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Enquête sur la performance des échangeurs de chaleur à tubes simples ou ailetés, et refroidis par évaporation.

Performance investigation of plain and finned tube evaporatively cooled heat exchangers.

Auteurs : HASAN A., SIRÉN K.

Type d'article : Article

Résumé

The performance of two evaporatively cooled heat exchangers is investigated under similar operating conditions in terms of air flow rates and inlet hot water temperatures. The heat exchangers are plain and plate-finned circular tube types which occupy the same volume. Spray water, which is circulated in a closed circuit, is injected onto the exposed surfaces of the tubes and fins. A substantial increase in heat transfer takes place in the case of the plate-finned tubes. The increase is 92-140% for air velocities from 1.66 to 3.57 m s-1. A model is used to calculate the thermal performance assuming a constant spray water temperature. The wet-finned surfaces show low fin efficiency compared with dry surfaces. An energy index defined as the ratio of volumetric thermal conductance to air pressure drop per unit length is found to be close for the two heat exchangers. This reveals higher thermal utilization of the occupied volume by the finned tubes with the same energy index.

Détails

  • Titre original : Performance investigation of plain and finned tube evaporatively cooled heat exchangers.
  • Identifiant de la fiche : 2003-1736
  • Langues : Anglais
  • Source : Applied Thermal Engineering - vol. 23 - n. 3
  • Date d'édition : 02/2003

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