Articles liés à Condensation of R-22 in Horizontal Smooth Tubes: Flow...

Condensation of R-22 in Horizontal Smooth Tubes: Flow Pattern-Based Heat Transfer and Pressure Drop Correlations - Couverture souple

Christians, Marcel

 
9783639130669: Condensation of R-22 in Horizontal Smooth Tubes: Flow Pattern-Based Heat Transfer and Pressure Drop Correlations
Couverture souple
ISBN 10 : 3639130669 ISBN 13 : 9783639130669
Editeur : VDM Verlag Dr. Müller, 2009

Synopsis

The phase-out of ozone-depleting refrigerants, such as R-12 and R-22, according to the Montreal Protocol of 1987, has provided the incentive to increase the thermal efficiency of current heating and refrigeration systems. The purpose of this study was to increase the accuracy of the predictions of both the heat transfer and pressure drop correlations for condensing refrigerants in the Intermittent flow regime. This was done utilizing a novel method involving the temporal and spectral analysis of the light intensity of the local flow regime, as seen through a sight glass. An experimental setup was designed, built and commissioned specifically for this purpose using refrigerant R-22 and a smooth tube. It was found that the accuracy of the mean heat transfer coefficient predictions increased substantially compared to other leading correlations, particularly at low mass fluxes. In terms of the pressure drop, the predictions also increased in accuracy, and it was found that the time fraction method allows for continuous predictions over flow regime transitions when using local flow pattern-based pressure drop models.

Les informations fournies dans la section « Synopsis » peuvent faire référence à une autre édition de ce titre.

Présentation de l'éditeur

The phase-out of ozone-depleting refrigerants, such as R-12 and R-22, according to the Montreal Protocol of 1987, has provided the incentive to increase the thermal efficiency of current heating and refrigeration systems. The purpose of this study was to increase the accuracy of the predictions of both the heat transfer and pressure drop correlations for condensing refrigerants in the Intermittent flow regime. This was done utilizing a novel method involving the temporal and spectral analysis of the light intensity of the local flow regime, as seen through a sight glass. An experimental setup was designed, built and commissioned specifically for this purpose using refrigerant R-22 and a smooth tube. It was found that the accuracy of the mean heat transfer coefficient predictions increased substantially compared to other leading correlations, particularly at low mass fluxes. In terms of the pressure drop, the predictions also increased in accuracy, and it was found that the time fraction method allows for continuous predictions over flow regime transitions when using local flow pattern-based pressure drop models.

Biographie de l'auteur

Marcel Christians received his B.Eng., B.Eng.(Hons) and M.Eng. degrees in Mechanical Engineering (cum laude) at the University of Pretoria in Pretoria, South Africa. He is currently employed at the Laboratory of Heat and Mass Transfer, at the Swiss Federal Institute of Technology in Lausanne, Switzerland.

Les informations fournies dans la section « A propos du livre » peuvent faire référence à une autre édition de ce titre.

Éditeur
VDM Verlag Dr. Müller
Date d'édition
2009
Langue
anglais
ISBN 10 
3639130669
ISBN 13 
9783639130669
Reliure
Broché
Nombre de pages
248
Coordonnées du fabricant
non disponible
Personne responsable
non disponible