JP3912215B2 - Converter blowing control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a converter blowing control method for performing control to match a molten steel temperature at the end of blowing to a converter to an end point target temperature.
[0002]
[Prior art]
The converter uses pig iron supplied from the blast furnace and scrap prepared separately as a main raw material. After adding auxiliary materials such as lime to this, oxygen is blown from above, sulfur S and phosphorus P contained inside It has a function of removing impurities such as oxidization, refining a steel having a desired composition and temperature, and supplying it to the next rolling step. Then, the main raw material and auxiliary raw material are supplied to the converter, oxygen is sprayed, and one process from the time when the steel having the desired composition and temperature is output (output steel) at the final (end point) time is “charged” ".
[0003]
The composition and temperature of pig iron and scrap supplied to the converter vary from charge to charge. Therefore, in order to produce steel having a uniform composition and a uniform temperature over all charges, it is It is necessary to carry out optimal blowing control.
[0004]
Therefore, in this blowing control, the target molten steel temperature (end point target) for the converter with respect to the blowing conditions (operation conditions) such as composition and temperature of pig iron and scrap that fluctuate for each charge of the converter. In order to obtain the end point temperature (molten steel temperature at the end of blowing) of the molten steel that matches the (temperature), a heat blending calculation is required. And end point temperature is computed based on this heat compounding calculation result. And the input amount with respect to the converter of cooling materials, such as iron ore, or heating materials, such as coke, is determined by temperature conversion so that the molten steel temperature at the time of completion | finish of this blowing may correspond with end point target temperature.
[0005]
However, when it is predicted that the end point temperature will not reach the end point target temperature, it is necessary to add a coolant or a heat-up material at the end of blowing. The introduction of the coolant or the heat-up material at the end of the blow smelting is poor in the cooling efficiency because the yield to the molten steel is poor, and it is necessary to increase the amount of input compared to the case of the introduction at the middle of the smelting. In addition, when the molten steel temperature increases, the furnace bricks are seriously damaged.
[0006]
Therefore, it is necessary to reduce as much as possible the error in adjusting the molten steel temperature by introducing a desired amount of the coolant obtained by converting the temperature into the initial stage of blowing.
[0007]
There is a comparative heat balance calculation method as one of the heat balance calculation methods for obtaining the input amount of the coolant or the temperature raising material. In this comparative heat balance calculation method, the actual data of each charge carried out in the past is compared with the calculation data of the charge carried out this time. The amount of material input is calculated [Proceedings of the Iron and Steel Institute Spring Lecture Meeting, VOL5, 1992, published by the Japan Iron and Steel Association, Shinichi Wakamatsu et al. "216p].
[0008]
More specifically, first, prioritize each item of the main raw material data (hot metal components, furnace time, total charge, etc.) of the charge to be implemented this time, and set the upper and lower limit values for the items with higher priority. A past charge example that is within is extracted. Next, the data input difference between the extracted past charge example and the current charge is corrected with respect to the actual input amount of the past charge example using the heat conversion coefficient, and the coolant or the heat-up material Find the input.
[0009]
Also, in Japanese Patent Application Laid-Open No. 9-25505, regarding the comparative heat balance calculation, out of the charge carried out in the past, the charge deviated from the standard due to the operator's operation etc. is excluded from the comparative heat balance calculation for the charge carried out this time. To do. In addition, the actual difference between the heat balance value model and the current charge is reflected in the calculation of the next charge. By taking such measures, the hit ratio of the actual end point temperature in the current charge to the end point target temperature is improved.
[0010]
[Problems to be solved by the invention]
However, with the above-described method, there is still the following problem to be solved even in the converter blowing control method in which the actual end point temperature in the charge newly performed this time matches the end point target temperature.
[0011]
That is, at the stage of collecting each similar data such as main raw material data (hot metal composition, furnace time, total charge) from a large number of charges carried out in the past, the similarity of this main raw material data is determined for each item. For example, only a specific difference such as within the upper and lower limit ranges is focused on, and the similarity of the entire features over all items in the similar charge is not evaluated.
