KR102065455B1 - Phosphorus concentration estimation method and converter blow control device in molten steel - Google Patents

Abstract

[Problem] To estimate phosphorus concentration in molten steel at the time of converter blow in pursuit by the multifunctional converter method with high precision. [Measures] The method for estimating phosphorus concentration in molten steel is applied to primary refining using a converter with an intermediate exclusion treatment, a slag level data acquisition step of acquiring a slag level during dephosphorization treatment, and exhaust gas during decarburization treatment. Exhaust gas data acquisition step of acquiring component and exhaust gas flow rate, Molten steel data acquisition step of acquiring molten steel temperature and carbon concentration in molten steel by sublance measurement at the time of decarburization, slag level, exhaust gas component, exhaust The dephosphorization rate constant is calculated using data on gas flow rate, molten steel temperature and carbon concentration, and operating conditions relating to dephosphorization, intermediate exclusion and decarburization, and the calculated dephosphorization rate constant and the molten iron phosphorus at the start of dephosphorization. Phosphorus concentration which estimates phosphorus concentration in molten steel at the time of decarburization process after a sub lance measurement using concentration. It includes a forward step.

Description

Phosphorus concentration estimation method and converter blow control device in molten steel

The present invention relates to a method for estimating phosphorus concentration in molten steel and an apparatus for estimating phosphorus concentration in molten steel for accurately estimating phosphorus concentration in molten steel at the time of blower blown in operation by the multifunctional converter method.

In the converter blow control, control of components in molten steel at the time of effect (especially control of phosphorus concentration in molten steel) is very important in quality control of steel. In order to control the phosphorus concentration in molten steel, the input amount of subsidiary materials such as blown oxygen amount, quicklime or scale, the input timing of the subsidiary material, the upper lance height, the upper odor oxygen flow rate and the lower odor gas flow rate are generally used as the operation amount. These operation amounts are often determined by the information obtained before the start of blown-out, such as the criteria created based on the target phosphorus concentration, molten iron data, past operation results, and the like.

However, even under the same operating conditions, the reproducibility of dephosphorization behavior in actual blowing was low, and there was a problem that the fluctuation of phosphorus concentration in molten steel at the time of increase became large. Therefore, it is difficult to suppress the fluctuation of the phosphorus concentration in molten steel at the time of blown by the operation amount determined based only on the information obtained before starting blown as mentioned above.

In order to cope with the above problem, a technique has been developed that utilizes measured values such as exhaust gas components and exhaust gas flow rates that are sequentially obtained at the time of blowing. For example, Patent Literature 1 below estimates dephosphorization rate constants using operating conditions relating to blowing and measured values relating to exhaust gas, and estimates phosphorus concentration in molten steel during blowing using estimated dephosphorization rate constants. Techniques are disclosed. In addition, Patent Literature 1 below discloses a technique for controlling phosphorus concentration in molten steel by comparing the estimated phosphorus concentration in molten steel with the concentration of phosphorus in target molten steel and changing the operating conditions related to blowing based on the comparison result. .

Japanese Patent Publication No. 2013-23696

In recent years, in primary refining, molten iron preliminary processing, such as dephosphorization processing using a converter, is generally performed. In particular, in the primary refining called the MULC (MUlti Refining Converter) (MURC), the development of the technology which can carry out molten iron preliminary processing and decarburization process by the same converter is progressing. Specifically, MURC charges molten iron into a converter (first step), performs molten iron preliminary treatment including dephosphorization by addition of flux and blowing of oxygen by a top lance (second step), and the converter It is an operation method of primary refining which consists of the process of performing the intermediate | middle discharge | exhaustion process which disposes the slag which arose in the 2nd process by the tilting (3rd process), and then performs decarburization process by the said converter (4th process). MURC has less heat loss and shorter lead time compared to the primary refining operation, which performs dephosphorization and decarburization in different converters, such as the conventional Simple Refining Process (SRP). It has the advantage that the production efficiency in the process is high.

In this MURC, the slag which occurred in the dephosphorization process which is the 2nd process mentioned above is discharged by the intermediate | middle discharging process which is a 3rd process. At this time, depending on the amount of slag generated in the dephosphorization treatment or the quality of the slag, the amount of slag discharged by the intermediate discharge treatment differs for each operation.

Phosphorus contained in the molten iron after the intermediate exclusion treatment is released from the molten iron by the dephosphorization reaction represented by the following general formula (101), which may occur in parallel with the decarburization reaction during decarburization, and is introduced into the slag, or conversely, slag. There is a case where it is detached from and introduced into the molten iron again. In addition, in the following general formula (101), the description "[substance X]" shows that substance X is a substance which exists in molten iron | metal, and the description "(substance Y)" shows that substance Y is a substance which exists in slag. Indicates.

The direction in which the dephosphorization reaction represented by the general formula (101) proceeds changes depending on the amount and component of slag (or the amount and component of slag remaining in the converter) during the intermediate exclusion treatment. That is, the reaction direction and reaction rate of the dephosphorization reaction depend on the amount of slag to be discharged during the intermediate discharge treatment. Therefore, it is thought that the amount of slag excreted at the time of the intermediate exclusion treatment affects the concentration of phosphorus in the molten steel during the decarburization treatment.

In the said patent document 1, the phosphorus concentration in molten steel is estimated using operating conditions, etc. at the time of the operation | work of converter blowing. However, in the said patent document 1, it does not consider about the quantity of slag discharged at the time of an intermediate discharge | release process. Considering that the phosphorus concentration in molten steel in the decarburization treatment affects the amount of slag excreted during the intermediate exclusion treatment, in the technique disclosed in Patent Document 1, in the primary refining involving the intermediate exclusion treatment It is difficult to accurately estimate phosphorus concentration in molten steel.

Therefore, this invention is made | formed in view of the said problem, The objective of this invention is the phosphorus concentration estimation method in molten steel which can estimate the phosphorus concentration in molten steel at the time of the purpose of converter conversion in MURC operation with high precision. And a converter blow control device.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, according to one aspect of this invention, it is used for the dephosphorization treatment, the intermediate | middle discharging process which excludes the slag produced | generated by the said dephosphorization treatment, and the primary refining which performs decarburization process using the same converter A method for estimating phosphorus concentration in molten steel, comprising: molten iron data acquisition step for acquiring molten iron data relating to molten iron before the dephosphorization treatment; slag level data acquiring step for acquiring slag level during the dephosphorization treatment; and exhaust gas during the decarburization treatment Exhaust gas data acquisition step of acquiring component and exhaust gas flow rate, molten steel data acquisition step of acquiring molten steel temperature and carbon concentration in molten steel by sublance measurement at the time of the decarburization treatment, the slag level, the exhaust gas Components, the exhaust gas flow rate, the molten steel temperature and the carbon concentration, and A dephosphorization rate constant is calculated using the operating conditions relating to the dephosphorization treatment, the intermediate exclusion treatment and the decarburization treatment, and the dephosphorization rate constant is calculated using the calculated dephosphorization rate constant and the molten iron phosphorus concentration at the start of the dephosphorization treatment. A phosphorus concentration estimation method in molten steel is provided, including a phosphorus concentration estimating step of estimating phosphorus concentration in the molten steel during the decarburization treatment after measurement.

In the calculation of the dephosphorization rate constant, a category variable for identifying a cluster obtained by time series clustering performed on a plurality of the slag level time series data obtained in past operation may be used.

In the calculation of the dephosphorization rate constant, an average value of time series data of the slag level obtained during the dephosphorization treatment may be used.

