are set in control devices 5, 6 for cutting of the respective strands and the actual cutting of the billet is executed by cutting machines 7, 8. Length measuring devices 9, 10 take the actual value of the casting length therein and also take the actual cutting length of the cut billets therein. The length measuring devices feedback such values to the computer 2. The actual cutting lengths of not only the own strand but also the other strands are thus taken into the above-mentioned devices and the target intended cutting length of the other strands is also handled as a reference product length and therefore the optimization of combination is made better than in a cutting method in which the strands are independent. The yield is thus improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to continuous casting equipment, and particularly to a cutting control method suitable for improving yield when cutting slabs in equipment having multiple strands.

[Background of the invention]

In recent years, with continuous casting equipment, as the continuous casting ratio within a steelmaking factory has improved, schedule coordination between the upper process, the converter (or electric furnace) factory, and the lower process, the rolling factory, has become more complicated. Due to the increasing production capacity, there is a trend toward shortening casting time by increasing casting speed and using multi-strand equipment.

Under these circumstances, when strands are multiplied, one charge is distributed over each strand during casting, which makes the product distribution method per p1 charge complicated, and as a result, the cutting control method for slabs becomes complicated. strands have also become much more complex than single strands.

For this reason, the upper-level computer (business computer) is in charge of product production planning, and the lower-level computer or control computer (process computer) is in charge of determining the final measuring and cutting length of the product, such as slabs and plumes. has become a common architecture for computer control in modern continuous casting equipment.

The lower-level computer calculates the cutting length of each slab by combining the cutting length of each slab corresponding to the actual casting length of the charge to be actually cast, based on the target planned cutting length determined by the upper-level computer. Determine the set length, and also feed back the actual value to recalculate the combination.
So-called cutting control is performed.

However, in conventional cutting control, the cutting method for each strand is determined independently, so the actual casting length may be changed to a large width, or the product distribution may be changed due to continuous casting of different steel types, width change control, etc. When the length of the product is changed to a larger width, the standard product length that serves as the basis for the combination becomes insufficient, and optimization often cannot be achieved.

When setting the cutting length of one's own strand, the inventor considered a combination that also took into consideration the target planned cutting length (standard product length) of other strands, and not only feedback of the actual cutting length of one's own strand, but also the actual cutting length of other strands. The yield was improved by controlling the cutting length of all strands at once by feeding back the length.

Incidentally, related known techniques include Japanese Patent Laid-Open No. 58-86652.

[Purpose of the invention]

An object of the present invention is to provide a cutting control method that can improve yield by performing batch cutting control including other strands in multi-strand continuous casting equipment.

[Summary of the invention]

The gist of the present invention is to realize a much higher yield improvement in multi-strand continuous casting equipment by changing the method to set cutting length at once, including other strands.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure shows an overview of continuous casting equipment.

The production plan information drawn up by the higher-level computer is transmitted to the lower-level computer as the first target planned cutting length at the time when the charge corresponding to the product is tapped from the converter. Now, for simplicity, we will consider a single strand (in this case, the first strand).

L+ =to +tts +・・・・・・+t1+・・
...10t1m...(1) Here, Ll: Planned casting length of the first strand i: Target planned cutting length of each product n: Number of products per strand Formula (1) can be calculated using various miscellaneous This is a general formula when there is a product, but the products that are actually cast using multi-strand continuous casting equipment are mass produced and have a small number of products.
If M types of product lengths t1° are selected instead of I, the equation can be rewritten as shown in equation (2).

L + = a + + ttt +
a+s ・tts + ...+a IJe 11
3..group.+aIM@tIM...(2) Here, tll: Standard product length of NoJ alJ: Number of zll When formula (2) is generalized and written in matrix form, Ls =
A+' LIM...
・(3) Here, AI=(an=atM:l: Combination matrix L IM= (t+t...tIM) t: Standard product length matrix (t means transposed matrix) Next, the actual casting length L;, this has a certain deviation ΔL1 with respect to the casting length obtained by equations (2) and (3), and as a result, the crop that cannot be manufactured with this strand (length t, 1 is C , consists of , pieces).If you convert it into a mathematical formula, Lτ=a■・4t +
”=+a1m@tsM+Ct・tal”(4)==
AO,・L9...(5
) where -A? =(att”.aIMcl)L
It can be expressed as τ=[t1bi...Lsw L, 1:1 t.

The evaluation value of the optimal combination pattern of this first strand is J
l, then λ J1=L1°−Lt...(6
) is a condition for finding an optimal pattern. The evaluation value Jt is calculated by formulas (3), (5), and (6).
"'CI" t, +1
...(7) becomes,
This clearly contradicts the idea of improving yield, which is to minimize the number of crops that cannot be commercialized. The minimum value of J+ can be easily obtained by repeatedly calculating the combination of L matrices in equations (3) and (5). If the optimal combination pattern at this time is OP T A l, this is the solution that should be finally obtained when only the first strand is considered.