[0012]
Therefore, even if the data of similar charges whose overall characteristics have not been evaluated are used to perform a comparative heat balance calculation with the current charge and the thermal margin is predicted, a high-accuracy thermal margin is expected. Therefore, there is a concern that the converter blowing control accuracy for making the end point temperature coincide with the end point target temperature is lowered.
[0013]
In addition, since the heat calculation only reflects the error in the previous charge, the error specific to the past charge collected as similar data is not reflected. In addition, because the heat prediction is a fixed heat conversion coefficient, the furnace pair situation and the heat yield are not taken into account, and the error is large.
[0014]
The present invention has been made in view of such circumstances, and by defining the entire charge item to be newly implemented as a single vector (set), it is possible to truly A similar actual charge can be selected, a high-accuracy thermal margin can be calculated from this actual charge, and the actual end point temperature can be reliably matched to the end point target temperature. The purpose of the present invention is to provide a converter blowing control method capable of improving the quality of steel products and extending the life of refractories such as bricks in the converter and reducing the secondary refining load.
[0015]
[Means for Solving the Problems]
The present invention provides a converter blowing control in which the molten steel temperature at the end of blowing of each charge coincides with the end point target temperature in each charge in which blowing is performed with at least pig iron and various auxiliary materials being charged into the converter. Applied to the method.
[0016]
And in order to eliminate the said subject, in the converter blowing control method of this invention, first, the quantity of at least pig iron in the charge newly implemented, temperature, the track record of a component, the input amount of various auxiliary materials, and end point target A blowing condition including a plurality of items including temperature and an end target component is defined as a new blowing vector. Next, the blowing of each charge stored in the blowing performance database storing the past blowing condition results for each charge performed in the past and the actual heat margin obtained by converting the actual inputs of the heat-increasing material and the coolant into heat amounts. The actual product of smelting conditions is defined as the actual blowing vector.
[0017]
Further, a predetermined number of actual blowing vectors similar to the new blowing vector are selected from the plurality of actual blowing vectors, and each blowing condition and each actual heat of the selected predetermined number of actual blowing vectors are selected. Create an approximate model to estimate the thermal margin of the charge to be newly implemented from the margin.
[0018]
Then, using the created approximate model, the thermal margin of the charge to be newly implemented is estimated, and based on the estimated thermal margin, the molten steel temperature at the end of the newly implemented charge blowing is set as the end point target temperature. The amount of coolant or heat-up material to be matched is determined.
[0019]
  The features of the converter blowing control method configured as described above will be described.
  Consider a method for efficiently predicting a thermal margin determined after execution of a charge in a newly executed charge. This search is performed by searching the database for past charges having blowing conditions similar to those of the newly executed charge.WasWith reference to the actual heat margin of the past charge, the post-execution thermal margin is estimated for the newly implemented charge.
[0020]
In this case, the problem is that there are a wide variety of items that make up the blowing conditions for each charge, and the number of items is very large, such as a dozen or so. There is rarely a past charge with blowing conditions. Therefore, it is necessary to select a past charge having similar blowing conditions. In this case, if only a specific item is selected and selected, a thermal margin far from the actual is estimated. Therefore, it is important how to select a past charge having similar blowing conditions.
[0021]
Therefore, in the present invention, each item such as pig iron and various auxiliary materials input amount and end point target temperature constituting the blowing condition in the charge to be newly implemented is not treated as an individual item, but a plurality of items This set of items is defined as a new blowing vector. Similarly, the set of each item which comprises the blowing conditions and performance value (blowing condition performance) in each charge implemented in the past is defined as a performance blowing vector.
[0022]
Then, a predetermined number of actual blown vectors similar to the new blown vector are selected from many past actual blown vectors, and the blowing conditions corresponding to the selected predetermined number of actual blown vectors. An approximate model is created using the value of each item of results and each heat margin.
