Control method for vacuum degassing equipment, control system for vacuum degassing equipment, model parameter determination method, and model parameter determination apparatus

Abstract

The control method for the vacuum degassing equipment includes a model parameter determination step of determining the model parameters of a molten steel carbon concentration estimation model, a molten steel carbon concentration estimation step of estimating the carbon concentration in molten steel, a decarburization treatment completion determination step of determining the end of the decarburization treatment, and a control step of controlling the manipulated variables related to the operation of the vacuum degassing equipment. The model parameter determination step determines the values ​​of the model parameters for the next charge based on the measured value of the molten steel carbon concentration after the decarburization treatment, the estimated value of the molten steel carbon concentration in the most recent predetermined charge, and the values ​​of the actual parameters of the molten steel carbon concentration estimation model.

Claims

1. A control method for a vacuum degassing system, which controls the operation of a vacuum degassing system that performs decarburization by placing molten steel under reduced pressure, A model parameter determination step is used to determine the completion of the decarburization process and to determine the model parameters of a molten steel carbon concentration estimation model that estimates the carbon concentration in molten steel after the decarburization process, A step of estimating the carbon concentration in molten steel, which involves estimating the carbon concentration in molten steel using the aforementioned carbon concentration estimation model in molten steel, A decarburization treatment completion determination step is performed to determine if the estimated carbon concentration in the molten steel is below the target value, and the decarburization treatment is completed when the estimated carbon concentration in the molten steel is below the target value. The control step includes controlling the amount of operation related to the operation of the vacuum degassing equipment based on the determination of the completion of the decarburization process, A control method for a vacuum degassing facility, wherein the model parameter determination step determines the value of the model parameter for the next charge based on the measured value of the carbon concentration in molten steel after decarburization treatment in the most recent predetermined charge, the estimated value of the carbon concentration in molten steel calculated using the molten steel carbon concentration estimation model in the most recent predetermined charge, and the value of the actual parameter, which is the value of the model parameter of the molten steel carbon concentration estimation model in the most recent predetermined charge.

2. A control method for a vacuum degassing facility according to claim 1, wherein the values ​​of the actual parameters are corrected to compensate for the estimation error calculated from the estimated value and the measured value in the most recent predetermined charge, using the influence coefficient of the model parameters on the estimated value of the carbon concentration in molten steel after decarburization treatment, which has been calculated in advance using the molten steel carbon concentration estimation model,

3. The statistical value of the performance parameter in the most recent predetermined charge is used as the reference parameter, and the influence coefficient is used to correct the estimation error when the performance parameter in each charge is adjusted to match the reference parameter. A control method for a vacuum degassing apparatus according to claim 2, comprising correcting the reference parameter to compensate for the corrected statistical value of the estimation error using the influence coefficient, and determining the corrected value of the reference parameter as the value of the model parameter for the next charge.

4. A control method for a vacuum degassing facility according to claim 2, wherein for each predetermined charge in the most recent period, the value of the actual parameter is corrected using the influence coefficient to compensate for the estimation error, and the statistical value of the corrected actual parameter is determined as the value of the model parameter for the next charge.

5. The control method for a vacuum degassing apparatus according to claim 3 or 4, wherein the aforementioned statistical value is the median.

6. The control method for a vacuum degassing apparatus according to claim 3 or 4, wherein the value of the model parameter for the next charge is determined such that the compensated estimation error falls within an acceptable range and the change from the actual parameter in the most recent predetermined charge is minimized.

7. The control method for a vacuum degassing apparatus according to any one of claims 2 to 4, wherein the influence coefficient is updated each predetermined number of charges.

8. The control method for a vacuum degassing apparatus according to any one of claims 1 to 4, wherein the model parameters are parameters that constitute the decarburization reaction capacity coefficient or the calculation formula for calculating the decarburization reaction capacity coefficient.

9. A control system for a vacuum degassing system that controls the operation of a vacuum degassing system that decarburizes molten steel by placing it in a reduced-pressure environment, A model parameter determination unit is used to determine the completion of the decarburization process and determines the model parameters of a molten steel carbon concentration estimation model that estimates the carbon concentration in molten steel after the decarburization process. A molten steel carbon concentration estimation unit that estimates the carbon concentration in molten steel using the molten steel carbon concentration estimation model, A decarburization treatment completion determination unit determines the end of the decarburization treatment when the estimated carbon concentration in the molten steel is below the target value, Includes a control unit that controls the amount of operation related to the operation of the vacuum degassing equipment based on the determination of the completion of the decarburization process, A control system for a vacuum degassing facility, wherein the model parameter determination unit determines the value of the model parameter for the next charge based on the measured value of the carbon concentration in the molten steel after decarburization treatment in the most recent predetermined charge, the estimated value of the carbon concentration in the molten steel calculated using the molten steel carbon concentration estimation model in the most recent predetermined charge, and the value of the actual parameter, which is the value of the model parameter of the molten steel carbon concentration estimation model in the most recent predetermined charge.

10. A method for determining model parameters of a molten steel carbon concentration estimation model used to determine the completion of a decarburization process in a vacuum degassing facility that decarburizes molten steel by placing it under reduced pressure, and for estimating the carbon concentration in molten steel after the decarburization process, wherein the model parameters are determined. The aforementioned model parameter determination method is performed by a model parameter determination device. A method for determining model parameters, which determines the values ​​of the model parameters for the next charge based on the measured value of the carbon concentration in molten steel after decarburization treatment in the most recent predetermined charge, the estimated value of the carbon concentration in molten steel calculated using the molten steel carbon concentration estimation model in the most recent predetermined charge, and the values ​​of the actual parameters, which are the values ​​of the model parameters of the molten steel carbon concentration estimation model in the most recent predetermined charge.

11. A model parameter determination device used to determine the completion of a decarburization process in a vacuum degassing facility that decarburizes molten steel by placing it under reduced pressure, and which determines the model parameters of a molten steel carbon concentration estimation model that estimates the carbon concentration in molten steel after the decarburization process, A model parameter determination device comprising a model parameter determination unit that determines the value of the model parameter for the next charge based on the measured value of the carbon concentration in molten steel after decarburization treatment in the most recent predetermined charge, the estimated value of the carbon concentration in molten steel calculated using the molten steel carbon concentration estimation model in the most recent predetermined charge, and the value of the actual parameter, which is the value of the model parameter of the molten steel carbon concentration estimation model in the most recent predetermined charge.

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