Partager

Document IIF

Bipasse de flash gaz pour améliorer la performance des systèmes transcritiques au R744 munis d'évaporateurs à microcanaux.

Flash gas bypass for improving the performance of transcritical R744 systems that use microchannel evaporators.

Auteurs : ELBEL S., HRNJAK P.

Type d'article : Article, Article de la RIF

Résumé

The performance of transcritical R744 systems with direct expansion (DX) can be significantly improved by implementing a Flash Gas Bypass (FGB). The idea behind the concept is to bypass refrigerant vapour, created during the isenthalpic expansion process, around the evaporator. By feeding the evaporator with liquid refrigerant, pressure drop is reduced and refrigerant distribution is improved. With R744 as the working fluid, increased refrigerant-side heat transfer coefficients are expected as well. In addition, the FGB concept proves to be beneficial in terms of system design, in particular for combined air-conditioning and heat pumping applications. An experimental comparison to a conventional DX-system reveals that FGB increases the cooling capacity and COP at the same time by up to 9 and 7%, respectively. Even larger improvements are possible in case a variable speed compressor is utilized to match the performance of the conventional DX-system. A simulation model helps to separate the individual improvement mechanisms. It was found that the reduction of refrigerant-side pressure drop is the dominant improvement mechanism of FGB.

Documents disponibles

Format PDF

Pages : 724-735

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 : Flash gas bypass for improving the performance of transcritical R744 systems that use microchannel evaporators.
  • Identifiant de la fiche : 2005-0049
  • Langues : Anglais
  • Source : International Journal of Refrigeration - Revue Internationale du Froid - vol. 27 - n. 7
  • Date d'édition : 11/2004

Liens


Voir d'autres articles du même numéro (9)
Voir la source

Indexation