[0023]
In this way, each blowing condition is treated as a vector consisting of a set of multiple items, and the past between those having similar blowing conditions more accurately by evaluating the similarity between the vectors by the similarity between the sets. Can be selected. Therefore, a more accurate thermal margin can be estimated.
[0024]
Further, according to another invention, in the converter blowing control method of the invention described above, a norm (distance) of a difference vector between a new blowing vector and each actual blowing vector is calculated, and the calculated norm is small. The predetermined number of actual blown vectors is a predetermined number of actual blown vectors similar to the new blown vector.
[0025]
Thus, by adopting a norm, which is a mathematically established technique, for quantitatively evaluating the degree of similarity between vectors, similar past charges can be selected more easily.
[0026]
Further, in another converter according to the above-described converter blowing control method, the norm of the difference vector between the vectors is the new blowing vector and the value of each item constituting each actual blowing vector. Is calculated by using a new blowing normalization vector normalized by the statistical value of each item stored in each item and each actual blowing normalization vector.
[0027]
Thus, by calculating the norm using the normalized vector obtained by normalizing each item constituting the blowing condition, the similarity between the vectors can be evaluated more accurately.
[0028]
Another invention assumes that, in the above-described converter blowing control method, the value of each item constituting each blowing condition of each predetermined number of actual blowing vectors and each actual thermal margin satisfy the approximate model. Then, this approximate model is identified using the regression equation.
[0029]
Further, according to another invention, in the converter blowing control method described above, the approximate model is assigned in accordance with each norm value of a difference vector between the selected predetermined number of actual blowing vectors and the new blowing vector. The thermal margin of the charge to be newly implemented is estimated from the weighted value thus obtained and the actual thermal margin of each corresponding charge.
[0030]
In this way, in the approximate model in the configured converter blowing control method, calculation is performed using the actual thermal margin of each charge of the predetermined number of selected actual results. Since the weighted value given according to the value of is added, it is possible to estimate the heat margin statistically more accurately.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a block diagram showing a schematic configuration of a converter blowing control apparatus to which the converter blowing control method according to the first embodiment of the present invention is applied. This converter blowing control device is formed of a kind of information processing device such as a computer.
[0032]
In the converter blowing control device, an operation unit 1 for an operator such as a keyboard to input various information, a blowing performance database 2 for storing data of each charge performed in the past, and a calculation A display 3 for displaying the heat margin and the input amount of the coolant or the temperature raising material is incorporated.
[0033]
In the blowing performance database 2, as shown in FIG. 2, a blowing condition performance 4 and a performance heat margin 5 are stored for each charge number that identifies each charge performed in the past. As blowing condition result 4, actual value x in a plurality of items 1 to n₁, X₂, X_Three, X_Four, X_Five, X₆, ..., x_nIs remembered. For example, item 1 (value x₁) Is the amount (actual) of hot metal charged to this converter, and item 2 (value x₂) Is the temperature (actual) of hot metal to be charged into this converter, and item 3 (value x_Three) Is one composition (for example, carbon content record) of the hot metal to be charged into this converter, and item 4 (value x_Four) Is the input amount (actual) of the auxiliary material to be input to this converter, and item 5 (value x_Five) Is the actual temperature at the end point, which is the temperature of the molten steel that is discharged from the converter at the end of blowing (end point). Item 6 (value x)₆) Is the actual end point composition (component) that is the composition of the molten steel that is discharged from the converter at the end of blowing (end point).
[0034]
  Although not shown in FIG. 2, the amount of sprayed oxygen in blowing, the record of the coolant or temperature rising material added to the converter for temperature adjustment during or at the beginning of blowing. The input amount is included. Further, as another composition, there is a content of each metal such as manganese Mn, silicon Si, phosphorus P, oxygen O and the like in addition to the above-described composition of the carbon C content.Therefore, in addition to the six items shown in FIG. 2, the items include the contents of manganese Mn, silicon Si, phosphorus P, oxygen O, and the like contained in the auxiliary material.
