0
Research Papers: Evaporation, Boiling, and Condensation

Utilization of Pore-Size Distributions to Predict Thermophysical Properties and Performance of Biporous Wick Evaporators

[+] Author and Article Information
Sean W. Reilly

Mechanical and
Aerospace Engineering Department,
University of California, Los Angeles,
Los Angeles, CA 91101
e-mail: swreilly@ucla.edu

Ivan Catton

Mechanical and
Aerospace Engineering Department,
University of California, Los Angeles,
Los Angeles, CA 91101
e-mail: catton@ucla.edu

1Corresponding author.

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received April 3, 2013; final manuscript received January 28, 2014; published online March 11, 2014. Assoc. Editor: Bruce L. Drolen.

J. Heat Transfer 136(6), 061501 (Mar 11, 2014) (10 pages) Paper No: HT-13-1183; doi: 10.1115/1.4026624 History: Received April 03, 2013; Revised January 28, 2014

A sintered copper porous medium is an extremely effective structure used to enhance the evaporative heat transfer properties of a heat pipe. It provides both capillary pressure to passively draw liquid in and increased surface area to more effectively heat the liquid. A biporous wick is particularly effective for this application as there are two distinct size distributions of pores; small pores to provide ample capillary pressure to drive flow through the wick and large pores to provide high permeability for escaping vapor. The modeling described in this work is based on the work of Kovalev who used a pore size distribution in order to determine the most probable liquid saturation at a given position. The model distinguishes phases by choosing a “cutoff” pore size, where larger pores were assumed to be filled with vapor and smaller pores were assumed to be filled with liquid. For a given thickness and thermophysical properties of the liquid, this 1-D model predicts the temperature difference across the wick for a given input power. The modeling proposed in this work yielded results that compare very well with experimental data collected on biporous evaporators by Semenic.

FIGURES IN THIS ARTICLE
<>
Copyright © 2014 by ASME
Your Session has timed out. Please sign back in to continue.

References

Semenic, T., 2007, “High Heat Flux Removal Using Biporous Heat Pipe Evaporators,” Ph.D. thesis, UCLA, Los Angeles, CA.
Semenic, T., Lin, Y., and Catton, I., 2008, “Thermophysical Properties of Biporous Heat Pipe Evaporators,” ASME J. Heat Transfer, 130(2), p. 022602. [CrossRef]
Wang, J., and Catton, I., 2001, “Biporous Heat Pipes for High Power Electronic Device Cooling,” Seventeenth IEEE SEMI-THERM Symposium2001, San Jose, CA.
Wang, J., and Catton, I., 2001, “Evaporation Heat Transfer in Thin Biporous Media,” Heat Mass Transfer, 37, pp. 275–281. [CrossRef]
Vityaz, P., Konev, S., Medvedev, V., and Sheleg, V., 1984, “Heat Pipe With Bidispersed Capillary Structures,” Proceedings of the 5th International Heat Pipe Conference, Tsukuba Japan, Vol. 1, pp. 127–135.
Hanlon, M. A., and Ma, H. B., 2003, “Evaporation Heat Transfer in Sintered Porous Media,” ASME J. Heat Transfer, 125(4), pp. 644–652. [CrossRef]
Kaya, T., and Goldak, J., 2006, “Numerical Analysis of Heat and Mass Transfer in the Capillary Structure of a Loop Heat Pipe,” Int. J. Heat Mass Transfer, 49(17–18), pp. 3211–3220. [CrossRef]
Kovalev, S. A., 1987, “Liquid Boiling on Porous Surfaces,” Heat Transfer: Soviet Res., 19(3), pp. 109–120.
Uhle, J., 1991, “Boiling Heat Transfer Characteristics of Steam Generator U-Tube Fouling Deposits,” Ph.D. dissertation, Department of Nuclear Engineering, MIT, Cambridge, MA.
Chernysheva, M. A., and Maydanik, Y. F., 2009, “Heat and Mass Transfer in Evaporator of Loop Heat Pipe,” J. Thermophys. Heat Transfer, 23(4), pp. 725–731. [CrossRef]
Annapragada, S., Murthy, J., and Garimella, S., 2008, “Permeability and Thermal Transport in Compressed Open-Celled Foams,” Numer. Heat Transfer, 54(1), pp. 1–22. [CrossRef]
Dullien, F. A. L., 1992, Porous Media: Fluid Transport and Pore Structure, Academic Press, San Diego, CA.
Vadnjal, A., 2007, “High Heat Flux Evaporator,” Ph.D. dissertation, Department of Mechanical Engineering, UCLA, Los Angeles, CA.
Carey, V. P., 1992, Liquid-Vapor Phase-Change Phenomena, Hemisphere, New York.
Lin, F., Liu, B., Huang, C., and Chen, Y., 2011, “Evaporative Heat Transfer Model of a Loop Heat Pipe With a Bidisperse Wick Structure,” Int. J. Heat Mass Transfer, 54, pp. 4621–4629. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

Boiling regime map for biporous media [1]

Grahic Jump Location
Fig. 2

Schematic of double layer wick

Grahic Jump Location
Fig. 3

Schematic of liquid/vapor counter-current flow

Grahic Jump Location
Fig. 4

Diagram of control volume

Grahic Jump Location
Fig. 5

Particle diameter distribution [1]

Grahic Jump Location
Fig. 6

Cluster diameter distribution [1]

Grahic Jump Location
Fig. 7

Standard deviation of particle and cluster sizes

Grahic Jump Location
Fig. 9

Estimates of pore and particle sizes

Grahic Jump Location
Fig. 10

PDF of pore size distribution, 69-275-907.5

Grahic Jump Location
Fig. 11

CDF of the pore size distribution, 69-275-907.5

Grahic Jump Location
Fig. 12

Liquid relative permeability, 69-275-907.5

Grahic Jump Location
Fig. 13

Vapor relative permeability, 69-275-907.5

Grahic Jump Location
Fig. 14

ΔT comparison 69-275-907.5

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