0
RESEARCH PAPERS: Evaporation, Boiling, and Condensation

Effect of Vapor Velocity on Condensation of Low-Pressure Steam on Integral-Fin Tubes

[+] Author and Article Information
Satesh Namasivayam

Department of Engineering, Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom

Adrian Briggs1

Department of Engineering, Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdoma.briggs@qmul.ac.uk

Throughout this paper, all vapor velocities are based on the cross-sectional area of the test section upstream of the test tube and all pressures are absolute.

Note that the discontinuity in the Briggs and Rose (8) model at a fin spacing of approximately 0.9mm occurs where the fin just becomes fully flooded. For spacing below this value, the enhancement begins to rise again as more fins, and therefore more fin-tip area is added for a given tube length.

1

Corresponding author.

J. Heat Transfer 129(11), 1486-1493 (Mar 08, 2007) (8 pages) doi:10.1115/1.2764085 History: Received September 03, 2006; Revised March 08, 2007

Experimental data are presented for forced-convection condensation of low-pressure steam on a set of single, integral-fin tubes. The five tubes had fin-root diameter of 12.7mm and identical fin geometry except for fin spacing, which was varied from 0.25mmto2mm. The range of vapor velocity was 14.762.3ms at an absolute pressure of 14kPa. Heat-transfer enhancement was a strong function of both vapor velocity and fin spacing, and the interrelationship of the two parameters led to complex trends in the data. Observations of the extent of condensate flooding (i.e., condensate trapped between the fins at the bottom of the tube) indicated that the effect of vapor shear on flooding was a significant controlling factor in the heat-transfer process, and this factor explained, at least quantitatively, the trends observed.

FIGURES IN THIS ARTICLE
<>
Copyright © 2007 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 2

Plain tube results

Grahic Jump Location
Figure 3

Variation of heat flux with vapor-side temperature difference—effect of vapour velocity

Grahic Jump Location
Figure 4

Variation of heat flux with vapor-side temperature difference—effect of fin spacing

Grahic Jump Location
Figure 5

Variation of enhancement ratio with fin spacing (lines through experimental data are shown to guide the eye)

Grahic Jump Location
Figure 6

Variation of enhancement ratio with vapor velocity

Grahic Jump Location
Figure 7

Variation of active area enhancement with fin spacing

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In