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An experimental and theoretical study of the influence of surfactant on the preparation and stability of ammonia-water nanofluids / Liu Yang in International journal of refrigeration, Vol. 34 N° 8 (Décembre 2011) 

Public ISBD [article]  in International journal of refrigeration > Vol. 34 N° 8 (Décembre 2011) . - pp. 1741–1748 Titre : An experimental and theoretical study of the influence of surfactant on the preparation and stability of ammonia-water nanofluids Titre original : Etude expérimentale et théorique sur l'influence d'agents tensio-actifs sur la préparation et la stabilité des nano-fluides à ammoniac / eau Type de document : texte imprimé Auteurs : Liu Yang, Auteur ; Kai Du, Auteur ; Xiaofeng Niu, Auteur Année de publication : 2012 Article en page(s) : pp. 1741–1748 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Absorption  Particle  Stability  Ammonia-water  Refrigerant Résumé : Two types of nanofluids are obtained by adding the mixture of carbon black nanoparticles with emulsifier OP-10, and Al2O3 nanoparticles with sodium dodecyl benzene sulfonate (SDBS) in the ammonia-water solution, respectively. The dispersion stability of the prepared nanofluids in different mass fractions of surfactants is investigated by the light absorbency ratio index methods. The results show that with the increase of mass fraction of surfactant, the stability of carbon black nanofluid is improved firstly and then is exacerbated, while the stability of Al2O3 nanofluid is exacerbated firstly, then is improved, and then is exacerbated again. The influences of surfactant on the stability of ammonia-water nanofluids abide by the monolayer adsorption theory or electric double layer adsorption theory. Finally, the theoretical surfactant mass fractions required in the preparation of ammonia-water nanofluids are calculated by simplifying the dispersion models and the results are in accordance with experimental results. ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700711001526 [article] An experimental and theoretical study of the influence of surfactant on the preparation and stability of ammonia-water nanofluids = Etude expérimentale et théorique sur l'influence d'agents tensio-actifs sur la préparation et la stabilité des nano-fluides à ammoniac / eau [texte imprimé] / Liu Yang, Auteur ; Kai Du, Auteur ; Xiaofeng Niu, Auteur . - 2012 . - pp. 1741–1748. Génie mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 34 N° 8 (Décembre 2011) . - pp. 1741–1748 Mots-clés : Absorption  Particle  Stability  Ammonia-water  Refrigerant Résumé : Two types of nanofluids are obtained by adding the mixture of carbon black nanoparticles with emulsifier OP-10, and Al2O3 nanoparticles with sodium dodecyl benzene sulfonate (SDBS) in the ammonia-water solution, respectively. The dispersion stability of the prepared nanofluids in different mass fractions of surfactants is investigated by the light absorbency ratio index methods. The results show that with the increase of mass fraction of surfactant, the stability of carbon black nanofluid is improved firstly and then is exacerbated, while the stability of Al2O3 nanofluid is exacerbated firstly, then is improved, and then is exacerbated again. The influences of surfactant on the stability of ammonia-water nanofluids abide by the monolayer adsorption theory or electric double layer adsorption theory. Finally, the theoretical surfactant mass fractions required in the preparation of ammonia-water nanofluids are calculated by simplifying the dispersion models and the results are in accordance with experimental results. ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700711001526

Investigation on capacity matching in liquid desiccant and heat pump hybrid air-conditioning systems / Xiaofeng Niu in International journal of refrigeration, Vol. 35 N° 1 (Janvier 2012) 

Public ISBD [article]  in International journal of refrigeration > Vol. 35 N° 1 (Janvier 2012) . - pp. 160–170 Titre : Investigation on capacity matching in liquid desiccant and heat pump hybrid air-conditioning systems Titre original : Etude sur l’adaptation de la puissance des systèmes de conditionnement d’air hybrides à déshydratant liquide et à pompe à chaleur Type de document : texte imprimé Auteurs : Xiaofeng Niu, Auteur ; Fu Xiao, Auteur ; Zhenjun Ma, Auteur Année de publication : 2012 Article en page(s) : pp. 160–170 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Desiccant  system  Heat  pump  Compression  system  Heat  balance  Simulation Résumé : Liquid desiccant and heat pump (LDHP) hybrid air-conditioning system provides a promising independent air dehumidification solution. Capacity matching among the four major heat and mass transfer components, i.e. dehumidifier, regenerator, evaporator and condenser, is essentially important for energy efficiency of the hybrid system. In this paper, the configuration of the hybrid system is firstly studied. Novel matching indices are proposed to evaluate the matching effect. The results show that a LDHP hybrid system with double-condenser, one solution-cooled and one air-cooled, is a feasible configuration for achieving capacity matching. To achieve dynamic capacity matching under real changing operating conditions, the effects of three critical operating variables, including solution flow rate, revolution of the compressor and air flow rate in the air-cooled condenser, on capacity matching and energy performance are studied. Simulation results show that dynamic capacity matching can only be achieved by regulating these three operating variables simultaneously. ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700711001939 [article] Investigation on capacity matching in liquid desiccant and heat pump hybrid air-conditioning systems = Etude sur l’adaptation de la puissance des systèmes de conditionnement d’air hybrides à déshydratant liquide et à pompe à chaleur [texte imprimé] / Xiaofeng Niu, Auteur ; Fu Xiao, Auteur ; Zhenjun Ma, Auteur . - 2012 . - pp. 160–170. Génie mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 35 N° 1 (Janvier 2012) . - pp. 160–170 Mots-clés : Desiccant  system  Heat  pump  Compression  system  Heat  balance  Simulation Résumé : Liquid desiccant and heat pump (LDHP) hybrid air-conditioning system provides a promising independent air dehumidification solution. Capacity matching among the four major heat and mass transfer components, i.e. dehumidifier, regenerator, evaporator and condenser, is essentially important for energy efficiency of the hybrid system. In this paper, the configuration of the hybrid system is firstly studied. Novel matching indices are proposed to evaluate the matching effect. The results show that a LDHP hybrid system with double-condenser, one solution-cooled and one air-cooled, is a feasible configuration for achieving capacity matching. To achieve dynamic capacity matching under real changing operating conditions, the effects of three critical operating variables, including solution flow rate, revolution of the compressor and air flow rate in the air-cooled condenser, on capacity matching and energy performance are studied. Simulation results show that dynamic capacity matching can only be achieved by regulating these three operating variables simultaneously. ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700711001939