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Experimental investigation of the surface temperature and water retention effects on the frosting performance of a compact microchannel heat exchanger for heat pump systems / Ehsan Moallem 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. 171–186 Titre : Experimental investigation of the surface temperature and water retention effects on the frosting performance of a compact microchannel heat exchanger for heat pump systems Titre original : Etude expérimentale sur les effets de la température superficielle et de la rétention d'eau sur le givrage d'un échangeur de chaleur compact à microcanaux pour les systémes à pompe à chaleur Type de document : texte imprimé Auteurs : Ehsan Moallem, Auteur ; Sankar Padhmanabhan, Auteur ; Lorenzo Cremaschi, Auteur Année de publication : 2012 Article en page(s) : pp. 171–186 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Frost  Microchannel  Surface  temperature  Pressure  drop  Heat  pump  Capacity  reduction Résumé : Frost formation on a louvered fin microchannel heat exchanger was experimentally investigated in this paper with the aim of determining the dominant factors affecting the time of frosting and frost growth rate. A novel methodology was developed to measure frost thickness and frost weight at intervals during the frosting period. Frost mass and thickness growth rates, corresponding coil heat transfer, capacity degradations and air pressure drop are measured and discussed. The experimental data showed that at a given air dry bulb temperature, the fin surface temperature and air humidity are the primary parameters that influence the frost growth rates. Water retention and air velocity had a secondary impact on the frosting performance. From digital images of the frost growth it was observed that frost does not nucleate from the water droplets retained in between fins but it developed from the leading edges of the fins. ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S014070071100212X [article] Experimental investigation of the surface temperature and water retention effects on the frosting performance of a compact microchannel heat exchanger for heat pump systems = Etude expérimentale sur les effets de la température superficielle et de la rétention d'eau sur le givrage d'un échangeur de chaleur compact à microcanaux pour les systémes à pompe à chaleur [texte imprimé] / Ehsan Moallem, Auteur ; Sankar Padhmanabhan, Auteur ; Lorenzo Cremaschi, Auteur . - 2012 . - pp. 171–186. Génie mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 35 N° 1 (Janvier 2012) . - pp. 171–186 Mots-clés : Frost  Microchannel  Surface  temperature  Pressure  drop  Heat  pump  Capacity  reduction Résumé : Frost formation on a louvered fin microchannel heat exchanger was experimentally investigated in this paper with the aim of determining the dominant factors affecting the time of frosting and frost growth rate. A novel methodology was developed to measure frost thickness and frost weight at intervals during the frosting period. Frost mass and thickness growth rates, corresponding coil heat transfer, capacity degradations and air pressure drop are measured and discussed. The experimental data showed that at a given air dry bulb temperature, the fin surface temperature and air humidity are the primary parameters that influence the frost growth rates. Water retention and air velocity had a secondary impact on the frosting performance. From digital images of the frost growth it was observed that frost does not nucleate from the water droplets retained in between fins but it developed from the leading edges of the fins. ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S014070071100212X