Moreover, in order to solve the said subject, according to another viewpoint of this invention, it uses for dephosphorization treatment, the intermediate | middle discharging process which excludes the slag produced | generated by the said dephosphorization treatment, and the primary refining which performs decarburization process using the same converter. A converter blow control device to be used, which is a molten iron data acquisition unit for acquiring molten iron data relating to molten iron before the dephosphorization treatment, a slag level data acquisition unit for acquiring a slag level during the dephosphorization treatment, and an exhaust gas component during the decarburization treatment. And an exhaust gas data acquiring unit for acquiring an exhaust gas flow rate, a molten steel data acquiring unit for acquiring molten steel temperature and carbon concentration in the molten steel by sublance measurement during the decarburization process, the slag level, and the exhaust gas component. And data relating to the exhaust gas flow rate, the molten steel temperature and the carbon concentration, and the dephosphorization treatment. , A dephosphorization rate constant is calculated using the operating conditions relating to the intermediate exclusion treatment and the decarburization treatment, and the calculated dephosphorization rate constant and the molten iron concentration at the start of the dephosphorization treatment are used. The converter blow control device provided with the phosphorus concentration estimation part which estimates the phosphorus concentration in the said molten steel at the time of the said decarburization process is provided.

In calculating the dephosphorization rate constant, the phosphorus concentration estimating unit may use a category variable for identifying a cluster obtained by time series clustering performed on a plurality of slag level time series data obtained in a past operation.

In the calculation of the dephosphorization rate constant, the phosphorus concentration estimating unit may use an average value of time series data of the slag level obtained during the dephosphorization treatment.

In the method for estimating phosphorus concentration in molten steel and the converter blow control device, dephosphorization rate constants are calculated using various data and operating conditions including slag levels, and the phosphorus concentration in molten steel is estimated using the calculated dephosphorization rate constants. . As a result, in the primary refining process in which dephosphorization treatment, intermediate excretion treatment and decarburization treatment are performed consistently by the same converter, operation factors related to the slag discharge occurring in the converter can be reflected in the estimation of phosphorus concentration in the molten steel. have. Therefore, phosphorus concentration in molten steel can be estimated more accurately.

As described above, according to the present invention, it is possible to accurately estimate the phosphorus concentration in the molten steel at the time of purging the converter in MURC operation.

1 is a graph showing time series data of a slag level at the time of dephosphorization.
FIG. 2A is a diagram showing the result of time series clustering performed on slag level time series data. FIG.
FIG. 2B is a diagram showing the results of time series clustering performed on slag level time series data. FIG.
FIG. 2C is a diagram showing the results of time series clustering performed on slag level time series data. FIG.
FIG. 2D is a diagram showing a result of time series clustering performed on slag level time series data. FIG.
FIG. 2E is a diagram showing a result of time series clustering performed on time series data of a slag level.
FIG. 2F is a diagram showing the result of time series clustering performed on time series data of a slag level.
It is a figure which shows the structural example of the converter blowing system which concerns on one Embodiment of this invention.
It is a figure which shows an example of the flowchart of the phosphorus concentration estimation method in molten steel by the converter blowing system which concerns on the same embodiment.
It is a figure which shows the estimation error with respect to the performance value of the dephosphorization rate constant k at the time of a sub lance measurement.
It is a figure which shows the estimation error with respect to the performance value of the dephosphorization rate constant k at the time of a sub lance measurement.
It is a figure which shows the estimation error with respect to the performance value of the dephosphorization rate constant k at the time of a sub lance measurement.
It is a figure which shows the estimation error with respect to the performance value of the dephosphorization rate constant k at the time of a sub lance measurement.
It is a figure which shows the estimation error with respect to the performance value of the phosphorus concentration in molten steel at the time of a sub lance measurement.
It is a figure which shows the estimation error with respect to the performance value of the phosphorus concentration in molten steel at the time of a sub lance measurement.
It is a figure which shows the estimation error with respect to the performance value of the phosphorus concentration in molten steel at the time of a sub lance measurement.
It is a figure which shows the estimation error with respect to the performance value of the phosphorus concentration in molten steel at the time of a sub lance measurement.
It is a figure which shows the estimation error with respect to the performance value of the dephosphorization rate constant k at the end point.
It is a figure which shows the estimation error with respect to the performance value of the dephosphorization rate constant k at the end point.
It is a figure which shows the estimation error with respect to the performance value of the dephosphorization rate constant k at the end point.
It is a figure which shows the estimation error with respect to the performance value of the dephosphorization rate constant k at the end point.
It is a figure which shows the estimation error with respect to the performance value of the phosphorus concentration in molten steel at the end point.
It is a figure which shows the estimation error with respect to the performance value of the phosphorus concentration in molten steel at the end point.
It is a figure which shows the estimation error with respect to the performance value of the phosphorus concentration in molten steel at the end point.
It is a figure which shows the estimation error with respect to the performance value of the phosphorus concentration in molten steel at the end point.

EMBODIMENT OF THE INVENTION Preferred embodiment of this invention is described in detail, referring an accompanying drawing below. In addition, in this specification and drawing, duplication description is abbreviate | omitted by attaching | subjecting the same number about the component which has a substantially same functional structure.

In addition, although iron and steel may exist in the converter at the time of decarburization, according to the carbon concentration, in the following description, in order to avoid the complicated description, "melting or molten steel in a converter" is conveniently referred to as " Molten steel ”. In addition, in the case of dephosphorization processing, the word "molten iron" is used.

<< 1. Estimation method of phosphorus concentration in molten steel which concerns on this embodiment >>

Before demonstrating the structure and function of the converter blowing system 1 which concerns on this embodiment, the estimation method of the phosphorus concentration in the molten steel which concerns on this embodiment is demonstrated. In addition, in the following description, unless otherwise indicated, (mass%) which is a unit of the density | concentration of each component is described as (%).

(Estimate method of phosphorus concentration in molten steel using operating conditions, operating factors)

Assuming that the time change of the phosphorus concentration [P] (%) in molten steel during blowdown is represented by a first-order reaction formula, the first-order reaction formula is expressed as in the following formula (1).

Here, in said Formula (1), [P] _ini is a phosphorus concentration initial value (melting phosphorus concentration) (%), and k is a dephosphorization rate constant (sec <^-1> ). In addition, the "phosphorus concentration initial value" here means the phosphorus concentration at the time of dephosphorization treatment start.

If an accurate dephosphorization rate constant k is obtained, the phosphorus concentration in the molten steel can be estimated with high accuracy. However, in general, the dephosphorization rate constant k in actual blowing is not constant, and it is considered to fluctuate under the influence of various operating conditions. Therefore, as disclosed, for example, in Patent Document 1 (Japanese Patent Laid-Open No. 2013-23696), not only static information such as molten iron components and molten iron temperatures, but also exhaust gas components measured sequentially. Estimation of the dephosphorization rate constant k is performed by utilizing dynamic information during blowing, such as exhaust gas data such as data and data on exhaust gas flow rate. Hereinafter, the estimation method of the dephosphorization rate constant k is demonstrated.

From said Formula (1), the phosphorus concentration in molten steel in t second after a blow start (dephosphorization start) is represented like following formula (2).

In this way, the deodorization rate constant k by charge can be calculated | required using past operation performance data. For example, the dephosphorization rate constant k _i in the charge i is calculated using the following formula (3).

Here, in said Formula (3), [P] _{end and i} are phosphorus concentrations (%) in molten steel at the time of application, and t _{end and i} are from the start of dephosphorization treatment (at the start of a blow) to the point of time. Elapsed time in seconds.

And the model formula which uses the dephosphorization rate constant k obtained by said formula (3) as an objective variable is created previously. This model formula can be suitably constructed by various statistical methods. In this embodiment, as the model equation, a regression equation using various operation factors X as an explanatory variable, which is obtained by a known multiple regression analysis method, is used. The regression formula is constructed as in the following formula (4). In actual blow, the dephosphorization rate constant k is estimated by substituting operation factor X at the time of the said blow in the following formula (4), and applying the said dephosphorization rate constant k to said Formula (2), Concentration can be estimated.

In Formula (4), α _j is a regression coefficient corresponding to the j-th operation factor X _j , and α ₀ is a constant. Moreover, the operation factor shown in following Table 1 is mentioned as a specific example of operation factor X. However, the operation factor shown in following Table 1 is an example to the last, and all the operation factors X may be considered in the estimation of the dephosphorization rate constant k. In addition, all or part of the operation factors contained in following Table 1 may be used for estimation of the dephosphorization rate constant k.

