Optimisation du cycle de dégivrage pour les évaporateurs tubulaires à ailettes alimentés par ventilateur soumis à des conditions de givrage.

Defrost cycle optimization for fan-supplied tube-fin evaporators subjected to frosting conditions.

Numéro : pap. 2107

Auteurs : DA SILVA D. L., HERMES C. J. L.

Résumé

Frost accretion on a tube-fin evaporator surface raises its thermal and hydraulic resistances, which in turn deteriorates the cooling capacity of the refrigeration system. For this reason, periodic defrost operations are required to recover the initial performance of the system. Most defrost techniques rely on supplying heat to the frost layer. Due to technological and thermodynamic limitations, only part of the heat supply is effectively used to melt the frost built-up on the evaporator, while the rest increases the refrigerator thermal load. Therefore, the amount of heat dissipated, the duration of a defrost operation, and the time between two consecutives defrost operations must be considered for properly designing the defrost system. The present paper assesses, by means of a simulation model that considers the airflow reduction with frost accretion, the effects of evaporator operating and geometric conditions, and defrost cycle parameters on the time-averaged cooling capacity. The results pointed out the existence of an optimum time for the defrost operation, indicating that short intervals between two defrost operations increase the thermal load by frequent heat supply, whilst long intervals promote severe capacity depletion by frost clogging.

Documents disponibles

Format PDF

Pages : 9

Disponible

  • Prix public

    20 €

  • Prix membre*

    15 €

* meilleur tarif applicable selon le type d'adhésion (voir le détail des avantages des adhésions individuelles et collectives)

Détails

  • Titre original : Defrost cycle optimization for fan-supplied tube-fin evaporators subjected to frosting conditions.
  • Identifiant de la fiche : 30024401
  • Langues : Anglais
  • Source : 2018 Purdue Conferences. 17th International Refrigeration and Air-Conditioning Conference at Purdue.
  • Date d'édition : 09/07/2018

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