Critical heat flux conditions for water at subatmospheric pressures in an array of silicon-based, 227μm hydraulic diameter, rectangular microchannels were experimentally studied. Experiments were conducted at exit pressures from 0.1atmto1atm, mass fluxes from 86kgm2sto303kgm2s, and an effective heat flux up to 444Wcm2. The annular flow pattern revealed during flow visualization and the high exit qualities at CHF conditions suggest dryout to be the CHF mechanism. An analysis, based on the experimental results and known CHF characteristics, on the dependency of the critical heat flux on various variables was performed. It was found that the boiling number at the CHF condition was approximately a constant.

1.
Bergles
,
A. E.
, and
Kandlikar
,
S. G.
, 2005, “
On the Nature of Critical Heat Flux in Microchannels
,”
ASME J. Heat Transfer
0022-1481,
127
(
10
), pp.
101
107
.
2.
Thome
,
J. R.
, 2004, “
Boiling in Microchannels: A Review of Experiment and Theory
,”
Int. J. Heat Fluid Flow
0142-727X,
25
, pp.
128
139
.
3.
Qu
,
W.
, and
Mudawar
,
I.
, 2004, “
Measurement and Correlation of Critical Heat Flux in Two-Phase Micro-Channel Heat Sinks
,”
Int. J. Heat Mass Transfer
0017-9310,
47
, pp.
2045
2059
.
4.
Bowers
,
M. B.
, and
Mudawar
,
I.
, 1994, “
High Flux Boiling in Low Flow Rate, Low Pressure Drop Mini-Channel and Micro-Channel Heat Sinks
,”
Int. J. Heat Mass Transfer
0017-9310,
37
(
2
), pp.
321
334
.
5.
Kandlikar
,
S. G.
,
Kuan
,
W. K.
,
Willistein
,
D. A.
, and
Borrelli
,
J.
, 2006, “
Stabilization of Flow Boiling in Microchannels Using Pressure Drop Elements and Fabricated Nucleation Sites
,”
ASME J. Heat Transfer
0022-1481,
128
(
4
), pp.
389
396
.
6.
Kuan
,
W. K.
, and
Kandlikar
,
S. G.
, 2006, “
Experimental Study on Saturated Flow Boiling Critical Heat Flux in Microchannels
,” Proceedings of the Fourth International Conference on Nanochannels, Microchannels and Minichannels, pp.
45
52
.
7.
Jiang
,
L.
,
Wong
,
M.
, and
Zohar
,
Y.
, 2001, “
Forced Convection Boiling in a Microchannel Heat Sinks
,”
J. Microelectromech. Syst.
1057-7157,
10
(
1
), pp.
80
87
.
8.
Zhang
,
L.
,
Koo
,
J.
,
Jiang
,
L.
,
Asheghi
,
M.
,
Goodson
,
K. E.
,
Santiago
,
J. G.
, and
Kenny
,
T. W.
, 2002, “
Measurements and Modeling of Two-Phase Flow in Microchannels With Nearly Constant Heat Flux Boundary Conditions
,”
J. Microelectromech. Syst.
1057-7157,
11
(
1
), pp.
12
19
.
9.
Flynn
,
R. D.
,
Kramer
,
T. A.
,
Koo
,
J. M.
,
Cheng
,
C. H.
,
Fogg
,
D. W.
,
Wang
,
E. N.
, and
Goodson
,
K. E.
, 2005, “
Convective Boiling in Silicon Microchannels With Localized Heating and Thermometry
,” ASME Paper No. ICMM2005-75209.
10.
Wojtan
,
L.
,
Revellin
,
R.
, and
Thome
,
J. R.
, 2006, “
Investigation of Saturated Critical Heat Flux in a Single, Uniformly Heated Microchannel
,”
Exp. Therm. Fluid Sci.
0894-1777,
30
(
8
), pp.
765
774
.
11.
Pate
,
D. T.
,
Jones
,
R. J.
, and
Bhavnani
,
S. H.
, 2006, “
Cavity-Induced Two-Phase Heat Transfer in Silicon Microchannels
,”
Thermomechanical Phenomena in Electronic Systems—Proceedings of the Intersociety Conference
, Tenth Intersociety Conference on Thermal and Thermomechanical Phenomena and Emerging Technologies in Electronic Systems, ITherm, pp.
71
78
.
12.
Hardt
,
S.
,
Schilder
,
B.
,
Tiemann
,
D.
,
Kolb
,
G.
,
Hessel
,
V.
, and
Stephan
,
P.
, 2007, “
Analysis of Flow Patterns Emerging During Evaporation in Parallel Microchannels
,”
Int. J. Heat Mass Transfer
0017-9310,
50
(
1–2
), pp.