Moreover, according to the said patent document 1, the influence of the original amount of the accumulated oxygen amount in the furnace obtained by calculating the oxygen resin from the exhaust gas flow rate, the exhaust gas component, the low odor gas flow rate, the auxiliary raw material input amount, and the molten iron component during blowing has a large influence on the dephosphorization rate constant. Appeared. Therefore, in the said patent document 1, the dynamic operation factor during blow-in, such as the accumulated unit of oxygen amount in a furnace obtained by utilizing exhaust gas data, etc., and the uptake lance height, the oxygen gas flow rate, and the low odor gas flow rate, is represented by said Formula (4). As explanatory variables of the regression equation to be expressed, it is described that by further employing in addition to the explanatory variables shown in Table 1, it is possible to estimate the dephosphorization rate constant with higher precision.

(Utilization of data about slag level)

By the way, in converter converter blowing methods like MURC mentioned above, dephosphorization treatment, intermediate | middle discharge | disassembly treatment, and decarburization process are performed continuously by the same converter. Therefore, not only the operating conditions regarding dephosphorization treatment and decarburization process as disclosed in the said patent document 1, but also the operating conditions regarding intermediate discharging treatment can be used for estimation of the dephosphorization rate constant which concerns on this embodiment. As an operating condition regarding intermediate | middle discharge | distribution process, the intermediate discharge | release time and the amount of slag discharged | intermediate are mentioned, for example.

Among these, the amount of slag interposed | disconnected is thought to have a big influence on the phosphorus concentration in molten steel at the time of decarburization process. The present inventors found out that the amount of slag interposed in the middle is deeply related to the slag level (slag height) at the time of dephosphorization treatment. For example, in the intermediate discharging treatment, when the slag level is high, the slag is likely to be discharged, and when the slag level is low, the slag is difficult to be discharged. In other words, the amount of slag interposed in the middle may vary depending on the slag level. Accordingly, the present inventors can further improve the estimation accuracy of the phosphorus concentration in the molten steel by employing the slag level of the slag that may occur in the converter during the blowdown during the dephosphorization treatment as an operation factor for the estimation of the phosphorus concentration in the molten steel. It was also intended. Hereinafter, the data concerning the slag level and its utilization example are demonstrated.

1 is a graph showing the time series data of the slag level in the dephosphorization process. In addition, the data shown by the said graph is data obtained by performing a normalization process so that average may become 0 and standard deviation = 1 with respect to the data of the slag level actually obtained. The said time series data is time series data acquired from the start of the blow in a dephosphorization process to the time of giving.

Referring to FIG. 1, it can be seen that the slag level is increased at the end of the dephosphorization treatment. That is, the generation of slag (slag forming) is in progress at the end of the dephosphorization treatment. Therefore, in this embodiment, the data regarding the slag level at the end of blow in the dephosphorization process can be used as one of the operation factors X _j which are explanatory variables of Formula (4). In addition, "the end of dephosphorization process (it is also called" the end of blow at dephosphorization process ")" is the time corresponding to about 1/3 to 1/4 of the total elapsed time from the start of the blow in dephosphorization process to the point of time. This means a period from the point of intent to the point of ascending back. For example, when the total elapsed time from the start of the blow to the point of time is 180 seconds, the end of the dephosphorization treatment corresponds to the period from the time of the start of blow to the point of about 120 seconds to 135 seconds. do.

In the present embodiment, for example, the average value of time series data of the slag level at the end of the dephosphorization treatment may be used as an operation factor X _j which is an explanatory variable of equation (4) which is a regression equation for estimating the dephosphorization rate constant k. As a result, the amount of slag generated by the dephosphorization treatment can be reflected in the estimation of the dephosphorization rate constant k.

In addition, in this embodiment, the category variable which identifies the cluster obtained by performing time series clustering with respect to the time series data of a slag level, for example may be used as explanatory variable. Time series clustering is a method of obtaining the distance between time series data and performing clustering based on the distance. By treating the trend of the slag level as time series data, grasp the complex behavior of the slag level (in other words, the sequential change of the slag level, which is averaged in the process of calculating the average value), which cannot be represented by a simple average value, as significant. This makes it possible to reflect such a complicated behavior of the slag level more accurately.

Hereinafter, the case where the category variable which identifies the cluster obtained by performing time series clustering with respect to the slag level time series data is used as an explanatory variable is demonstrated in detail.

In the present embodiment, first, time series clustering is performed in advance on time series data of slag level at the end of the blow-up obtained from past operation data. In this embodiment, as a method of time series clustering, the most recent method of hierarchical clustering is used. As a method of time series clustering, it is not limited to this method, For example, the k-means method of non-hierarchical clustering may be sufficient. In addition, in this embodiment, although time-series clustering is performed so that these time-series data may be classified into six clusters, the number of clusters is not particularly limited. About the number of clusters, it sets suitably according to the result of clustering.

2A to 2F are diagrams showing the results of time series clustering performed on slag level time series data. 2A to 2F are diagrams showing the results of time series clustering for clusters corresponding to respective category variables (No. 1 to 6), respectively. In addition, the data concerning the slag level shown in each figure is the data obtained by performing normalization process so that the average of the slag level data actually obtained may be set to 0, and standard deviation = 1. In addition, the time series data of the slag level used for time series clustering which concerns on this embodiment are data obtained from the slag level from the time of the blown-out in a dephosphorization process to the time point which went back 50 seconds, respectively (in FIGS. 2A-2F). The time point of blowing time = 50 seconds corresponds to the time of blowing in the dephosphorization process, and the time point of blowing time = 0 seconds corresponds to the time point which goes back 50 seconds from the time of drawing). The time range for selecting the time series data of the slag level used for this time series clustering is not particularly limited, and the target range is, for example, the trend of the time series data of the slag level actually obtained by the level meter or the operation state of the converter scavenging facility. Or the like can be set appropriately.

In FIGS. 2A to 2F, each of the broken lines in each of the figures shows a change over time of the slag level in any one dephosphorization treatment. As shown in Figs. 2A to 2F, data having high similarity of time series data of slag level are classified into the same cluster, respectively. For example, cluster No. 2 classifies time series data having a high rate of increase of the slag level and a high slag level (ie, slag level at the time of blowing in the dephosphorization process) at the time of intermediate discharge. have. On the other hand, in cluster No. 5, time-series data with a small change of the slag level change is classified.

In this way, each cluster classified by clustering executed in advance and the slag level time series data obtained at the time of blowing in the dephosphorization process are compared to select the cluster having the highest similarity, and the category variable corresponding to the cluster is selected. , Can be employed as the operation factor X _j which is the explanatory variable of equation (4). As a result, not only the amount of slag generated in the dephosphorization treatment, but also the tendency of slag forming at the end of the blow in the dephosphorization treatment can be reflected in the estimation of the phosphorus concentration in the molten steel. The difference in the tendency of slag forming is considered to be based on slag properties such as slag components. Therefore, the influence of slag properties in the dephosphorization reaction is further added to the estimation of the phosphorus concentration in the molten steel, so that the accuracy of estimating the phosphorus concentration in the molten steel can be further improved.

Here, a method of using the clustering result of slag level data for estimation of dephosphorization rate constant k in actual operation is demonstrated. First, time series clustering is performed in advance on the slag level time series data obtained at the end of the blow-up obtained from past operation data, and the time series data is classified into a plurality of clusters. Then, a regression equation (Equation (4) above) using these cluster-specific category variables as one of the explanatory variables is preliminarily constructed for each cluster.

Next, the average value (beta) _{ave , j} in the measurement point j (j = 1 thru | or n) of the some time series data of the slag level classified into each cluster is computed for every measurement point. A measurement point means the measurement time point of a slag level in the target range of the said time series data. For example, in each cluster shown in Figs. 2A to 2F, time series data from a point in time to a point in time dating back 50 seconds are classified. When the slag level is measured every second, the measurement score is 50 points.

Subsequently, the slag level time series data S _j at the time of actual dephosphorization processing, which is a target for estimating the dephosphorization rate constant k, is obtained, and the similarity between the obtained slag level time series data and each cluster is, for example, given. The difference between the time series data S _j and the above average values β _{ave and j} is obtained for each cluster. The smallest cluster of the difference is determined as the cluster to which the time series data S _j belongs, and the category variable corresponding to this cluster is used as an explanatory variable regarding an operation factor. As the difference, any known one can be used, but the difference may be, for example, a sum of squared difference (SSD) represented by the following formula (5). This difference is appropriately calculated | required by a well-known statistical method.

