Refining process control device and refining process control method

Abstract

The refining process control device of the present invention includes: a past similar performance extraction unit that extracts, from a refining performance database, the performance value of a past refining process whose refining conditions are similar to the refining process conditions to be calculated and whose evaluation value is upper, the refining conditions being the refining process conditions obtained before the start of the refining process and including the result of the refining process immediately preceding in the refining equipment; and an operation amount determination unit that determines an initial operation amount at the start of the refining process based on the performance value of the past refining process extracted by the past similar performance extraction unit, and determines the operation amount based on the change amount after the start of the refining process based on the initial operation amount.

Description

Technical Field

[0001] The present invention relates to a refining process control device and a refining process control method in refining equipment in the iron and steel industry. Background Art

[0002] In an ironworks, the composition and temperature of hot metal tapped from a blast furnace are adjusted in refining equipment such as pretreatment equipment, a converter, and secondary refining equipment. For such refining equipment, accurately adjusting the composition and temperature of the processed molten metal to target values and improving the efficiency of the treatment are very important in aspects such as steel quality management and rationalization of refining costs. In the control of the composition and temperature of molten metal in refining equipment, the conditions and environments of refining processes such as the composition and temperature of hot metal and the state of the refining equipment are various. In addition, taking a converter as an example, the operation amounts in the refining process are composed of countless combinations such as the top-blown oxygen flow rate and speed, the height of the top-blown lance, the bottom-blown gas flow rate, and the input amounts and input timing of auxiliary materials such as lime and iron ore. In the refining process as described above, it is difficult to appropriately control the operation amounts composed of countless combinations for various treatment conditions and treatment environments, and the resulting treatment fluctuations become a problem. To solve such a problem, Patent Document 1 describes a dephosphorization treatment method using a converter-type refining furnace, in which the operation amount is changed in such a way that state quantities such as decarburization oxygen efficiency follow a target change curve set in advance for each treatment mode, thereby suppressing fluctuations in the P concentration in the processed molten metal.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent No. 5211895 Gazette Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] In the method described in Patent Document 1, charging processes are performed multiple times in advance in the same each treatment mode, and a target change curve is set based on the results of charging with good dephosphorization, taking into account the influence of the treatment mode. However, in the method described in Patent Document 1, the influences of the conditions and environments of refining processes such as the composition and temperature of hot metal charged into the refining furnace, the amount of slag remaining from the previous treatment, and the state of the refining furnace are not considered. In the refining process, even when the treatment is performed in the same mode, the change situations of the reaction amount and state quantity vary greatly depending on the conditions of hot metal and the refining furnace. Therefore, in the method described in Patent Document 1, since the set target change curve is not optimal, there is a possibility that the fluctuations in each treatment cannot be reduced.

[0008] The present invention has been completed in view of the above problems, and an object thereof is to provide a refining process control device and a refining process control method capable of reducing fluctuations in each process.

[0009] Method for solving the problem

[0010] The refining process control device of the present invention includes: a model calculation unit that acquires, as input information, the actual values of the refining process conditions in the refining equipment, the measurement results of the temperature and component concentration of the molten metal in the refining equipment, the measurement results related to the refining equipment including the flow rate of the exhaust gas discharged from the refining equipment and the component concentration in the exhaust gas, and the results of the refining process immediately preceding the refining process in the refining equipment, and calculates the reaction amount and state amount in the refining equipment during the refining process using the acquired input information; a refining process evaluation calculation unit that calculates an evaluation value of the refining process using the input information acquired by the model calculation unit or past input information; a refining actual result database that stores the input information acquired by the model calculation unit, the reaction amount and state amount calculated by the model calculation unit, and the evaluation value calculated by the refining process evaluation calculation unit; a past similar actual result extraction unit that extracts, from the refining actual result database, the actual values of past refining processes that are similar to the refining process conditions of the calculation target in terms of the refining process conditions acquired before the start of the refining process and including the results of the refining process immediately preceding the refining process in the refining equipment and whose evaluation value is high; and an operation amount determination unit that determines the initial operation amount at the start of the refining process based on the actual values of the past refining processes extracted by the past similar actual result extraction unit and determines the operation amount based on the change amount after the start of the refining process based on the initial operation amount.

[0011] The results of the refining process immediately preceding the refining process in the refining equipment may include: the temperature of the molten metal after the immediately preceding refining process, the refining process results of the molten metal and slag components, the elapsed time from the end of the immediately preceding refining process to the start of the target refining process, and information related to the processes implemented during this period.

[0012] The input information may include: information related to the state of the refining equipment including the number of uses of the refining equipment.

[0013] The refining process evaluation calculation unit may calculate the evaluation value based on the cost of the auxiliary raw materials input during the refining process, the difference between the actual values and the target values of the temperature and component concentration of the molten metal after the refining process, and an index indicating the refining process efficiency.

[0014] The past similar performance extraction unit can calculate the distance between the vector representing the characteristics of the refining process conditions and the refining process performance obtained before the start of the refining process and the vector representing the characteristics of the refining process conditions and the refining process performance of the calculation object, and extract the performance value of the past refining process with a short distance.

