THERMAL ANALYSIS OF HEAT PIPE USING SELF REWETTING FLUIDS

Abstract

This paper discuses the use of self rewetting fluids in the heat pipe. In conventional heat pipes, the working fluid used has a negative surface-tension gradient with temperature. It is an unfavourable one and it decreases the heat transport between the evaporator section and the condenser section. Self rewetting fluids are dilute aqueous alcoholic solutions which have the number of carbon atoms more than four. Unlike other common liquids, self-rewetting fluids have the property that the surface tension increases with temperature up to a certain limit. The experiments are conducted to improve the heat-transport capability and thermal efficiency of capillary assisted heat pipes with the self rewetting fluids like aqueous solutions of n-Butanol and n-Pentanol and its performance is compared with that of pure water. The n-Butanol and n-Pentanol are added to the pure water at a concentration of 0.001moles/lit to prepare the self rewetting fluids. The heat pipes are made up of copper container with a two-layered stainless steel wick consisting of mesh wrapped screen. The experimental results show that the maximum heat transport of the heat pipe is enhanced and the thermal resistances are considerably decreased than the traditional heat pipes filled with water. The fluids used exhibit an anomalous increase in the surface tension with increasing temperature.

Keywords

Dates

  • Submission Date2010-11-02
  • Revision Date2011-02-22
  • Acceptance Date2011-03-15

DOI Reference

10.2298/TSCI101102020S

References

  1. Amir Faghri, Heat pipe Science and Technology, Taylor & Francis, Washington, 1995.
  2. G.P. Peterson, An Introduction to Heat Pipes, Wiley and Sons, 1994.
  3. Chi S.W, Heat pipe theory and practice, McGraw-Hill, Washington, 1976.
  4. Sonan R et al, Transient thermal and hydrodynamic model of flat heat pipe for the cooling of electronics components, Int. J. of Heat and Mass Transfer, 51 (2008), pp. 6006-6017.
  5. Bloem H, et al, An evacuated tubular solar collector incorporating a heat pipe, Philips Technical Rev, 40 (1982), pp. 181-191.
  6. Mariya Ivanova et al, Heat Pipe Integrated in Direct Bonded Copper (DBC) Technology for Cooling of Power Electronics Packaging, IEEE Transactions on Power electronics, 21 (2006), pp. 1541
  7. Kaminaga F, et al, Heat transfer characteristics of evaporation and condensation in a two-phase closed thermosyphon, Proc. 10th Int. Heat pipe Conf.,1997, pp. 21-25 . 7
  8. . M.P. Mughal, O.A. Plumb, An experimental study of boiling on a wicked surface, Int. J. Heat Mass Transfer, 39, (1996), pp. 771-777.
  9. A. Brautsch, P.A. Kew, Examination and visualization of heat transfer processes during evaporation in capillary porous structures , Appl. Therm. Eng, 22 (2002), pp. 815-824.
  10. J.E. Eninger, B.D. Marcus, The Marangoni effect and capacity degradation in axially grooved heat pipes, Proceedings of the International Heat Pipe Conference, 1978, pp. 414-417.
  11. C.L. Tien, Two-Components Heat Pipes, Thermo physics: Application to Thermal Design of Spacecraft, Academic Press, New York, 1970.
  12. C.L. Tien, A.R. Rohani, Theory of two-component heat pipes, J. Heat Transfer (1972), pp. 479-484.
  13. H.J. Brommer, Theoretical and experimental investigation of two-component heat pipes, Proceedings of the Thermo physics and Heat Transfer Conference, July 15-17, 1974, American Institute of Aeronautics and Astronautics and American Society of Mechanical Engineers, Boston
  14. K. Kadoguchi, T. Fukano, Y. Emi, Heat-transfer characteristics in the heating section of a closed two-phase thermosyphon working with a binary mixture, Heat Transfer. Jpn. Res. 23 (1994), pp. 128-140.
  15. M. Kuramae, M. Suzuki, Two component heat pipes utilizing the Marangoni effect, J. Chem. Eng. Jpn. 26 (1993), pp. 230-231.
  16. M. Kuramae, Condensation mechanism of binary mixture under a microgravity condition, Proceedings of the 11th International Heat Pipe Conference,Tokio 1999.
  17. M. Kuramae, Numerical simulation of the Marangoni convection in a two component heat pipe, Proceedings of the 6th International Heat Pipe Symposium, Chiang Mai, 2000.
  18. N. Zhang, Innovative heat pipe systems using a new working fluid, Int. Communications of Heat Mass Transfer, 28 (2001), pp. 1025-1033.
  19. Iwasaki, E., Higashi Y. and Okada, N. Measurements of the surface tension and density for 1-butanol, aqueous solution, Proc. 25th Japan Symp. Thermophys. Properties 2004, pp. 32-34.
  20. Ono, N, et al. The aqueous solutions with nonlinear surface tension energy and their application to flow boiling in a mini/micro tube, Proc. ASME ICNMM2007 (5th Int. Conf. Nanochannels, Microchannels and Minichannels),2007, Papers No. ICNMM2007-30166.
  21. Savino, R et al. Heat pipes with binary mixtures and inverse Marangoni effects for microgravity applications, Proc. 57th Int. Astronaut. Cong. 2006, IAC-06-A2.3, pp. 57-67.
  22. Yoshiyuki Abe, Self-Rewetting Fluids Beneficial Aqueous Solutions, Interdisciplinary Transport Phenomena in The Space Sciences, 1077 (2006), pp. 650-667.
  23. Raffaele Savino, et al, Heat Pipes with Self-Rewetting Fluids for Space Applications, International Conference On Environmental Systems, 2008, Paper Number: 2008-01-1954.
  24. Alexander Oron and Philip Rosenau, On a nonlinear thermocapillary effect in thin liquid layers, J. Fluid Mech., 273, (1994), 361-374.
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