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Heat and Mass Transfer

, 47:933 | Cite as

Effect of pore size distribution in bidisperse wick on heat transfer in a loop heat pipe

  • Fang-Chou Lin
  • Bing-Han Liu
  • Chun-Chia Juan
  • Yau-Ming ChenEmail author
Original

Abstract

The purpose of this article is to experimentally investigate the effect of different pore size distributions in bidisperse wicks upon the heat transfer performance in a LHP. Three bidisperse wicks and one monoporous wick were tested in a loop heat pipe. The pore size distributions of the bidisperse wicks were measured, and the results reflected the three different large/small pore size ratios. The experiments showed that the maximum heat load of the monoporous wick reached about 400 W; and the three bidisperse wicks showed improvements on the maximum heat load up to 570 W. For the monoporous wick, the evaporator heat transfer coefficients of 10 kW/m2 K and total thermal resistance of 0.19°C/W were achieved at a high heat load of 400 W. For the better bidisperse wick, the evaporator heat transfer coefficients could attain about 23 kW/m2 K and total thermal resistance of 0.13°C/W. The results also indicated that a smaller cluster size in a bidisperse structure created a small pore size ratio. It was also found that the bidisperse wick with smaller clusters had a better enhancement in terms of the evaporator heat transfer coefficient.

Keywords

Heat Transfer Coefficient Pore Size Distribution Heat Pipe Heat Load Critical Heat Flux 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

List of symbols

A

Area, m2

D

Wick diameter, m

hev

Heat transfer coefficient, W/m2K

K

Permeability, m2

L

Length, m

\( \dot{m} \)

Mass flow rate, kg/s

\( \Updelta P \)

Pressure drop, Pa

Q

Applied heat load, W

Rtotal

Total thermal resistance, K/W

T

Temperature, K

Greek symbols

\( \rho \)

Density, kg/m3

\( \mu \)

Viscosity, Pa s

Subscripts

amb

Ambient

ev

Evaporator

i

Inner

o

Outer

sink

Sink

v

Vapor

w

Wick

References

  1. 1.
    Maydanik YF (2005) Loop heat pipes. Appl Therm Eng 25:635–657CrossRefGoogle Scholar
  2. 2.
    Khrustalev D, Faghri A (2005) Heat transfer in the inverted meniscus type evaporator at high heat fluxes. Int J Heat Mass Transf 38:3091–3101CrossRefGoogle Scholar
  3. 3.
    Zhao TS, Liao Q (2000) On capillary-driven flow and phase-change heat transfer in a porous structure heated by a finned surface: measurements and modeling. Int J Heat Mass Transf 43:1141–1155zbMATHCrossRefGoogle Scholar
  4. 4.
    Vityaz PA, Konev SV, Medvedev VB, Sheleg VK (1984) Heat pipe with bidispersed capillary structures. In: Proceedings of the fifth international heat pipe conference, Tsukuba, JapanGoogle Scholar
  5. 5.
    Rosenfeld JH, North MT (1995) Porous media heat exchangers for cooling of high power optical components. Opt Eng 34:335–341CrossRefGoogle Scholar
  6. 6.
    Wang J, Catton I (2001) Biporous heat pipes for high power electronic device cooling. In: Proceedings of the seventeenth annual IEEE symposium on semiconductor thermal measurement and management, San Jose, CA, USAGoogle Scholar
  7. 7.
    Wang J, Catton I (2001) Evaporation heat transfer in thin biporous media. Heat Mass Transf 37:275–281CrossRefGoogle Scholar
  8. 8.
    Cao XL, Cheng P, Zhao TS (2002) Experimental study of evaporative heat transfer in sintered copper bidispersed wick structures. J Thermophys Heat Transf 16:547–552CrossRefGoogle Scholar
  9. 9.
    Semenic T, Lin YY, Catton I (2008) Use of biporous wicks to remove high heat fluxes. Appl Therm Eng 28:278–283CrossRefGoogle Scholar
  10. 10.
    Semenic T, Lin YY, Catton I (2008) Thermophysical properties of biporous heat pipe evaporators. J Heat Transf 130:022602(1)–022602(10)CrossRefGoogle Scholar
  11. 11.
    Semenic T, Catton I (2009) Experimental study of biporous next term wicks for high heat flux applications. Int J Heat Mass Transf 52:5113–5121CrossRefGoogle Scholar
  12. 12.
    North MT, Sarraf DB, Rosenfeld JH, Maidanik YF, Vershinin S (1997) High heat flux loop heat pipes. In: Proceedings of the sixth European symposium on space environmental control systems, Noordwijk, the NetherlandsGoogle Scholar
  13. 13.
    Yeh CC, Chen CN, Chen YM (2009) Heat transfer analysis of a loop heat pipe with biporous wicks. Int J Heat Mass Transf 52:4426–4434CrossRefGoogle Scholar
  14. 14.
    Singh R, Akbarzadeh A, Mochizuki M (2009) Effect of wick characteristics on the thermal performance of the miniature loop heat pipe. J Heat Transf 131:082601(1)–082601(10)CrossRefGoogle Scholar
  15. 15.
    Hwang KS, Hsieh YM (1996) Comparative study of pore structure evolution during solvent and thermal debinding of powder injection molded parts. Metall Mater Trans A 27:245–253CrossRefGoogle Scholar
  16. 16.
    Oktay S (1982) Departure from natural convection (DNC) in low-temperature boiling heat transfer encountered in cooling microelectronic LSI devices. In: Proceedings of the 7th international heat transfer conference, Munich, Germany, vol 4, pp 113–118Google Scholar
  17. 17.
    ASTM Standard E128-99 (2005) Standard test method for maximum pore diameter and permeability of rigid porous filters for laboratory use, ASTM International, West Conshohocken, PA, 2005. http://www.astm.org. doi:  10.1520/E0128-99R05
  18. 18.
    Webb PA, Orr C (1997) Analytical methods in fine particle technology. Micromeritics Instrument Corporation, USAGoogle Scholar
  19. 19.
    Moffat RJ (1988) Describing the uncertainties in experimental result. Exp Therm Fluid Sci 1:3–17CrossRefGoogle Scholar
  20. 20.
    Ku J (1999) Operating characteristics of loop heat pipes. In: Proceedings of the 24th international conference on environmental systems, Denver, Colorado, USAGoogle Scholar

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Fang-Chou Lin
    • 1
  • Bing-Han Liu
    • 1
  • Chun-Chia Juan
    • 1
  • Yau-Ming Chen
    • 1
    Email author
  1. 1.Department of Mechanical EngineeringNational Taiwan UniversityTaipeiTaiwan

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