[0015] The operation amount determination unit can determine the initial operation amount based on the past refining process results including the amount of change in the molten metal temperature and the amount of change in the molten metal composition and the performance of the past operation amount extracted by the past similar performance extraction unit, and change the operation amount in a manner following the trend of the reaction amount and the state amount in the refining process in the past refining performance extracted by the past similar performance extraction unit after the start of the refining process to determine the operation amount.

[0016] The refining process control method of the present invention includes: a model calculation step in which the performance value of the refining process conditions in the refining equipment, the measurement results of the temperature and composition concentration of the molten metal in the refining equipment, the measurement results related to the refining equipment including the flow rate of the exhaust gas discharged from the refining equipment and the composition concentration in the exhaust gas, and the results of the refining process immediately preceding in the refining equipment are obtained as input information, and the reaction amount and the state amount in the refining equipment during the refining process are calculated using the obtained input information; a refining process evaluation calculation step in which the evaluation value of the refining process is calculated using the input information obtained in the model calculation step or the past input information; a storage step in which the input information obtained in the model calculation step, the reaction amount and the state amount calculated in the model calculation step, and the evaluation value calculated in the refining process evaluation calculation step are stored in the refining performance database; a past similar performance extraction step in which the performance value of the past refining process that is similar to the refining process conditions of the calculation object and is the refining process conditions obtained before the start of the refining process and includes the results of the refining process immediately preceding in the refining equipment and has a superior evaluation value is extracted from the refining performance database; and an operation amount determination step in which the initial operation amount at the start of the refining process is determined based on the performance value of the past refining process extracted in the past similar performance extraction step, and the operation amount is determined based on the change amount after the start of the refining process based on the initial operation amount.

[0017] Advantages of the Invention

[0018] According to the refining process control device and the refining process control method of the present invention, the fluctuations in each process can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 FIG. is a schematic diagram showing the configuration of a refining process control device as an embodiment of the present invention.

[0020] Figure 2 is a flowchart showing the process of control processing as an embodiment of the present invention.

[0021] Figure 3 is a graph showing the distribution of the final dissolved oxygen concentration of the molten metal in the present invention example and the conventional example.

[0022] Figure 4 is a graph showing the distribution of the final temperature of the molten metal in the present invention example and the conventional example. Detailed Embodiments

[0023] Hereinafter, the configuration and operation of a refining process control device as an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0024] [Configuration]

[0025] First, with reference to Figure 1 the configuration of a refining process control device as an embodiment of the present invention will be described.

[0026] Figure 1 is a schematic diagram showing the configuration of a refining process control device as an embodiment of the present invention. As Figure 1 shown, a refining process control device 1 as an embodiment of the present invention is a device for controlling the component concentration and temperature of molten metal 101 and the component concentration of slag 103 processed in a refining device 2 in the steel industry. Here, the refining device 2 includes a converter 100, a lance 102, and a pipe 104. The lance 102 is disposed above the molten metal 101 in the converter 100. High-pressure oxygen is sprayed from the tip of the lance 102 downward onto the molten metal 101. Impurities in the molten metal 101 are oxidized by the high-pressure oxygen and enter the slag 103 (refining process). An exhaust gas guiding pipe 104 is provided at the upper part of the converter 100.

[0027] An exhaust gas detection unit 105 is disposed inside the pipe 104. The exhaust gas detection unit 105 detects the flow rate of the exhaust gas discharged during the refining process and the components in the exhaust gas (for example, CO, CO2, O2, N2, H2O, Ar, etc.). The exhaust gas detection unit 105 measures the flow rate of the exhaust gas in the pipe 104 based on, for example, the pressure difference before and after a Venturi tube provided in the pipe 104. In addition, the exhaust gas detection unit 105 measures the concentration [%] of each component in the exhaust gas. The flow rate and component concentration of the exhaust gas are measured, for example, at several-second intervals. A signal indicating the detection result of the exhaust gas detection unit 105 is sent to the control terminal 10.

[0028] The stirring gas is blown into the molten metal 101 in the converter 100 through the vent holes 106 formed at the bottom of the converter 100. The stirring gas is an inert gas such as Ar or N2. The blown stirring gas stirs the molten metal 101, promoting the reaction between the high-pressure oxygen and the molten metal 101. The flowmeter 107 measures the flow rate of the stirring gas blown into the converter 100. Before the start of blowing and after blowing, the temperature and composition concentration of the molten metal 101 are analyzed. In addition, the temperature and composition concentration of the molten metal 101 are measured one or more times during the blowing process, and the supply amount (oxygen supply amount) and speed (oxygen supply speed) of the high-pressure oxygen, the flow rate of the stirring gas (stirring gas flow rate), etc. are determined based on the measured temperature and composition concentration.

[0029] The refining process control system applying the refining process control device 1 and the refining process control method includes a control terminal 10, a refining process control device 1, and a display device (CRT) 20 as main components. The control terminal 10 is composed of an information processing device such as a personal computer or a workstation, controls the oxygen supply amount, oxygen supply speed, and stirring gas flow rate so that the composition concentration and temperature of the molten metal 101 are within the desired range, and collects data on the actual values of the oxygen supply amount, oxygen supply speed, and stirring gas flow rate.

