Document IIF

Coefficients de transfert de chaleur lors de l'évaporation de R-417A à l'intérieur de tubes horizontaux lisses et à micro-ailettes.

Evaporation heat transfer coefficients of R-417A in horizontal smooth and microfin tubes.

Résumé

An experimental investigation of evaporation for R-417A in horizontal smooth and microfin tubes has been carried out with evaporation temperature between 0 and 5.5°C, mass flow rates between 176 and 344 kg/m2.s, heat fluxes between 11 and 32 kW/m2, and vapour qualities between 0.2 and 1. The heat transfer characteristics of R-417A were compared with R-22, it indicates that the enhancement is more efficient on pure refrigerants than non-azeotropic refrigerant mixtures using the same enhanced surface. And the heat transfer coefficients of R-417A inside different tubes were compared, the enhancement mechanism of inner grooved tube on evaporation heat transfer were analyzed. Based on the experimental results of R-417A, a new microfin model was suggested. The comparison of calculations with the experimental results indicated that the new model offered a much better agreement with the experimental results with the reducing average deviation by 30-50% than the model by Cavallini.

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Pages : ICR07-B1-228

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Détails

  • Titre original : Evaporation heat transfer coefficients of R-417A in horizontal smooth and microfin tubes.
  • Identifiant de la fiche : 2008-0075
  • Langues : Anglais
  • Source : ICR 2007. Refrigeration Creates the Future. Proceedings of the 22nd IIR International Congress of Refrigeration.
  • Date d'édition : 21/08/2007

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