[0035]
The actual heat margin 5 is a value obtained by converting the total input amount of each actual result of the heating material such as coke and the cooling material such as iron ore determined when the blowing of the corresponding charge is finished (the actual heat Margin h).
[0036]
In the converter blowing control apparatus shown in FIG. 1, in addition to the operation unit 1, the blowing performance database 2, and the display 3 described above, a new condition input unit 6 and a new condition formed on the application program are provided. A vector definition unit 7, a performance condition vector definition unit 8, a normalized vector creation unit 9, a norm calculation unit 10, a similar vector selection unit 11, an approximate model creation unit 12, a thermal margin calculation unit 13, an input amount calculation unit 14 and the like are provided. It has been.
[0037]
Next, operation | movement of each part 6-14 of the converter blowing control apparatus comprised in this way is demonstrated using the flowchart shown in FIG.
[0038]
The actual value x in each item 1 to n in the charge newly performed by the operator via the operation unit 1 is described above.₁, X₂, X_Three, X_Four, X_Five, X₆, ..., x_nNew blowing conditions [x ’₁, X ’₂, X ’_Three, X ’_Four, X ’_Five, X ’₆, ..., x '_n], The new condition input unit 6 is activated, and the input new blowing condition [x ′₁, X ’₂, X ’_Three, X ’_Four, X ’_Five, X ’₆, ..., x '_n] Is sent to the new condition vector definition unit 7 (step S1). The new condition vector definition unit 7 converts the input new blowing condition into a new blowing vectorVa is defined (S2).
[0039]
Va = (x ′₁, X ’₂, X ’_Three, X ’_Four, X ’_Five, X ’₆, ..., x '_n)
It should be noted that the actual value x in each of the items 1 to n in the charge to be newly implemented is described above.₁, X₂, X_Three, X_Four, X_Five, X₆, ..., x_nIs given not only through the operation unit 1 by the operator, but also from the host computer.
[0040]
Next, the performance condition vector definition unit 8 is activated, and the blowing condition results [x for each charge stored in the blowing performance database 2 of FIG.₁, X₂, X_Three, X_Four, X_Five, X₆, ..., x_n] Each achievement blown vectorVb.
[0041]
Vb = (x₁, X₂, X_Three, X_Four, X_Five, X₆, ..., x_n)
Next, the normalized vector creation unit 9 is activated, and the actual values xi (i = 1, 2,..., N) of the items 1 to n stored in the blowing performance database 2 are all charged. The average value ui and standard deviation σi are calculated (S3). Next, the value xi (i = 1, 2,..., N) of each item in the actual blowing conditions in each charge is normalized. The normalized value xib of each item is
xib = (xi-ui) / σi
(S4).
[0042]
Next, each charge performance blowing vectorVA vector obtained by replacing the value xi of each item of b with the normalized value xibVbo is defined (S5).
[0043]
Vbo = (x_1b, X_2b, X_3b, X_4b, X_5b, X_6b, ..., x_nb)
In addition, new blowing vectorVThe value x'i of each item of a is normalized using the average value ui and standard deviation σi obtained from each value of the blowing performance database 2 described above,
xia = (x'i-ui) / σi
Replace each normalized value xia with a new blowing normalization vectorVDefine ao (S6).
[0044]
Vao = (x_1a, X_2a, X_3a, X_4a, X_5a, X_6a, ..., x_na)
The norm calculation unit 10 is activated and this new blowing normalization vectorVao and each achievement blowing normalization vectorVEach deviation vector Δ between boVab is set (S7),
ΔVab =Vao―Vbo
Each deviation vector ΔVab to vectorVao,VNorm | Δ as a quantitative criterion for similarity between boVab | is calculated (S8).
[0045]
| ΔVab ｜
= [(X_1a―X_1b)²+ (X_2a―X_2b)²+ ... + (x_na―X_nb)²]^1/2
In addition, weighting factor w for each item in blowing condition₁, W₂... w_nNorm calculated by multiplying || ΔVab |.
