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Nonlinear modeling method applied to prediction of Hot metal silicon in the ironmaking blast furnace / Antti Nurkkala in Industrial & engineering chemistry research, Vol. 50 N° 15 (Août 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 9236-9248 [ Titre : Nonlinear modeling method applied to prediction of Hot metal silicon in the ironmaking blast furnace Type de document : texte imprimé Auteurs : Antti Nurkkala, Auteur ; Frank Pettersson, Auteur ; Henrik Saxe, Auteur Année de publication : 2011 Article en page(s) : pp. 9236-9248 [ Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Blast  furnace  Prediction  Modeling  Non  linear  model Résumé : Feedforward neural networks have been established as versatile tools for nonlinear black-box modeling, but in many data-mining tasks the choice of relevant inputs and network complexity still constitute major challenges. Statistical tests for detecting relations between inputs and outputs proposed in the literature are largely based on the theory for linear systems, and laborious retraining combined with the risk of getting stuck in local minima make the application of exhaustive search through all possible network configurations impossible but for toy problems. This paper proposes a systematic method to tackle the problem where an output shall be estimated on the basis of a (large) set of potential inputs. Feedforward neural networks of multilayer perceptron type are used in the three-stage approach: First, starting from sufficiently large networks, an efficient pruning method is applied to detect potential model candidates. Next, the best results of the pruning runs are extracted by forming a Pareto-frontier, with the contradictory objectives of minimizing network complexity and estimation error. The networks on this frontier are considered to contain promising hidden nodes with their specific connections to relevant input variables. These hidden nodes are therefore optimally combined by mixed-integer linear programming to form a final set of neural network models, from which the user can select a model of suitable complexity. The modeling method is applied on an illustrative test example as well as on a complex modeling problem in the metallurgical industry, i.e., prediction of the silicon content of hot metal produced in a blast furnace. It is demonstrated to find relevant inputs and to yield parsimonious sparsely connected neural models of the output. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24395869 [article] Nonlinear modeling method applied to prediction of Hot metal silicon in the ironmaking blast furnace [texte imprimé] / Antti Nurkkala, Auteur ; Frank Pettersson, Auteur ; Henrik Saxe, Auteur . - 2011 . - pp. 9236-9248 [. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 9236-9248 [ Mots-clés : Blast  furnace  Prediction  Modeling  Non  linear  model Résumé : Feedforward neural networks have been established as versatile tools for nonlinear black-box modeling, but in many data-mining tasks the choice of relevant inputs and network complexity still constitute major challenges. Statistical tests for detecting relations between inputs and outputs proposed in the literature are largely based on the theory for linear systems, and laborious retraining combined with the risk of getting stuck in local minima make the application of exhaustive search through all possible network configurations impossible but for toy problems. This paper proposes a systematic method to tackle the problem where an output shall be estimated on the basis of a (large) set of potential inputs. Feedforward neural networks of multilayer perceptron type are used in the three-stage approach: First, starting from sufficiently large networks, an efficient pruning method is applied to detect potential model candidates. Next, the best results of the pruning runs are extracted by forming a Pareto-frontier, with the contradictory objectives of minimizing network complexity and estimation error. The networks on this frontier are considered to contain promising hidden nodes with their specific connections to relevant input variables. These hidden nodes are therefore optimally combined by mixed-integer linear programming to form a final set of neural network models, from which the user can select a model of suitable complexity. The modeling method is applied on an illustrative test example as well as on a complex modeling problem in the metallurgical industry, i.e., prediction of the silicon content of hot metal produced in a blast furnace. It is demonstrated to find relevant inputs and to yield parsimonious sparsely connected neural models of the output. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24395869

Optimization study of steelmaking under novel blast furnace operation combined with methanol production / Hamid Ghanbari in Industrial & engineering chemistry research, Vol. 50 N° 21 (Novembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12103-12112 Titre : Optimization study of steelmaking under novel blast furnace operation combined with methanol production Type de document : texte imprimé Auteurs : Hamid Ghanbari, Auteur ; Mikko Helle, Auteur ; Frank Pettersson, Auteur Année de publication : 2011 Article en page(s) : pp. 12103-12112 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Production  Blast  furnace  Optimization Résumé : The opportunities to improve the performance of an existing production concept by plant retrofit are largely dependent on the available knowledge of the best operational state of the plant and its parameters and conditions. In this paper, nonlinear programming was used to analyze the economic potential of the use of large volumes of gases in a steel plant to produce methanol as a valuable byproduct in steelmaking. Conventional blast furnace operation was compared with the option of operating the blast furnace with top gas recycling after carbon dioxide stripping. The optimal integration of the processes was investigated by minimizing the cost of liquid steel production, considering the cost of raw materials and fuels, CO2 emission, and stripping, as well as credits for power, district heat, and methanol production. It was found that the novel way of operating the blast furnace with cold oxygen blowing and top gas recycling was well suited for combination with a polygeneration system using the residual gases of the steel plant. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697527 [article] Optimization study of steelmaking under novel blast furnace operation combined with methanol production [texte imprimé] / Hamid Ghanbari, Auteur ; Mikko Helle, Auteur ; Frank Pettersson, Auteur . - 2011 . - pp. 12103-12112. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12103-12112 Mots-clés : Production  Blast  furnace  Optimization Résumé : The opportunities to improve the performance of an existing production concept by plant retrofit are largely dependent on the available knowledge of the best operational state of the plant and its parameters and conditions. In this paper, nonlinear programming was used to analyze the economic potential of the use of large volumes of gases in a steel plant to produce methanol as a valuable byproduct in steelmaking. Conventional blast furnace operation was compared with the option of operating the blast furnace with top gas recycling after carbon dioxide stripping. The optimal integration of the processes was investigated by minimizing the cost of liquid steel production, considering the cost of raw materials and fuels, CO2 emission, and stripping, as well as credits for power, district heat, and methanol production. It was found that the novel way of operating the blast furnace with cold oxygen blowing and top gas recycling was well suited for combination with a polygeneration system using the residual gases of the steel plant. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697527