[0030] The refining process control device 1 is composed of an information processing device such as a personal computer or a workstation. The refining process control device 1 includes an input device 11, a refining performance database (refining performance DB) 12, and an arithmetic processing unit 13. The arithmetic processing unit 13 functions as a model calculation unit 14, a refining process evaluation calculation unit 15, a past similar performance extraction unit 16, and an operation amount determination unit 17.

[0031] The input device 11 is an input interface for inputting various measurement results and actual performance information related to the refining equipment 2. The input device 11 includes a keyboard, a mouse, a pointing device, a data receiving device, and a graphical user interface (GUI). The input device 11 receives actual performance data, parameter setting values, etc. from the outside, and writes this information to the refining actual performance DB 12 and sends it to the model calculation unit 14. The refining processing conditions and the refining actual performance information are input from the control terminal 10 into the input device 11. The refining processing conditions include: standards or target values related to the composition and temperature of the molten metal 101 after the refining process, limiting conditions related to the types and input amounts of the added auxiliary materials, information related to the processing of the molten metal 101 after the next process after the refining process, the specifications of the lance 102 used, the position and number of the ventilation holes 106, the preset height of the lance 102, information on the change mode of the oxygen supply amount, etc. The refining actual performance information includes: the measurement results of the composition concentration and temperature of the molten metal 101, the measurement results related to the refining equipment including the flow rate of the exhaust gas and the components in the exhaust gas output from the exhaust gas detection unit 105, the actual performance of the operation amounts including the oxygen supply amount and the oxygen supply rate, the stirring gas flow rate, the input amounts of the raw materials (main raw materials, auxiliary materials), the information related to the state of the refining equipment including the number of times the refining furnace in the refining equipment is used, the composition concentration and temperature of the molten metal 101 after the immediately preceding refining process, the amount and composition of the slag 103, the processing results, the elapsed time from the end of the immediately preceding refining process to the start of the target refining process, and the information related to the processing implemented during this period. As the information on the processing implemented during the period from the end of the immediately preceding refining process to the start of the target refining process, examples can be given: the presence or absence of the implementation of the refractory protection treatment in the furnace, the amount of the refractory protection material used during the implementation, the input amount of the auxiliary material for solidifying the molten metal 101, the presence or absence of the implementation of the oxygen supply treatment for dissolving the solidified matter including the iron component near the furnace mouth and the furnace bottom, the oxygen supply amount during the implementation, the presence or absence of the implementation of the treatment for removing the solidified matter above the furnace mouth, the amount of the solidified matter removed during the implementation, etc.

[0032] The refining actual performance DB 12 is a storage device for storing the refining processing conditions and the refining actual performance information related to the refining process input into the input device 11, the calculation results of the in-furnace reaction amount and the in-furnace state amount output from the model calculation unit 14, and the refining process evaluation value output from the refining process evaluation calculation unit 15. The data storage period of the refining actual performance DB 12 is preferably at least half a year or more.

[0033] The arithmetic processing unit 13 is an arithmetic processing device such as a CPU, which controls the overall operation of the refining process control device 1. The arithmetic processing unit 13 has functions as a model calculation unit 14, a refining process evaluation calculation unit 15, a past similar performance extraction unit 16, and an operation amount determination unit 17. The model calculation unit 14, the refining process evaluation calculation unit 15, the past similar performance extraction unit 16, and the operation amount determination unit 17 are realized, for example, by the arithmetic processing unit 13 executing a computer program. The arithmetic processing unit 13 functions as the model calculation unit 14 by executing the computer program for the model calculation unit 14, functions as the refining process evaluation calculation unit 15 by executing the computer program for the refining process evaluation calculation unit 15, functions as the past similar performance extraction unit 16 by executing the computer program for the past similar performance extraction unit 16, and functions as the operation amount determination unit 17 by executing the computer program for the operation amount determination unit 17. It should be noted that the arithmetic processing unit 13 may also have dedicated arithmetic devices and arithmetic circuits that function as the model calculation unit 14, the refining process evaluation calculation unit 15, the past similar performance extraction unit 16, and the operation amount determination unit 17.

[0034] The model calculation unit 14 calculates the in-furnace reaction amount and the in-furnace state amount based on the information sent from the input device 11 and the information stored in the refining performance DB 12. As the in-furnace reaction amount, examples include the amount of C oxidation in the molten metal, the amount of Si oxidation in the molten metal, the amount of Mn oxidation and reduction in the molten metal, the amount of P oxidation and reduction in the molten metal, the amount of Fe oxidation and reduction in the molten metal, the amount of CO oxidation in the furnace, etc. In addition, as the in-furnace state amount, examples include the molten metal temperature, the molten metal composition, the slag composition, the amount of C oxidation in the molten metal per unit oxygen (decarbonization oxygen efficiency), the P equilibrium constant between the slag and the metal, the slag weight, the in-furnace slag level, the stirring power applied to the molten metal 101, the reaction interface area (hot spot area) between the top-blown oxygen and the molten metal 101, etc. The model calculation unit 14 calculates the in-furnace reaction amount and the in-furnace state amount for any plurality of elapsed times during the primary refining process after obtaining the refining process result. The model calculation unit 14 may also perform the calculation process at an arbitrary cycle during the refining process. The calculation result of the model calculation unit 14 is stored in the refining performance DB 12.

