Documents disponibles écrits par cet auteur

Dual composition control in continuous, middle - vessel distillation columns, with a draw stream in the middle vessel / Rosendo Monroy-Loperena in Industrial & engineering chemistry research, Vol. 51 N° 12 (Mars 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4624–4631 Titre : Dual composition control in continuous, middle - vessel distillation columns, with a draw stream in the middle vessel Type de document : texte imprimé Auteurs : Rosendo Monroy-Loperena, Auteur ; José Alvarez-Ramírez, Auteur Année de publication : 2012 Article en page(s) : pp. 4624–4631 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Distillation  Continuous  middle Résumé : The dual composition control problem for a class of continuous middle-vessel distillation, which accepts a draw stream in the middle vessel, is studied in this work. This distillation configuration is advantageous when the separation goal is to recover high-purity light and heavy components from a multicomponent mixture with sufficiently large separation between relative volatilities. By using an estimator of the input–output modeling error, a first-order output-feedback compensator is designed which is shown to be equivalent to a multi-input multi-output proportional–integral (MIMO PI) controller. Tuning issues in terms of two time constants are given, and the ability of the controller to regulate the distillate and bottom product compositions in the face of sampled/delayed measurements is shown via numerical simulations. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie203018k [article] Dual composition control in continuous, middle - vessel distillation columns, with a draw stream in the middle vessel [texte imprimé] / Rosendo Monroy-Loperena, Auteur ; José Alvarez-Ramírez, Auteur . - 2012 . - pp. 4624–4631. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4624–4631 Mots-clés : Distillation  Continuous  middle Résumé : The dual composition control problem for a class of continuous middle-vessel distillation, which accepts a draw stream in the middle vessel, is studied in this work. This distillation configuration is advantageous when the separation goal is to recover high-purity light and heavy components from a multicomponent mixture with sufficiently large separation between relative volatilities. By using an estimator of the input–output modeling error, a first-order output-feedback compensator is designed which is shown to be equivalent to a multi-input multi-output proportional–integral (MIMO PI) controller. Tuning issues in terms of two time constants are given, and the ability of the controller to regulate the distillate and bottom product compositions in the face of sampled/delayed measurements is shown via numerical simulations. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie203018k

Effect analysis from dynamic regulation of vacuum pressure in an adiabatic batch crystallizer using data and image acquisition / Eusebio Bolaños-Reynoso in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9426–9436 Titre : Effect analysis from dynamic regulation of vacuum pressure in an adiabatic batch crystallizer using data and image acquisition Type de document : texte imprimé Auteurs : Eusebio Bolaños-Reynoso, Auteur ; Omar Xaca-Xaca, Auteur ; José Alvarez-Ramírez, Auteur Année de publication : 2009 Article en page(s) : p. 9426–9436 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Effect  analysis  Dynamic  regulation  Vacuum  pressure  Adiabatic Résumé : The effect of dynamic regulation of vacuum pressure was analyzed in an adiabatic batch crystallizer using data and image acquisition, virtual instruments, and supervisor control to obtain a controlled vacuum pressure, confirming that the process follows programmed routes in the central computer to obtain both programmed vacuum pressure and cooling dynamic profiles inside the crystallizer (direct design approach). The dynamical regulation profile of vacuum pressure called “adiabatic natural cooling” was able to originate an abrupt cooling effect by adiabatic evaporation inside of the crystallizer (e.g., natural cooling in batch crystallizers operated to atmospheric pressure), benefiting the seeded crystal growth from cane sugar until it reached a size of 732.7 μm (% volume). In turn, the increase in crystal growth, formed mass, and the available supersaturation depletion in the system, contribute to final molasses reduction. From a process dynamics viewpoint, the use of dynamic regulation profiles of vacuum pressure reduces batch time and energy consumption (steam) in the process operation. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071594i [article] Effect analysis from dynamic regulation of vacuum pressure in an adiabatic batch crystallizer using data and image acquisition [texte imprimé] / Eusebio Bolaños-Reynoso, Auteur ; Omar Xaca-Xaca, Auteur ; José Alvarez-Ramírez, Auteur . - 2009 . - p. 9426–9436. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9426–9436 Mots-clés : Effect  analysis  Dynamic  regulation  Vacuum  pressure  Adiabatic Résumé : The effect of dynamic regulation of vacuum pressure was analyzed in an adiabatic batch crystallizer using data and image acquisition, virtual instruments, and supervisor control to obtain a controlled vacuum pressure, confirming that the process follows programmed routes in the central computer to obtain both programmed vacuum pressure and cooling dynamic profiles inside the crystallizer (direct design approach). The dynamical regulation profile of vacuum pressure called “adiabatic natural cooling” was able to originate an abrupt cooling effect by adiabatic evaporation inside of the crystallizer (e.g., natural cooling in batch crystallizers operated to atmospheric pressure), benefiting the seeded crystal growth from cane sugar until it reached a size of 732.7 μm (% volume). In turn, the increase in crystal growth, formed mass, and the available supersaturation depletion in the system, contribute to final molasses reduction. From a process dynamics viewpoint, the use of dynamic regulation profiles of vacuum pressure reduces batch time and energy consumption (steam) in the process operation. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071594i