[0046]
| ΔVab ｜
= [W₁(X_1a―X_1b)²+ W₂(X_2a―X_2b)²+ ... + w_n(X_na―X_nb)²]^1/2Each norm for a new charge in all the actual charges stored in the blow blowing actual database 2 | ΔVWhen the calculation processing of ab | is completed, the pseudo vector selection unit 11 is activated and each calculated norm | ΔVab |, k (predetermined number) norm | ΔVab | is selected (S9).
[0047]
K selected norms | ΔVThe value x of each item in the performance blowing condition of the performance charge corresponding to ab |₁, X₂, X_Three, X_Four, X_Five, X₆, ..., x_n, And the corresponding actual heat margin h is read (S10).
[0048]
Next, the approximate model creation unit 12 is activated, and the value x of each item of the blowing conditions described above for the thermal margin Hd as an approximate model of the thermal margin Hd.₁, X₂, X_Three, X_Four, X_Five, X₆, ..., x_nIs set as a linear approximation expression represented by a linear function (S11).
Hd = c₁x₁+ C₂x₂+ C_Threex_Three+ C_Fourx_Four+ C_Fivex_Five+ ... + c_nx_n+ C₀
Where c₁, C₂, C_Three, ..., c_nIs a coefficient and c₀Is a constant.
[0049]
Considering the heat balance in the charge including blowing to the converter, the heat margin Hd at the end of the charge is obtained by subtracting the total heat output from the total heat input to the converter. The total heat input to the converter and the total heat output are the value x of each item of the above-mentioned blowing conditions.₁, X₂, X_Three, X_Four, X_Five, X₆, ..., x_nTherefore, the thermal margin Hd at the end of charging is also the value x of each item of the blowing condition.₁, X₂, X_Three, X_Four, X_Five, X₆, ..., x_nIt can be expressed by the function
[0050]
  Therefore, the heat margin Hd is the value x of each item of the blowing condition.₁, X₂, X_Three, X_Four, X_Five, X₆, ..., x_nLinear approximation using as a variable is possible. Therefore, each coefficient c₁, C₂, C_Three, ..., c_nAnd constant c₀Is obtained, the above-described linear approximation formula is determined.
[0051]
Value x of each item of actual blowing conditions for each actual charge similar to newly implemented charge₁, X₂, X_Three, X_Four, X_Five, X₆, ..., x_n, And the corresponding actual heat margin h should almost satisfy the above-mentioned linear approximation formula, the value x of each item of the k actual blowing conditions₁, X₂, X_Three, X_Four, X_Five, X₆, ..., x_n, And the corresponding actual heat margin h are substituted into the above-mentioned linear approximation formula, and each coefficient c is calculated by the least square method or the like.₁, C₂, C_Three, ..., c_nAnd constant c₀Is obtained (S12).
[0052]
The thermal margin calculation unit 13 is activated, and the value of each item in the charge blowing condition to be newly implemented is added to the linear approximation obtained in this way.₁, X₂, X_Three, X_Four, X_Five, X₆, ..., x_nIs substituted to calculate the expected thermal margin Hd of the newly implemented charge (S13). In addition, when this thermal margin Hd is positive, it indicates that the temperature of the final molten steel is higher than the end point target temperature, and when this thermal margin Hd is negative, the temperature of the final molten steel is lower than the end point target temperature. Show.
[0053]
  Next, the input amount calculation unit 14 is activated, and the input amount of the cooling material such as iron ore or the temperature rising material such as coke that is input into the converter during the blowing so that the thermal margin Hd becomes zero. Is calculated using a predetermined heat conversion rate. Then, the calculation result is displayed and output on the display 3 (S14).
[0054]
In the converter blowing control method configured in this way, each item of 1 to n constituting the blowing condition in the charge to be newly implemented is not treated as an individual item, but a set of a plurality of items The set of each item is treated as a new blowing vectorVa. Similarly, a set of items constituting the blowing conditions in each charge carried out in the past is used as the actual blowing vector.Vb.
