Documents disponibles écrits par cet auteur

Assessment of tandem venturi on enhancement of cavitational chemical reaction / Hoseyn Sayyaadi in Transactions of the ASME . Journal of fluids engineering, Vol. 131 N° 1 (Janvier 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 131 N° 1 (Janvier 2009) . - 07 p. Titre : Assessment of tandem venturi on enhancement of cavitational chemical reaction Type de document : texte imprimé Auteurs : Hoseyn Sayyaadi, Auteur Année de publication : 2009 Article en page(s) : 07 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : hydrodynamic  cavitation  reactors;  single  Venturi Résumé : The collapsing phenomenon of cavitation bubbles generates extremely high local pressures and temperatures that can be utilized for the chemical oxidation process. This process is carried out in cavitation reactors. A Venturi tube is one of the most common forms of hydrodynamic cavitation reactors, which is suitable for industrial scale applications. In this work, the hydraulic performance and efficiency in chemical reaction of a new form of hydrodynamic cavitation reactors, which is called “tandem Venturi,” were studied and compared with the conventional type of the single Venturi. The tandem Venturi is used for enhancement of the chemical reaction of hydrodynamic cavitating flow. The reaction enhancement is useful especially for the reaction of aqueous solutions not containing volatile organic compounds (VOCs). The operating pressure, inlet pressure, flow rate, and consequently the cavitation number were controlled and systematically varied for both single and tandem Venturis. Moreover, a specified amount of H2O2 was injected into the flow as required. The effects of operating pressure and the cavitation number on cavitating flow characteristics for single and tandem Venturis were experimentally observed and the results were compared. In addition, the performance of the tandem-Venturi reactor for degradation of non-VOC contaminants (2-chlorophenol) was studied. Its performance was compared with the performance of a conventional Venturi reactor. Two different categories were conducted for the experiments. In the first category, the effect of the net cavitating flow on degradation of non-VOC for the single and tandem Venturis was compared. In the second category, the effect of H2O2 injection into the cavitating flow on degradation of non-VOC (“cavitation-oxidation” process) was studied. The performance of the single and tandem Venturis for the cavitation-oxidation process was compared. Further investigation was performed to assess the advantage of utilizing the tandem Venturi from the viewpoint of efficiency of the oxidation process. The results of the energy efficiency were compared with the corresponding efficiency of the single Venturi. Finally, the relationship between the main parameters of cavitation reaction flow with the chemical performance was discussed. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] Assessment of tandem venturi on enhancement of cavitational chemical reaction [texte imprimé] / Hoseyn Sayyaadi, Auteur . - 2009 . - 07 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 131 N° 1 (Janvier 2009) . - 07 p. Mots-clés : hydrodynamic  cavitation  reactors;  single  Venturi Résumé : The collapsing phenomenon of cavitation bubbles generates extremely high local pressures and temperatures that can be utilized for the chemical oxidation process. This process is carried out in cavitation reactors. A Venturi tube is one of the most common forms of hydrodynamic cavitation reactors, which is suitable for industrial scale applications. In this work, the hydraulic performance and efficiency in chemical reaction of a new form of hydrodynamic cavitation reactors, which is called “tandem Venturi,” were studied and compared with the conventional type of the single Venturi. The tandem Venturi is used for enhancement of the chemical reaction of hydrodynamic cavitating flow. The reaction enhancement is useful especially for the reaction of aqueous solutions not containing volatile organic compounds (VOCs). The operating pressure, inlet pressure, flow rate, and consequently the cavitation number were controlled and systematically varied for both single and tandem Venturis. Moreover, a specified amount of H2O2 was injected into the flow as required. The effects of operating pressure and the cavitation number on cavitating flow characteristics for single and tandem Venturis were experimentally observed and the results were compared. In addition, the performance of the tandem-Venturi reactor for degradation of non-VOC contaminants (2-chlorophenol) was studied. Its performance was compared with the performance of a conventional Venturi reactor. Two different categories were conducted for the experiments. In the first category, the effect of the net cavitating flow on degradation of non-VOC for the single and tandem Venturis was compared. In the second category, the effect of H2O2 injection into the cavitating flow on degradation of non-VOC (“cavitation-oxidation” process) was studied. The performance of the single and tandem Venturis for the cavitation-oxidation process was compared. Further investigation was performed to assess the advantage of utilizing the tandem Venturi from the viewpoint of efficiency of the oxidation process. The results of the energy efficiency were compared with the corresponding efficiency of the single Venturi. Finally, the relationship between the main parameters of cavitation reaction flow with the chemical performance was discussed. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]

Multi-objective optimization of a cooling tower assisted vapor compression refrigeration system / Hoseyn Sayyaadi in International journal of refrigeration, Vol. 34 N° 1 (Janvier 2011) 

