Amélioration du transfert de chaleur lors de la condensation en utilisant l'écoulement du condensat électrohydrodynamique.

Enhancement of condensation heat transfer by means of EHD condensate drainage.

Résumé

The problem of electrohydrodynamic (EHD) condensation enhancement was studied very recently. The electric field is commonly generated in such case by means of rod and mesh electrodes. The EHD method is suitable for dielectric media used in refrigeration and heat-pump devices. A strong positive EHD effect has been obtained so far for vertical and horizontal bare tubes. However, it was found that this effect for horizontal integral-fin tubes, commonly used in heat exchangers, is negligible. The mechanism of the EHD condensation enhancement is discussed in this article and a novel arrangement of the tube-electrode system is proposed. It consists of a horizontal finned tube with a rod type electrode placed beneath the tube. The experimental investigations were carried out for this tube-electrode arrangement using HCFC-123 as a working medium. The results obtained confirmed expectations since the application of the EHD method for the new tube-electrode configuration increased the heat transfer coefficient from 27 to 110%, depending on the electrode potential. A simple model of the EHD condensate drainage has been proposed for the new tube-electrode arrangement.

Détails

  • Titre original : Enhancement of condensation heat transfer by means of EHD condensate drainage.
  • Identifiant de la fiche : 2004-2730
  • Langues : Anglais
  • Date d'édition : 07/2002
  • Source : Source : Int. J. therm. Sci./Proc. ExHFT-5, Thessaloniki
    vol. 41; n. 7; 646-657; fig.; tabl.; 19 ref.