Documents disponibles écrits par cet auteur

Condensation heat transfer coefficients of R1234yf on plain, low fin, and Turbo-C tubes / Ki-Jung Park 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. 317-321 Titre : Condensation heat transfer coefficients of R1234yf on plain, low fin, and Turbo-C tubes Titre original : Coefficients de transfert de chaleur lors de la condensation du R1234yf sur les tubes lisses, aux ailettes basses et de type “Turbo C” Type de document : texte imprimé Auteurs : Ki-Jung Park, Auteur ; Dong Gyu Kang, Auteur ; Dongsoo Jung, Auteur Année de publication : 2011 Article en page(s) : pp. 317-321 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Heat  exchanger  Condenser  R1234yf  R134a  Measurement  Heat  transfer  coefficient  Plain  tube  Finned  tube  Air  conditioning  Automobile Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : In this study, external condensation heat transfer coefficients (HTCs) of HFC134a and R1234yf are measured on a plain, low fin, and Turbo-C tubes at the saturated vapor temperature of 39 °C with the wall subcooling of 3–8 °C. R1234yf is a new alternative refrigerant of low greenhouse warming potential for replacing HFC134a, one of the greenhouse gases in Kyoto protocol, used extensively in automobile air conditioners and other refrigeration systems. Test results show that the condensation HTCs of R1234yf are very similar to those of HFC134a for all three surfaces tested. For the development of heat transfer correlations, thorough property measurements are needed for R1234yf in the near future. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710001295 [article] Condensation heat transfer coefficients of R1234yf on plain, low fin, and Turbo-C tubes = Coefficients de transfert de chaleur lors de la condensation du R1234yf sur les tubes lisses, aux ailettes basses et de type “Turbo C” [texte imprimé] / Ki-Jung Park, Auteur ; Dong Gyu Kang, Auteur ; Dongsoo Jung, Auteur . - 2011 . - pp. 317-321. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 34 N° 1 (Janvier 2011) . - pp. 317-321 Mots-clés : Heat  exchanger  Condenser  R1234yf  R134a  Measurement  Heat  transfer  coefficient  Plain  tube  Finned  tube  Air  conditioning  Automobile Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : In this study, external condensation heat transfer coefficients (HTCs) of HFC134a and R1234yf are measured on a plain, low fin, and Turbo-C tubes at the saturated vapor temperature of 39 °C with the wall subcooling of 3–8 °C. R1234yf is a new alternative refrigerant of low greenhouse warming potential for replacing HFC134a, one of the greenhouse gases in Kyoto protocol, used extensively in automobile air conditioners and other refrigeration systems. Test results show that the condensation HTCs of R1234yf are very similar to those of HFC134a for all three surfaces tested. For the development of heat transfer correlations, thorough property measurements are needed for R1234yf in the near future. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710001295

Nucleate boiling heat transfer coefficients of HFO1234yf on various enhanced surfaces / Yohan, Lee in International journal of refrigeration, Vol. 38 (Février 2014) 

Public ISBD [article]  in International journal of refrigeration > Vol. 38 (Février 2014) . - pp. 198–205 Titre : Nucleate boiling heat transfer coefficients of HFO1234yf on various enhanced surfaces Titre original : Coefficients de transfert de chaleur d'ébullition nucléée d'HFO1234yf sur diverses surfaces augmentées Type de document : texte imprimé Auteurs : Yohan, Lee, Auteur ; Dong Gyu Kang, Auteur ; Joo-Hyung Kim, Auteur Année de publication : 2014 Article en page(s) : pp. 198–205 Note générale : Refrigeration Langues : Anglais (eng) Mots-clés : Nucleate  boiling;  Heat  transfer  coefficient;  Alternative  refrigerant;  Enhanced  surfaces;  Evaporators;  HFO1234yf Résumé : In this study, nucleate boiling heat transfer coefficients (HTCs) of HFO1234yf HFC134a are measured on a flat plain, Turbo-B, Turbo-C, and Thermoexcel-E surfaces. All data are taken at the liquid pool temperature of 7 °C on small flat horizontal square copper plates (9.53 mm × 9.53 mm) at heat fluxes from 10 kW m−2 to 200 kW m−2 with an interval of 10 kW m−2. Test results show that nucleate boiling HTCs of HFO1234yf on all four surfaces are similar to those of HFC134a at all heat fluxes tested in this study. At heat fluxes below 150 kW m−2, Thermoexcel-E surface shows the highest heat transfer performance and hence is the best surface for the manufacture of the evaporators in refrigeration and air-conditioning equipment. On the other hand, at high heat fluxes above 150 kW m−2, Turbo-B and Turbo-C show better heat transfer performance than Thermoexcel-E and hence are good for electronic cooling applications. Overall, HFO1234yf is a good long term candidate with excellent environmental properties to replace successfully HFC134a from the view point of pool boiling heat transfer. Hence HFO1234yf can be readily applied to the conventional evaporators designed for HFC134a. En ligne : http://www.sciencedirect.com/science/article/pii/S014070071300248X [article] Nucleate boiling heat transfer coefficients of HFO1234yf on various enhanced surfaces = Coefficients de transfert de chaleur d'ébullition nucléée d'HFO1234yf sur diverses surfaces augmentées [texte imprimé] / Yohan, Lee, Auteur ; Dong Gyu Kang, Auteur ; Joo-Hyung Kim, Auteur . - 2014 . - pp. 198–205. Refrigeration Langues : Anglais (eng) in International journal of refrigeration > Vol. 38 (Février 2014) . - pp. 198–205 Mots-clés : Nucleate  boiling;  Heat  transfer  coefficient;  Alternative  refrigerant;  Enhanced  surfaces;  Evaporators;  HFO1234yf Résumé : In this study, nucleate boiling heat transfer coefficients (HTCs) of HFO1234yf HFC134a are measured on a flat plain, Turbo-B, Turbo-C, and Thermoexcel-E surfaces. All data are taken at the liquid pool temperature of 7 °C on small flat horizontal square copper plates (9.53 mm × 9.53 mm) at heat fluxes from 10 kW m−2 to 200 kW m−2 with an interval of 10 kW m−2. Test results show that nucleate boiling HTCs of HFO1234yf on all four surfaces are similar to those of HFC134a at all heat fluxes tested in this study. At heat fluxes below 150 kW m−2, Thermoexcel-E surface shows the highest heat transfer performance and hence is the best surface for the manufacture of the evaporators in refrigeration and air-conditioning equipment. On the other hand, at high heat fluxes above 150 kW m−2, Turbo-B and Turbo-C show better heat transfer performance than Thermoexcel-E and hence are good for electronic cooling applications. Overall, HFO1234yf is a good long term candidate with excellent environmental properties to replace successfully HFC134a from the view point of pool boiling heat transfer. Hence HFO1234yf can be readily applied to the conventional evaporators designed for HFC134a. En ligne : http://www.sciencedirect.com/science/article/pii/S014070071300248X

