JP2012149341A - Estimation method of molten metal component and estimation apparatus of molten metal component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately estimate the component of a molten metal in blowing operation.SOLUTION: An arithmetic processing part 21 calculates the oxygen amount as an oxidation reaction amount used for an oxidation reaction of molten steel 101 based on the component of an exhaust gas generated during blowing operation of the molten steel 101, generates a plurality of groups of oxygen amounts used for oxidization of each component constituting the molten steel 101 based on the calculated oxidization reaction amount, calculates the reaction equilibrium evaluation value per generated group, extracts the group in a predetermined area where the calculated reaction equilibrium evaluation value exists, and calculates the concentration range of each component constituting the molten steel 101 based on the extracted groups.

Description

  The present invention relates to a molten metal component estimation method and a molten metal component estimation device for estimating a molten metal component during blowing.

  Generally, when performing the refining process which removes the impurity contained in a molten metal, the blowing equipment which performs oxygen blowing represented by the converter is used. In this blowing facility, blowing control is performed so that the impurity concentration after blowing falls within the range specified by the order standard. However, since the molten metal is very hot, it is difficult to continuously measure the component concentration of the molten metal. For this reason, in actual operation, the component concentration of the molten metal is often measured immediately before the blowing process, once or several times during the blowing process, and after the completion of the blowing process, and little information obtained by these measurements. Blowing control is performed using

  However, according to such a small amount of information, the component concentration of the molten metal during blowing cannot be measured with high accuracy. As a result, the accuracy of the blowing control is reduced, and the impurity concentration after blowing is desired. It becomes difficult to control within the range. For this reason, the method of estimating the component density | concentration in a molten metal is proposed (refer patent document 1, 2). Specifically, the method described in Patent Document 1 calculates the oxygen potential in the slag from the exhaust gas component continuously obtained in the converter and the information on the slag level, and the component concentration in the molten metal from the calculated oxygen potential. Is estimated. Moreover, the method of patent document 2 estimates the silicon concentration in a molten metal by measuring the temperature of a molten metal continuously.

JP-A-5-239524 JP 7-173516 A

  By the way, the molten metal contains a plurality of impurity components such as carbon (C), silicon (Si), phosphorus (P), manganese (Mn), oxygen (O), and the like during the blowing process. It is necessary to estimate the plurality of impurity components and control the concentration of the impurity components within a predetermined range based on the estimation result. However, Patent Document 1 does not disclose a method for estimating the concentration of each impurity component from the oxygen potential in the slag. Further, Patent Document 2 does not disclose a method for estimating the concentration of impurity components other than silicon. For this reason, it has been expected to provide a method capable of accurately estimating the concentration of each impurity component in the molten metal and controlling the blowing process with high accuracy based on the estimation result.

  This invention is made | formed in view of the said subject, The objective is to provide the molten metal component estimation method and molten metal component estimation apparatus which can estimate the component of the molten metal in blowing highly accurately.

  In order to solve the above problems and achieve the object, the molten metal component estimation method according to the present invention is based on the components of exhaust gas generated during blowing of the molten metal, and the amount of oxygen used in the oxidation reaction of the molten metal. Is calculated as an oxidation reaction amount, and based on the oxidation reaction amount, a plurality of combinations of oxygen amounts used for oxidation of each component constituting the molten metal are generated, and a reaction equilibrium evaluation value is generated for each of the generated combinations. And a step of extracting a set in which the reaction equilibrium evaluation value is within a predetermined range, and calculating a concentration range of each component constituting the molten metal based on the extracted set.

  In order to solve the above problems and achieve the object, the molten metal component estimation apparatus according to the present invention is based on the components of exhaust gas generated during blowing of the molten metal, and the amount of oxygen used in the oxidation reaction of the molten metal. Based on the oxidation reaction amount, a plurality of oxygen amount sets used to oxidize each component constituting the molten metal are generated, and a reaction is performed on each generated set. Reaction equilibrium evaluation value calculation means for calculating an equilibrium evaluation value, and a concentration at which the reaction equilibrium evaluation value is extracted within a predetermined range, and a concentration for calculating a concentration range of each component constituting the melt based on the extracted set Range calculation means.

