Effects of Working Fluid Filling Ration and Heat Flux on Correlations of Heat Transfer Coefficient in Loop Thermosyphon

  • Chang, Ki-Chang (Unutilized Energy Research Team, Korea Institute of Energy Research) ;
  • Lee, Young-Soo (Unutilized Energy Research Team, Korea Institute of Energy Research)
  • Published : 2002.09.01

Abstract

Due to the coupling between momentum and energy transport theoretical analysis of the loop performance is very complicate, therefore it is necessary that these problems be solved by experimental investigation before applying the loop thermosyphon to heat exchanger de-sign. The evaporator and condenser of the loop thermosyphon were made of carbon-steel, and distilled water was used as working fluid in the experiments. From the experimental data correlations of heat transfer coefficient for evaporator and condenser sections were obtained. For heat fluxes in the range of 13000~78000 W/$m^2$, the correlation equations of heat transfer coefficients in evaporator and condenser predict the experimental behavior to within $\pm$5% and $\pm$20% respectively.

Keywords

References

  1. Japkise, D., 1973, Advance in thermosyphon technology, in J. P. Hartnett, T. F. Irvine(eds.), Advances in Heat Transfer, Vol. 9, Academic Press, New York
  2. Zvirin, Y., 1981, A review of natural circu-lation loops in pressurized water reactors and other systems, Nucl. Engng Des. 67 pp.203-225
  3. Mertol, A., Place, W., Webster, T. and Greif, R., 1981, Detailed loop model (DLM) analysis of liquid solar thermosyphons with heat ex-changers, Solar Energy 27, pp.367-386
  4. Parent, M. G., Van Der Meer, Th. H. and Hollands, K. G. T., 1990, Natural convection heat exchangers in solar water heating sys-tems: theory and experiment, Solar Energy 45, pp. 43-52
  5. Karl Stephan and Hein Auracher, 1981, Cor-relation for nucleate boiling heat transfer in forced convection, Int. J. Heat Mass Trans-fer 24, pp. 99-107
  6. Huang, B.J. and Zelaya, R., 1988, Heat trans-fer behavior of a rectangular thermosyphon loop, Journal of Heat Transfer Transactions of the ASME 110, pp.487-493
  7. Chang, K. C., Lee, K. W. and Yoo, S. Y, 1998, Experimental study on the heat trans-fer characteristics of separate type thermo-syphon, Korean Journal of Air-Conditioning and Refrigeration Engineering 10(1), pp.22-32
  8. Chang, K. C., Lee, K. W. and Yoo, S. Y.,1998, Effects of working fluid filling ratio and heat flux on heat transfer for sepa-rate type thermosyphon, Proceedings of the SAREK'98 Winter Annual Conference, pp. 263-268
  9. Chang, K. C., Lee, K. W., Ra, H. S. and Yoo, S. Y., 1999, Correlations of Heat Transfer Coefficient in Separate Type Thermosyphon, Proceedings of the SAREK'99 Summer An-nual Conference, pp.77-83