Document IIF

R134a et R123 : impacts des additifs sur la performance du transfert de chaleur lors de l'ébullition.

Effect of refrigerant oil additive on R134a and R123 boiling heat transfer performance.

Auteurs : KEDZIERSKI M. A.

Type d'article : Article, Article de la RIF

Résumé

This paper investigates the effect that an additive had on the boiling performance of an R134a/polyolester lubricant (POE) mixture and an R123/naphthenic mineral oil mixture on a roughened, horizontal flat surface. Both pool boiling heat transfer data and lubricant excess surface density data are given for the R134a/POE (98% mass fraction/2% mass fraction) mixture before and after use of the additive. A spectrofluorometer was used to measure the lubricant excess density that was established by the boiling of the R134a/POE lubricant mixture before and after use of the additive. The measurements obtained from the spectrofluorometer suggest that the additive increases the total mass of lubricant on the boiling surface. The heat transfer data show that the additive caused an average and a maximum enhancement of the R134a/POE heat flux between 5 and 22 kW/m2 of approximately 73 and 95%, respectively. Conversely, for nearly the same heat flux range, the additive caused essentially no change in the pool boiling heat flux of an R123/mineral oil mixture. The lubricant excess surface density and interfacial surface tension measurements of this study were used to form the basis of a hypothesis for predicting when additives will enhance or degrade refrigerant/lubricant pool boiling.

Documents disponibles

Format PDF

Pages : 144-154

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 : Effect of refrigerant oil additive on R134a and R123 boiling heat transfer performance.
  • Identifiant de la fiche : 2006-2852
  • Langues : Anglais
  • Source : International Journal of Refrigeration - Revue Internationale du Froid - vol. 30 - n. 1
  • Date d'édition : 01/2007

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