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Study of heat transfer during evaporation and condensation of the zeotropic blends HFC23/HFC134a inside a horizontal smooth tube.

Etude des transferts de chaleur lors de l'évaporation et de la condensation de mélanges zéotropes HFC23/HFC134a à l'intérieur d'un tube lisse horizontal.

Author(s) : BERRADA N.

Type of monograph: Doctoral thesis

Summary

This dissertation presented at the Faculté des Sciences of Dhar El Mehraz, Morocco, for the title of doctor in physical sciences (specialty: heat transfer), deals with an experimental study of evaporation and condensation, inside a horizontal smooth tube, of HFC-22 and HFC-134a and of a HFC-23/HFC-134a zeotropic blend of different compositions. Correlations for calculating the coefficient of exchange during evaporation and condensation were validated in tests on pure refrigerants. In the case of zeotropic blends, a significant drop in the evaporative exchange coefficient was observed. A model was presented and validated to account for this drop, in both nucleate-boiling and convective evaporation. In condensation, the exchange coefficients obtained were scarcely affected by the blend. A conventional correlation taking into account the physical properties of the blend was presented. Pressure losses can be estimated with conventional models through the use of the blend's physical properties.

Details

  • Original title: Etude des transferts de chaleur lors de l'évaporation et de la condensation de mélanges zéotropes HFC23/HFC134a à l'intérieur d'un tube lisse horizontal.
  • Record ID : 1997-2563
  • Languages: French
  • Publication: Université Sidi Mohamed Ben Abdellah, Faculté des Sciences Dhar El Mehraz, Département de physique - Morocco/Morocco
  • Publication date: 1996/06/18
  • Source: Source: 272 p. (20.3 x 28.8); fig.; tabl.; append.
  • Document available for consultation in the library of the IIR headquarters only.

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