In the above, the case where the category variable which identifies the cluster obtained by performing time series clustering with respect to the time series data of slag level is used as explanatory variable was demonstrated in detail.

The explanatory variable based on the time series data of the slag level is not limited to the above-described example. For example, the intermediate value of the time series data of the slag level at the time of the blow in the dephosphorization process, or the slag level at the end of the blow, or the rate of change of the time series data may be used as the explanatory variable.

In the above, the estimation method of the phosphorus concentration in the molten steel which concerns on this embodiment was demonstrated.

<< 2. Converter blow system >> which concerns on this embodiment

<2.1. Configuration of Converter Blowing System>

Subsequently, an example of a system for realizing a method for estimating phosphorus concentration in molten steel according to the present embodiment described above will be described. 3 is a diagram illustrating a configuration example of the converter blowdown system 1 according to the embodiment of the present invention. Referring to FIG. 3, the converter blowing system 1 according to the present embodiment includes a converter blowing facility 10, a converter blowing control device 20, a measurement control device 30, and an operation database 40.

(Electric converter blow facilities)

The converter blowdown equipment 10 includes a converter 11, a flue 12, a top lance 13, a sub lance 14, an exhaust gas component analyzer 101, an exhaust gas flowmeter 102 and a level meter 103. Equipped. The converter blowdown facility 10 starts and stops supply of oxygen to the molten iron by the uptake lance 13, and the sub lance 14, for example, on the basis of a control signal output from the measurement control device 30. The measurement of the component concentration and molten steel temperature in molten steel, the addition of cold ash, and the treatment of the molten iron and slag exhaust by the converter 11 are performed. In the converter blower facility 10, a feedstock device for supplying oxygen to the upper lance 13, a cold material input device having a drive system for injecting cold material into the converter 11, and auxiliary raw materials are introduced into the converter 11. Various apparatuses generally used for blowing by converters, such as a feedstock input device having a drive system for driving, can be provided.

From the furnace port of the converter 11, the upper lance 13 used for blowing is inserted, and the oxygen 15 sent to the delivery device is supplied to the molten iron in a furnace through the upper lance 13. In addition, in order to stir the molten iron, an inert gas such as nitrogen gas or argon gas or the like can be introduced from the bottom of the converter 11 as the odor gas 16. In the converter 11, a subsidiary material for slag formation such as molten iron drawn out from the blast furnace, a small amount of iron scrap, a cold material for adjusting the molten iron (molten steel) temperature, and quicklime is charged / injected. In addition, when a subsidiary material is powder, the subsidiary material of powder may be supplied in the converter 11 with oxygen 15 via the uptake lance 13.

In the primary refining, as represented by the general formula (101), phosphorus contained in the molten iron chemically reacts with a sub-material containing iron oxide and calcium oxide-containing material contained in the slag in the converter (dephosphorization reaction) to the slag. Is introduced. That is, by increasing the concentration of the iron oxide of the slag by blowing, dephosphorization reaction is promoted.

In primary refining, the carbon in the molten iron is oxidized with oxygen supplied from the upper lance 13 (decarburization reaction). As a result, it is the CO or CO ₂ exhaust gas is generated. These exhaust gases are discharged from the converter 11 into the flue 12.

In this way, in the blower blown, the blown oxygen reacts with carbon, phosphorus, silicon, and the like in the molten iron, and an oxide is generated. The oxide generated by blowing is discharged as exhaust gas or stabilized as slag. The carbon is removed by the oxidation reaction in the blowdown, and phosphorus and the like are introduced into and removed from the slag, thereby producing a low carbon and low impurity steel.

Further, the sub lance 14 inserted from the furnace port of the converter 11 has its tip immersed in the molten steel at a predetermined timing during decarburization, and measures the component concentration in the molten steel including the carbon concentration, the molten steel temperature, and the like. To be used. The measurement of molten steel data such as component concentration and / or molten steel temperature by this sublance 14 is referred to as "sub-lance measurement" below. The molten steel data obtained by the sub lance measurement is transmitted to the converter blow control device 20 through the measurement control device 30.

The exhaust gas generated by blown flows into the flue 12 provided outside the converter 11. In the flue 12, an exhaust gas component analyzer 101 and an exhaust gas flow meter 102 are provided. The exhaust gas component analyzer 101 analyzes a component included in the exhaust gas. The exhaust gas component analyzer 101 analyzes the concentrations of CO and CO ₂ contained in the exhaust gas, for example. The exhaust gas flowmeter 102 measures the flow rate of the exhaust gas. The exhaust gas component analyzer 101 and the exhaust gas flow meter 102 sequentially perform exhaust gas component analysis and flow rate measurement at predetermined sampling cycles (for example, 5 to 10 second cycles). Although component analysis and flow rate measurement of exhaust gas are performed at least at the time of a decarburization process, in order to calculate the unit amount of accumulated oxygen amount in a furnace used as explanatory variable of the regression formula represented by said formula (4), It is desirable to lose. The data concerning the exhaust gas component analyzed by the exhaust gas component analyzer 101 and the data about the exhaust gas flow rate measured by the exhaust gas flowmeter 102 (hereinafter, these data are referred to as "exhaust gas data") Is output as time series data to the converter blow control device 20 via the measurement control device 30. In addition, in order to sequentially estimate the concentration of phosphorus in the molten steel in the converter blow control device 20, it is preferable that the exhaust gas data is sequentially output to the converter blow control device 20.

In addition, the converter blower installation 10 is equipped with the level meter 103 in the vicinity of the opening of the converter 11. The level meter 103 is an apparatus which measures bathing surface levels, such as molten iron (molten steel) and slag, in the converter 11 at the time of converter blow blow. In addition, in this specification, this bath surface level is called slag level.

The slag level obtained by the level system 103 is information reflecting the goods state of the slag, and is used directly or indirectly as an explanatory variable of the regression equation represented by the above formula (4). The level meter 103 measures the slag level sequentially in a predetermined sampling period (for example, one second period). The data concerning the slag level obtained by the level meter 103 is output as time-series data to the converter blow control device 20 via the measurement control device 30.

In addition, this level meter 103 can be realized by a microwave injection apparatus, an antenna, a computing device, etc., as disclosed, for example in Unexamined-Japanese-Patent No. 2015-110817. In the level meter disclosed in the document, the microwave injection device emits microwaves into the converter, detects reflected waves reflected from the bath surface by the antenna, and the calculation device measures the bath surface level based on the emitted microwaves and the detected reflected waves. do.

(Electric converter blow control device)

The converter blow control device 20 includes a data acquisition unit 201, a cluster determination unit 202, a clustering execution unit 203, a phosphorus concentration estimation unit 204, a converter blow database 21 and an input / output unit 22. It is provided. The converter blow control device 20 has hardware configurations such as a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), a storage and a communication device, and the data acquisition by these hardware configurations. Each function of the unit 201, the cluster determination unit 202, the clustering execution unit 203, the phosphorus concentration estimating unit 204, and the converter blowing database 21 is realized. In addition, the input / output unit 22 is realized by an input device such as a keyboard, a mouse or a touch panel, an output device such as a display or a printer, and a communication device.

The converter blow control device 20 is obtained from various data stored in the converter blowdown database 21, exhaust gas data obtained from the exhaust gas component analyzer 101 and the exhaust gas flow meter 102, and the sub lance 14. The phosphorus concentration in the molten steel is estimated using the molten steel data to be obtained and the data relating to the slag level obtained from the level meter 103 (that is, the time series data of the slag level). The phosphorus concentration in molten steel is estimated by the function which each functional part of the converter blow control apparatus 20 has. In addition, the converter blow control device 20 may use the estimated phosphorus concentration in the molten steel for control of operation in converter blow blow. For example, when it is determined that the estimated phosphorus concentration in the molten steel exceeds the phosphorus concentration in the target molten steel stored as one of the target data 212, the converter blow control device 20 determines that the phosphorus concentration in the molten steel is increased. The operating conditions of converter blow can be changed to fall below the target phosphorus concentration. Thus, if the phosphorus concentration in molten steel can be estimated with high precision, the quality of the molten steel obtained by primary refining can be kept high.

