Documents disponibles écrits par cet auteur

Detailed scheduling of operations in single-source refined products pipelines / Vanina G. Cafaro in Industrial & engineering chemistry research, Vol. 50 N° 10 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6240-6259 Titre : Detailed scheduling of operations in single-source refined products pipelines Type de document : texte imprimé Auteurs : Vanina G. Cafaro, Auteur ; Diego C. Cafaro, Auteur ; Carlos A. Méndez, Auteur Année de publication : 2011 Article en page(s) : pp. 6240-6259 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Scheduling Résumé : The short-term scheduling of refined products pipelines is a very complex problem with many operational constraints to be considered Available nondiscrete planning approaches just provide the input schedule and the set of aggregate product deliveries to be performed from in-transit lots to depots at every batch injection. To determine the sequence of individual cuts on each batch to be accomplished by the pipeline operator, it is still necessary to refine such an aggregate plan. To do so, new computational tools for efficiently generating the detailed schedule of single-source pipelines with multiple distribution terminals are presented. Two types of methodologies are proposed. On one hand, it is developed a continuous-time mixed-integer linear programming (MILP) formulation that seeks to minimize both the total flow restart volume and the number of single-delivery pumping runs over the planning horizon. In this way, substantial savings in energy consumption and pump maintenance costs are achieved. Effective solution strategies for the MILP model are also designed to deal with large pipeline scheduling problems. On the other hand, three different heuristic rules for selecting the receiving terminal are introduced. By applying those rules in combination with a discrete-event simulation model, not only alternative detailed schedules can be generated in a very short CPU time but also some of them are near-optimal solutions. Three instances of a case study aimed at finding the detailed schedule of a real-world single-source pipeline system are solved through the proposed optimization and discrete-event simulation methods. Results are analyzed to assess the quality of the generated solutions and the required computational costs. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158921 [article] Detailed scheduling of operations in single-source refined products pipelines [texte imprimé] / Vanina G. Cafaro, Auteur ; Diego C. Cafaro, Auteur ; Carlos A. Méndez, Auteur . - 2011 . - pp. 6240-6259. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6240-6259 Mots-clés : Scheduling Résumé : The short-term scheduling of refined products pipelines is a very complex problem with many operational constraints to be considered Available nondiscrete planning approaches just provide the input schedule and the set of aggregate product deliveries to be performed from in-transit lots to depots at every batch injection. To determine the sequence of individual cuts on each batch to be accomplished by the pipeline operator, it is still necessary to refine such an aggregate plan. To do so, new computational tools for efficiently generating the detailed schedule of single-source pipelines with multiple distribution terminals are presented. Two types of methodologies are proposed. On one hand, it is developed a continuous-time mixed-integer linear programming (MILP) formulation that seeks to minimize both the total flow restart volume and the number of single-delivery pumping runs over the planning horizon. In this way, substantial savings in energy consumption and pump maintenance costs are achieved. Effective solution strategies for the MILP model are also designed to deal with large pipeline scheduling problems. On the other hand, three different heuristic rules for selecting the receiving terminal are introduced. By applying those rules in combination with a discrete-event simulation model, not only alternative detailed schedules can be generated in a very short CPU time but also some of them are near-optimal solutions. Three instances of a case study aimed at finding the detailed schedule of a real-world single-source pipeline system are solved through the proposed optimization and discrete-event simulation methods. Results are analyzed to assess the quality of the generated solutions and the required computational costs. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158921

Efficient tool for the scheduling of multiproduct pipelines and terminal operations / Diego C. Cafaro ; Jaime Cerdá in Industrial & engineering chemistry research, Vol. 47 n°24 (Décembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°24 (Décembre 2008) . - p. 9941–9956 Titre : Efficient tool for the scheduling of multiproduct pipelines and terminal operations Type de document : texte imprimé Auteurs : Diego C. Cafaro, Auteur ; Jaime Cerdá, Auteur Année de publication : 2009 Article en page(s) : p. 9941–9956 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Pipelines  Mixed-integer  linear  programming  (MILP) Résumé : This paper addresses the problem of scheduling a transmission pipeline carrying several petroleum products from a single oil refinery to a unique distribution center over a monthly horizon. The proposed approach is based on a very efficient mixed-integer linear programming (MILP) continuous-time formulation that is capable of determining the optimal pipeline batch sequence and lot sizes as well as the schedule of lot injections in the line and the timing of product deliveries to the distribution terminal. Moreover, the MILP model rigorously accounts for customer product demands on a daily basis, key terminal operations like lot settling periods for quality control tasks, and a predefined set of alternative lot sizes to get better control of tank availability. The approach also does not require the division of pipeline segments into a number of single-product packs of known capacities since the volume scale is also handled in a continuous manner. Results found for several examples involving the schedule of a real-world single-source single-destination multiproduct pipeline under different operational scenarios show that the proposed method leads to better pipeline schedules than previous approaches in a more rigorous way and at much lower computational cost. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071630d [article] Efficient tool for the scheduling of multiproduct pipelines and terminal operations [texte imprimé] / Diego C. Cafaro, Auteur ; Jaime Cerdá, Auteur . - 2009 . - p. 9941–9956. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°24 (Décembre 2008) . - p. 9941–9956 Mots-clés : Pipelines  Mixed-integer  linear  programming  (MILP) Résumé : This paper addresses the problem of scheduling a transmission pipeline carrying several petroleum products from a single oil refinery to a unique distribution center over a monthly horizon. The proposed approach is based on a very efficient mixed-integer linear programming (MILP) continuous-time formulation that is capable of determining the optimal pipeline batch sequence and lot sizes as well as the schedule of lot injections in the line and the timing of product deliveries to the distribution terminal. Moreover, the MILP model rigorously accounts for customer product demands on a daily basis, key terminal operations like lot settling periods for quality control tasks, and a predefined set of alternative lot sizes to get better control of tank availability. The approach also does not require the division of pipeline segments into a number of single-product packs of known capacities since the volume scale is also handled in a continuous manner. Results found for several examples involving the schedule of a real-world single-source single-destination multiproduct pipeline under different operational scenarios show that the proposed method leads to better pipeline schedules than previous approaches in a more rigorous way and at much lower computational cost. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071630d