  According to the molten metal component estimation method and the molten metal component estimation apparatus according to the present invention, it is possible to accurately estimate the components of the molten metal during blowing.

FIG. 1 is a schematic diagram illustrating a configuration of a blowing control system to which a molten metal component estimation apparatus according to an embodiment of the present invention is applied. FIG. 2 is a diagram illustrating an example of completed blown charge information and incomplete blown charge information. FIG. 3 is a diagram illustrating an example of model estimation calculation information. FIG. 4 is a flowchart showing a flow of component estimation processing according to an embodiment of the present invention. FIG. 5 is a flowchart showing the flow of a reaction equilibrium evaluation value calculation process according to an embodiment of the present invention.

  Hereinafter, with reference to the drawings, the configuration and operation of a molten metal component estimation apparatus according to an embodiment of the present invention will be described.

[Blowing process]
First, with reference to FIG. 1, a blowing process to which a molten metal component estimation apparatus according to an embodiment of the present invention is applied will be described.

As shown in FIG. 1, in a blowing process to which a molten metal component estimation apparatus according to an embodiment of the present invention is applied, a lance 102 is arranged on a molten steel 101 in a converter 100, and the molten steel starts from the tip of the lance 102. High pressure oxygen is ejected toward 101. The high-pressure oxygen causes the impurity components in the molten steel 101 to be oxidized and taken into the slag 103 (blowing process). An exhaust gas smoke duct 104 is installed in the upper part of the converter 100, and exhaust gas components (for example, CO, CO ₂ , O ₂ , N ₂ , H ₂ O, etc.) are provided.

  An inert gas is blown into the molten steel 101 in the converter 100 through a vent hole 106 formed at the bottom of the converter 100, and the molten steel 101 is agitated by the inert gas. The reaction has been promoted. The temperature of the molten steel 101 is measured once in the course of blowing, and the supply amount (acid supply amount) and speed (acid supply rate) of high-pressure oxygen, the flow rate of inert gas (stirring gas flow rate), etc. based on the measured temperature. It is decided. Moreover, immediately before the start of blowing and after blowing, the temperature and components of the molten metal 101 are analyzed.

[Configuration of blowing control system]
Next, with reference to FIG. 1, the structure of the blowing control system to which the molten metal component estimation apparatus which is one Embodiment of this invention is applied is demonstrated.

  As shown in FIG. 1, a blowing control system to which a molten metal component estimation device according to an embodiment of the present invention is applied includes a control terminal 10, a molten metal component estimation device 20, and a display device 30 as main components. . The control terminal 10 is configured by an information processing device such as a personal computer or a workstation, and controls the amount of acid sent, the rate of acid delivery, and the flow rate of stirring gas so that the component concentration of the molten steel 101 falls within a desired range. Collect data on the actual amount of acid, acid delivery rate, and stirring gas flow rate.

  The molten metal component estimation device 20 is configured by an information processing device such as a personal computer or a workstation. The molten metal component estimation device 20 includes an arithmetic processing unit 21 and an operation database (DB) 22 as main components. The arithmetic processing unit 21 is configured by an arithmetic processing device such as a CPU, and controls the overall operation of the component estimation device 20. The arithmetic processing unit 21 functions as an oxidation reaction amount calculation unit, a reaction equilibrium evaluation value calculation unit, and a concentration range calculation unit according to the present invention. Operation DB22 memorizes various information required in order to perform molten steel ingredient presumption processing mentioned below. Specifically, the operation DB 22 stores completed blowing charge information 23, model estimation calculation information 24, and incomplete blowing blow information 25.