Performance of virtually non-flammable azeotropic HFO1234yf/HFC134a mixture for HFC134a applications / Yohan, Lee in International journal of refrigeration, Vol. 36 N° 4 (Juin 2013) 

Public ISBD [article]  in International journal of refrigeration > Vol. 36 N° 4 (Juin 2013) . - pp. 1203–1207 Titre : Performance of virtually non-flammable azeotropic HFO1234yf/HFC134a mixture for HFC134a applications Titre original : Performance du mélange azéotropique non inflammable HFO1234yf/HFC134a pour les applications du HFC134a Type de document : texte imprimé Auteurs : Yohan, Lee, Auteur ; Dong Gyu Kang, Auteur ; Dongsoo Jung, Auteur Année de publication : 2013 Article en page(s) : pp. 1203–1207 Note générale : Refrigeration Langues : Anglais (eng) Mots-clés : Alternative  refrigerant;  HFO1234yf;  HFC134a;  HFO1234yf/HFC134a  mixture;  Mobile  air-conditioner Résumé : In this study, ‘drop-in’ performance of HFC134a, HFO1234yf and HFO1234yf/HFC134a mixture at three compositions of 5%, 10%, and 15% HFC134a is measured in a heat pump bench tester under summer and winter conditions. Test results show that the COP, capacity, discharge temperature of HFO1234yf and HFO1234yf/HFC134a mixture are similar to those of HFC134a. For HFO1234yf/HFC134a mixture, flammability decreases as more HFC134a is added and at compositions of more than 10% of HFC134a, the mixture becomes non-flammable. The amount of charge for HFO1234yf and HFO1234yf/HFC134a mixture is up to 11% lower than that of HFC134a. Since HFO1234yf/HFC134a mixture with 10–11% HFC134a is virtually non-flammable and azeotropic and has no ODP and GWP of less than 150 meeting the requirement of European mobile air-conditioner directive, it can be used as an environmentally friendly solution for various HFC134a applications including mobile air-conditioners with minor modifications. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713000388 [article] Performance of virtually non-flammable azeotropic HFO1234yf/HFC134a mixture for HFC134a applications = Performance du mélange azéotropique non inflammable HFO1234yf/HFC134a pour les applications du HFC134a [texte imprimé] / Yohan, Lee, Auteur ; Dong Gyu Kang, Auteur ; Dongsoo Jung, Auteur . - 2013 . - pp. 1203–1207. Refrigeration Langues : Anglais (eng) in International journal of refrigeration > Vol. 36 N° 4 (Juin 2013) . - pp. 1203–1207 Mots-clés : Alternative  refrigerant;  HFO1234yf;  HFC134a;  HFO1234yf/HFC134a  mixture;  Mobile  air-conditioner Résumé : In this study, ‘drop-in’ performance of HFC134a, HFO1234yf and HFO1234yf/HFC134a mixture at three compositions of 5%, 10%, and 15% HFC134a is measured in a heat pump bench tester under summer and winter conditions. Test results show that the COP, capacity, discharge temperature of HFO1234yf and HFO1234yf/HFC134a mixture are similar to those of HFC134a. For HFO1234yf/HFC134a mixture, flammability decreases as more HFC134a is added and at compositions of more than 10% of HFC134a, the mixture becomes non-flammable. The amount of charge for HFO1234yf and HFO1234yf/HFC134a mixture is up to 11% lower than that of HFC134a. Since HFO1234yf/HFC134a mixture with 10–11% HFC134a is virtually non-flammable and azeotropic and has no ODP and GWP of less than 150 meeting the requirement of European mobile air-conditioner directive, it can be used as an environmentally friendly solution for various HFC134a applications including mobile air-conditioners with minor modifications. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713000388