Research Papers: Evaporation, Boiling, and Condensation

Experimental Measurements of Critical Heat Flux in Expanding Microchannel Arrays

[+] Author and Article Information
Mark J. Miner

e-mail: mark.miner@asu.edu

Patrick E. Phelan

e-mail: phelan@asu.edu

Carlos A. Ortiz

Department of Mechanical Engineering,
Arizona State University,
Tempe, AZ 85287-6106

1Corresponding author.

Contributed by the Heat Transfer Division of ASME for publication in the Journal of Heat Transfer. Manuscript received November 13, 2012; final manuscript received April 25, 2013; published online August 19, 2013. Assoc. Editor: W. Q. Tao.

J. Heat Transfer 135(10), 101501 (Aug 19, 2013) (8 pages) Paper No: HT-12-1606; doi: 10.1115/1.4024388 History: Received November 13, 2012; Revised April 25, 2013

The effect of an expanding microchannel cross-section on flow boiling critical heat flux (CHF) is experimentally investigated across four rates of expansion. A pumped-loop apparatus is developed to boil R-134a in an array of microchannels cut into copper; a test section is designed to facilitate interchange of the microchannel specimens, allowing consistency across experiments. An optimum expansion angle allowing maximum heat flux is observed, the location of which increases with the mass flow rate. The boiling number does not indicate any optimum in the range observed, showing a nearly monotonic increase with expansion angle. The familiar increase in critical heat flux with mass flux is observed, though expansion shifts the CHF-mass flux curves in a favorable direction. The existence of an optimum expansion angle confirms an earlier qualitative hypothesis by the authors and suggests that microchannel heat sinks offer opportunities for methodical improvement of flow boiling stability and performance.