[0035] The refining process evaluation calculation unit 15 calculates an evaluation value (refining process evaluation value) of the refining process performance based on the information stored in the refining performance DB 12. The refining process evaluation calculation is automatically executed at the moment when the information required for the refining process evaluation calculation including the refining process result is obtained, or is executed by the operator inputting an execution command to the control terminal 10. The refining process evaluation value can be calculated, for example, using the evaluation function shown in the following formula (1).

[0036]

[0037] Here, i is the number of molten metal components managed in the refining process, represented by the C concentration, Si concentration, Mn concentration, and P concentration in the molten metal; j is the number of types of auxiliary materials input in the refining process; T.CaO is the cumulative value of the CaO component in the auxiliary materials input in the refining process; and A to F are parameters for weighting each item. In formula (1), when all of A to F are set to positive values, the lower the calculated value of the evaluation function, the better the refining process. Additionally, when the values of A to F are changed, the refining process evaluation value is recalculated based on past refining performance. The calculation result of the refining process evaluation calculation unit 15 is stored in the refining performance DB 12.

[0038] The past similar performance extraction unit 16 extracts past refining performances that are similar to the refining process conditions obtained before the start of the refining process and have a superior refining process evaluation value based on the information stored in the refining performance DB 12. The extraction of past refining performances is automatically executed before the start of the refining process of the calculation object and after obtaining the refining process condition information required for the extraction calculation of past similar performances, or is executed by the operator inputting an execution command to the control terminal 10. The extracted past performance information is output to the operation amount determination unit 17.

[0039] The operation amount determination unit 17 determines the operation amount of the calculation object based on the past refining performance information extracted by the past similar performance extraction unit 16 and outputs it to the control terminal 10. Examples of the operation amount to be determined include the oxygen supply amount and oxygen supply speed, the height of the lance 102, the stirring gas flow rate, and the auxiliary material input amount. After the start of the refining process, refining process control is implemented based on the operation amount output from the operation amount determination unit 17. Additionally, the operation amount determination unit 17 also has the function of outputting the past refining performance information and the operation amount of the calculation object to the display device 20 and using it for guiding display of refining process control.

[0040] The refining process control device 1 having such a configuration determines the operation amount by executing the control process shown below, implements refining process control with good precision, and reduces the fluctuations in each process. Hereinafter, Figure 2 The operation of the refining process control device 1 during the execution of the control process will be described with reference to the

[0041] [Control Process]

[0042] Figure 2 is a flowchart showing the flow of the control process as one embodiment of the present invention. In Figure 2In the flowchart shown, before the start of the refining process of the calculation object and after obtaining the refining process condition information required for the calculation process in the past similar performance extraction unit 16, it starts automatically or by the operator inputting an execution command to the control terminal 10, and the control process enters the process of step S1.

[0043] In the process of step S1, the operation processing unit 13 obtains from the input device 11 and the refining performance DB 12: refining process conditions, which include standards or target values related to the composition and temperature of the molten metal 101 after the refining process, limiting conditions related to the variety and input amount of the added auxiliary raw materials, information related to the processing of the molten metal 101 after the next process after the refining process, the specifications of the lance 102 used, the position and quantity of the ventilation holes 106, the preset height of the lance 102, information on the change mode of the oxygen supply amount; information required for the calculation process in the past similar performance extraction unit 16, which is the measurement results of the composition concentration and temperature of the molten metal 101, measurement results related to the refining equipment including the flow rate of the exhaust gas and the composition concentration in the exhaust gas output from the exhaust gas detection unit 105, actual performance of the operation amounts including the oxygen supply amount and oxygen supply speed, stirring gas flow rate, raw material (main raw material, auxiliary raw material) input amount, information related to the state of the refining equipment including the number of times the refining furnace in the refining equipment is used, processing results including the composition concentration and temperature of the molten metal 101, slag amount, and composition after the immediately preceding refining process, the elapsed time from the end of the immediately preceding refining process to the start of the object's refining process, and information related to the processing implemented during the period from the end of the immediately preceding refining process to the start of the object's refining process, etc. Thus, the process of step S1 ends, and the control process enters the process of step S2.

[0044] In the process of step S2, the operation processing unit 13 obtains the in-furnace reaction amount and in-furnace state amount in the refining process calculated by the model calculation unit 14. The obtained model calculation result corresponds to the past refining process performance used in the past similar performance extraction step of step S4. Thus, the process of step S2 ends, and the control process enters the process of step S3.

[0045] In the process of step S3, the operation processing unit 13 obtains the refining process evaluation value in the past refining process calculated by the refining process evaluation calculation unit 15. The obtained refining process evaluation value corresponds to the past refining process performance used in the past similar performance extraction step of step S4. Thus, the process of step S3 ends, and the control process enters the process of step S4.