  As shown in FIG. 2, the completed blown charge information 23 and the incomplete blown charge information 25 are time-series information related to a charge in which blown is completed or blown incomplete (melted steel for one converter) and Contains information other than time series. The time series information includes information on the amount of blowing, such as the amount of acid delivered, the rate of acid delivery, the flow rate of stirring gas, the lance height, the input amount of raw materials (main raw materials and auxiliary raw materials), the composition and flow rate of exhaust gas, etc. Exhaust gas information and molten steel information such as the temperature of the molten steel 101 are included. Information other than the time series includes information on the amount of acid delivered (or information on the amount of acid delivered), information on the raw material input (or information on the raw material introduction), and before and after the temperature and composition of the molten steel 101 before and after blowing. Molten steel information is included. As shown in FIG. 3, the model estimation calculation information 24 includes information on the components of the molten steel 101 and the slag 103 estimated by the component estimation process described later and information on the oxidation reaction amount.

[Component estimation processing]
In the blowing control system having such a configuration, the component estimation apparatus 20 estimates the components of the molten steel 101 at the time of temperature measurement during the blowing by executing the component estimation process shown below. Hereinafter, with reference to the flowchart shown in FIG. 4, the operation of the component estimation device 20 when executing this component estimation process will be described.

  FIG. 4 is a flowchart showing a flow of component estimation processing according to an embodiment of the present invention. The flowchart shown in FIG. 4 starts at the timing when a component estimation process execution command is input to the component estimation apparatus 20 via the control terminal 10, and the component estimation process proceeds to step S1.

  In the process of step S <b> 1, the arithmetic processing unit 21 acquires incomplete blown charge information 25 relating to the charge currently being blown from the operation DB 22. Thereby, the process of step S1 is completed and a component estimation process progresses to the process of step S2.

In the process of step S2, the arithmetic processing unit 21 uses the incomplete blown charge information 25 acquired by the process of step S1 and the components of the exhaust gas detected by the exhaust gas detection unit 105 to determine the components in the molten steel 101. The amount of oxygen used in the oxidation reaction is calculated as the oxidation reaction amount _Ototal . Specifically, first, the arithmetic processing unit 21 has already been charged with the total amount of high-pressure gas (injected oxygen amount) supplied to the molten steel 101 based on the incomplete blowing charge information 25 acquired by the processing of step S1. Is calculated as the INPUT oxygen amount.

Table 1 shown below shows an example of time-series data of the amount of blown oxygen. For example, in the subsequent processing, when predicting the concentration of the component at the time when the time has elapsed by 26 since the start of blowing (blowing elapsed time = 26), as shown in Table 1, the amount of blown oxygen (volume) The cumulative value is 255. When the amount of oxygen in the auxiliary raw material is 100 kg, the amount of oxygen in the auxiliary raw material is 70 (= (100/32) × 22.4) Nm ^{3 in} terms of volume. Therefore, in this case, the arithmetic processing unit 21 calculates the sum (= 255 + 70) of the cumulative value of the amount of blown oxygen and the amount of oxygen contained in the auxiliary raw material in volume as the INPUT oxygen amount. Note that the blow-in elapsed time and the cumulative blow-in oxygen amount are each expressed in units of minutes and Nm ³ , for example.

Next, based on the exhaust gas component detected by the exhaust gas detection unit 105, the arithmetic processing unit 21 detects oxygen (O ₂ ), carbon monoxide (CO), and carbon dioxide (CO ₂ ) in the exhaust gas. The amount of oxygen contained in is calculated as the amount of OUTPUT oxygen. Then, the arithmetic processing unit 21 calculates a value obtained by subtracting the OUTPUT oxygen amount from the INPUT oxygen amount as the oxidation reaction amount O _total . When calculating the amount of OUTPUT oxygen, the arithmetic processing unit 21 takes into account the difference between the sampling time of the exhaust gas component and the calculation time of the exhaust gas component and the amount of oxygen contained in the outside air flowing into the converter. It is desirable to correct the amount.

