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Simple Flow-Pattern Based Heat Transfer Correlations for Flow Boiling in Micro/Minichannels

Wu, Zan LU ; Sundén, Bengt LU ; Yao, Shi-chune; Wadekar, Vishwas V. and Li, Wei (2014) 12th International Conference on Nanochannels, Microchannels and Minichannels (ICNMM) In Proceedings of the Asme 12th International Conference on Nanochannels, Microchannels, and Minichannels, 2014 p.001-04
Abstract
An improved conventional-to-micro/minichannel threshold was proposed as Bo = 4 and BoRe(1)(0.5) = 200, where Bo is the Bond number and Re-1 is the liquid Reynolds number. The region Bo < 4 and BoRe(1)(0.5) < 200 is termed as micro/minichannel because bubbles tend to be confined and elongated in the channel and the conventional two-phase flow theory loses its applicability. Flow-pattern based heat transfer correlations for elongated bubbly flow and annular flow in flow boiling micro/minichannels were developed separately based on a collected micro/minichannel heat-transfer database. As significant disagreement in experimental trends and heat transfer mechanisms was reported for flow boiling in micro/minichannels in the literature, it... (More)
An improved conventional-to-micro/minichannel threshold was proposed as Bo = 4 and BoRe(1)(0.5) = 200, where Bo is the Bond number and Re-1 is the liquid Reynolds number. The region Bo < 4 and BoRe(1)(0.5) < 200 is termed as micro/minichannel because bubbles tend to be confined and elongated in the channel and the conventional two-phase flow theory loses its applicability. Flow-pattern based heat transfer correlations for elongated bubbly flow and annular flow in flow boiling micro/minichannels were developed separately based on a collected micro/minichannel heat-transfer database. As significant disagreement in experimental trends and heat transfer mechanisms was reported for flow boiling in micro/minichannels in the literature, it is not possible to explain the discrepancy and predict all data points by a single correlation without considering the different flow patterns. The newly developed flow-pattern based predictive tool can not only present a decent overall accuracy, but also estimate the parametric trends correctly. Over 95% of the data points can be predicted by the proposed correlations within a +/- 50% error band for both elongated bubbly flow and annular flow. Therefore, the simple flow-pattern based correlations can be applied for heat exchanger design, improve understanding of the underlying heat transfer mechanisms, and guide development of further enhancement techniques for flow boiling in micro/minichannels. (Less)
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author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
in
Proceedings of the Asme 12th International Conference on Nanochannels, Microchannels, and Minichannels, 2014
pages
001 - 04
publisher
Amer Soc. Mechanical Engineers
conference name
12th International Conference on Nanochannels, Microchannels and Minichannels (ICNMM)
external identifiers
  • WOS:000360511900032
  • Scopus:84920388905
DOI
10.1115/ICNMM2014-21025
language
English
LU publication?
yes
id
149d900d-3dc6-4663-9ff4-2db3461efd45 (old id 8080637)
date added to LUP
2015-10-22 09:49:51
date last changed
2016-10-13 04:42:47
@misc{149d900d-3dc6-4663-9ff4-2db3461efd45,
  abstract     = {An improved conventional-to-micro/minichannel threshold was proposed as Bo = 4 and BoRe(1)(0.5) = 200, where Bo is the Bond number and Re-1 is the liquid Reynolds number. The region Bo &lt; 4 and BoRe(1)(0.5) &lt; 200 is termed as micro/minichannel because bubbles tend to be confined and elongated in the channel and the conventional two-phase flow theory loses its applicability. Flow-pattern based heat transfer correlations for elongated bubbly flow and annular flow in flow boiling micro/minichannels were developed separately based on a collected micro/minichannel heat-transfer database. As significant disagreement in experimental trends and heat transfer mechanisms was reported for flow boiling in micro/minichannels in the literature, it is not possible to explain the discrepancy and predict all data points by a single correlation without considering the different flow patterns. The newly developed flow-pattern based predictive tool can not only present a decent overall accuracy, but also estimate the parametric trends correctly. Over 95% of the data points can be predicted by the proposed correlations within a +/- 50% error band for both elongated bubbly flow and annular flow. Therefore, the simple flow-pattern based correlations can be applied for heat exchanger design, improve understanding of the underlying heat transfer mechanisms, and guide development of further enhancement techniques for flow boiling in micro/minichannels.},
  author       = {Wu, Zan and Sundén, Bengt and Yao, Shi-chune and Wadekar, Vishwas V. and Li, Wei},
  language     = {eng},
  pages        = {001--04},
  publisher    = {ARRAY(0xa14fd40)},
  series       = {Proceedings of the Asme 12th International Conference on Nanochannels, Microchannels, and Minichannels, 2014},
  title        = {Simple Flow-Pattern Based Heat Transfer Correlations for Flow Boiling in Micro/Minichannels},
  url          = {http://dx.doi.org/10.1115/ICNMM2014-21025},
  year         = {2014},
}