Documents disponibles écrits par cet auteur

Effect of inlet configuration on the refrigerant distribution in a parallel flow minichannel heat exchanger / Nae-Hyun Kim in International journal of refrigeration, Vol. 34 N° 5 (Août 2011) 

Public ISBD [article]  in International journal of refrigeration > Vol. 34 N° 5 (Août 2011) . - pp. 1209-1221 Titre : Effect of inlet configuration on the refrigerant distribution in a parallel flow minichannel heat exchanger Titre original : Impact de la configuration de l'entrée sur la distribution du frigorigéne en écoulement paralléle dans un échangeur de chaleur á microcanaux Type de document : texte imprimé Auteurs : Nae-Hyun Kim, Auteur ; Do-Young Kim, Auteur ; Ho-Won Byun, Auteur Année de publication : 2011 Article en page(s) : pp. 1209-1221 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Heat  exchanger  Micro-channel  Experimentr  Distribution  Refrigerant  Piping-flow Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The refrigerant R-134a flow distribution was experimentally studied for a round header/ten flat tube test section simulating a brazed aluminum heat exchanger. Three different inlet configurations (parallel, normal, vertical) were investigated. Tests were conducted with downward flow for mass flux from 70 to 130 kg m−2 s−1 and quality from 0.2 to 0.6. Tubes were flush-mounted in the test section, with no protrusion into the header. It is shown that normal and vertical inlet yielded similar flow distribution. As mass flux or quality increased, however, better results were obtained for normal inlet configuration. The flow distribution was worst for the parallel inlet configuration. Possible explanation is provided based on flow visualization results. Correlations were developed to predict the fraction of liquid or gas taken off by downstream channel as a function of header gas Reynolds number at immediate upstream. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710001179 [article] Effect of inlet configuration on the refrigerant distribution in a parallel flow minichannel heat exchanger = Impact de la configuration de l'entrée sur la distribution du frigorigéne en écoulement paralléle dans un échangeur de chaleur á microcanaux [texte imprimé] / Nae-Hyun Kim, Auteur ; Do-Young Kim, Auteur ; Ho-Won Byun, Auteur . - 2011 . - pp. 1209-1221. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 34 N° 5 (Août 2011) . - pp. 1209-1221 Mots-clés : Heat  exchanger  Micro-channel  Experimentr  Distribution  Refrigerant  Piping-flow Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The refrigerant R-134a flow distribution was experimentally studied for a round header/ten flat tube test section simulating a brazed aluminum heat exchanger. Three different inlet configurations (parallel, normal, vertical) were investigated. Tests were conducted with downward flow for mass flux from 70 to 130 kg m−2 s−1 and quality from 0.2 to 0.6. Tubes were flush-mounted in the test section, with no protrusion into the header. It is shown that normal and vertical inlet yielded similar flow distribution. As mass flux or quality increased, however, better results were obtained for normal inlet configuration. The flow distribution was worst for the parallel inlet configuration. Possible explanation is provided based on flow visualization results. Correlations were developed to predict the fraction of liquid or gas taken off by downstream channel as a function of header gas Reynolds number at immediate upstream. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710001179

Effect of inlet configuration on upward branching of two-phase refrigerant in a parallel flow heat exchanger / Nae-Hyun Kim in International journal of refrigeration, Vol. 36 N° 3 (Mai 2013) 