The specific calculation method of OUTPUT oxygen content is shown below. Table 2 shown below shows an example of time-series data of the exhaust gas flow rate per unit time, and shows how much exhaust gas was discharged while the blow-in elapsed time increased by one. For example, Nm It is expressed in units of ³ . Table 3 shown below shows time-series data of measured values of exhaust gas components, and indicates the volume% concentration of each component. Since the exhaust gas is measured by moving it to the analyzer through a conduit, the measured value of the exhaust gas component is stored in consideration of the delay time with respect to the elapsed time of blowing. Specifically, when the delay time is 5, the result of the component analysis performed at the time of blowing elapsed time 10 is stored as the component data of blowing elapsed time 5.

  First, the arithmetic processing unit 21 sets τ as the elapsed blowing time, ρ (i, τ) as the component ratio (0 to 1) of the component i at the elapsed blowing time τ, and V ( As τ), the cumulative flow rate X (i, 26) of the component i in the exhaust gas up to the blow-in elapsed time 26 is calculated by the following formula (1). Note that Σ (i, τ) in formula (1) (the description of i at the bottom of Σ is omitted) is the total value of all component ratios ρ (i, τ), and this value is 1 due to an error or the like. The calculation is performed when correction is not made. Here, ρ (i, τ) is a value obtained from Table 3. For example, ρ (CO, τ) is 0.41 obtained by dividing the CO concentration of 41 vol% at the blow-in elapsed time by 100.

Next, the arithmetic processing unit 21 calculates the OUTPUT oxygen amount by the following mathematical formula (2) using the cumulative flow rate X (i, 26). In Equation (2), the cumulative flow rate of each component is multiplied by a coefficient. For example, in the case of CO, since oxygen that can be generated from oxygen contained in 1 Nm ³ of CO is 0.5 Nm ³ , this is used as a coefficient. Further, the exhaust gas of the converter includes blown oxygen and oxygen other than oxygen contained in the raw material and the auxiliary raw material. This is oxygen contained in the inflowing outside air, and this oxygen may react with the exhaust gas to become CO, CO ₂ or the like. Therefore, an example of a method for correcting the OUTPUT oxygen amount in consideration of this inflow amount is shown below.

When N ₂ is not used for the bottom blowing stirring gas, it is considered that all the amount of N ₂ contained in the exhaust gas has flowed from outside air. If the ratio of nitrogen and oxygen in the air is 78:21, the inflowing oxygen amount can be calculated from the following equation (3). Therefore, using this value, the OUTPUT oxygen amount is corrected as in the following equation (4). it can. For this reason, the arithmetic processing unit 21 calculates the oxidation reaction amount O _total as shown in the following formula (5) using the above values. Thereby, the process of step S2 is completed and a component estimation process progresses to the process of step S3.

In the process of step S3, the arithmetic processing unit 21 generates a plurality of pairs of reaction amounts of components with _respect to the oxidation reaction amount O _total calculated by the process of step S2. Specifically, the components contained in the molten steel 101 are only iron (Fe), carbon (C), and phosphorus (P), and the oxygen used in the oxidation reaction amount O _total is iron monoxide (FeO), five When only phosphorus oxide (P ₂ O ₅ ) is generated (for example, when the desiliconization and dephosphorization processes are completed in the pretreatment facility, this state is obtained), the arithmetic processing unit 21 oxidizes as follows. A set of reaction amounts of the components with respect to the reaction amount O _total is generated.

First, the component estimation apparatus 20 uses the phosphorus concentration before blowing and the input amounts of raw materials and auxiliary raw materials, and the maximum amount O _{P of} oxygen used to generate phosphorus pentoxide (P ₂ O ₅ ). (max) and calculates the minimum value _O P (min). The maximum value O _P (max) and the minimum value O _P (min) are necessary for oxidizing the minimum value O _P (min) to 0 and the maximum value O _P (max) to all P in the molten steel 101. It may be calculated as a simple oxygen amount, or at this time, the minimum value O _P (min) may be made larger and the maximum value O _P (max) may be made smaller by adding a constraint condition.

