Documents disponibles écrits par cet auteur

Nonconvex generalized benders decomposition with piecewise convex relaxations for global optimization of integrated process design and operation problems / Xiang Li in Industrial & engineering chemistry research, Vol. 51 N° 21 (Mai 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7287–7299 Titre : Nonconvex generalized benders decomposition with piecewise convex relaxations for global optimization of integrated process design and operation problems Type de document : texte imprimé Auteurs : Xiang Li, Auteur ; Yang Chen, Auteur ; Paul I. Barton, Auteur Année de publication : 2012 Article en page(s) : pp. 7287–7299 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Optimization  Nonconvex Résumé : This paper considers the global optimization of challenging stochastic or multiperiod mixed-integer nonconvex programs that arise from integrated process design and operation. The difficulties of the problems are large scale and the nonconvexity involved. Recently, a novel decomposition method, called nonconvex generalized Benders decomposition (NGBD), has been developed to solve this problem to global optimality finitely, and this method shows dramatic computational advantages over traditional branch-and-bound based global optimization methods because it can exploit well the decomposable structure of such problems. Since the convergence rate of NGBD is largely dependent on the tightness of the convex relaxations of the nonconvex functions, the efficiency of NGBD can be improved by generating tighter convex relaxations. Building on the success of piecewise linearization for bilinear programs in the process systems engineering literature, this paper develops a piecewise convex relaxation framework, which can yield tighter convex relaxations for factorable nonconvex programs, and integrates this framework into NGBD to expedite the solution. Case studies of a classical literature problem and an industry-level problem show that, while NGBD can solve problems that are intractable for a state-of-the-art global optimization solver, integrating the proposed piecewise convex relaxation into NGBD helps to reduce the solution time by up to an order of magnitude. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201262f [article] Nonconvex generalized benders decomposition with piecewise convex relaxations for global optimization of integrated process design and operation problems [texte imprimé] / Xiang Li, Auteur ; Yang Chen, Auteur ; Paul I. Barton, Auteur . - 2012 . - pp. 7287–7299. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7287–7299 Mots-clés : Optimization  Nonconvex Résumé : This paper considers the global optimization of challenging stochastic or multiperiod mixed-integer nonconvex programs that arise from integrated process design and operation. The difficulties of the problems are large scale and the nonconvexity involved. Recently, a novel decomposition method, called nonconvex generalized Benders decomposition (NGBD), has been developed to solve this problem to global optimality finitely, and this method shows dramatic computational advantages over traditional branch-and-bound based global optimization methods because it can exploit well the decomposable structure of such problems. Since the convergence rate of NGBD is largely dependent on the tightness of the convex relaxations of the nonconvex functions, the efficiency of NGBD can be improved by generating tighter convex relaxations. Building on the success of piecewise linearization for bilinear programs in the process systems engineering literature, this paper develops a piecewise convex relaxation framework, which can yield tighter convex relaxations for factorable nonconvex programs, and integrates this framework into NGBD to expedite the solution. Case studies of a classical literature problem and an industry-level problem show that, while NGBD can solve problems that are intractable for a state-of-the-art global optimization solver, integrating the proposed piecewise convex relaxation into NGBD helps to reduce the solution time by up to an order of magnitude. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201262f

Optimal design and operation of flexible energy polygeneration systems / Yang Chen in Industrial & engineering chemistry research, Vol. 50 N° 8 (Avril 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 8 (Avril 2011) . - pp. 4553–4566 Titre : Optimal design and operation of flexible energy polygeneration systems Type de document : texte imprimé Auteurs : Yang Chen, Auteur ; Thomas A. Adams, Auteur ; Paul I. Barton, Auteur Année de publication : 2011 Article en page(s) : pp. 4553–4566 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Flexible  energy  Polygeneration  systems Résumé : The optimal design and operation of flexible polygeneration systems using coal and biomass to coproduce power, liquid fuels, and chemicals is studied. In flexible systems, the various product rates change throughout the lifetime of the plant in response to market conditions in different scenarios. A two-stage programming formulation is proposed to optimize simultaneously the design decision variables and the operational decision variables in all scenarios. The optimal product portfolios, equipment capacity usages, and CO2 emissions of flexible polygeneration systems under different market conditions are discussed. In general, flexible polygeneration systems achieve higher net present values than static ones for the same oil price and carbon tax. Higher net present values can be obtained with increasing operational flexibility. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1021267 [article] Optimal design and operation of flexible energy polygeneration systems [texte imprimé] / Yang Chen, Auteur ; Thomas A. Adams, Auteur ; Paul I. Barton, Auteur . - 2011 . - pp. 4553–4566. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 8 (Avril 2011) . - pp. 4553–4566 Mots-clés : Flexible  energy  Polygeneration  systems Résumé : The optimal design and operation of flexible polygeneration systems using coal and biomass to coproduce power, liquid fuels, and chemicals is studied. In flexible systems, the various product rates change throughout the lifetime of the plant in response to market conditions in different scenarios. A two-stage programming formulation is proposed to optimize simultaneously the design decision variables and the operational decision variables in all scenarios. The optimal product portfolios, equipment capacity usages, and CO2 emissions of flexible polygeneration systems under different market conditions are discussed. In general, flexible polygeneration systems achieve higher net present values than static ones for the same oil price and carbon tax. Higher net present values can be obtained with increasing operational flexibility. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1021267

Optimal design and operation of static energy polygeneration systems / Yang Chen in Industrial & engineering chemistry research, Vol. 50 N° 9 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5099-5113 Titre : Optimal design and operation of static energy polygeneration systems Type de document : texte imprimé Auteurs : Yang Chen, Auteur ; Thomas A. Adams, Auteur ; Paul I. Barton, Auteur Année de publication : 2011 Article en page(s) : pp. 5099-5113 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optimal  design Résumé : The optimal design and operation of static polygeneration systems using coal and biomass to coproduce power, liquid fuels and chemicals is studied under different economic and policy scenarios. A mathematical model including material and energy balances, capital cost estimations, and economic analyses is proposed. Optimal product portfolios are obtained under different product price scenarios. The influence of different carbon tax policies on the optimal production strategy, such as the implementation of carbon capture and sequestration (CCS) or biomass usage, is also discussed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24128636 [article] Optimal design and operation of static energy polygeneration systems [texte imprimé] / Yang Chen, Auteur ; Thomas A. Adams, Auteur ; Paul I. Barton, Auteur . - 2011 . - pp. 5099-5113. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5099-5113 Mots-clés : Optimal  design Résumé : The optimal design and operation of static polygeneration systems using coal and biomass to coproduce power, liquid fuels and chemicals is studied under different economic and policy scenarios. A mathematical model including material and energy balances, capital cost estimations, and economic analyses is proposed. Optimal product portfolios are obtained under different product price scenarios. The influence of different carbon tax policies on the optimal production strategy, such as the implementation of carbon capture and sequestration (CCS) or biomass usage, is also discussed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24128636