Finite-element inductance computation in 2-D eddy-current systems using sensitivity analysis / Melgoza, E. in IEEE transactions on energy conversion, Vol. 25, N° 3 (Septembre 2010) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 25, N° 3 (Septembre 2010) . - pp. 690 - 697 Titre : Finite-element inductance computation in 2-D eddy-current systems using sensitivity analysis Type de document : texte imprimé Auteurs : Melgoza, E., Auteur ; Escarela-Perez, R., Auteur ; José Alvarez-Ramírez, Auteur Année de publication : 2011 Article en page(s) : pp. 690 - 697 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : Jacobian  matrices;  asynchronous  machines;  eddy  currents;  finite  element  analysis;  machine  theory;  sensitivity  analysis Résumé : A new finite-element (FE) method for the determination of differential and apparent inductances of massive conductors is proposed using a sensitivity analysis approach. The new technique is a one-step computation procedure in which the definition of distribution vectors makes possible a unified treatment of solid and filamentary conductors. Since massive conductors are included in the formulation, eddy-current and proximity effects are properly considered. The inductance matrix expression, formally derived from the sensitivity analysis, requires only one evaluation of the Jacobian matrix of the FE system at the solution point. As a result, an efficient calculation can be performed using the same solver employed in the FE solution. The computation of a multiport equivalent of an induction machine has been used to show the power of the proposed method. Our FE and multiport network results have been validated using a well-known commercial FE package. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5552141&sortType%3Das [...] [article] Finite-element inductance computation in 2-D eddy-current systems using sensitivity analysis [texte imprimé] / Melgoza, E., Auteur ; Escarela-Perez, R., Auteur ; José Alvarez-Ramírez, Auteur . - 2011 . - pp. 690 - 697. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 25, N° 3 (Septembre 2010) . - pp. 690 - 697 Mots-clés : Jacobian  matrices;  asynchronous  machines;  eddy  currents;  finite  element  analysis;  machine  theory;  sensitivity  analysis Résumé : A new finite-element (FE) method for the determination of differential and apparent inductances of massive conductors is proposed using a sensitivity analysis approach. The new technique is a one-step computation procedure in which the definition of distribution vectors makes possible a unified treatment of solid and filamentary conductors. Since massive conductors are included in the formulation, eddy-current and proximity effects are properly considered. The inductance matrix expression, formally derived from the sensitivity analysis, requires only one evaluation of the Jacobian matrix of the FE system at the solution point. As a result, an efficient calculation can be performed using the same solver employed in the FE solution. The computation of a multiport equivalent of an induction machine has been used to show the power of the proposed method. Our FE and multiport network results have been validated using a well-known commercial FE package. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5552141&sortType%3Das [...]

A note on the controllability of two short-cut designs for a class of thermally coupled distillation sequence / Miguel Vaca in Industrial & engineering chemistry research, Vol. 48 N°4 (Février 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°4 (Février 2009) . - p. 2283–2289 Titre : A note on the controllability of two short-cut designs for a class of thermally coupled distillation sequence Type de document : texte imprimé Auteurs : Miguel Vaca, Auteur ; Arturo Jimenez-Gutierrez, Auteur ; José Alvarez-Ramírez, Auteur Année de publication : 2009 Article en page(s) : p. 2283–2289 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Ternary  mixtures  Thermally  coupled  sequence  Open-loop  transfer  function Résumé : The separation of multicomponent mixtures with conventional distillation sequences is energy-intensive. The use of thermal coupling sequences provides a more-efficient alternative, although their industrial usage has been quite limited, because of the complexity of design methods and potential difficulties during operation. In this work, we study a direct thermally coupled sequence for the separation of ideal ternary mixtures and perform a comparative study of two different designs, one based on the tray structure of an equivalent conventional sequence and the other specifically considering the effect of the thermal coupling on tray distribution and operational flows. Using the singular value decomposition technique on open-loop transfer function matrixes, controllability indexes were obtained. The controllability indexes of both designs are of the same order of magnitude, which means that their dynamic responses are basically the same. Although additional studies of dynamic simulation under closed-loop conditions are necessary, our results indicate that the controllability properties are similar, and that the design that provides the smallest energy consumption should be favored. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800993u [article] A note on the controllability of two short-cut designs for a class of thermally coupled distillation sequence [texte imprimé] / Miguel Vaca, Auteur ; Arturo Jimenez-Gutierrez, Auteur ; José Alvarez-Ramírez, Auteur . - 2009 . - p. 2283–2289. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°4 (Février 2009) . - p. 2283–2289 Mots-clés : Ternary  mixtures  Thermally  coupled  sequence  Open-loop  transfer  function Résumé : The separation of multicomponent mixtures with conventional distillation sequences is energy-intensive. The use of thermal coupling sequences provides a more-efficient alternative, although their industrial usage has been quite limited, because of the complexity of design methods and potential difficulties during operation. In this work, we study a direct thermally coupled sequence for the separation of ideal ternary mixtures and perform a comparative study of two different designs, one based on the tray structure of an equivalent conventional sequence and the other specifically considering the effect of the thermal coupling on tray distribution and operational flows. Using the singular value decomposition technique on open-loop transfer function matrixes, controllability indexes were obtained. The controllability indexes of both designs are of the same order of magnitude, which means that their dynamic responses are basically the same. Although additional studies of dynamic simulation under closed-loop conditions are necessary, our results indicate that the controllability properties are similar, and that the design that provides the smallest energy consumption should be favored. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800993u