Documents disponibles écrits par cet auteur

Comparison of the heating performance of air-source heat pumps using various types of refrigerant injection / Jaehyeok Heo in International journal of refrigeration, Vol. 34 N° 2 (Mars 2011) 

Public ISBD [article]  in International journal of refrigeration > Vol. 34 N° 2 (Mars 2011) . - pp. 444-453 Titre : Comparison of the heating performance of air-source heat pumps using various types of refrigerant injection Titre original : Comparaison de la performance en mode chauffage des pompes à chaleur air-eau utilisant diffàrents types d'injection de frigorigàne Type de document : texte imprimé Auteurs : Jaehyeok Heo, Auteur ; Min Woo Jeong, Auteur ; Changhyun Baek, Auteur Année de publication : 2011 Article en page(s) : pp. 444-453 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Heat  pump  Two-stage  System  injection  Performance-heating Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The performance degradation of air-source heat pumps cannot be avoided when they operate at both very low and high ambient temperatures. The refrigerant injection technique has rapidly developed in recent years due to its outstanding performance at low ambient temperatures. This study measured the heating performance of air-source heat pumps in which novel vapor injection techniques of a combined flash tank and sub-cooler (FTSC) cycle and a double expansion sub-cooler (DESC) cycle were applied. The performance of these cycles was compared with that of a flash tank (FT) and a sub-cooler (SC) cycle. The average heating capacities of the FT, FTSC, and DESC cycles were higher by 14.4%, 6.0%, and 3.8%, respectively, relative to that of the SC cycle, but the average COPs for the respective cycle options were very similar. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710002318 [article] Comparison of the heating performance of air-source heat pumps using various types of refrigerant injection = Comparaison de la performance en mode chauffage des pompes à chaleur air-eau utilisant diffàrents types d'injection de frigorigàne [texte imprimé] / Jaehyeok Heo, Auteur ; Min Woo Jeong, Auteur ; Changhyun Baek, Auteur . - 2011 . - pp. 444-453. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 34 N° 2 (Mars 2011) . - pp. 444-453 Mots-clés : Heat  pump  Two-stage  System  injection  Performance-heating Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The performance degradation of air-source heat pumps cannot be avoided when they operate at both very low and high ambient temperatures. The refrigerant injection technique has rapidly developed in recent years due to its outstanding performance at low ambient temperatures. This study measured the heating performance of air-source heat pumps in which novel vapor injection techniques of a combined flash tank and sub-cooler (FTSC) cycle and a double expansion sub-cooler (DESC) cycle were applied. The performance of these cycles was compared with that of a flash tank (FT) and a sub-cooler (SC) cycle. The average heating capacities of the FT, FTSC, and DESC cycles were higher by 14.4%, 6.0%, and 3.8%, respectively, relative to that of the SC cycle, but the average COPs for the respective cycle options were very similar. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710002318

Effects of flash tank vapor injection on the heating performance of an inverter-driven heat pump for cold regions / Jaehyeok Heo in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 848-855 Titre : Effects of flash tank vapor injection on the heating performance of an inverter-driven heat pump for cold regions Titre original : Effets de ĺinjection de la vapeur du réservoir intermédiaire sur la performance en application chauffage d'une pompe à chaleur entraînée par convertisseur dans les climats froids Type de document : texte imprimé Auteurs : Jaehyeok Heo, Auteur ; Min Woo Jeong, Auteur ; Yongchan Kim, Auteur Année de publication : 2010 Article en page(s) : pp. 848-855 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Heat  pump  Two-stage  system  Variable  speed  Compressor  Experiment  Injection  Performance  COP Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A heat pump has received much attention as substitute for the conventional boiler or heating coil because of its high efficiency. For the wide application of the heat pump, the most important design factor is the performance degradation upon its installation in tropical and cold regions. In this study, the effects of flash tank vapor injection on the heating performance of a two-stage heat pump with an inverter-driven twin rotary compressor were measured and analyzed for compressor frequency ranging from 50 to 100 Hz at ambient temperatures of −15, −5, and 5 °C. The COP and heating capacity of the injection cycle were enhanced by 10% and 25%, respectively, at the ambient temperature of −15 °C. The total mass flow rate of the injection cycle was 30–38% higher than that of the non-injection cycle. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000022 [article] Effects of flash tank vapor injection on the heating performance of an inverter-driven heat pump for cold regions = Effets de ĺinjection de la vapeur du réservoir intermédiaire sur la performance en application chauffage d'une pompe à chaleur entraînée par convertisseur dans les climats froids [texte imprimé] / Jaehyeok Heo, Auteur ; Min Woo Jeong, Auteur ; Yongchan Kim, Auteur . - 2010 . - pp. 848-855. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 848-855 Mots-clés : Heat  pump  Two-stage  system  Variable  speed  Compressor  Experiment  Injection  Performance  COP Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A heat pump has received much attention as substitute for the conventional boiler or heating coil because of its high efficiency. For the wide application of the heat pump, the most important design factor is the performance degradation upon its installation in tropical and cold regions. In this study, the effects of flash tank vapor injection on the heating performance of a two-stage heat pump with an inverter-driven twin rotary compressor were measured and analyzed for compressor frequency ranging from 50 to 100 Hz at ambient temperatures of −15, −5, and 5 °C. The COP and heating capacity of the injection cycle were enhanced by 10% and 25%, respectively, at the ambient temperature of −15 °C. The total mass flow rate of the injection cycle was 30–38% higher than that of the non-injection cycle. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000022