Heat Transfer in Flow Boiling Over a Bundle of Horizontal Tubes
The paper describes tests boiling R 113 at atmospheric pressure in upward flow over a 17 row column of square pitched electrically heated tubes. Uniform heat fluxes of 10–65 kW m –2 and maximum Reynolds numbers, Re max, between 7800 and 27 000 were used. The data at the lower heat fluxes of 10 and 2...
Saved in:
Published in | Chemical engineering research & design Vol. 83; no. 5; pp. 527 - 538 |
---|---|
Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Rugby
Elsevier B.V
01.05.2005
Institution of Chemical Engineers |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | The paper describes tests boiling R 113 at atmospheric pressure in upward flow over a 17 row column of square pitched electrically heated tubes. Uniform heat fluxes of 10–65 kW m
–2 and maximum Reynolds numbers, Re
max, between 7800 and 27 000 were used. The data at the lower heat fluxes of 10 and 20 kW m
–2 consistently exhibited a linear increase of heat transfer coefficient,
h, with quality, the slope lower at 20 kW m
–2, so that h at 10 kW m
–2 exceeded that at 20 kW m
–2 and both reached
h at 40 kW m
–2 for the maximum quality tested. At the higher heat fluxes a nucleate boiling controlled region was observed at low quality, with
h equal to the value at the same heat flux as observed with an isolated tube in a pool, followed by a rise in
h at higher quality. The results were compared with the work of other researchers. Heat transfer coefficients for
q ≥ 40 kW m
–2 were predicted to an average r.m.s. deviation of 7%, using the asymptotic flow boiling model. However, the sensitivity of
h to change of quality and flow rate predicted was much lower than measured and in some cases exhibited opposite trends. |
---|---|
Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0263-8762 1744-3563 |
DOI: | 10.1205/cherd.04313 |