In addition, the specific function which each functional part of the converter blow control apparatus 20 which concerns on this embodiment is mentioned later.

In addition, the converter blow control device 20 has a function of controlling the entire process related to the molten iron preliminary treatment such as blowing of oxygen into the converter 11 and addition of cold materials and auxiliary materials. In addition, for example, the converter blow control device 20 uses a predetermined mathematical model or the like before the start of blowing, which is performed in general static control, and the amount of blown oxygen to the converter 11 and the input amount of the coolant (hereinafter, cold). Discretion), and the function of determining the input amount of the subsidiary materials and the like. In addition, for example, the converter blow control device 20 has a function of controlling the measurement target, measurement timing, and the like with respect to the sub lance measurement performed in general dynamic control.

Specific processing in each function not shown (for example, the above-mentioned control method of input of cold materials and subsidiary materials, static control, a method of determining the amount of oxygen to be blown, the input amounts of various cold materials and subsidiary materials, etc. before the start of blowing), and the sub Since various well-known methods can be applied as a control method of a lance measurement, detailed description is abbreviate | omitted here.

The converter blowdown database 21 is a database that stores various data used in the converter blowdown control device 20, and is realized by a storage device such as storage. For example, as illustrated in FIG. 3, the converter blowdown database 21 stores the molten iron data 211, the target data 212, the parameter 213, and the like. These data may be added, updated, changed or deleted via an input device or communication device (not shown). For example, among the various data stored in the operation database 40 mentioned later, the data used for the converter blow job may be added to the converter blow job database 21. The various data stored in the converter blowdown database 21 are called by the data acquisition part 201. In addition, although the memory | storage device which has converter converter database 21 which concerns on this embodiment is comprised integrally with converter converter control apparatus 20 as shown in FIG. 3, in another embodiment, converter blower database The storage device having 21 may have a configuration separate from the converter blow control device 20.

The molten iron data 211 is various data regarding the molten iron in the converter 11. For example, the molten iron data 211 includes information on molten iron (the molten iron weight at the initial stage of charge, the concentration of molten iron components (carbon, phosphorus, silicon, iron, manganese, etc.), molten iron temperature, molten iron ratio, and the like). . In addition to the molten iron data 211, various types of information generally used in the molten iron preliminary treatment and decarburization treatment (for example, information related to the input of the subsidiary materials and the cold ash (information about the subsidiary materials and the cold ash quantity) and sublance measurement). Information regarding the measurement target, measurement timing, and the like, information on the amount of injected oxygen, and the like. The target data 212 includes data such as a target component concentration and target temperature in molten iron (in molten steel) after dephosphorization, decarburization, sublance measurement, and the like. The parameters 213 are various parameters used in the cluster determination unit 202 and the phosphorus concentration estimating unit 204. For example, the parameter 213 includes a parameter in a regression equation using an operation factor as an explanatory variable and a parameter (such as dephosphorization rate constant) for estimating phosphorus concentration.

The input / output unit 22 has a function of obtaining, for example, an estimation result of phosphorus concentration in molten steel by the phosphorus concentration estimating unit 204 and outputting the result to various output devices. For example, the input / output unit 22 may display the estimated phosphorus concentration in the molten steel to the operator. In addition, when the converter blow control device 20 performs converter blow control based on the estimated concentration of phosphorus in the molten steel, the input / output unit 22 measures an instruction relating to converter blow based on the estimated concentration of phosphorus in the molten steel. You may output to the control apparatus 30. FIG. In this case, the instruction may be an instruction automatically generated by a function relating to converter blow control of the converter blow control device 20, and may be used for an operation of an operator who has read the information on the displayed phosphorus concentration (estimated value). It may be an instruction input by. In addition, the input / output unit 22 may have a function of an input interface for adding, updating, changing or deleting various data stored in the converter blowing database 21. In addition, the input / output unit 22 stores various data acquired by the data acquisition unit 201, the determination result by the cluster determination unit 202, and the estimation result by the phosphorus concentration estimation unit 204. ) May be output.

(Measuring control unit)

The measurement control device 30 has hardware configurations such as a CPU, a ROM, a RAM, a storage, and a communication device. The measurement control device 30 has a function of communicating with each device included in the converter blowing facility 10 to control the overall operation of the converter blowing facility 10. For example, the measurement control device 30, according to the instructions from the converter blow control device 20, tilts the converter 11 for the intermediate discharging treatment, adds coolant and subsidiary materials to the converter 11, and lifts up. The operation of blowing the oxygen 15 of the lance 13 and immersion of the sub lance 14 into the molten steel, measurement of the sub lance, and the like are controlled. In addition, the measurement control device 30 receives data obtained from each device of the converter blowdown equipment 10 such as the exhaust gas component analyzer 101, the exhaust gas flow meter 102, the level meter 103, and the sub lance 14. It acquires and transmits it to the converter blow control apparatus 20. FIG.

(Operation database)

The operation database 40 is a database realized by storage devices, such as storage, and is a database which stores various data regarding the operation | work of converter conversion. The said various data are the data obtained from each apparatus of the converter blow-in installation 10 acquired by the data acquisition part 201, the determination result by the cluster determination part 202, and the estimation by the phosphorus concentration estimation part 204. Include the result. The operation database 40 which concerns on this embodiment accumulates the data regarding slag level (namely, time series data of slag level) measured by the level meter 103 for every operation. In addition, the operation database 40 which concerns on this embodiment outputs time series data of the slag level by operation to the clustering execution part 203. FIG. In addition, although the memory | storage device which has the operation database 40 which concerns on this embodiment is comprised separately from the converter blow control apparatus 20 as shown in FIG. 3, in another embodiment, the operation database 40 is carried out. The memory | storage device which has a structure may be the structure integrated with the converter blow control apparatus 20. FIG.

<2.2. Configuration and Function of Each Function Part>

Next, the structure and function of each functional part of the converter blow control device 20 which concerns on this embodiment are demonstrated.

Referring back to FIG. 3, the converter blow control device 20 according to the present embodiment includes a data acquisition unit 201, a cluster determination unit 202, a clustering execution unit 203, and a phosphorus concentration estimation unit 204. Each functional unit is provided.

(Data acquisition section)

The data acquisition unit 201 acquires various data for estimating the phosphorus concentration in the molten steel. For example, the data acquisition unit 201 acquires the molten iron data 211, the target data 212, and the parameters 213 stored in the converter blowdown database 21. In other words, the data acquisition unit 201 has a function as a molten iron data acquisition unit. These data are acquired at least before the process of estimating the phosphorus concentration in molten steel by the phosphorus concentration estimation part 204 starts. The data acquisition part 201 which concerns on this embodiment acquires the various data memorize | stored in the converter blowup database 21 before a converter blow start.

In addition, the data acquisition unit 201 acquires the exhaust gas data output from the exhaust gas component analyzer 101 and the exhaust gas flowmeter 102. In other words, the data acquisition unit 201 has a function as an exhaust gas data acquisition unit. The obtained exhaust gas data is time series data. The data acquisition unit 201 according to the present embodiment sequentially acquires the exhaust gas data measured by the exhaust gas component analyzer 101 and the exhaust gas flowmeter 102. In another embodiment, the data acquisition unit 201 may collectively acquire the exhaust gas data after the dephosphorization processing.

In addition, the data acquisition unit 201 acquires data relating to the slag level output from the level meter 103. That is, the data acquisition unit 201 has a function as a slag level data acquisition unit. Data relating to the obtained slag level is time series data. Acquisition of slag level is performed at the time of dephosphorization process. The data acquisition part 201 which concerns on this embodiment acquires the data regarding the slag level which the level meter 103 sequentially measures at the time of the dephosphorization process. In another embodiment, the data acquisition unit 201 may collectively acquire data regarding the slag level after dephosphorization processing.