Next, the arithmetic processing unit 21 calculates an oxygen amount O _P (t) (where 0 ≦ t ≦ 1) used for phosphorous oxidation using the following formula (6). Next, the arithmetic processing unit 21, n number of values in the parameter t (t1, t2, ..., tn) by substituting, a plurality of which is used in the oxidation of the phosphorus oxygen _{O P (t1), O P} ( t2),... O _P (tn) is calculated. Finally, the arithmetic processing unit 21 calculates the oxygen amount O 2 _FeO used for the generation of FeO by substituting each oxygen amount into the following formula (7). As a result, a plurality of reaction volume set _{[O P (t1), O} FeO (t1)], [O P (t2), O FeO (t2)], ..., [O P (tn), O FeO (tn )] Can be generated.

For example, the minimum value O _P (min) is 0, the maximum value O _P (max) is 5, the oxidation reaction amount O _total is 15, and the parameters t are t1 = 0, t2 = 0.1, t3 = 0.3, ..., T10 = 0.9, t11 = 1.0 and set in increments of 0.1, a set of reaction amounts is generated as shown in (8) below. The total value of the oxygen amount O _P (t) used for the oxidation of phosphorus and the oxygen amount O _FeO used for the formation of _FeO is equal to the oxidation reaction amount O _total, and the set of reaction amounts is used It is a set with different ratios. Thereby, the process of step S3 is completed and a component estimation process progresses to the process of step S4.

  In the process of step S4, the arithmetic processing unit 21 calculates a reaction equilibrium evaluation value for each set of reaction amounts generated by the process of step S3. In this specification, the reaction equilibrium evaluation value is a mathematical expression that assumes a value close to 0 when the equilibrium state is reached, assuming that the oxidation reaction and the reverse reaction are in an equilibrium state during blowing. It means a value that is derived from data and that is calculated by substituting measured values, manipulated variables, and the like for variables included in the mathematical formula, and evaluating the proximity to the equilibrium state for each blowing.

Specifically, the oxidation reaction of phosphorus is given by the chemical reaction formula (9) shown below. Further, in this chemical reaction formula (9), the reaction rate V1 from the left side to the right side is represented by the following formula (10), and the reaction rate V2 from the right side to the left side is represented by the following formula (11). It is expressed in In addition, [P] and [Fe] in the formulas (10) and (11) respectively indicate the concentrations of phosphorus and iron in the molten steel, and (FeO), (CaO), and (P ₂ O ₅ ) are respectively Indicates the concentration of iron monoxide, calcium monoxide, and phosphorus pentoxide in the slag.

  In the equilibrium state, it is considered that the reaction speed V1 from the left side to the right side and the reaction speed V2 from the right side to the left side are equal to each other. Therefore, the following formula (12) is established. When the natural logarithm of both sides of the equation (12) is calculated, the following equation (13) is obtained. When the parameter Eq shown in the following equation (14) is defined using the equation (13), the value of the parameter Eq is obtained. It can be considered that the reaction has reached an equilibrium state when is approaching zero. Therefore, in this embodiment, this parameter Eq is defined as a reaction equilibrium evaluation value.

The phosphorus concentration in the equation (14) above [P], the iron concentration [Fe], monoxide iron concentration (FeO), and phosphorus pentoxide concentration _(P 2 _{O 5)} reaction of the set _[O P (t), O 2 _FeO (t)]. For example, reaction of the set _{[O P (t2), O} FeO (t2)] For = [0.5,14.5], [amount of oxygen contained in the _P 2 _{O 5} produced] = 0.5 , And [the amount of oxygen contained in the produced FeO] = 14.5.

