Document IIF

Évaluation numérique des mélanges à base de CO2 pour les systèmes frigorifiques en mettant l’accent sur le processus d’évaporation.

Numerical assessment of CO2-based mixtures for refrigeration systems: focus on the evaporation process.

Résumé

A large number of refrigeration systems operate on a stream that is not changing phase, i.e. has a finite heat capacity. The matching between the cooled stream and the evaporation of a pure refrigerant causes therefore significant irreversibility in the heat exchange. The use of mixtures is a well-known option for the mitigation of this problem. In this work, the use of a CO2-based mixture is proposed to allow the possibility of matching variable-temperature heat sources with the glide of the working fluid in the evaporator to minimize the heat exchange irreversibility. Modelling of a mini-channel evaporator by means of numerical techniques, accounting for the variable fluid composition, is presented. Several flow boiling correlations are assessed for pure CO2 (170<G<900) and CO2-propane blends (200<G<650). An optimized correlation for CO2-propane is proposed. As a final result, a high fidelity CO2 correlation for flow boiling is presented, which is also able to predict quite accurately the CO2-propane mixture heat transfer coefficient.

Documents disponibles

Format PDF

Pages : 12 p.

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 : Numerical assessment of CO2-based mixtures for refrigeration systems: focus on the evaporation process.
  • Identifiant de la fiche : 30031631
  • Langues : Anglais
  • Sujet : Technologie
  • Source : Proceedings of the 26th IIR International Congress of Refrigeration: Paris , France, August 21-25, 2023.
  • Date d'édition : 21/08/2023
  • DOI : http://dx.doi.org/10.18462/iir.icr.2023.0544

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