In addition, the data acquisition unit 201 acquires molten steel data obtained by sublance measurement by the sublance 14 at the time of decarburization processing. In other words, the data acquisition unit 201 has a function as a molten steel data acquisition unit.

In addition to the various data described above, the data acquisition unit 201 acquires data relating to dephosphorization, intermediate exhaustion, and decarburization. The data acquisition part 201 acquires the data output from the various apparatuses provided in the converter blow installation facility 10 through the measurement control apparatus 30.

The data acquisition unit 201 outputs the acquired data to the cluster determination unit 202 and the phosphorus concentration estimation unit 204. In addition, the data acquired by the data acquisition unit 201 is stored in the operation database 40.

(Cluster Decision Unit, Clustering Execution Unit)

The cluster determination unit 202 determines the cluster having the highest similarity with respect to the slag level time series data acquired from the data acquisition unit 201 among the plurality of clusters extracted by the clustering execution unit 203. Here, the calculation method of the similarity is not particularly limited, and various known methods can be appropriately used. As such a similarity, for example, the slag level time series data of interest and the sum of the difference squares of the respective clusters can be used as described above. The category variable corresponding to the cluster determined by the cluster determination unit 202 is output to the phosphorus concentration estimation unit 204. This category variable is used as an operation factor X _{j which} is an explanatory variable of a regression equation expressed by equation (4) used for estimation by the phosphorus concentration estimating unit 204.

In addition, the clustering execution unit 203 performs clustering on the slag level time series data in past operations acquired from the operation database 40, and extracts a plurality of clusters. Information about the cluster taken out by the clustering execution unit 203 is output to the cluster determination unit 202. In addition, the information about the cluster may be output to the operation database 40. In addition, the clustering execution unit 203 may perform clustering as appropriate when the time series data of the slag level in the past operation stored in the operation database 40 is updated.

In addition, in another embodiment, when the said category variable is not used as explanatory variable, the cluster determination part 202 and the clustering execution part 203 do not need to be included in the converter blow control device 20.

(Phosphorus concentration estimation part)

The phosphorus concentration estimating unit 204 uses the dephosphorization rate constant k and the molten steel using a category variable which is a variable for identifying the cluster output from the data acquisition unit 201 and the cluster output from the cluster determination unit 202. Estimate the concentration. Specifically, the phosphorus concentration estimating unit 204 first calculates the dephosphorization rate constant k by substituting the above-described various data and category variables as explanatory variables into the regression equation represented by the above formula (4). The phosphorus concentration estimating unit 204 estimates the phosphorus concentration in the molten steel by substituting the dephosphorization rate constant k calculated in the above formula (2). Phosphorous concentration estimating unit 204 sequentially performs dephosphorization rate constant k and phosphorus concentration in molten steel after the sub-lance measurement by sub-lance 14 (that is, after the start of acquisition of molten steel data by data acquisition unit 201). Estimate That is, after the sub-lance measurement, the phosphorus concentration constant k and the phosphorus concentration in the molten steel in the range up to the time of decarburization (end point) are estimated by the phosphorus concentration estimating unit 204.

In the above, with reference to FIG. 3, the structure and function of each functional part of the converter blow control device 20 which concerns on this embodiment were demonstrated. In addition, although not shown in FIG. 3, the converter blow control device 20 may further include an operation amount calculation unit. The manipulated variable calculating unit may calculate an manipulated amount such as the amount of oxygen to be taken in the decarburization process, the amount of coolant, or the uptake lance height based on the phosphorus concentration in the molten steel estimated by the phosphorus concentration estimating unit 204. The function of the manipulated variable calculating unit may be the same as the function disclosed in Patent Document 1, for example. The phosphorus concentration in molten steel estimated by the phosphorus concentration estimation part 204 which concerns on this embodiment is higher in precision than the phosphorus concentration in molten steel estimated by the technique disclosed by the said patent document 1. Therefore, since the reliability of the manipulated variable calculated by the manipulated variable calculating unit is also high, it is possible to bring the actual phosphorus concentration in the molten steel closer to the phosphorus concentration in the target molten steel.

<< 3. Flow of phosphorus concentration estimation method in molten steel >>

4 is a diagram illustrating an example of a flowchart of a method for estimating phosphorus concentration in molten steel by the converter blowing system 1 according to the present embodiment. With reference to FIG. 4, the flow of the phosphorus concentration estimation method in the molten steel by the converter blowing system 1 which concerns on this embodiment is demonstrated. In addition, each process shown in FIG. 4 respond | corresponds to each process performed by the converter blow control device 20 shown in FIG. Therefore, the detail of each process shown in FIG. 4 is abbreviate | omitted, and only the outline | summary of each process is demonstrated.

In the method for estimating phosphorus concentration in molten steel according to the present embodiment, first, various data such as data stored in the converter blowdown database 21 are acquired before the start of converter blowdown (step S101). Specifically, in step S101, the data acquisition unit 201 acquires the molten iron data 211, the target data 212, and the parameter 213.

Subsequently, at the time of dephosphorization treatment and intermediate discharging treatment, data relating to the dephosphorization treatment and intermediate disposing treatment is obtained (step S103). Specifically, in step S103, the data acquisition unit 201 sequentially acquires data on the slag level measured by the level meter 103 from the level meter 103.

Next, based on the time series data of the slag level at the time of the dephosphorization process acquired in step S103, the cluster used as an operation factor is determined (step S105). Specifically, in step S105, the cluster determination unit 202 selects the cluster having the highest similarity among the clusters extracted by the clustering execution unit 203 with respect to the time series data of the slag level during the dephosphorization processing of the main charge. Decide The category variable corresponding to the cluster determined here is output to the phosphorus concentration estimating unit 204.

Next, data concerning the decarburization process is obtained (step S107). Specifically, in step S107, the data acquisition unit 201 stores the exhaust gas data measured by the exhaust gas component analyzer 101 and the exhaust gas flow meter 102, and the exhaust gas component analyzer 101 and the exhaust gas flow meter. Obtained sequentially from (102). Acquisition of the exhaust gas data is performed continuously from the start of the decarburization process to the end point. In addition, at the timing at which the sub lance measurement is performed, the data acquisition unit 201 acquires molten steel data.

In the method for estimating the phosphorus concentration in the molten steel according to the present embodiment, subsequent processing changes depending on whether or not the sub lance measurement has already been performed (step S109). If the sub lance measurement has not yet been performed (S109 / NO), the phosphorus concentration in the molten steel is not estimated, and data relating to decarburization processing such as exhaust gas data is repeatedly obtained (step S107). On the other hand, when the sub lance measurement is already performed (S109 / YES), the phosphorus concentration in molten steel is estimated (step S111). Specifically, the phosphorus concentration estimating unit 204 first uses the various data acquired by the data acquiring unit 201 to first estimate the dephosphorization rate constant k and the phosphorus concentration in the molten steel at the time of sublance measurement. This is because the molten steel temperature performance value and molten steel carbon concentration performance value obtained by the sub lance measurement are more effective for the high precision of the estimation of the dephosphorization rate constant k. More specifically, the dephosphorization rate constant k is substituted by first substituting the regression formula of the said formula (4) into the explanatory variable based on the various data containing the molten steel temperature performance value obtained by the sublance measurement, and the carbon steel concentration performance value in molten steel. Get Subsequently, the obtained dephosphorization rate constant k is regarded as the same value from the start of the dephosphorization treatment to the measurement of the sublance, and the molten iron phosphorus concentration is the phosphorus concentration initial value [P] _ini , and from the start of the dephosphorization treatment to the measurement of the sublance. Phosphorus concentration [P] at the time of sub lance measurement is calculated | required by substituting it in said Formula (2) by making elapsed time into t. In this way, even if the phosphorus concentration at the time of the sublance measurement from the start of the dephosphorization treatment is estimated using the dephosphorization rate constant k estimated at the time of the sublance measurement, the phosphorus concentration is estimated with sufficient precision as described in the following examples. Since it is possible, there is no practical problem.