The weight of P ₂ O ₅ and FeO can be calculated using the above-mentioned [amount of oxygen contained in the produced P ₂ O ₅ ] and [amount of oxygen contained in the produced FeO], respectively. The calculated weights of P ₂ O ₅ and FeO are defined as P ₂ O ₅ weight in slag and FeO weight in slag, respectively. In addition, the weight of CaO entering the furnace is known from the raw material input results. Multiplying the weight of CaO by a constant (yield rate) is the weight of CaO in the slag, and among the input materials other than CaO, the weight entering the slag is (raw material input amount) x (ratio of components entering the slag) When calculating by x (yield), the total weight of the slag is calculated by the following formula (15). Moreover, the density | concentration of the component in molten steel in object time (for example, blowing elapsed time 26) is computable by Numerical formula (16) shown below. The other reaction amount sets can be similarly calculated by changing [the amount of oxygen contained in the produced P ₂ O ₅ ] and [the amount of oxygen contained in the produced FeO].

  The arithmetic processing unit 21 determines the coefficients a, b, c, d, e and the constant term lnk1-lnk2 (hereinafter referred to as f) of the equation (14) by executing a reaction equilibrium evaluation value calculation process described later. By doing so, the reaction equilibrium evaluation value Eq can be calculated for each set of reaction amounts. Since the reaction shown in the chemical reaction formula (9) is also affected by changes in slag, temperature, etc., the function f (x) is added to these explanatory variables as in the following formula (17). The reaction equilibrium evaluation value Eq may be set by (for example, the explanatory variable may be the molten steel temperature T, the coefficient is α, and the function portion may be α / T). Thereby, the process of step S4 is completed and a component estimation process progresses to the process of step S5.

In the process of step S5, the arithmetic processing unit 21 extracts a set of reaction amounts in which the absolute value of the reaction equilibrium evaluation value Eq is less than a predetermined value based on the reaction equilibrium evaluation value Eq calculated by the process of step S4. The upper limit value and the lower limit value of the concentration of the component contained in the molten steel 101 are calculated based on the extracted reaction amount set. Specifically, the reaction amount of the set _{[O P (t5), O} FeO (t5)], [O P (t6), O FeO (t6)], [O P (t7), O FeO (t7)] The absolute value of the reaction equilibrium evaluation value Eq determined for is less than a predetermined value, and the oxygen amounts O _P and O _FeO used for the production of phosphorus pentoxide (P ₂ O ₅ ) and iron monoxide (FeO) are as follows: When satisfying the mathematical expressions (18) and (19) shown in FIG. 5, the arithmetic processing unit 21 calculates the phosphorus concentration calculated from O _P (t7) and O _P (t5) as the lower limit value and the upper limit value of the phosphorus concentration, respectively. . Thereby, the process of step S5 is completed and a component estimation process progresses to the process of step S6.

  In the process of step S6, the arithmetic processing unit 21 outputs information on the component concentration calculated by the process of step S5 to the display device 30. Thereafter, the operator adjusts the operation amount of the blowing control based on the information output to the display device 30 such that the component concentration after the blowing is within a predetermined range. Thereby, the process of step S6 is completed and a series of component estimation processes are complete | finished.

[Reaction equilibrium evaluation value calculation processing]
Next, the flow of processing for determining the coefficients a, b, c, d, e, and f in the equation (14) in the processing of step S4 will be described with reference to the flowchart shown in FIG.

  FIG. 5 is a flowchart showing the flow of a reaction equilibrium evaluation value calculation process according to an embodiment of the present invention. The flowchart shown in FIG. 5 starts at the timing when the process of step S3 is completed, and the reaction equilibrium evaluation value calculation process proceeds to the process of step S11.