[0055]
And many past achievements of this pastVNew blowing vector from bVk performance blow vectors similar to aVSelect b and select k actual blown vectorsVActual value x in each item of actual blowing conditions corresponding to b₁, X₂, X_Three, X_Four, X_Five, X₆, ..., x_nEach coefficient c of the linear approximation formula as an approximation model using the value and each actual heat margin h₁, C₂, C_Three, ..., c_nAnd constant c₀Has been identified.
[0056]
In this case, each blowing condition is a vector consisting of a set of multiple items.Va,Vnorm indicating the degree of similarity between sets, treating the degree of similarity between vectors as bVBy evaluating with ab |, past charges having similar blowing conditions can be selected more accurately. Therefore, it is possible to estimate a more accurate thermal margin Hd for a newly implemented charge.
[0057]
As a result, it is possible to more accurately set the amount of coolant or temperature rising material to be charged into the converter in the middle of blowing so that this thermal margin Hd becomes 0, and the actual end point temperature in the newly implemented charge Can accurately match the end point target temperature, improve the quality of steel products made of steel produced from this converter, extend the life of refractories such as bricks in the converter, and The load of the next refining can be reduced.
[0058]
(Second Embodiment)
Hereinafter, a converter blowing control method according to the second embodiment of the present invention will be described.
The converter blowing control method of the second embodiment differs only in the approximation model for obtaining the heat margin Hd in the converter blowing control method of the first embodiment described above. A method for obtaining an approximate model for obtaining Hd will be described.
[0059]
Each norm for the charge newly implemented in all the actual charges stored in the blowing performance database 2 | ΔVWhen the calculation processing of ab | is completed, the pseudo vector selection unit 11 is activated and each calculated norm | ΔVab |, the smaller of the k norms | ΔVUntil ab | is selected, it is the same as the converter blowing control method of the first embodiment described above.
[0060]
In the converter blowing control method of the second embodiment, each norm | Δ representing the similarity (distance) between k vectors.Vab |₁, D₂, D_Three, D_Four, ..., d_kAnd And this k distances d₁, D₂, D_Three, D_Four, ..., d_kThe maximum distance is dmax. K distances d₁, D₂, D_Three, D_Four, ..., d_kThe actual heat margin for each charge corresponding to₁, H₂, H_Three, H_Four... h_kAnd
[0061]
Here, each actual heat margin h₁, H₂, H_Three, H_Four... h_kFor each weighting factor to multiply₁, W₂, W_Three... w_kThen, each weight coefficient w_i(I = 1,2,3, ..., k) for each distance d_i(I = 1,2,3, ..., k) and defined by the following formula.
[0062]
w_i= [1- (d_i/ Dmax)^Three]^Three
W = w₁+ W₂+ W_Three+ ... + w_k
That is, the shorter the distance (the more similar the vectors), the weighting factor w_iBecomes bigger.
[0063]
Then, an approximate model of the newly obtained charge thermal margin Hd is defined by the following equation.
[0064]
Hd = [w₁h₁+ W₂h₂+ W_Threeh_Three+ ... + w_kh_k] / W
Then, when the thermal margin Hd is obtained, the amount of the coolant or the temperature rising material to be charged into the converter during the blowing is calculated using a predetermined temperature conversion rate so that the thermal margin Hd becomes zero. To do. Then, the calculation result is displayed and output on the display 3.
[0065]
Each weight coefficient w_iAs a setting method of (i = 1, 2, 3,..., K), various methods such as a normal distribution function can be considered in addition to the above formula.
[0066]
Also in the converter blowing control method of the second embodiment configured as described above, a new blowing vector of charge to be newly implementedVk actual blown vectors approximating aVSelect b and select k actual blown vectorsVSince the actual heat margin Hd of the newly implemented charge is calculated using the actual heat margin h of the actual charge corresponding to b, it is almost the same as the converter blowing control method of the first embodiment described above. It is possible to achieve an effect.