[0046] In the process of step S4, the past similar performance extraction unit 16 extracts the past refining performances that are similar to the refining processing conditions and refining processing performances of the calculation object and have a superior refining processing evaluation value among the information obtained by using the processes of steps S1 to S3 and are obtained before the start of the refining process. The similarity between the refining processing conditions of the calculation object and the past refining performances can be evaluated, for example, by calculating the Euclidean distance shown in the following formula (2).

[0047] Similarity = (∑ k ((Past performance condition k - Object processing condition k)^2 / G k ^2))^0.5

[0048] …(2)

[0049] Among them, k is the number of refining processing conditions and refining processing performances, and G k is a parameter used for weighting each refining processing condition and refining processing performance. Examples of the refining processing conditions and refining processing performances include: refining processing date and time, charged hot metal weight, charged scrap weight, hot metal temperature, component concentrations of C, Si, Mn, P, etc. in the hot metal, standards or target values related to the components and temperature of the molten metal 101 after refining processing, usage times of the refining furnace and top-blowing lance, temperature of the molten metal after the previous refining processing and elapsed time since the processing, information related to temperature changes caused by processes implemented after refining processing such as auxiliary material input processing, oxygen blowing processing, and removal of adherences on the upper part of the furnace mouth, remaining slag weight and components, input weight of each auxiliary material variety input or determined to be input before the start of the refining process, input weight of each scrap variety, etc. In addition, when evaluating the similarity, only the performances with the same forms of the used refining furnace, lance 102, vent hole 106, etc. can be used as objects. It should be noted that the similarity is not limited to the Euclidean distance shown in formula (2), and can also be evaluated by methods for evaluating the distance between k-dimensional vectors represented by city block distance, Minkowski distance, Mahalanobis distance, cosine similarity, etc.

[0050] Here, a high similarity has the same meaning as a short distance between the calculated k-dimensional vectors. Regarding the extraction of past refining achievements, it is possible to extract past refining achievements with a calculated similarity higher than a set threshold, or it is also possible to extract any number of top past refining achievements with a high similarity. As a method for extracting similar achievements, the following method can be used: For each item of the refining processing conditions and the refining processing achievements k, calculate the difference between the refining processing conditions and the refining processing achievements of the processing object to be calculated and the past refining processing conditions and the refining processing achievements, and extract k achievements where the differences are less than their respective set thresholds. In the processing of step S4, extract the achievement with the highest refining processing evaluation value or multiple top achievements obtained in the processing of step S3 from the past similar achievements extracted by the above method. Thus, the processing of step S4 ends, and the control processing proceeds to the processing of step S5.

[0051] In the processing of step S5, the operation amount determination unit 17 determines the operation amount after the start of the refining process based on the information of the past refining achievements extracted in the processing of step S4 and the calculated values of the in-furnace reaction amount and the in-furnace state amount in the past refining achievements obtained in the processing of step S2. Regarding the operation amount at the start of the refining process, for example, the same operation amount as the extracted past refining achievements or the conditions calculated based on the extracted past achievements are sent to the control terminal 10. As the operation amount at the start of the refining process, for example, using the following formula (3), based on the refining processing results including the temperature change amount of the molten metal 101 and the molten metal composition change amount in the past refining achievements, the achievements of the operation amount including the amount of auxiliary material input, and the refining processing target values including the target temperature change amount of the molten metal 101, the target molten metal composition, and the planned operation amount including the planned amount of auxiliary material input in the target refining process, calculate the difference between the past refining achievements and the conditions of the target refining process, and thus calculate the corrected temperature change amount of the molten metal 101 to determine the input amount of auxiliary materials such as cooling materials and heating materials for the temperature operation of the molten metal 101 in such a way that the equation shown in the following formula (4) holds.

[0052] Corrected temperature change amount [℃]

[0053] = Target temperature change amount [℃] - Past actual temperature change amount [℃]

[0054] -∑ l {α l [℃ / (kg / t)]

[0055] × (Scrap variety l input amount_target [kg / t]

[0056] - Scrap variety l input amount_past [kg / t])}

[0057] -∑m {β m [℃ / %]

[0058] ×(Concentration of Component m before Treatment_Object [%] - Concentration of Component m before Treatment_Past [%])}

[0059] -∑ n {γ n [℃ / %]

[0060] ×(Concentration of Target Component n after Treatment_Object [%] - Concentration of Component n after Treatment_Past [%])}

[0061] -∑ p {δ p [℃ / (kg / t)]

[0062] ×(Planned Input Quantity of Auxiliary Material Variety p_Object [kg / t]

[0063] - Input Quantity of Auxiliary Material Variety p_Past [kg / t])}

[0064] …(3)

[0065] ∑ q {Quantity of Auxiliary Material Variety q Input for Temperature Operation [kg] × εq [℃ / kg]} = Revised Temperature Change [℃]

[0066] ···(4)