Optimal scheduling of refined products pipelines with multiple sources / Diego C. Cafaro in Industrial & engineering chemistry research, Vol. 48 N° 14 (Juillet 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 14 (Juillet 2009) . - pp. 6675–6689 Titre : Optimal scheduling of refined products pipelines with multiple sources Type de document : texte imprimé Auteurs : Diego C. Cafaro, Auteur ; Jaime Cerdá, Auteur Année de publication : 2009 Article en page(s) : pp. 6675–6689 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Pipelines  Optimal  scheduling Résumé : Most contributions on short-term planning of multiproduct pipeline operations deal with pipelines featuring a single input terminal. In common-carrier pipelines, however, several refineries located at different sites use the same trunk line for shipping refined petroleum products to downstream output terminals. They can be regarded as multiple-source pipelines with input facilities at nonorigin points. The operation of intermediate sources raises some new difficult issues. Pumping runs taking place at intermediate locations can either insert a new lot or increase the size of a batch in transit. Batches are no longer arranged in the line in the same order that they are injected, and tracking the batch sequence becomes a more complex task. This paper introduces a novel continuous formulation for the scheduling of multiple-source pipelines operating on fungible or segregated mode. A case study involving a single pipeline that transports three distillates from two input to three output terminals was successfully solved over a 10-day time horizon. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900015b [article] Optimal scheduling of refined products pipelines with multiple sources [texte imprimé] / Diego C. Cafaro, Auteur ; Jaime Cerdá, Auteur . - 2009 . - pp. 6675–6689. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 14 (Juillet 2009) . - pp. 6675–6689 Mots-clés : Pipelines  Optimal  scheduling Résumé : Most contributions on short-term planning of multiproduct pipeline operations deal with pipelines featuring a single input terminal. In common-carrier pipelines, however, several refineries located at different sites use the same trunk line for shipping refined petroleum products to downstream output terminals. They can be regarded as multiple-source pipelines with input facilities at nonorigin points. The operation of intermediate sources raises some new difficult issues. Pumping runs taking place at intermediate locations can either insert a new lot or increase the size of a batch in transit. Batches are no longer arranged in the line in the same order that they are injected, and tracking the batch sequence becomes a more complex task. This paper introduces a novel continuous formulation for the scheduling of multiple-source pipelines operating on fungible or segregated mode. A case study involving a single pipeline that transports three distillates from two input to three output terminals was successfully solved over a 10-day time horizon. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900015b

A rigorous mathematical formulation for the scheduling of tree-structure pipeline networks / Diego C. Cafaro 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. 5064–5085 Titre : A rigorous mathematical formulation for the scheduling of tree-structure pipeline networks Type de document : texte imprimé Auteurs : Diego C. Cafaro, Auteur ; Jaime Cerdá, Auteur Année de publication : 2011 Article en page(s) : pp. 5064–5085 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Pipeline  Networks Résumé : Pipeline networks are the dominant mode of conveying a wide variety of oil refined products from refineries to distribution terminals. Pipeline infrastructure usually comprises trunk lines serving high-volume, long-haul transportation requirements, and delivering lines moving smaller volumes over shorter distances. Lots of products are mostly sent through trunk lines to bulk terminals, while some portions are branched to delivering lines and supplied to nearby market areas. This work presents a novel continuous-time mixed-integer linear (MILP) formulation for the short-term operational planning of tree-structure pipeline systems. The problem goal is to find the optimal schedule of pumping and delivery operations to satisfy all terminal requirements at minimum operating cost. To this end, model constraints strictly monitor the branching of batches and the creation of new interfaces in delivering lines to avoid forbidden sequences and determine additional reprocessing costs. By allowing the transfer of multiple products to delivering lines during a batch injection, longer runs can be executed, and fewer ones are needed to find the optimal solution. The new approach has been successfully applied to three examples, one of them involving a real-world pipeline network. As compared to previous contributions, significant improvements in both solution quality and CPU time have been obtained. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101462k [article] A rigorous mathematical formulation for the scheduling of tree-structure pipeline networks [texte imprimé] / Diego C. Cafaro, Auteur ; Jaime Cerdá, Auteur . - 2011 . - pp. 5064–5085. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5064–5085 Mots-clés : Pipeline  Networks Résumé : Pipeline networks are the dominant mode of conveying a wide variety of oil refined products from refineries to distribution terminals. Pipeline infrastructure usually comprises trunk lines serving high-volume, long-haul transportation requirements, and delivering lines moving smaller volumes over shorter distances. Lots of products are mostly sent through trunk lines to bulk terminals, while some portions are branched to delivering lines and supplied to nearby market areas. This work presents a novel continuous-time mixed-integer linear (MILP) formulation for the short-term operational planning of tree-structure pipeline systems. The problem goal is to find the optimal schedule of pumping and delivery operations to satisfy all terminal requirements at minimum operating cost. To this end, model constraints strictly monitor the branching of batches and the creation of new interfaces in delivering lines to avoid forbidden sequences and determine additional reprocessing costs. By allowing the transfer of multiple products to delivering lines during a batch injection, longer runs can be executed, and fewer ones are needed to find the optimal solution. The new approach has been successfully applied to three examples, one of them involving a real-world pipeline network. As compared to previous contributions, significant improvements in both solution quality and CPU time have been obtained. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101462k