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Design and analysis of an ammonia/water absorption refrigeration cycle by means of an equation-oriented method / Luz María Chávez-Islas 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) . - pp. 1944–1956 Titre : Design and analysis of an ammonia/water absorption refrigeration cycle by means of an equation-oriented method Type de document : texte imprimé Auteurs : Luz María Chávez-Islas, Auteur ; Christopher L. Heard, Auteur Année de publication : 2009 Article en page(s) : pp. 1944–1956 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Equation-oriented  model  Ammonia/water  absorption  refrigeration  cycle  Thermodynamic  model  Thermophysical  property  model Résumé : An equation-oriented model for the design of a simple ammonia/water absorption refrigeration cycle is presented, which due to the nature of the working mixture, includes high-quality thermodynamic and thermophysical property models. There are four versions of the model, depending on heat rejection media and distillation column feed conditions. Solution of the model requires the given variables and designer competence-based variables. The column equilibrium stages, diameter, and height use binary decision variables. The solution of the equation set was developed with a General Algebraic Modeling System (GAMS) general purpose nonlinear solver. An equation solution strategy is described. Once solved, exergy balances are made and irreversibilities and exergy efficiency are calculated globally and for each unit operation. Two examples are compared. The great number of factors that can be varied in the absorption refrigeration system makes manual optimization of an industrial design a formidable task. However, good design makes a decisive difference in regard to the use of waste heat absorption refrigeration. The model forms the basis for the simultaneous optimization of design variables with an appropriate objective function. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800827z [article] Design and analysis of an ammonia/water absorption refrigeration cycle by means of an equation-oriented method [texte imprimé] / Luz María Chávez-Islas, Auteur ; Christopher L. Heard, Auteur . - 2009 . - pp. 1944–1956. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°4 (Février 2009) . - pp. 1944–1956 Mots-clés : Equation-oriented  model  Ammonia/water  absorption  refrigeration  cycle  Thermodynamic  model  Thermophysical  property  model Résumé : An equation-oriented model for the design of a simple ammonia/water absorption refrigeration cycle is presented, which due to the nature of the working mixture, includes high-quality thermodynamic and thermophysical property models. There are four versions of the model, depending on heat rejection media and distillation column feed conditions. Solution of the model requires the given variables and designer competence-based variables. The column equilibrium stages, diameter, and height use binary decision variables. The solution of the equation set was developed with a General Algebraic Modeling System (GAMS) general purpose nonlinear solver. An equation solution strategy is described. Once solved, exergy balances are made and irreversibilities and exergy efficiency are calculated globally and for each unit operation. Two examples are compared. The great number of factors that can be varied in the absorption refrigeration system makes manual optimization of an industrial design a formidable task. However, good design makes a decisive difference in regard to the use of waste heat absorption refrigeration. The model forms the basis for the simultaneous optimization of design variables with an appropriate objective function. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800827z

Optimization of a simple ammonia-water absorption refrigeration cycle by application of mixed-integer nonlinear programming / Luz María Chávez-Islas 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) . - pp. 1957–1972 Titre : Optimization of a simple ammonia-water absorption refrigeration cycle by application of mixed-integer nonlinear programming Type de document : texte imprimé Auteurs : Luz María Chávez-Islas, Auteur ; Christopher L. Heard, Auteur Année de publication : 2009 Article en page(s) : pp. 1957–1972 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Ammonia-water  absorption  refrigeration  system  Mixed-integer  nonlinear  programming  Heat  rejection Résumé : Optimization of an ammonia−water absorption refrigeration system, minimizing operating and annualized capital costs, is described. A mixed-integer nonlinear programming (MINLP) model, with the inclusion of discontinuous functions for capital costs for the main components of the system, is presented. The minimum total annualized cost is achieved with the simultaneous optimization of seven design variables. Practical limits of the design variables are established for the purpose of generating design parameters in accordance with the type of system studied. The model is applied to two examples. The analysis considers two types of heat rejection media: cooling water and air. The results obtained indicate that the selection of cooling medium is dependent on the refrigeration level that is required. The optimum configuration and operating conditions do not correspond to the best process integration and the coefficients of performance, and irreversibilities are high. The design variables with the highest impact on the objective function are dependent on the heat rejection medium characteristics and the process requirements. A sensitivity analysis of the effects of the evaluation criteria on the minimization of operating and capital costs is presented. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800828w [article] Optimization of a simple ammonia-water absorption refrigeration cycle by application of mixed-integer nonlinear programming [texte imprimé] / Luz María Chávez-Islas, Auteur ; Christopher L. Heard, Auteur . - 2009 . - pp. 1957–1972. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°4 (Février 2009) . - pp. 1957–1972 Mots-clés : Ammonia-water  absorption  refrigeration  system  Mixed-integer  nonlinear  programming  Heat  rejection Résumé : Optimization of an ammonia−water absorption refrigeration system, minimizing operating and annualized capital costs, is described. A mixed-integer nonlinear programming (MINLP) model, with the inclusion of discontinuous functions for capital costs for the main components of the system, is presented. The minimum total annualized cost is achieved with the simultaneous optimization of seven design variables. Practical limits of the design variables are established for the purpose of generating design parameters in accordance with the type of system studied. The model is applied to two examples. The analysis considers two types of heat rejection media: cooling water and air. The results obtained indicate that the selection of cooling medium is dependent on the refrigeration level that is required. The optimum configuration and operating conditions do not correspond to the best process integration and the coefficients of performance, and irreversibilities are high. The design variables with the highest impact on the objective function are dependent on the heat rejection medium characteristics and the process requirements. A sensitivity analysis of the effects of the evaluation criteria on the minimization of operating and capital costs is presented. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800828w

Synthesis and optimization of an ammonia-water absorption refrigeration cycle considering different types of heat exchangers by application of mixed-integer nonlinear programming / Luz María Chávez-Islas in Industrial & engineering chemistry research, Vol. 48 N° 6 (Mars 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 2972–2990 Titre : Synthesis and optimization of an ammonia-water absorption refrigeration cycle considering different types of heat exchangers by application of mixed-integer nonlinear programming Type de document : texte imprimé Auteurs : Luz María Chávez-Islas, Auteur ; Christopher L. Heard, Auteur ; Ignacio E. Grossmann, Auteur Année de publication : 2009 Article en page(s) : pp. 2972–2990 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Ammonia-water  absorption  Refrigeration  system  Heat-exchangers  Mixed-integer  nonlinear  programming Résumé : Optimization of the operating conditions and process scheme of an ammonia−water absorption refrigeration system, minimizing operating and annualized capital costs, is described. Various heat-exchanger technologies, the effect of the evaporator purge, and the thermodynamic restrictions of the system are taken into account. The objective is to make optimum use of various heat-exchange technologies to reduce the capital cost and meet the process refrigeration service requirements. A procedure to take account of the film coefficients and pressure drops of the different types of heat exchangers considered is proposed, which gives a solid basis for making decisions regarding the use of industrial ammonia−water absorption refrigeration. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801309h [article] Synthesis and optimization of an ammonia-water absorption refrigeration cycle considering different types of heat exchangers by application of mixed-integer nonlinear programming [texte imprimé] / Luz María Chávez-Islas, Auteur ; Christopher L. Heard, Auteur ; Ignacio E. Grossmann, Auteur . - 2009 . - pp. 2972–2990. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 2972–2990 Mots-clés : Ammonia-water  absorption  Refrigeration  system  Heat-exchangers  Mixed-integer  nonlinear  programming Résumé : Optimization of the operating conditions and process scheme of an ammonia−water absorption refrigeration system, minimizing operating and annualized capital costs, is described. Various heat-exchanger technologies, the effect of the evaporator purge, and the thermodynamic restrictions of the system are taken into account. The objective is to make optimum use of various heat-exchange technologies to reduce the capital cost and meet the process refrigeration service requirements. A procedure to take account of the film coefficients and pressure drops of the different types of heat exchangers considered is proposed, which gives a solid basis for making decisions regarding the use of industrial ammonia−water absorption refrigeration. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801309h