[0067] Among them, in Formulas (3) and (4), Object refers to the items in the refining treatment of the object, Past refers to the items in the past refining performance, 1 is the number of waste material varieties to be calculated, m is the number of calculated object components in the molten metal 101 or slag 103 before refining treatment, n is the number of calculated object components in the molten metal 101 or slag 103 after refining treatment, p is the number of auxiliary material varieties to be calculated, and α, β, γ, δ are constants related to each calculation item of the difference between the past refining performance and the object refining treatment conditions. As the calculated object component m before refining treatment, C, Si, Mn, P, etc. in the molten metal 101 can be exemplified. As the calculated object component n after refining treatment, C, Si, Mn, P, O in the molten metal 101 and FeO, Fe2O3, etc. in the slag 103 can be exemplified. As the auxiliary material variety p to be calculated, lime source, cooling material, heating material, refractory protection material, etc. can be exemplified. The temperature operation auxiliary material variety q is a cooling material or a heating material, and ε represents the cooling or heating coefficient of the temperature operation auxiliary material. The temperature operation auxiliary material variety q can be selected according to conditions such as the positive or negative of the revised temperature change and the input quantity limit of the auxiliary material. In addition, the temperature operation auxiliary material variety q can be a single auxiliary material variety or determined as a combination of multiple auxiliary materials and varieties in total.

[0068] In addition, the following formula (5) can be used to calculate the difference between the past refining performance and the target refining process based on the refining treatment results including the change amount of molten metal components, the actual performance of the operation amount including oxygen supply amount and auxiliary material input amount, and the treatment target value including the target molten metal components and the planned operation amount including the planned input amount of auxiliary materials in the target refining process, thereby calculating the oxygen supply amount for the target refining process. This point is also considered when determining the variety q of the temperature operation auxiliary material as shown in formulas (3) and (4).

[0069] Oxygen supply amount [Nm 3 = Oxygen supply amount_past [Nm 3 × Amount of molten iron_target [t] / Amount of molten iron_past [t]

[0070] + ∑ l {ζ l [Nm 3 / (kg / t)]

[0071] × (Input amount of scrap variety l_target [kg / t]

[0072] - Input amount of scrap variety l_past [kg / t])}

[0073] + ∑ m {η m [Nm 3 / %]

[0074] × (Concentration of pre-treatment component m_target [%] - Concentration of pre-treatment component m_past [%])}

[0075] + ∑ n {θ n [Nm 3 / %]

[0076] × (Concentration of post-treatment target component n_target [%] - Concentration of post-treatment component n_past [%])}

[0077] + ∑ p {λ p [Nm 3 / (kg / t)]

[0078] × (Planned input amount of auxiliary material variety p_target [kg / t]

[0079] - Input amount of auxiliary material variety p_past [kg / t])}

[0080] + ∑ q {λ q [Nm 3 / (kg / t)]

[0081] × Temperature operation auxiliary material q input amount [kg] / Total charge _ Object [t]}

[0082] …(5)

[0083] Among them, ζ, η, θ, and λ are constants related to each calculation item of the difference between the past refining performance and the target refining treatment conditions. Other variables and constants are the same as those used in formulas (3) and (4). It should be noted that formulas (3) to (5) represent the temperature change amount or the oxygen supply amount in the form of a weighted sum of the differences between the past refining performance and the target. However, in the case where it is clear that the temperature change amount or the oxygen supply amount has a non-linear relationship with the differences of each calculation item, an appropriate function representing this relationship can be used for calculation. In addition, regarding the constants α, β, γ, δ, ε, ζ, η, θ, and λ, they can be determined in such a way that the error between the true value of the temperature change amount or the optimal value of the oxygen supply amount that becomes obvious after the refining treatment and their calculated values is minimized, or they can also be determined using a learning model with the true value of the temperature change amount or the optimal value of the oxygen supply amount as training data.

[0084] As the operation amount after the start of refining treatment, for example, based on the past refining results displayed on the guidance screen, the operation amount is determined and sent to the control terminal 10 in a manner that follows the change curves of the reaction amount and state amount in the refining furnace during the refining treatment in the past refining results. When controlling the temperature of the molten metal 101, the heating efficiency obtained from the temperature change results of the molten metal 101 in the past refining results is used to calculate the optimal temperature change curve of the temperature of the molten metal 101 during the refining treatment in the target refining treatment, and the input amounts of the heating material and the cooling material are corrected or the heating material and the cooling material are additionally input to reduce the deviation between the estimated value or measured value of the temperature of the molten metal 101 during the refining treatment and the optimal temperature change curve. In addition, when controlling the decarburization and oxygen removal efficiency during the refining treatment, the height of the lance 102, the oxygen supply speed, and the stirring gas flow rate are changed to reduce the deviation between the estimated value or measured value of the decarburization and oxygen removal efficiency during the refining treatment in the target refining treatment and the change curve of the decarburization and oxygen removal efficiency in the past results. The operation amounts such as the input amounts of the heating material and the cooling material after the start of refining, the height of the lance 102, the oxygen supply speed, and the change amount of the stirring gas flow rate can be calculated using a model representing the relationship between the changes in control amounts such as the temperature and decarburization and oxygen removal efficiency of the molten metal 101 and the operation amount. As the model representing the relationship between the changes in control amounts and the operation amount, a model based on physical laws or empirical rules can be used, or it can be derived from the relationship between the control amount change results and the operation amount results in the past refining results. The control terminal 10 implements refining treatment control based on the sent refining treatment conditions. In addition, the information of the past refining results extracted by the past similar results extraction unit 16, the reaction amount in the furnace and the state amount in the furnace calculated by the model calculation unit 14, and the refining treatment conditions determined by the operation amount determination unit 17 are sent to the display device 20. The display device 20 displays guidance for refining treatment control based on the sent information. Thus, the processing of step S5 ends, and a series of control processes end.