226
239
.
13.
Chang
,
K. H.
, and
Pan
,
C.
, 2007, “
Two-Phase Flow Instability for Boiling in a Microchannel Heat Sink
,”
Int. J. Heat Mass Transfer
0017-9310
50
(
11–12
), pp.
2078
2088
.
14.
Chen
,
T.
, and
Garimella
,
S. V.
, 2006, “
Measurements and High-Speed Visualizations of Flow Boiling of a Dielectric Fluid in a Silicon Microchannel Heat Sink
,”
Int. J. Multiphase Flow
0301-9322,
32
(
8
), pp.
957
971
.
15.
Koşar
,
A.
,
Kuo
,
C.-J.
, and
Peles
,
Y.
, 2005, “
Boiling Heat Transfer in Rectangular Microchannels With Reentrant Cavities
,”
Int. J. Heat Mass Transfer
0017-9310,
48
(
23–24
), pp.
4867
4886
.
16.
Koşar
,
A.
,
Kuo
,
C.-J.
, and
Peles
,
Y.
, 2005, “
Reduced Pressure Boiling Heat Transfer in Rectangular Microchannels With Interconnected Reentrant Cavities
,”
ASME J. Heat Transfer
0022-1481,
127
, pp.
1106
1114
.
17.
Koşar
,
A.
, and
Peles
,
Y.
, 2007, “
Critical Heat Flux of R-123 in Silicon-Based Microchannels
,”
ASME J. Heat Transfer
0022-1481,
129
(
7
), pp.
844
851
.
18.
Kuo
,
C.-J.
, and
Peles
,
Y.
, 2007, “
Local Measurement of Flow Boiling in Structured Surface Microchannels
,”
Int. J. Heat Mass Transfer
0017-9310,
50
(
23-24
), pp.
4513
4526
.
19.
Carey
,
V. P.
, 1992,
Liquid-Vapor Phase-Change Phenomena
,
Taylor & Francis
,
London
.
20.
Collier
,
J. G.
, and
Thome
,
J. R.
, 1994,
Convective Boiling and Condensation
,
3rd ed.
,
Oxford University Press
,
New York
.
21.
Celata
,
G. P.
, and
Mariani
,
A.
, 1999, “
CHF and Post-CHF (Post-Dryout) Heat Transfer
,”
Handbook of Phase Change: Boiling and Condensation
,
Taylor & Francis
,
Philadelphia
, pp.
443
493
.
22.
Katto
,
Y.
, 1994, “
Critical Heat Flux
,”
Int. J. Multiphase Flow
0301-9322,
20
, pp.
563
590
.
23.
Gambill
,
W. R.
, and
Lienhard
,
J. H.
, 1987, “
An Upper Bound for the Critical Boiling Heat Flux
,”
Proceedings of ASME-JSME Thermal Engineering Joint Conference
,
3
, pp.
621
626
.
24.
Carey
,
V. P.
, 2007,
Thermal Challenges in Next Generation Electronic Systems (THERMES 2007) Conference
,
S. V.
Garimella
and
A. S.
Fleisher
, eds., Santa Fe, NM, Jan. 7–10,
25.
Koşar
,
A.
,
Kuo
,
C. J.
, and
Peles
,
Y.
, 2006, “
Suppression of Boiling Flow Oscillations in Parallel Microchannels With Inlet Restrictors
,”
ASME J. Heat Transfer
0022-1481,
128
(
3
), pp.
251
260
.
26.
Kline
,
S.
, and
McClintock
,
F. A.
, 1953, “
Describing Uncertainties in Single-Sample Experiments
,”
Mech. Eng. (Am. Soc. Mech. Eng.)
0025-6501,
75
(
1
), pp.
3
8
.
27.
Revellin
,
R.
, and
Thome
,
J. R.
, 2008, “
A Theoretical Model for the Prediction of the Critical Heat Flux in Heated Microchannels
,”
Int. J. Heat Mass Transfer
0017-9310,
51
(
5-6
), pp.
1216
1225
.
28.
Katto
,
Y.
, and
Ohne
,
H.
, 1984, “
An Improved Version of the Generalized Correlation of Critical Heat Flux for Convection Boiling in Uniformly Heated Vertical Tubes
,”
Int. J. Heat Mass Transfer
0017-9310,
27
(
9
), pp.
1641
1648
.
29.
Shah
,
M. M.
, 1987, “
Improved General Correlation for Critical Heat Flux During Upflow in Uniformly Heated Vertical Tubes
,”
Int. J. Heat Mass Transfer
0017-9310,
8
(
4
), pp.
326
335
.
You do not currently have access to this content.