[0067]
Furthermore, in the converter blowing control method of the second embodiment, the actual heat margin h₁, H₂, H_Three, H_Four... h_k, Weighting factor w given according to norm value₁, W₂, W_Three... w_kTherefore, the statistically more accurate thermal margin Hd can be estimated.
[0068]
【The invention's effect】
As described above, in the converter blowing control method of the present invention, a predetermined number of actual blowing vectors that approximate the new blowing vector of the charge to be newly selected are selected, and each selected actual blowing is performed. Using the actual heat margin of the actual charge corresponding to the vector, an approximate model for estimating the thermal margin of the charge to be newly made is created.
[0069]
Therefore, it is possible to select an actual charge that is truly similar from a large number of actual charges that have been implemented in the past, to calculate a high-accuracy thermal margin from this actual charge, and to accurately match the actual end point temperature with the end point target temperature It is possible to improve the quality of steel products produced from the steel produced from the converter, to extend the life of refractories such as bricks in the converter and to reduce the load of secondary refining.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of a converter blowing control apparatus to which a converter blowing control method according to a first embodiment of the present invention is applied.
FIG. 2 is a diagram showing storage contents of a blowing performance database formed in the converter blowing control device.
FIG. 3 is a flowchart showing the operation of the converter blowing control device.
[Explanation of symbols]
1 ... operation part
2 ... Blowing performance database
3 ... Display section
6 ... New condition input part
7 ... New condition vector definition part
8 ... Achievement condition vector definition part
9 ... Normalized vector generator
10: Norm calculation unit
11: Similar vector selection unit
12 ... Approximate model creation unit
13 ... Thermal margin calculation part
14: Input amount calculation unit

Claims (5)

In each charge in which blowing is performed with at least pig iron and various auxiliary materials charged to the converter, in the converter blowing control method in which the molten steel temperature at the end of blowing of each charge matches the end point target temperature,
A new blowing vector is defined as a blowing condition consisting of a plurality of items including at least the amount of pig iron, temperature, component results, input amounts of various auxiliary materials, end point target temperature, and end point target component in a newly implemented charge. ,
Blowing condition results for each charge stored in the blowing performance database that stores the past blowing condition results for each charge implemented and the actual heat margin converted from the actual input of heat-increasing material and coolant into heat quantity. Each product is defined as an actual blown vector,
A predetermined number of performance blowing vectors similar to the new blowing vector are selected from the plurality of performance blowing vectors,
Create an approximate model for estimating the thermal margin of the newly implemented charge from each blowing condition and each actual thermal margin of the selected predetermined number of actual blowing vectors,
Estimate the thermal margin of the newly implemented charge using this created approximate model,
Based on the estimated thermal margin, the amount of the coolant or the heating material to be used for making the molten steel temperature at the end of the newly implemented charge blown finish coincide with the end point target temperature is determined. Furnace blowing control method. A norm of a difference vector between the new blowing vector and each actual blowing vector is calculated, and a predetermined number of actual blowing vectors having a small calculated norm are set to a predetermined number similar to the new blowing vector. The converter blowing control method according to claim 1, wherein the actual blowing vector is used. Each norm is a new blowing normalization in which the value of each item constituting the new blowing vector and each actual blowing vector is normalized by the statistical value of each item stored in the blowing actual database. 3. The converter blowing control method according to claim 2, wherein the calculation is performed using a vector and each actual blowing normalization vector. It is assumed that the value of each item constituting each blowing condition of the predetermined number of actual blowing vectors and each actual heat margin satisfy the approximate model, and this approximate model is identified using a regression equation. A converter blowing control method according to any one of claims 1 to 3. The approximate model includes a weight value assigned according to each norm value of the selected predetermined number of actual blown vectors, new blown vectors, and difference vectors, and the actual heat margin of each corresponding charge. 4. A converter blowing control method according to claim 2, wherein a thermal margin of a newly implemented charge is estimated.

Images