[0085] As described above, in the refining process control device and the refining process control method according to an embodiment of the present invention, past refining results that are similar to the refining process conditions and refining process results of the calculation target and have a higher refining process evaluation value are extracted from the refining process conditions and refining process results obtained before the start of the refining process, and the operation amount after the start of the refining process is determined based on the extracted results. In addition, the refining process conditions and refining process results obtained before the start of the refining process include the results of the refining process immediately preceding in the refining equipment, the elapsed time from the end of the immediately preceding refining process to the start of the target refining process, and information related to the processes implemented during this period. Therefore, even if the conditions and environments of the refining process, such as the composition, temperature, amount of slag remaining from the previous process, and state of the refining furnace, of the molten iron charged into the refining furnace are various, their influences are taken into account to determine the operation amount. Thus, it is possible to perform a process identical to the past good processing results with good reproducibility and reduce the fluctuations in each process. In addition, in the determination of the operation amount, a correction amount for correcting the difference between the refining process conditions and refining process result conditions similar to the past good processing results is also considered to determine the operation amount, and the operation determination before the start of refining and the change of the operation amount after the start of refining are also implemented. Thereby, by approaching the past good processing results and appropriately correcting the different parts at the same time, it is possible to absorb the differences in each refining process, and thus achieve a higher-precision refining control.

[0086] Example

[0087] For the case where refining is performed for implementing the present invention (example of the present invention) and the case where refining is performed without implementing the present invention (existing example), the results of evaluating the final dissolved oxygen concentration and final temperature of the molten metal are shown in Figure 3 and Figure 4 respectively. In addition, the average values (μ) and standard deviations (σ) of the final dissolved oxygen concentration / target dissolved oxygen concentration, the average values and standard deviations of the final temperature / target temperature, and the improvement rate of the final hit rate in the example of the present invention and the existing example are shown in Table 1 below. From Figure 3 and Figure 4 and Table 1, it can be seen that according to the example of the present invention, compared with the existing example, the fluctuations in the final dissolved oxygen concentration and final temperature of the molten metal become smaller. Thus, it is confirmed that the fluctuations in each process can be reduced by the present invention.

[0088] [Table 1]

[0089] (Table 1)

[0090]

[0091] As described above, embodiments of the invention accomplished by the present inventor have been described. However, the present invention is not limited by the descriptions and drawings that are part of the disclosure of the present invention constituting these embodiments. For example, although these embodiments are for a refining process control device and a refining process control method for a converter-type refining furnace, even when an electric furnace, a vacuum degassing device, etc. are the objects, the control device and control method for the refining process of the present invention can execute the same process as the good past processing results with good reproducibility. Thus, other embodiments, examples, application techniques, etc. carried out by those skilled in the art according to these embodiments are included in the scope of the present invention.

[0092] Industrial Applicability

[0093] According to the present invention, a refining process control device and a refining process control method capable of reducing fluctuations in each process can be provided.

[0094] Symbol Explanation

[0095] 1 Refining process control device

[0096] 2 Refining equipment

[0097] 10 Control terminal

[0098] 11 Input device

[0099] 12 Refining performance database (refining performance DB)

[0100] 13 Arithmetic processing unit

[0101] 14 Model calculation unit

[0102] 15 Refining process evaluation calculation unit

[0103] 16 Past similar performance extraction unit

[0104] 17 Operation amount determination unit

[0105] 20 Display device

[0106] 100 Converter

[0107] 101 Molten metal

[0108] 102 Lance

[0109] 103 Slag

[0110] 104 Pipeline

[0111] 105 Exhaust gas detection unit

[0112] 106 Vent hole

[0113] 107 Flowmeter

Claims

1. A refining process control device, characterized in that, Comprising: A model calculation unit that obtains actual values of refining treatment conditions in a refining apparatus, measurement results of the temperature and component concentration of molten metal in the refining apparatus, measurement results related to the refining apparatus including the flow rate of exhaust gas discharged from the refining apparatus and the component concentration in the exhaust gas, and results of the immediately preceding refining treatment in the refining apparatus as input information, and calculates the reaction amount and state amount in the refining apparatus during the refining treatment using the obtained input information; A refining treatment evaluation calculation unit that calculates an evaluation value of the refining treatment using the input information obtained by the model calculation unit or past input information; A refining actual result database that stores the input information obtained by the model calculation unit, the reaction amount and state amount calculated using the model calculation unit, and the evaluation value calculated using the refining treatment evaluation calculation unit; A past similar actual result extraction unit that extracts, from the refining actual result database, actual values of past refining treatments where the refining conditions including the results of the immediately preceding refining treatment in the refining apparatus, which are obtained before the start of the refining treatment, are similar to the refining conditions of the calculation target and the evaluation value is superior; And An operation amount determination unit that determines the initial operation amount at the start of the refining treatment based on the actual values of the past refining treatments extracted by the past similar actual result extraction unit, and determines the operation amount based on the change amount after the start of the refining treatment based on the initial operation amount; The results of the immediately preceding refining treatment in the refining apparatus include: the molten metal temperature after the immediately preceding refining treatment, the refining treatment results of the molten metal and slag components, the elapsed time from the end of the immediately preceding refining treatment to the start of the target refining treatment, and information related to the treatments implemented during this period.

