Pool Boiling Heat Transfer Coefficients Upto Critical Heat flux

임계 열유속 근방까지의 풀 비등 열전달계수

  • Published : 2008.09.10

Abstract

In this work, pool boiling heat transfer coefficients(HTCs) of 5 refrigerants of differing vapor pressure are measured on horizontal smooth square surface of 9.52 mm length. Tested refrigerants are R123, R152a, R134a, R22, and R32 and HTCs are taken from $10\;kW/m^2$ to critical heat flux of each refrigerant. Wall and fluid temperatures are measured directly by thermocouples located underneath the test surface and by thermocouples in the liquid pool. Test results show that pool boiling HTCs of refrigerants increase as the heat flux and vapor pressure increase. This typical trend is maintained even at high heat fluxes above $200\;kW/m^2$. Zuber's prediction equation for critical heat flux is quite accurate showing a maximum deviation of 21% for all refrigerants tested. For all refrigerant data up to the critical heat flux, Stephan and Abdelsalam's well known correlation underpredicted the data with an average deviation of 21.3% while Cooper's correlation overpredicted the data with an average deviation of 14.2%. On the other hand, Gorenflo's and lung et al.'s correlation showed only 5.8% and 6.4% deviations respectively in the entire nucleate boiling range.

Keywords

References

  1. Hsu, Y. Y. and Graham, R. W., 1976, Transport Processes in Boiling and Two-Phase System, Hemisphere Publishing Company, Washington, D. C.JSES
  2. Van Stralen, S. J. D., 1968, The Growth Rate of Vapor Bubbles in Superheated Pure Liquidsuids and Binary Mixtures, Int. J. Heat Mass Transfer, Vol. 11, pp. 1467-1512 https://doi.org/10.1016/0017-9310(68)90112-9
  3. Stephan, K., and Abdelsalam, M., 1980, Heat Transfer Correlations for Natural Convection Boiling, Int. Journal of Heat and Mass Transfer, Vol. 23, pp. 73-87 https://doi.org/10.1016/0017-9310(80)90140-4
  4. Cooper, M. G., 1982, Correlations for nucleate boiling formulation using reduced properties, Physico Chemical Hydrodynamics, Vol. 3, No. 2, pp. 89-111
  5. Gorenflo, D., 1984, Pool Boiling. In : VDI Heat Atlas, Chapter Ha
  6. Gorenflo, D., Chandra, U., Kottoff, S. and Luke, A., 2004, Influence of thermophysical properties on pool boiling heat transfer of refrigerants, Int. J. of Refrigeration, Vol. 27, No. 5, pp. 492-502 https://doi.org/10.1016/j.ijrefrig.2004.03.004
  7. Jung, D., Kim, Y., Ko, Y. and Song, K., 2003, Nucleate boiling heat transfer coefficients of pure halogenated refrigerants, Int. J. of Refrigeration, Vol. 26, No. 2, pp. 240-248 https://doi.org/10.1016/S0140-7007(02)00040-3
  8. Jung, D., Lee, H., Bae, D. and Ohc, S., 2004, Nucleate boiling heat transfer coefficients of flammable refrigerants, Int. J. of Refrigeration, Vol. 27, No. 4, pp. 409-414 https://doi.org/10.1016/j.ijrefrig.2003.11.007
  9. Thome, J. R., 1996, Boiling of new refrigerants : a state-of-the-art review, Int. J. of Refrigeration, Vol. 19, No. 7, pp. 435-457 https://doi.org/10.1016/S0140-7007(96)00004-7
  10. Gorenflo, D., 2001, State of the art pool boiling heat transfer of new refrigerants, Int. J. of Refrigeration, Vol. 24, No. 1, pp. 6-14 https://doi.org/10.1016/S0140-7007(00)00046-3
  11. Molina, M. J. and Rowland, F. S., 1974, Stratospheric sink for chlorofluoromethanes : chlorine atom catalyzed destruction of ozones, Nature, Vol. 249, pp. 810-812 https://doi.org/10.1038/249810a0
  12. Zuber, N., 1959, Hydrodynamic aspects of boiling heat transfer, AEC Report no. AECU-4439, Physics and Mathematics
  13. Kline, S. J. and McClintock, F. A., 1953, Describing uncertainties in single-sample experiments, Mechanical Engineer, Vol. 75, pp. 3-8