Public ISBD [article]  in International journal of refrigeration > Vol. 34 N° 1 (Janvier 2011) . - pp. 243-256 Titre : Multi-objective optimization of a cooling tower assisted vapor compression refrigeration system Titre original : Optimisation d'un système frigorifique à compression de vapeur doté d'une tour de refroidissement menée avec plusieurs objectifs Type de document : texte imprimé Auteurs : Hoseyn Sayyaadi, Auteur ; Mostafa Nejatolahi, Auteur Année de publication : 2011 Article en page(s) : pp. 243-256 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Refrigeration  system  Cooling  tower  Exergy  Economy  Optimization Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A cooling tower assisted vapor compression refrigeration machine has been considered for optimization with multiple criteria. Two objective functions including the total exergy destruction of the system (as a thermodynamic criterion) and the total product cost of the system (as an economic criterion), have been considered simultaneously. A thermodynamic model based on energy and exergy analyses and an economic model according to the Total Revenue Requirement (TRR) method have been developed. Three optimized systems including a single-objective thermodynamic optimized, a single-objective economic optimized and a multi-objective optimized are obtained. In the case of multi-objective optimization, an example of decision-making process for selection of the final solution from the Pareto frontier has been presented. The exergetic and economic results obtained for three optimized systems have been compared and discussed. The results have shown that the multi-objective design more acceptably satisfies generalized engineering criteria than other two single-objective optimized designs. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710001726 [article] Multi-objective optimization of a cooling tower assisted vapor compression refrigeration system = Optimisation d'un système frigorifique à compression de vapeur doté d'une tour de refroidissement menée avec plusieurs objectifs [texte imprimé] / Hoseyn Sayyaadi, Auteur ; Mostafa Nejatolahi, Auteur . - 2011 . - pp. 243-256. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 34 N° 1 (Janvier 2011) . - pp. 243-256 Mots-clés : Refrigeration  system  Cooling  tower  Exergy  Economy  Optimization Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A cooling tower assisted vapor compression refrigeration machine has been considered for optimization with multiple criteria. Two objective functions including the total exergy destruction of the system (as a thermodynamic criterion) and the total product cost of the system (as an economic criterion), have been considered simultaneously. A thermodynamic model based on energy and exergy analyses and an economic model according to the Total Revenue Requirement (TRR) method have been developed. Three optimized systems including a single-objective thermodynamic optimized, a single-objective economic optimized and a multi-objective optimized are obtained. In the case of multi-objective optimization, an example of decision-making process for selection of the final solution from the Pareto frontier has been presented. The exergetic and economic results obtained for three optimized systems have been compared and discussed. The results have shown that the multi-objective design more acceptably satisfies generalized engineering criteria than other two single-objective optimized designs. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710001726

Thermoeconomic optimization of a cryogenic refrigeration cycle for re-liquefaction of the LNG boil-off gas / Hoseyn Sayyaadi in International journal of refrigeration, Vol. 33 N° 6 (Septembre 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 6 (Septembre 2010) . - pp. 1197-1207 Titre : Thermoeconomic optimization of a cryogenic refrigeration cycle for re-liquefaction of the LNG boil-off gas Titre original : Optimisation thermoéconomique d'un cycle frigorifique cryogénique utilisé dans la reliquéfaction du gaz GNL vaporisé Type de document : texte imprimé Auteurs : Hoseyn Sayyaadi, Auteur ; M. Babaelahi, Auteur Année de publication : 2010 Article en page(s) : pp. 1197-1207 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : LNG  Marine  transport  Optimisation  Process  Liquefaction  Vapour  Modelling  Economic  analysis Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The development of the liquefaction process for the Liquefied Natural Gas (LNG) boil-off re-liquefaction plants will be addressed to provide an environmentally friendly and cost effective solution for the gas transportation. In this manner, onboard boil-off gas (BOG) re-liquefaction system as a cryogenic refrigeration cycle is utilized in order to re-liquefy the BOG and returns it to the cargo tanks instead of burning it. In this paper, a thermoeconomic optimization of the LNG-BOG liquefaction system is performed. A thermoeconomic model based on energy and exergy analyses and an economic model according to the total revenue requirement (TRR) are developed. Minimizing of the unit cost of the refrigeration effect as a product of BOG re-liquefaction plant is performed using the genetic algorithm. Results of thermoeconomic optimization are compared with corresponding features of the base case system. Finally, sensitivity of the total cost of the system product with respect to the variation of some operating parameters is studied. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000630 [article] Thermoeconomic optimization of a cryogenic refrigeration cycle for re-liquefaction of the LNG boil-off gas = Optimisation thermoéconomique d'un cycle frigorifique cryogénique utilisé dans la reliquéfaction du gaz GNL vaporisé [texte imprimé] / Hoseyn Sayyaadi, Auteur ; M. Babaelahi, Auteur . - 2010 . - pp. 1197-1207. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 6 (Septembre 2010) . - pp. 1197-1207 Mots-clés : LNG  Marine  transport  Optimisation  Process  Liquefaction  Vapour  Modelling  Economic  analysis Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The development of the liquefaction process for the Liquefied Natural Gas (LNG) boil-off re-liquefaction plants will be addressed to provide an environmentally friendly and cost effective solution for the gas transportation. In this manner, onboard boil-off gas (BOG) re-liquefaction system as a cryogenic refrigeration cycle is utilized in order to re-liquefy the BOG and returns it to the cargo tanks instead of burning it. In this paper, a thermoeconomic optimization of the LNG-BOG liquefaction system is performed. A thermoeconomic model based on energy and exergy analyses and an economic model according to the total revenue requirement (TRR) are developed. Minimizing of the unit cost of the refrigeration effect as a product of BOG re-liquefaction plant is performed using the genetic algorithm. Results of thermoeconomic optimization are compared with corresponding features of the base case system. Finally, sensitivity of the total cost of the system product with respect to the variation of some operating parameters is studied. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000630