2. The refining process control device according to claim 1, characterized in that The input information includes: information related to the state of the refining apparatus including the number of uses of the refining apparatus.

3. The refining process control device according to claim 1 or 2, characterized in that, The refining treatment evaluation calculation unit calculates the evaluation value based on the cost of the auxiliary raw materials input during the refining treatment, the difference between the actual values and the target values of the temperature and component concentration of the molten metal after the refining treatment, and an index indicating the refining treatment efficiency.

4. The refining process control device according to claim 1 or 2, characterized in that, The past similar actual result extraction unit calculates the distance between a vector representing the characteristics of the refining treatment conditions and refining treatment actual results obtained before the start of the refining treatment and a vector representing the characteristics of the refining treatment conditions and refining treatment actual results of the calculation target, and extracts the actual values of the past refining treatments with a short distance.

5. The refining process control device according to claim 3, characterized in that, The past similar actual result extraction unit calculates the distance between a vector representing the characteristics of the refining treatment conditions and refining treatment actual results obtained before the start of the refining treatment and a vector representing the characteristics of the refining treatment conditions and refining treatment actual results of the calculation target, and extracts the actual values of the past refining treatments with a short distance.

6. The refining process control device according to claim 1 or 2, characterized in that The operation amount determination unit determines an initial operation amount based on past refining processing results including a molten metal temperature change amount and a molten metal composition change amount extracted by the past similar performance extraction unit and past operation amount performance, and determines the operation amount by changing the operation amount after the refining processing starts in a manner that follows the changes in the reaction amount and the state amount in the refining processing in the past refining performance extracted by the past similar performance extraction unit.

7. The refining process control device according to claim 3, characterized in that The operation amount determination unit determines an initial operation amount based on past refining processing results including a molten metal temperature change amount and a molten metal composition change amount extracted by the past similar performance extraction unit and past operation amount performance, and determines the operation amount by changing the operation amount after the refining processing starts in a manner that follows the changes in the reaction amount and the state amount in the refining processing in the past refining performance extracted by the past similar performance extraction unit.

8. The refining process control device according to claim 4, characterized in that, The operation amount determination unit determines an initial operation amount based on past refining processing results including a molten metal temperature change amount and a molten metal composition change amount extracted by the past similar performance extraction unit and past operation amount performance, and determines the operation amount by changing the operation amount after the refining processing starts in a manner that follows the changes in the reaction amount and the state amount in the refining processing in the past refining performance extracted by the past similar performance extraction unit.

9. The refining process control device according to claim 5, wherein The operation amount determination unit determines an initial operation amount based on past refining processing results including a molten metal temperature change amount and a molten metal composition change amount extracted by the past similar performance extraction unit and past operation amount performance, and determines the operation amount by changing the operation amount after the refining processing starts in a manner that follows the changes in the reaction amount and the state amount in the refining processing in the past refining performance extracted by the past similar performance extraction unit.

10. A refining process control method, characterized in that, include: a model calculation step, wherein actual values ​​of refining treatment conditions in a refining facility, measurement results of the temperature and component concentration of molten metal in the refining facility, measurement results related to the refining facility including the flow rate of exhaust gas discharged from the refining facility and the component concentration in the exhaust gas, and a result of the refining treatment immediately before being performed in the refining facility are acquired as input information, and a reaction amount and a state amount in the refining facility during the refining treatment are calculated using the acquired input information; a refinement process evaluation calculation step, wherein an evaluation value of the refinement process is calculated using the input information acquired in the model calculation step or past input information; a storing step of storing the input information acquired in the model calculating step, the reaction amount and state amount calculated in the model calculating step, and the evaluation value calculated in the refining treatment evaluation calculating step in a refining performance database; a past similar performance extraction step of extracting, from the refining performance database, a performance value of a past refining process in which the refining condition, which is a refining process condition acquired before the start of the refining process and includes a result of the refining process performed immediately before in the refining facility, is similar to the refining process condition of the calculation object and the evaluation value is higher; and An operation amount determination step, in which an initial operation amount at the start of the refining process is determined based on the actual performance values of past refining processes extracted in the past similar actual performance extraction step, and the operation amount is determined based on the change amount after the start of the refining process with the initial operation amount. The results of the immediately preceding refining process in the refining equipment include: the molten metal temperature after the immediately preceding refining process, the refining process results of the molten metal and slag components, the elapsed time from the end of the immediately preceding refining process to the start of the target refining process, and information related to the processes implemented during this period.

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