Partager

Document IIF

Etudes expérimentales sur le transfert de chaleur lors de l'évaporation et la chute de pression du CO2 dans les tubes lisses et à micro-ailettes d'un diamètre de 5 ou 9,52 mm.

Experimental studies on the evaporative heat transfer and pressure drop of CO2 in smooth and micro-fin tubes of the diameters of 5 and 9.52 mm.

Auteurs : CHO J. M., KIM M. S.

Type d'article : Article, Article de la RIF

Résumé

Carbon dioxide among natural refrigerants has gained a considerable attention as an alternative refrigerant due to its excellent thermophysical properties. In-tube evaporation heat transfer characteristics of carbon dioxide were experimentally investigated and analyzed as a function of evaporating temperature, mass flux, heat flux and tube geometry. Heat transfer coefficient data during evaporation process of carbon dioxide were measured for 5 m long smooth and micro-fin tubes with outer diameters of 5 and 9.52 mm. The tests were conducted at mass fluxes of from 212 to 656 kg/m2.s, saturation temperatures of from 0 to 20°C and heat fluxes of from 6 to 20 kW/m2. The difference of heat transfer characteristics between smooth and micro-fin tubes and the effect of mass flux, heat flux, and evaporation temperature on enhancement factor and penalty factor were presented. Average evaporation heat transfer coefficients for a micro-fin tube were approximately 150-200% for 9.52 mm OD tube and 170-210% for 5 mm OD tube higher than those for the smooth tube at the same test conditions. The effect of pressure drop expressed by measured penalty factor of 1.2-1.35 was smaller than that of heat transfer enhancement.

Documents disponibles

Format PDF

Pages : 986-994

Disponible

  • Prix public

    20 €

  • Prix membre*

    Gratuit

* meilleur tarif applicable selon le type d'adhésion (voir le détail des avantages des adhésions individuelles et collectives)

Détails

  • Titre original : Experimental studies on the evaporative heat transfer and pressure drop of CO2 in smooth and micro-fin tubes of the diameters of 5 and 9.52 mm.
  • Identifiant de la fiche : 2007-2516
  • Langues : Anglais
  • Source : International Journal of Refrigeration - Revue Internationale du Froid - vol. 30 - n. 6
  • Date d'édition : 09/2007

Liens


Voir d'autres articles du même numéro (16)
Voir la source

Indexation