From the sublance measurement to the end of the decarburization treatment, the estimated phosphorus concentration in molten steel at the time of the above-described sublance measurement was set as an initial value, and the estimation of the dephosphorization rate constant k according to Equation (4) above and the estimated k were used. The estimation of the phosphorus concentration in the molten steel by the formula (2) is repeatedly performed (step S113). Specifically, when the decarburization process is not finished (S113 / NO), the processes relating to steps S107 to S111 are repeatedly performed. On the other hand, when a decarburization process is complete | finished (S113 / YES), the estimation process of the phosphorus concentration in the molten steel which concerns on this embodiment is complete | finished.

In the above, with reference to FIG. 4, the flow of the estimation method of the phosphorus concentration in the molten steel which concerns on this embodiment was demonstrated. In addition, the step shown to the flowchart regarding the estimation method of the phosphorus concentration in the molten steel which concerns on this embodiment shown in FIG. 4 is only an example to the last.

For example, the timing at which the processing relating to steps S101 to S105 is executed is not particularly limited as long as the estimation process of the phosphorus concentration in molten steel in step S111 is started. Specifically, in another embodiment, in the case where the data acquisition unit 201 collectively acquires the data relating to the exhaust gas data and the slag level from various devices, the data acquisition process in steps S101 and S103, and The determination process of the cluster in S105 may be completed before the estimation process of the phosphorus concentration in molten steel in step S111 starts. This is because it is sufficient that data used for estimating the phosphorus concentration in the molten steel is provided at the start of the estimation process of the phosphorus concentration in the molten steel in step S111.

<< 4. Organize >>

The amount of slag excreted in the intermediate exclusion treatment affects the reaction direction and reaction rate of the dephosphorization reaction which affects the phosphorus concentration in the molten steel. It is also known that the slag level in the dephosphorization treatment relates to the amount of slag to be excluded in the intermediate discharge treatment. According to this embodiment, as one of the operating factors used for the explanatory variable for calculating the dephosphorization rate constant k, the slag level time series data (and / or the average value of the slag level time series data) at the time of blowing in dephosphorization process is used. Is used. That is, the amount of slag excretion during the intermediate exclusion treatment related to the dephosphorization reaction is applied to the estimation of the phosphorus concentration in the molten steel. Therefore, according to this embodiment, the precision of the estimation of the phosphorus concentration in molten steel in converter blowdown by which intermediate | middle exclusion process is performed can be made higher.

Further, according to the present embodiment, a category variable for identifying a cluster obtained by time series clustering performed on slag level time series data at the time of past operation is used as an explanatory variable relating to the operation factor. Then, a cluster similar to the tendency indicated by the time series data of the slag level obtained in actual operation is determined, and the category variable corresponding to the determined cluster is substituted into the regression equation as an explanatory variable regarding the operation factor of the charge. As a result, not only the amount of slag generated in the dephosphorization treatment, but also the tendency of slag forming at the end of the blowing process during the dephosphorization treatment can be reflected in the estimation of the dephosphorization rate constant k. That is, the accuracy of estimating the phosphorus concentration in molten steel in converter blowdown where intermediate treatment is performed can be further improved.

3 is an example of the converter blowdown system 1 which concerns on this embodiment to the last, and the specific structure of the converter blowdown system 1 is not limited to this example. The converter blowing system 1 should just be comprised so that the function demonstrated above can be implement | achieved and can take all the structures which can be generally assumed.

For example, all of the functions of the converter blow control device 20 may not be executed in one device, or may be performed by cooperation of a plurality of devices. For example, one device having only one or a plurality of functions of the data acquisition unit 201, the cluster determination unit 202, the clustering execution unit 203, and the phosphorus concentration estimating unit 204 may have different functions. The function equivalent to the converter blow control apparatus 20 shown in figure may be implement | achieved by being connected so that communication with the other apparatus which it has is possible.

Moreover, it is possible to produce the computer program for implementing each function of the converter blow control device 20 which concerns on this embodiment shown in FIG. 3, and to mount in a processing apparatus, such as a PC. In addition, a computer-readable recording medium having such a computer program stored therein can also be provided. The recording medium is, for example, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, or the like. The computer program described above may be distributed through, for example, a network without using a recording medium.

Example

Next, the Example of this invention is described. In order to confirm the effect of this invention, in this Example, the dephosphorization rate constant k obtained by the phosphorus concentration estimation method in molten steel which concerns on this embodiment, and the estimation precision of phosphorus concentration in molten steel were verified. In addition, the following Example is only what was performed in order to verify the effect of this invention, and this invention is not limited to the following Example.

As an explanatory variable used for the regression equation represented by the above formula (4), in Comparative Example 1, the operating factors shown in Table 1 above were used. In addition, in Example 1, as an explanatory variable, in addition to the operation factor shown in the said Table 1, the average value of the time series data of the slag level at the end of the blow-in at the time of dephosphorization process was used. In Example 2, a category variable corresponding to the cluster determined by the cluster determination unit 202 for the slag level time series data was used as the explanatory variable, in addition to the operation factors shown in Table 1 above. In addition, in Example 3, in addition to the average value of the operation factor and the slag level time series data shown in the said Table 1 as explanatory variables, it respond | corresponds to the cluster determined by the cluster determination part 202 about the time series data of the slag level. Category variables were used.

About each Example and the comparative example, the dephosphorization rate constant k and the phosphorus concentration in molten steel at the time of a sub lance measurement and the effect at the time of decarburization (end point) were computed, respectively. The dephosphorization rate constant k was computed using said Formula (4). In addition, the phosphorus concentration in molten steel was computed by substituting the dephosphorization rate constant k obtained by said Formula (4) into said Formula (2). The calculated dephosphorization rate constant k and the phosphorus concentration in molten steel are called "estimation value" below.

In addition, in order to verify the dephosphorization rate constant k and the estimated precision of phosphorus concentration in molten steel about each Example and a comparative example, the performance value of the phosphorus concentration in molten steel at the time of a sub lance measurement and the end point was measured. Moreover, the dephosphorization rate constant k based on the said performance value was computed by substituting the performance value of the phosphorus concentration in molten steel into said Formula (2). The error (estimation error) of the dephosphorization rate constant k and the estimated value of phosphorus concentration in molten steel, and a performance value concerning each Example and a comparative example were computed, respectively, and the standard deviation S.D. (%) Of the estimated error was calculated | required. The smaller the standard deviation S.D., the smaller the estimation error (that is, the higher the accuracy of estimation).

First, the results regarding the dephosphorization rate constant k and the estimation accuracy of the phosphorus concentration in molten steel at the time of the sub lance measurement are shown in Figs. 5A to 6D. 5A to 5D are diagrams showing the estimation error for the performance value of the dephosphorization rate constant k in the sublance measurement. FIG. 5A is a diagram showing an estimation error of the dephosphorization rate constant k at the time of sublance measurement in Example 1. FIG. FIG. 5B is a diagram showing an estimation error of the dephosphorization rate constant k at the time of sublance measurement in Example 2. FIG. FIG. 5C is a diagram showing an estimation error of the dephosphorization rate constant k at the time of sublance measurement in Example 3. FIG. It is a figure which shows the estimation error of the dephosphorization rate constant k at the time of the sub lance measurement in a comparative example.

6A to 6D are diagrams showing the estimation error for the performance value of the phosphorus concentration in the molten steel at the time of the sub lance measurement. It is a figure which shows the estimation error with respect to the performance value of the phosphorus concentration in molten steel at the time of the sub lance measurement in Example 1. FIG. It is a figure which shows the estimation error with respect to the performance value of the phosphorus concentration in molten steel at the time of the sublance measurement in Example 2. FIG. It is a figure which shows the estimation error with respect to the performance value of the phosphorus concentration in molten steel at the time of the sub lance measurement in Example 3. FIG. It is a figure which shows the estimation error with respect to the performance value of the phosphorus concentration in molten steel at the time of the sub lance measurement in a comparative example.