In the process of step S11, the arithmetic processing unit 21 acquires the values of the explanatory variables Y ₁ , Y ₂ ,..., Y _m of the target charge. Specifically, when the reaction equilibrium evaluation value Eq is expressed as in the above equation (17), the arithmetic processing unit 21 calculates the target charge ln [P], ln (FeO), ln (CaO), ln. The values of (P ₂ O ₅ ) and ln (Fe) are acquired. Here, when the values of the explanatory variables are expressed as y ₁ , y ₂ ,..., Y _m , the reaction equilibrium evaluation value Eq can be expressed as the following formula (20). _{Here, y 1, y 2, ...} , among the explanatory variables of y _m, those strong correlation with almost unchanged those and other explanatory variable values may be removed. Further, the parameter a _j (j = 0,..., M) in the equation (20) is a coefficient to be determined. According to the equation (20) shown below, when the parameters a _j are all 0, The value of the reaction equilibrium evaluation value Eq becomes 0. For this reason, the value obtained by dividing the right side by one of the parameters a _j (in this example, a ₁ ) may be used as the reaction equilibrium evaluation value Eq, as in the following formula (21). In Equation (21), it is assumed that the explanatory variable corresponding to ln [P] is y ₁ . Thereby, the process of step S11 is completed, and the reaction equilibrium evaluation value calculation process proceeds to the process of step S12.

In the process of step S12, the arithmetic processing unit 21 calculates the similarity between the charge to be processed and the completed blowing charge based on the completed blowing charge information 23 stored in the operation DB 22 as follows. The weighted norm Nr (z ⁱ ) of the explanatory variable is calculated using the following mathematical formula (22). In Equation (22), the parameter Z _j represents the initial molten metal component of the target charge, the initial molten metal temperature, the amount of oxygen blown in, the amount of charged raw material, and the amount of added auxiliary raw material, and the parameter z _j ⁱ is the i th the indicated value for the parameter Z _j completion blowing charge, the parameter w denotes a weight to be multiplied to each explanatory variable. Then, the arithmetic processing unit 21 extracts the completed blowing charge information for the set number in order from the smallest weighted norm Nr (z ⁱ ). That is, the arithmetic processing unit 21 extracts the completed blowing charge information having an explanatory variable similar to the explanatory variable of the charge to be processed by the set number. Thereby, the process of step S12 is completed and the reaction equilibrium evaluation value calculation process proceeds to the process of step S13.

In the process of step S13, the arithmetic processing unit 21 collects information (time-series information, molten metal information before and after blowing) from the completed blowing charge information 23, and each component included in the molten metal information before and after blowing. Acquire information on phosphorus concentration before and after blowing (or during blowing) from analysis information. Further, the arithmetic processing unit 21 calculates the amount of P ₂ O ₅ after blowing from Equation (23) below using the obtained phosphorus concentration information. Next, the arithmetic processing unit 21 calculates the total value of the oxygen amounts used for the oxidation of phosphorus and iron by the same process as the process of step S2 using the time series information. The amount of oxygen used for oxidation of phosphorus is obtained from the amount of P ₂ O ₅ after blowing, and the amount of oxygen used for oxidation of iron is determined by obtaining the amount of oxygen used for oxidation of phosphorus. Can be calculated. The amount of CaO in the slag is calculated from the raw material input performance information of the completed blowing charge 23 information. In this way, the values of ln (P ₂ O ₅ ), ln (FeO), ln (CaO), ln [P], and ln [Fe] are calculated. In other words, even if other parameters are included in the explanatory variable of the reaction equilibrium evaluation value Eq, all the explanatory variables can be obtained by extracting necessary values from the completed charge information.