On the other hand, the actual cutting length can be handled as follows: (new actual casting length) = (actual casting length before cutting) - (actual cutting length of slab) (8)
Since the optimum combination pattern can be calculated for each slab cut using the same method, Figure 2 compares the cutting method of the present invention with the conventional method to clarify the differences. Shown.

For other strands, OP T Ak can be similarly obtained using equations (2) to (7), but in this way, in the conventional method, the reference cutting length and It merely aims at optimization within that strand by using only the actual cutting length.

This method is intended to select the optimal combination pattern by taking into consideration the target planned cutting length of other strands when setting the cutting length of the own strand, and to calculate the optimal combination pattern for each slab cutting by feedback of the actual cutting length. be.

For convenience, by viewing the problem as a change in the actual casting length, it is possible to obtain an optimal combination solution that takes into account the actual cutting length.

Now, considering the second strand in the same way as the first strand, the planned casting length L2 is Ls = ax
1”L2I tena*a'4a +-+aaj@kj+-
a2M"t2M...(9) ""A2 "L4M"'α
0 Here, it can be expressed as A2=(a鵞1...a2M): Combination matrix L* M= (Ax t...42m:]t: Standard product matrix, and the actual casting length Lr is L
ff=as+ et*+ +”・+a2Mm12M+c
2 mm, ・(11) = A o ・L; Rei
...(I thirst here, Am=Cast
°−a2yc2]L9=[tII...L2wl
-3] becomes 1. Similarly, if we extend this idea to the Nth strand and summarize it in matrix form, L'=A
-LM...0Here, L'= (LY L!'...L'M)'LM=C
L9 tl-, -t...1:Mt)t, Lo is the actual casting length matrix with N rows and columns, and LM is (M+1
)·N rows and columns of reference cutting length matrix, and A is a selection matrix of N rows and (M+1)·N columns for selecting the reference cutting length.

When this method is applied using the formula 0 as a reference, each item of the casting length matrix can be expressed as the following formula, since the reference matrix corresponding to each strand can be arbitrarily selected.

L0=A/ ・LM ・・・aa
Here, L'=l"LYLexpansion/old...La)'LM=[L
tl-:, t... t]tBt 1=Cb+
Otori j b! +J ・・・・・・ b
[Old 1] Here, A' is the selection matrix of this method, and the matrix BIJ therein is a matrix for selecting a reference cutting length from j strands that satisfies the casting length of i strand.Here, (
Similarly to equation 6), when evaluating the optimal combination pattern, N
The evaluation value JT that takes into account all the strands of the machine is JT - ΣJk = Σ (-Lk to L') = Σc 'b - L'ak...f161 (here c'
, l-a' are c and L of the conventional method. These are the number of crops and the crop length expressed to distinguish between the two. ), and the selection matrix that minimizes this can be the optimal combination.

To demonstrate the effectiveness of this method, Σ (Ck conflict t, b @l' in C'.k) - ≧ 0
...All you have to do is show αη. The aforementioned optimal pattern 0PTA
Using k, Lo: 0PTAk@LkM
...(1 mallet (here: the second strand) -(akl m l* + ten・"・+aku"4M
)+CN tsk...01, which is from equation 04) = (ak+ °tk1+゛-kakM''mu1)+c/ni・t/., +ΣBk, @L',.

(t key j) ... (a) Since it can be written as (17), α1. Kanshiki Yoshik

kl(i4k)...li2]), and it was confirmed that this method is more optimal. (If B kl is all 0, the evaluation of the conventional method and this method will be the same.) Figure 1 shows an outline of a device that implements this method. The cutting length for each slab is set in the cutting control device 5.6 for each strand, and while the cutting machine 7.8 actually cuts the slab, the length measuring device 9.10 measures the actual casting length. At the same time as taking in the values, the actual cutting lengths of these cut slabs are also taken in, and the values are fed back to the control computer 2.

In this way, with this method, the error is not limited to the own string →
Since the actual cutting length of other strands can also be taken in, and the target planned cutting length of other strands can also be treated as the standard product length, optimization of combinations is improved compared to the cutting method of independent strands, and as a result, yield is improved. A more cutting control method can be provided.

〔Effect of the invention〕

According to the present invention, compared to a method of cutting each strand independently, all the strands can be controlled at once, so there is an effect of improving the yield.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the equipment and device of the present invention, and FIG. 2 is a diagram for explaining the cutting control method according to the present invention. 2... Control computer, 3, 4... Casting length and cutting length measuring device, 5, 6... Cutting control device, 11... Cropping by conventional method, 12... Cropping by this method .

Claims (1)

[Claims] 1. In multi-strand continuous casting equipment, when setting the cutting length of the own strand, consider not only the target planned cutting length and actual cutting length of the own strand, but also the actual cutting length of other strands, and set the cutting length of the other strand. A cutting control method for continuous casting equipment, characterized by exchanging with a target planned cutting length, making a selection, and changing the set cutting length.