Partager

Document IIF

Transfert de chaleur par évaporation et caractéristiques de l'écoulement vertical ascendant dans un échangeur de chaleur à plaque à ailettes.

Evaporation heat transfer and flow characteristics of vertical upward flow in a plate-fin heat exchanger.

Auteurs : JIGE D., SUGIHARA K., INOUE N.

Type d'article : Article de la RIF

Résumé

This study experimentally investigated the evaporation heat transfer and two-phase flow characteristics of a vertical upward flow using R1234ze(E) and R32 as test refrigerants in a plate-fin heat exchanger with offset fins. The adiabatic and evaporation flows of R1234ze(E) were visualized using a high-speed camera. Owing to the asymmetry of the inlet and outlet of the channel, a non-uniform velocity profile in the channel-width direction was observed under both adiabatic and evaporation flows. Evaporation flow accompanied by nucleate bubble generation at the lower area of the channel and the occurrence of a dry area at the upper side of the channel were observed. The heat transfer coefficients of R1234ze(E) and R32 were measured, and the effects of mass flux, quality, and heat flux on heat transfer were clarified. The heat transfer was strongly affected by forced convection at higher mass fluxes and quality whereas nucleate boiling dominated at higher heat fluxes and lower quality. The difference in the heat transfer characteristics at local positions in the channel was also investigated by measuring the local wall temperatures. Comparing refrigerants, the heat transfer coefficient of R32 was higher than that of R1234ze(E), regardless of the mass flux and quality, especially at lower mass flux conditions.

Documents disponibles

Format PDF

Pages : 165-171

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 : Evaporation heat transfer and flow characteristics of vertical upward flow in a plate-fin heat exchanger.
  • Identifiant de la fiche : 30029270
  • Langues : Anglais
  • Source : International Journal of Refrigeration - Revue Internationale du Froid - vol. 133
  • Date d'édition : 01/2022
  • DOI : http://dx.doi.org/10.1016/j.ijrefrig.2021.09.030
  • Document disponible en consultation à la bibliothèque du siège de l'IIF uniquement.

Liens


Voir d'autres articles du même numéro (32)
Voir la source

Indexation