Adaptive First Principles Model for the CAS-OB Process for Real-Time Applications

A model-based system for real-time monitoring and operational support has been developed for the Composition Adjustment by Sealed argon-bubbling with Oxygen Blowing (CAS-OB) process. The model of the system is based on a previously developed dynamic model using first principles, i.e., mass and energ...

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Main Authors: Kasper Linnestad, Seppo Ollila, Stein O. Wasbø, Agne Bogdanoff, Torstein Rotevatn
Format: Article
Language:English
Published: MDPI AG 2021-09-01
Series:Metals
Subjects:
Online Access:https://www.mdpi.com/2075-4701/11/10/1554
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author Kasper Linnestad
Seppo Ollila
Stein O. Wasbø
Agne Bogdanoff
Torstein Rotevatn
author_facet Kasper Linnestad
Seppo Ollila
Stein O. Wasbø
Agne Bogdanoff
Torstein Rotevatn
author_sort Kasper Linnestad
collection DOAJ
description A model-based system for real-time monitoring and operational support has been developed for the Composition Adjustment by Sealed argon-bubbling with Oxygen Blowing (CAS-OB) process. The model of the system is based on a previously developed dynamic model using first principles, i.e., mass and energy balances, reaction kinetics, and thermodynamics. Adaptive estimation of state variables has been implemented using a Kalman filter to ensure that the model is able to correct for deviations between measured and calculated temperatures in real-time operation. The estimation technique reduces the standard deviation of the predicted end temperature from 19.5 °C to 5.5 °C in a data series with more than 1000 heats. The system also includes an endpoint optimisation, which calculates the amount of scrap or oxygen to be added to achieve the target temperature at the end of the heat. The model has been implemented in the Cybernetica<sup>®</sup> CENIT™ framework. The overall model can be regarded as a hybrid digital twin, where a first principles model is adapted in real time using process measurements. The system also includes user interfaces for operators where process predictions can be followed, and suggested optimised inputs are presented. The system has been deployed at two refining stations at SSAB Europe OY in Raahe, Finland. The optimized suggestions for oxygen and scrap are presented to the operators in the graphical user interface. A projected temperature profile is calculated into the near future using the planned operational procedure as well as the projected temperature profile using optimised inputs. Both profiles are displayed in the user interface. Based on these trajectories, the operator can decide on whether to follow the nominal trajectory, or the recommendation from the optimisation This will help the operators make better decisions, which in turn reduces the number of rejected heats in the CAS-OB process.
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spelling doaj.art-5546ae19970f4e6991a45fdbe3b65a3f2023-11-22T19:08:42ZengMDPI AGMetals2075-47012021-09-011110155410.3390/met11101554Adaptive First Principles Model for the CAS-OB Process for Real-Time ApplicationsKasper Linnestad0Seppo Ollila1Stein O. Wasbø2Agne Bogdanoff3Torstein Rotevatn4Cybernetica AS, Leirfossvegen 27, 7038 Trondheim, NorwaySSAB Europe OY, Rautaruukintie 155, 92100 Raahe, FinlandCybernetica AS, Leirfossvegen 27, 7038 Trondheim, NorwaySSAB Europe OY, Rautaruukintie 155, 92100 Raahe, FinlandAdigo AS, Berghagan 3, 1405 Langhus, NorwayA model-based system for real-time monitoring and operational support has been developed for the Composition Adjustment by Sealed argon-bubbling with Oxygen Blowing (CAS-OB) process. The model of the system is based on a previously developed dynamic model using first principles, i.e., mass and energy balances, reaction kinetics, and thermodynamics. Adaptive estimation of state variables has been implemented using a Kalman filter to ensure that the model is able to correct for deviations between measured and calculated temperatures in real-time operation. The estimation technique reduces the standard deviation of the predicted end temperature from 19.5 °C to 5.5 °C in a data series with more than 1000 heats. The system also includes an endpoint optimisation, which calculates the amount of scrap or oxygen to be added to achieve the target temperature at the end of the heat. The model has been implemented in the Cybernetica<sup>®</sup> CENIT™ framework. The overall model can be regarded as a hybrid digital twin, where a first principles model is adapted in real time using process measurements. The system also includes user interfaces for operators where process predictions can be followed, and suggested optimised inputs are presented. The system has been deployed at two refining stations at SSAB Europe OY in Raahe, Finland. The optimized suggestions for oxygen and scrap are presented to the operators in the graphical user interface. A projected temperature profile is calculated into the near future using the planned operational procedure as well as the projected temperature profile using optimised inputs. Both profiles are displayed in the user interface. Based on these trajectories, the operator can decide on whether to follow the nominal trajectory, or the recommendation from the optimisation This will help the operators make better decisions, which in turn reduces the number of rejected heats in the CAS-OB process.https://www.mdpi.com/2075-4701/11/10/1554real-time modelestimationmodel predictive controlsteel refining
spellingShingle Kasper Linnestad
Seppo Ollila
Stein O. Wasbø
Agne Bogdanoff
Torstein Rotevatn
Adaptive First Principles Model for the CAS-OB Process for Real-Time Applications
Metals
real-time model
estimation
model predictive control
steel refining
title Adaptive First Principles Model for the CAS-OB Process for Real-Time Applications
title_full Adaptive First Principles Model for the CAS-OB Process for Real-Time Applications
title_fullStr Adaptive First Principles Model for the CAS-OB Process for Real-Time Applications
title_full_unstemmed Adaptive First Principles Model for the CAS-OB Process for Real-Time Applications
title_short Adaptive First Principles Model for the CAS-OB Process for Real-Time Applications
title_sort adaptive first principles model for the cas ob process for real time applications
topic real-time model
estimation
model predictive control
steel refining
url https://www.mdpi.com/2075-4701/11/10/1554
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AT steinowasbø adaptivefirstprinciplesmodelforthecasobprocessforrealtimeapplications
AT agnebogdanoff adaptivefirstprinciplesmodelforthecasobprocessforrealtimeapplications
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