Transfert de chaleur lors de la condensation et caractéristiques d'écoulement du R134a en écoulement à l'intérieur de tubes ondulés.

Condensation heat transfer and flow characteristics of R134a flowing through corrugated tubes.

Auteurs : LAOHALERTDECHA S., WONGWISES S.

Type d'article : Article

Résumé

This article presents the condensation heat transfer and flow characteristics of R134a flowing through corrugated tubes experimentally. The test section is a horizontal counter-flow concentric tube-in-tube heat exchanger 2000 mm in length. A smooth copper tube and corrugated copper tubes having inner diameters of 8.7 mm are used as an inner tube. The outer tube is made from smooth copper tube having an inner diameter of 21.2 mm. The corrugation pitches used in this study are 5.08, 6.35, and 8.46 mm. Similarly, the corrugation depths are 1, 1.25, and 1.5 mm, respectively. The test conditions are performed at saturation temperatures of 40–50°C, heat fluxes of 5–10 kW/m2, mass fluxes of 200–700 kg/m2.s, and equivalent Reynolds numbers of 30000–120000. The Nusselt number and two-phase friction factor obtained from the corrugated tubes are significantly higher than those obtained from the smooth tube. Finally, new correlations are developed based on the present experimental data for predicting the Nusselt number and two-phase friction factor for corrugated tubes. [Reprinted with permission from Elsevier. Copyright, 2011.]

Détails

  • Titre original : Condensation heat transfer and flow characteristics of R134a flowing through corrugated tubes.
  • Identifiant de la fiche : 30001829
  • Langues : Anglais
  • Source : International Journal of Heat and Mass Transfer - vol. 54 - n. 11-12
  • Date d'édition : 05/2011
  • DOI : http://dx.doi.org/10.1016/j.ijheatmasstransfer.2010.12.034

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