Next, the sum of squares ΣWeq ⁱ Eq ² (y ⁱ ) of the reaction equilibrium evaluation value Eq when the arithmetic processing unit 21 substitutes the explanatory variable of the past charge extracted by the process of step S12 into the equation (21) is the minimum. The value of the parameter aj (j = 0,..., M, j ≠ 1) is determined using optimization calculation. Here, the parameter Weq ⁱ in the square sum ΣWeq ⁱ Eq ² (y ⁱ ) is a weighting factor assigned to the completed blowing charge. Since the parameter y ₁ is a nonlinear function ln [P] of the phosphorus concentration [P], the change ratio between the reaction equilibrium evaluation value Eq and the phosphorus concentration [P] varies greatly depending on the value of the phosphorus concentration [P]. For this reason, when evaluating the value of the reaction equilibrium evaluation value Eq on the basis of the value of the phosphorus concentration [P], the weighting coefficient Weq ⁱ may be set to (d [P] / dEq) ² . Since d [P] / dEq is approximately [P], the weighting coefficient Weq ⁱ may be ([P]) ² . As an optimization calculation method, normal regression calculation is used if the reaction equilibrium evaluation value Eq is a linear expression, and nonlinear programming (for example, Newton method, conjugate gradient method, quasi-Newton method, sequential quadratic programming if the function is a nonlinear function). For details, refer to the reference (see “Optimization Techniques” by Ibaraki and Fukushima, Kyoritsu Shuppan). Thereby, the process of step S13 is completed and a series of reaction equilibrium evaluation value calculation processes are complete | finished.

  As is apparent from the above description, in the component estimation process according to an embodiment of the present invention, the arithmetic processing unit 21 performs an oxidation reaction of the molten steel 101 based on the components of exhaust gas generated during the blowing of the molten steel 101. The amount of oxygen used in the calculation is calculated as the amount of oxidation reaction, and based on the calculated amount of oxidation reaction, a plurality of sets of oxygen amounts used for the oxidation of each component constituting the molten steel 101 are generated, and each generated Since the reaction equilibrium evaluation value is calculated for the set, the set in which the calculated reaction equilibrium evaluation value is within a predetermined range is extracted, and the concentration range of each component constituting the molten steel 101 is calculated based on the extracted set. The component of the molten steel 101 can be estimated with high accuracy.

  Although the embodiment to which the invention made by the present inventor is applied has been described above, the present invention is not limited by the description and the drawings that form a part of the disclosure of the present invention according to this embodiment. That is, other embodiments, examples, operational techniques, and the like made by those skilled in the art based on the present embodiment are all included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Control terminal 20 Molten component estimation apparatus 21 Arithmetic processing part 22 Operation database (DB)
23 Completed blown charge information 23 Model estimation calculation information 24 Incomplete blown charge information 30 Display device

Claims (4)

Calculating the amount of oxygen used for the oxidation reaction of the molten metal as an oxidation reaction amount based on the component of the exhaust gas generated during the blowing of the molten metal;
Based on the oxidation reaction amount, generating a plurality of sets of oxygen amounts used for oxidation of each component constituting the molten metal, and calculating a reaction equilibrium evaluation value for each generated set;
Extracting a set in which the reaction equilibrium evaluation value is within a predetermined range, and calculating a concentration range of each component constituting the melt based on the extracted set;
The molten metal component estimation method characterized by including.   2. The molten component estimation according to claim 1, wherein the reaction equilibrium evaluation value includes at least one of molten metal information, operation amount information of a blowing process, exhaust gas information, and slag information as an explanatory variable. Method.   The step of calculating the reaction equilibrium evaluation value is performed on the charge to be processed with respect to at least one of the molten metal information, the operation amount information of the blowing process, the exhaust gas information, and the slag information before calculating the component concentration range. The melt component estimation method according to claim 2, further comprising: extracting similar past charges, and calculating the reaction equilibrium evaluation value using the extracted past charge explanatory variables. An oxidation reaction amount calculating means for calculating the amount of oxygen used in the oxidation reaction of the molten metal as an oxidation reaction amount based on the components of exhaust gas generated during the blowing of the molten metal;
Based on the oxidation reaction amount, a plurality of pairs of oxygen amounts used for the oxidation of each component constituting the molten metal, and a reaction equilibrium evaluation value calculation means for calculating a reaction equilibrium evaluation value for each of the generated groups,
A concentration range calculating means for extracting a set in which the reaction equilibrium evaluation value is within a predetermined range, and calculating a concentration range of each component constituting the melt based on the extracted set;
A molten metal component estimation apparatus comprising:

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