Public ISBD [article]  in International journal of refrigeration > Vol. 36 N° 3 (Mai 2013) . - pp. 1062–1077 Titre : Effect of inlet configuration on upward branching of two-phase refrigerant in a parallel flow heat exchanger Titre original : Effet de la configuration sur les branchements ascendants d'un frigorigène diphasique dans un échangeur de chaleur à écoulement parallèle Type de document : texte imprimé Auteurs : Nae-Hyun Kim, Auteur ; Ho-Won Byun, Auteur Année de publication : 2013 Article en page(s) : pp. 1062–1077 Note générale : Refrigeration Langues : Anglais (eng) Mots-clés : Flow  distribution;  Heat  exchanger;  Inlet  configuration Résumé : The refrigerant R-134a flow distributions were experimentally studied for a round header-10 flat tube test section simulating a brazed aluminum heat exchanger. Three different inlet orientations (parallel, normal, vertical) were investigated. Tests were conducted with upward flow for the mass flux from 70 to 130 kg m−2 s−1 and quality from 0.2 to 0.6. Tubes were flush-mounted in the header with no protrusion. Both for liquid and gas, the best flow distribution was obtained from vertical inlet configuration. Between other two inlet configurations, parallel inlet was better for liquid distribution, and normal inlet was better for gas distribution. In general, the effect of mass flux or quality on flow distribution was not significant. Correlations were developed to predict the fraction of liquid or gas taken off by downstream channel as a function of header liquid Reynolds number at immediate upstream. Header pressure drop was obtained by subtracting appropriate pressure drops from the measured pressure drop. The header pressure drops were mostly negative, which implied that the pressure was recovered in the header. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700712003428 [article] Effect of inlet configuration on upward branching of two-phase refrigerant in a parallel flow heat exchanger = Effet de la configuration sur les branchements ascendants d'un frigorigène diphasique dans un échangeur de chaleur à écoulement parallèle [texte imprimé] / Nae-Hyun Kim, Auteur ; Ho-Won Byun, Auteur . - 2013 . - pp. 1062–1077. Refrigeration Langues : Anglais (eng) in International journal of refrigeration > Vol. 36 N° 3 (Mai 2013) . - pp. 1062–1077 Mots-clés : Flow  distribution;  Heat  exchanger;  Inlet  configuration Résumé : The refrigerant R-134a flow distributions were experimentally studied for a round header-10 flat tube test section simulating a brazed aluminum heat exchanger. Three different inlet orientations (parallel, normal, vertical) were investigated. Tests were conducted with upward flow for the mass flux from 70 to 130 kg m−2 s−1 and quality from 0.2 to 0.6. Tubes were flush-mounted in the header with no protrusion. Both for liquid and gas, the best flow distribution was obtained from vertical inlet configuration. Between other two inlet configurations, parallel inlet was better for liquid distribution, and normal inlet was better for gas distribution. In general, the effect of mass flux or quality on flow distribution was not significant. Correlations were developed to predict the fraction of liquid or gas taken off by downstream channel as a function of header liquid Reynolds number at immediate upstream. Header pressure drop was obtained by subtracting appropriate pressure drops from the measured pressure drop. The header pressure drops were mostly negative, which implied that the pressure was recovered in the header. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700712003428

Evaporation heat transfer and pressure drop of R-410A in flattened smooth tubes having different aspect ratios / Nae-Hyun Kim in International journal of refrigeration, Vol. 36 N° 2 (N° spécial) (Mars 2013) 

Public ISBD [article]  in International journal of refrigeration > Vol. 36 N° 2 (N° spécial) (Mars 2013) . - pp. 363–374 Titre : Evaporation heat transfer and pressure drop of R-410A in flattened smooth tubes having different aspect ratios Titre original : Transfert de chaleur et chute de pression lors de l'évaporation du R-410A à l'intérieur de tubes lisses aplatis avec différents rapports longueur-diamètre Type de document : texte imprimé Auteurs : Nae-Hyun Kim, Auteur ; Eul-Jong Lee, Auteur ; Ho-Won Byun, Auteur Année de publication : 2013 Article en page(s) : pp. 363–374 Note générale : Refrigeration Langues : Anglais (eng) Mots-clés : Evaporation;  Heat  transfer  coefficient;  Pressure  drop;  Tube;  R-410A Résumé : In this study, evaporation heat transfer coefficients and pressure drops of R-410A were obtained in flat tubes. Flat tubes were made by progressively deforming 5.0 mm I.D. round tube. The test range covered mass flux 200–400 kg m−2 s−1, heat flux from 5 to 15 kW m−2 and saturation temperature from 10 to 15 °C. Results show that both evaporation heat transfer coefficients and pressure drops increased as aspect ratio increased, and were reasonably predicted by appropriate round tube correlations. It is shown that usage of equivalent diameter than hydraulic diameter yields better prediction of heat transfer coefficient. For pressure drop, however, the success is dependent on the correlation. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700712002472 [article] Evaporation heat transfer and pressure drop of R-410A in flattened smooth tubes having different aspect ratios = Transfert de chaleur et chute de pression lors de l'évaporation du R-410A à l'intérieur de tubes lisses aplatis avec différents rapports longueur-diamètre [texte imprimé] / Nae-Hyun Kim, Auteur ; Eul-Jong Lee, Auteur ; Ho-Won Byun, Auteur . - 2013 . - pp. 363–374. Refrigeration Langues : Anglais (eng) in International journal of refrigeration > Vol. 36 N° 2 (N° spécial) (Mars 2013) . - pp. 363–374 Mots-clés : Evaporation;  Heat  transfer  coefficient;  Pressure  drop;  Tube;  R-410A Résumé : In this study, evaporation heat transfer coefficients and pressure drops of R-410A were obtained in flat tubes. Flat tubes were made by progressively deforming 5.0 mm I.D. round tube. The test range covered mass flux 200–400 kg m−2 s−1, heat flux from 5 to 15 kW m−2 and saturation temperature from 10 to 15 °C. Results show that both evaporation heat transfer coefficients and pressure drops increased as aspect ratio increased, and were reasonably predicted by appropriate round tube correlations. It is shown that usage of equivalent diameter than hydraulic diameter yields better prediction of heat transfer coefficient. For pressure drop, however, the success is dependent on the correlation. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700712002472