5A to 5D, it can be seen that in each example, the estimation accuracy of the dephosphorization rate constant k is improved as compared with the comparative example. Specifically, as shown in FIG. 5D, in the comparative example, the standard deviation S.D. of the estimation error was 0.00395. 5A, 5B and 5C, on the other hand, in Example 1, the standard deviation SD of the estimation error is 0.00385. In Example 2, the standard deviation SD of the estimation error is 0.00368. The standard deviation SD of the estimation error was 0.00361.

6A to 6D, it can be seen that in each example, the accuracy of estimating phosphorus concentration in molten steel is improved as compared with the comparative example. Specifically, as shown in FIG. 6D, in the comparative example, the standard deviation S.D. of the estimation error was 0.00420. 6A, 6B and 6C, on the other hand, in Example 1, the standard deviation SD of the estimation error is 0.00406. In Example 2, the standard deviation SD of the estimation error is 0.00385, and Example 3 The standard deviation SD of the estimation error was 0.00377.

From the above results, it can be seen that in each of the examples, the dephosphorization rate constant k and the phosphorus concentration in the molten steel at the time of sub-lance measurement can be estimated with high accuracy, compared with the comparative example. In particular, in Examples 2 and 3 in which variables corresponding to clusters obtained from time series data on slag levels are used as explanatory variables, it is shown that the dephosphorization rate constant k and the phosphorus concentration in molten steel can be more accurately estimated.

Next, the result regarding the dephosphorization rate constant k at the end point in a decarburization process, and the estimation precision of phosphorus concentration in molten steel is shown to FIG. 7A-8D.

7A to 7D are diagrams showing the estimation error with respect to the performance value of the dephosphorization rate constant k at the end point. FIG. 7A is a diagram showing an estimation error of the dephosphorization rate constant k at the end point in Example 1. FIG. FIG. 7B is a diagram showing an estimation error of the dephosphorization rate constant k at the end point in Example 2. FIG. FIG. 7C is a diagram showing an estimation error of the dephosphorization rate constant k at the end point in Example 3. FIG. 7D is a diagram showing an estimation error of the dephosphorization rate constant k at the end point in the comparative example.

8A to 8D are diagrams showing the estimation error for the performance value of the phosphorus concentration in the molten steel at the end point. It is a figure which shows the estimation error with respect to the performance value of the phosphorus concentration in the molten steel at the end point in Example 1. FIG. It is a figure which shows the estimation error with respect to the performance value of the phosphorus concentration in the molten steel at the end point in Example 2. FIG. It is a figure which shows the estimation error with respect to the performance value of the phosphorus concentration in the molten steel at the end point in Example 3. FIG. It is a figure which shows the estimation error with respect to the performance value of the phosphorus concentration in molten steel at the end point in a comparative example.

7A to 7D, it can be seen that in each example, the estimation accuracy of the dephosphorization rate constant k is improved as compared with the comparative example. Specifically, as shown in FIG. 7D, in the comparative example, the standard deviation S.D. of the estimation error was 0.00664. On the other hand, as shown in Figs. 7A, 7B and 7C, in Example 1, the standard deviation SD of the estimation error is 0.00656. In Example 2, the standard deviation SD of the estimation error is 0.00656. , The standard deviation SD of the estimation error was 0.00650.

8A to 8D, it can be seen that in each example, the accuracy of estimating phosphorus concentration in molten steel is improved in comparison with the comparative example. Specifically, as shown in FIG. 8D, in the comparative example, the standard deviation S.D. of the estimation error was 0.00102. 8A, 8B and 8C, on the other hand, in Example 1, the standard deviation SD of the estimation error is 0.000101. In Example 2, the standard deviation SD of the estimation error is 0.000986 and in Example 3, respectively. , The standard deviation SD of the estimation error was 0.000982.

From the above result, in each Example, compared with the comparative example, the dephosphorization rate constant k and the phosphorus concentration in molten steel at the time of an endpoint can be estimated with high precision. In particular, in Examples 2 and 3 in which variables corresponding to clusters obtained from time series data on slag levels are used as explanatory variables, it is shown that the dephosphorization rate constant k and the phosphorus concentration in molten steel can be more accurately estimated.

As mentioned above, in each Example, compared with the comparative example, the dephosphorization rate constant k and the phosphorus concentration in molten steel at the time of a sub lance measurement and an end point can be estimated with high precision. In particular, as shown in Examples 2 and 3, it was shown that the accuracy is further improved by using the variable corresponding to the cluster obtained from the time series data regarding the slag level as the explanatory variable in the calculation of the dephosphorization rate constant k.

As mentioned above, although preferred embodiment of this invention was described in detail, referring an accompanying drawing, this invention is not limited to this example. If it is a person having ordinary knowledge in the field of the technology of the present invention, it is clear that various changes or modifications can be conceived within the range of the technical idea described in the claim, and also about these naturally It is understood to belong to the technical scope of the present invention.

1: converter blow system
10: converter blow equipment
11: conversion
12: year
13: odor lance
14: Sublance
20: converter blow control device
21: Conversion of the Converter Database
22: input / output unit
30: instrumentation control unit
40: Operational Database
101: exhaust gas composition analyzer
102: exhaust gas flow meter
103: level meter
201: data acquisition unit
202: cluster determination unit
203: clustering execution unit
204: phosphorus concentration estimating unit

Claims (6)

It is a method for estimating the phosphorus concentration in molten steel used for the dephosphorization treatment, the intermediate discharging treatment which excludes the slag produced by the dephosphorization treatment, and the primary refining which performs the decarburization treatment using the same converter,
A slag level data acquisition step of acquiring a slag level during the dephosphorization processing;
An exhaust gas data acquisition step of acquiring exhaust gas components and exhaust gas flow rates during the decarburization;
Molten steel data acquisition step of acquiring molten steel temperature and carbon concentration in molten steel by the sub lance measurement at the time of the said decarburization process,
A dephosphorization rate constant is calculated using data on the slag level, the exhaust gas component, the exhaust gas flow rate, the molten steel temperature and the carbon concentration, and operating conditions relating to the dephosphorization treatment, the intermediate exclusion treatment and the decarburization treatment. And a phosphorus concentration estimating step of estimating the phosphorus concentration in the molten steel during the decarburization treatment after the sublance measurement using the calculated dephosphorization rate constant and the molten iron phosphorus concentration at the start of the dephosphorization treatment.
Including, phosphorus concentration estimation method in the molten steel. The molten steel according to claim 1, wherein in the calculation of the dephosphorization rate constant, a molten steel using a category variable for identifying a cluster obtained by time series clustering performed on a plurality of slag level time series data obtained in a past operation. Method of estimating the concentration of phosphorus. The method for estimating phosphorus concentration in molten steel according to claim 1 or 2, wherein in calculating the dephosphorization rate constant, an average value of time series data of the slag level obtained at the dephosphorization treatment is used. It is a converter blow control device used for the dephosphorization treatment, the intermediate discharging treatment which excludes the slag produced by the said dephosphorization treatment, and the primary refining which performs a decarburization process using the same converter,
A slag level data acquisition unit for acquiring the slag level during the dephosphorization;
An exhaust gas data acquisition unit for acquiring exhaust gas components and exhaust gas flow rates during the decarburization;
A molten steel data acquisition unit for acquiring molten steel temperature and carbon concentration in the molten steel by sub-lance measurement during the decarburization treatment;
A dephosphorization rate constant is calculated using data on the slag level, the exhaust gas component, the exhaust gas flow rate, the molten steel temperature and the carbon concentration, and operating conditions relating to the dephosphorization treatment, the intermediate exclusion treatment and the decarburization treatment. And a phosphorus concentration estimating unit for estimating the phosphorus concentration in the molten steel during the decarburization treatment after the sublance measurement using the calculated dephosphorization rate constant and the molten iron phosphorus concentration at the start of the dephosphorization treatment.
Converter blow control apparatus provided with. The said phosphorus concentration estimating part is a category which identifies the cluster obtained by time series clustering performed with respect to the time series data of the said slag level acquired in past operation in calculation of the said dephosphorization rate constant. Converter blow control device, using variable. The converter blow control device according to claim 4 or 5, wherein the phosphorus concentration estimating unit uses an average value of time series data of the slag level obtained in the dephosphorization process in calculating the dephosphorization rate constant.

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