Documents disponibles écrits par cet auteur

Experimental study on the improvement of CO2 air conditioning system performance using an ejector / Jae Seung Lee in International journal of refrigeration, Vol. 34 N° 7 (Novembre 2011) 

Public ISBD [article]  in International journal of refrigeration > Vol. 34 N° 7 (Novembre 2011) . - pp. 1614-1625 Titre : Experimental study on the improvement of CO2 air conditioning system performance using an ejector Titre original : Etude expérimentale sur l'amélioration de la performance d'un système de conditionnement d'air au CO2 à l'aide d'un éjecteur Type de document : texte imprimé Auteurs : Jae Seung Lee, Auteur ; Mo Se Kim, Auteur ; Min Soo Kim, Auteur Année de publication : 2011 Article en page(s) : pp. 1614-1625 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Air  conditioning  Carbon  dioxide  Ejector  Performance Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Several preceding researches have evidenced that the transcritical air conditioning system using CO2 as a refrigerant has an inherent inefficiency resulting in degraded steady-state system performance of a CO2 air conditioning system compared with that of a conventional air conditioning system. As a practical improvement, two-phase ejector was considered in place of expansion device in this study. The two-phase ejector for CO2 air conditioning system was designed and developed considering the non-equilibrium state for evaluating the sonic velocity and the critical mass flux. The experiments of performance with respect to variation of ejector geometry such as the motive nozzle throat diameter, mixing section diameter and the distance between motive nozzle and diffuser were carried out. There exist optimum design parameters in each test. Experiments showed that the coefficient of performance of the system using an ejector was about 15% higher than that of the conventional system. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710001714 [article] Experimental study on the improvement of CO2 air conditioning system performance using an ejector = Etude expérimentale sur l'amélioration de la performance d'un système de conditionnement d'air au CO2 à l'aide d'un éjecteur [texte imprimé] / Jae Seung Lee, Auteur ; Mo Se Kim, Auteur ; Min Soo Kim, Auteur . - 2011 . - pp. 1614-1625. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 34 N° 7 (Novembre 2011) . - pp. 1614-1625 Mots-clés : Air  conditioning  Carbon  dioxide  Ejector  Performance Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Several preceding researches have evidenced that the transcritical air conditioning system using CO2 as a refrigerant has an inherent inefficiency resulting in degraded steady-state system performance of a CO2 air conditioning system compared with that of a conventional air conditioning system. As a practical improvement, two-phase ejector was considered in place of expansion device in this study. The two-phase ejector for CO2 air conditioning system was designed and developed considering the non-equilibrium state for evaluating the sonic velocity and the critical mass flux. The experiments of performance with respect to variation of ejector geometry such as the motive nozzle throat diameter, mixing section diameter and the distance between motive nozzle and diffuser were carried out. There exist optimum design parameters in each test. Experiments showed that the coefficient of performance of the system using an ejector was about 15% higher than that of the conventional system. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710001714

Studies on the performance of a CO2 air conditioning system using an ejector as an expansion device / Jae Seung Lee in International journal of refrigeration, Vol. 38 (Février 2014) 

Public ISBD [article]  in International journal of refrigeration > Vol. 38 (Février 2014) . - pp. 140–152 Titre : Studies on the performance of a CO2 air conditioning system using an ejector as an expansion device Titre original : Etudes de la performance d'un système de conditionnement d'air au CO2 utilisant un éjecteur comme détendeur Type de document : texte imprimé Auteurs : Jae Seung Lee, Auteur ; Mo Se Kim, Auteur ; Min Soo Kim, Auteur Année de publication : 2014 Article en page(s) : pp. 140–152 Note générale : Refrigeration Langues : Anglais (eng) Mots-clés : Carbon  dioxide;  Performance;  Ejector;  Air  conditioning Résumé : Environmental issues such as stratospheric ozone depletion and global warming have been the primary motivations for recent research in the air-conditioning and refrigeration fields. The CO2 air-conditioning system forms a transcritical cycle which shows slightly degraded performance compared to the conventional system. To overcome this disadvantage, a cycle adopting an ejector is suggested. Experimental results of a CO2 air-conditioning system using an ejector were compared for various outdoor temperatures and inverter frequencies. The COPs of an air-conditioning system using an ejector and conventional system were calculated and compared based on the pressures and temperatures of experiments. The cooling capacity and COP in the air-conditioning system using an ejector are higher than those in the conventional system at an entrainment ratio greater than 0.76. In addition, better performance is shown at entrainment ratio greater than a certain value in other test conditions. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713002272 [article] Studies on the performance of a CO2 air conditioning system using an ejector as an expansion device = Etudes de la performance d'un système de conditionnement d'air au CO2 utilisant un éjecteur comme détendeur [texte imprimé] / Jae Seung Lee, Auteur ; Mo Se Kim, Auteur ; Min Soo Kim, Auteur . - 2014 . - pp. 140–152. Refrigeration Langues : Anglais (eng) in International journal of refrigeration > Vol. 38 (Février 2014) . - pp. 140–152 Mots-clés : Carbon  dioxide;  Performance;  Ejector;  Air  conditioning Résumé : Environmental issues such as stratospheric ozone depletion and global warming have been the primary motivations for recent research in the air-conditioning and refrigeration fields. The CO2 air-conditioning system forms a transcritical cycle which shows slightly degraded performance compared to the conventional system. To overcome this disadvantage, a cycle adopting an ejector is suggested. Experimental results of a CO2 air-conditioning system using an ejector were compared for various outdoor temperatures and inverter frequencies. The COPs of an air-conditioning system using an ejector and conventional system were calculated and compared based on the pressures and temperatures of experiments. The cooling capacity and COP in the air-conditioning system using an ejector are higher than those in the conventional system at an entrainment ratio greater than 0.76. In addition, better performance is shown at entrainment ratio greater than a certain value in other test conditions. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713002272