Copyright © 2013 by ASME
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Tuckerman, D. B., and Pease, R. F. W., 1981, “High-Performance Heat Sinking for VLSI,” IEEE Electron Device Lett., 2(5), pp. 126–129. [CrossRef]
Khan, M., and Fartaj, A., 2011, “A Review on Microchannel Heat Exchangers and Potential Applications,” Int. J. Energy Res., 35, pp. 553–582. [CrossRef]
Kandlikar, S. G., 2012, “History, Advances, and Challenges in Liquid Flow and Flow Boiling Heat Transfer in Microchannels: A Critical Review,” ASME J. Heat Transfer, 134(3), p. 034001. [CrossRef]
Hwang, J., Tseng, F., and Pan, C., 2005, “Ethanol-CO2 Two-Phase Flow in Diverging and Converging Microchannels,” Int. J. Multiphase Flow, 31(5), pp. 548–570. [CrossRef]
Mukherjee, A., and Kandlikar, S. G., 2009, “The Effect of Inlet Constriction on Bubble Growth During Flow Boiling in Microchannels,” Int. J. Heat Mass Transfer, 52(21), pp. 5204–5212. [CrossRef]
Mukherjee, A., and Kandlikar, S. G., 2005, “Numerical Study of the Effect of Inlet Constriction on Bubble Growth During Flow Boiling in Microchannels,” International Conference on Microchannels and Minichannels ICMM2005-75143, ASME.
Lee, P. C., and Pan, C., 2007, “Boiling Heat Transfer and Two-Phase Flow of Water in a Single Shallow Microchannel With a Uniform or Diverging Cross Section,” J. Micromech. Microeng., 18(2), p. 025005. [CrossRef]
Lu, C. T., and Pan, C., 2008, “Stabilization of Flow Boiling in Microchannel Heat Sinks With a Diverging Cross-Section Design,” J. Micromech. Microeng., 18(7), p. 075035. [CrossRef]
Lu, C. T., and Pan, C., 2009, “A Highly Stable Microchannel Heat Sink for convective Boiling,” J. Micromech. Microeng., 19(5), p. 055013. [CrossRef]
Lu, C. T., and Pan, C., 2011, “Convective Boiling in a Parallel Microchannel Heat Sink With a Diverging Cross Section and Artificial Nucleation Sites,” Exp. Therm. Fluid Sci., 35(5), pp. 810–815. [CrossRef]
Liu, T.-L., Fu, B.-R., and Pan, C., 2012, “Boiling Two-Phase Flow and Efficiency of Co- and Counter-Current Microchannel Heat Exchangers With Gas Heating,” Int. J. Heat Mass Transfer, 55(21–22), pp. 6130–6141. [CrossRef]
Quinn, G., and O'Connor, E., 2008, “Assessment of the Multifluid Evaporator Technology,” AIP Conf. Proc., 969, pp. 53–61.
Lee, H., 2008, “Experimental and Numerical Study of Evaporating Flow Heat Transfer in Micro-Channel,” Ph.D. thesis, Washington State University, Pullman, WA.
Balasubramanian, K., Lee, P. C., Jin, L., Chou, S., Teo, C., and Gao, S., 2011, “Experimental Investigations of Flow Boiling Heat Transfer and Pressure Drop in Straight and Expanding Microchannels—A Comparative Study,” Int. J. Therm. Sci., 50(12), pp. 2413–2421. [CrossRef]
Chen, T., and Garimella, S. V., 2012, “A Study of Critical Heat Flux During Flow Boiling in Microchannel Heat Sinks,” ASME J. Heat Transfer, 134(1), p. 011504. [CrossRef]
Chun, M.-S., Lee, S.-Y., and Yang, S.-M., 2003, “Estimation of Zeta Potential by Electrokinetic Analysis of Ionic Fluid Flows Through a Divergent Microchannel,” J. Colloidal Interface Sci., 266(1), pp. 120–126. [CrossRef]
Ross, D., Ivory, C. F., Locascio, L. E., and Cott, K. E. V., 2004, “Peak Compression and Resolution for Electrophoretic Separations in Diverging Microchannels,” Electrophoresis, 25(21–22), pp. 3694–3704. [CrossRef] [PubMed]
Miner, M. J., Odom, B. A., Ortiz, C. A., Sherbeck, J., Prasher, R., and Phelan, P. E., 2011, “Optimized Expanding Microchannel Geometry for Flow Boiling,” International Mechanical Engineering Congress and Exposition IMECE2011-63592, ASME.
Miner, M. J., Phelan, P. E., Odom, B. A., Ortiz, C. A., Prasher, R., and Sherbeck, J., 2013, “Optimized Expanding Microchannel Geometry for Flow Boiling,” ASME J. Heat Transfer, 135(4), p. 042901. [CrossRef]
Revellin, R., and Thome, J. R., 2007, “A Theoretical Model for the Prediction of the Critical Heat Flux in Heated Microchannels,” Int. J. Heat Mass Transfer, 51(5), pp. 1216–1225. [CrossRef]
LabVIEW, 2006, version 8.2.0, National Instruments, Austin, TX.
matlab, 2010, version 7.13.0 (R2011b), The MathWorks Inc., Natick, MA.
Miner, M. J., and Phelan, P. E., 2012, “Effect of Cross-Sectional Perturbation on Critical Heat Flux Criteria in Microchannels,” ASME J. Heat Transfer (in press).
Carey, V. P., 2008, Liquid-Vapor Phase-Change Phenomena (2e), Taylor and Francis, New York.
Odom, B. A., Miner, M. J., Ortiz, C. A., Sherbeck, J., Prasher, R., and Phelan, P. E., 2012, “Microchannel Two-Phase Flow Oscillation Control With an Adjustable Inlet Orifice,” ASME J. Heat Transfer, 134(12), p. 122901. [CrossRef]


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Fig. 1

Microchannel turret

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Fig. 2

Expanding channel schematic

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Fig. 3

Points of interest for dimension measurements in Table 1

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Fig. 4

Cutaway view of test section

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Fig. 5

Turret housing and plenum block

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Fig. 6

Flow loop schematic

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Fig. 7

Qin and TC-B profile, 0.369 deg channels, 3 g/s flow

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Fig. 8

Heat–cool cycles for losses

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Fig. 9

Thermocouple locations

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Fig. 10

Optimum expansion with mean lines

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Fig. 11

CHF versus mass flux

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Fig. 12

Average boiling number with linear fits and 95% confidence bounds

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Fig. 13

Experiment-averaged inlet subcooling

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Fig. 14

Damage at straight-channel outlet



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