Document IIF

Conception d'une tuyère et théories empiriques applicables aux chutes de pression dues au frottement pour l'écoulement supersonique diphasique du CO2.

Nozzle design and applicable empirical theories of frictional pressure drop for supersonic two-phase flow of CO2.

Auteurs : NAKAGAWA M., BERANA M.

Résumé

CO2 is a promising natural replacement of ozone-depleting, global-warming and hazardous refrigerants. Using it in the ejector-refrigeration cycle gives a higher coefficient of performance than in the vapour compression cycle. An efficient nozzle leads to a high ejector pressure recovery. Energy-conversion efficiencies of rectangular converging-diverging ejector nozzles were calculated from measured pressure profiles. The momentum-conservation equation containing empirical theories for frictional pressure drop of two-phase flow were used. Homogeneous Model, Chrisholm-Sutherland and Martinelli-Nelson were the theories tested. This paper presents the applicable empirical theories and the dependence of efficiency and optimal divergence angle to pressure difference between the inlet and the outlet. Four nozzles with different divergence angle were tested in a blowdown apparatus. Homogeneous Model and Chrisholm-Sutherland were applicable. Each efficiency curve showed a maximum value at an optimum pressure difference. There was an optimum divergence angle for each pressure difference. The optimum divergence angle increased with pressure difference.

Documents disponibles

Format PDF

Pages : 2008-2

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 : Nozzle design and applicable empirical theories of frictional pressure drop for supersonic two-phase flow of CO2.
  • Identifiant de la fiche : 2009-0608
  • Langues : Anglais
  • Source : 8th IIR-Gustav Lorentzen Conference on Natural Working Fluids (GL2008)
  • Date d'édition : 07/09/2008

Liens


Voir d'autres communications du même compte rendu (132)
Voir le compte rendu de la conférence