External Condensation Heat Transfer Coefficients of R245fa on Low Fin and Turbo-C Tubes

낮은 핀관과 Turbo-C 촉진관에서 R245fa의 외부 응축 열전달계수

  • 심윤보 (인하대학교 대학원 기계공학과) ;
  • 박기정 (인하대학교 대학원 기계공학과) ;
  • 정동수 (인하대학교 기계공학과)
  • Published : 2009.03.10

Abstract

In this study, condensation heat transfer coefficients(HTCs) of R22, R123, R134a and R245fa are measured on both 26fpi low fin and Turbo-C tubes. All data are taken at the vapor temperature of $39^{\circ}C$ with a wall subcooling of $3{\sim}8^{\circ}C$. Test results show that HTCs of the newly developed low vapor pressure alternative refrigerant, R245fa, are $7.8{\sim}9.2%$ and $10.3{\sim}18.6%$ higher than those of R123 for 26fpi low fin tube and Turbo-C tube respectively. For all refrigerants tested, HTCs of Turbo-C enhanced tube are higher than those of 26fpi low fin tube. For the low fin tube, Beatty and Katz's prediction equation yielded 20% deviation for all fluids. The heat transfer enhancement ratio of R245fa on the Turbo-C tube is $5.9{\sim}6.4$ while that of R123 is $5.7{\sim}5.9$. From the view point of environmental safety and condensation heat transfer, R245fa is a long term candidate to replace R123 currently used in centrifugal chillers.

Keywords

References

  1. 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
  2. Global Environmental Change Report., 1997, A brief analysis of the kyoto protocol, Vol. Ⅸ, No. 24, December
  3. Calm, J. M. and Hourahan, G. C., 2001, Refrigerant data summary, Engineered Systems, Vol. 18, No. 11, pp. 74-88
  4. Furuta, T., 2006, Development of centrifugal refrigeration machine with R245fa, The International Symposium on New Refrigerants and Environmental Technology 2006, Session 7
  5. Johnson, R. W., 2004, The effect of blowing agent choice on energy use and global warming impact of a refrigerator, International Journal of Refrigeration, Vol. 27, pp. 794-799 https://doi.org/10.1016/j.ijrefrig.2004.07.005
  6. Angelino, G. and Invernizzi, C. C., 2003, Experimental investigation on the thermal stability of some new zero ODP refrigerants, International Journal of Refrigeration, Vol. 26, p. 51-58 https://doi.org/10.1016/S0140-7007(02)00023-3
  7. Beatty, K. O. and Katz, D. L., 1948, Condensation of vapors on outside of finned tubes, Chemical Engineering Progress, Vol. 44, No. 1, pp. 55-70
  8. Nusselt W., 1916, Die oberflachenkondensa tion des wasserdampfes, Z. Ver. Deut. Ing., Vol. 60, p. 541
  9. Carnavos, T. C., 1980, An experimental study : Condensing R-11 on augmented tubes, ASME, Vol. 80-HT-54, pp. 54-60
  10. Rudy, T. M. and Webb, R. L., 1985, An analytical model to predict condensate retention on horizontal integral-fin tubes, Journal of Heat Transfer, Vol. 107, pp. 361-368 https://doi.org/10.1115/1.3247423
  11. Sukhatme, S. P., Jagadish, B. S. and Prabhakran, P., 1990, Film condensation of R-11 vapor on single horizontal enhanced condenser tubes, Journal of Heat Transfer, Vol. 112, pp. 229-234 https://doi.org/10.1115/1.2910350
  12. Kumar, R., Gupta, A. and Vishvakarma, S., 2005, Condensation of R-134a vapour over single horizontal integral-fin tubes : effect of fin height, International Journal of Refrigeration, Vol. 28, pp. 428-435 https://doi.org/10.1016/j.ijrefrig.2004.04.007
  13. Kim, N. H., Cho, S. J. and Kim, K. H., 1995, An experimental study on condensation heat transfer of low-finned tubes, Korean Journal of Air-Conditioning and Refrigeration Engineering, Vol. 7, No. 2, pp. 298-309
  14. Webb, R. L. and Murawski, C. G., 1990, Row effective for R-11 condensation on enhanced tubes, Transactions of the ASME, Vol. 112, pp. 768-776 https://doi.org/10.1115/1.2910452
  15. Park, C. H., Lee, Y. S., Jeong, J. H. and Kang, Y. T., 2006, The experimental study on the heat transfer of HFC134a for condensation tubes with various enhanced surfaces, Korea Journal of Air-Conditioning and Refrigeration Engneering, Vol. 18, No. 8, pp. 613-619
  16. Jung, D. S., Chae, S. N., Bae, D. S. and Oho, S. J., 2004, Condensation heat transfer coefficients of flammable refrigerants, International Journal of Refrigeration, Vol. 27, pp. 314-317 https://doi.org/10.1016/j.ijrefrig.2003.09.006
  17. Jung, D. S., Chae, S. N., Bae, D. S. and Yoo, G. S., 2005, Condensation heat transfer coefficients of binary HFC mixtures on low fin and Turbo-C tubes, International Journal of Refrigeration, Vol. 28, pp. 212-217 https://doi.org/10.1016/j.ijrefrig.2004.07.023
  18. Webb. R. L., 1994, Principles of enhanced heat transfer, John Wiley and Sons, Inc.,New York, pp. 21-29
  19. Jung, D. S., Kim, C. B., Cho, S. J. and Song, K. H., 1999, Condensation heat transfer coefficients of enhanced tubes with alternative refrigerants for CFC11 and CFC12, International Journal or Refrigeration, Vol. 22, pp. 548-557 https://doi.org/10.1016/S0140-7007(99)00020-1
  20. McLinden, M. O., Klein, S. A., Lemmon, E. W. and Peskin, A. P., 1998, NIST thermodynamics and transport properties of refrigerants and refrigerant mixtures, REFPROP version 6.0
  21. Kline, S. J. and McClintock, F. A., 1953, Describing uncertainties in single-sample experiments, Mechanical Engineer, Vol. 75, pp. 3-8
  22. Yoo, G. S., Hwang, J. H., Park, K. J. and Jung, D. S., 2005, External condensation heat transfer coefficients of R22 alternative refrigerants and R134a according to the saturated vapor temperature change on an enhanced tube, Korea Journal of Air-Conditioning and Refrigeration Engineering, Vol. 17, No. 11, pp. 981-989