Korean Journal of Air-Conditioning and Refrigeration Engineering (설비공학논문집)

The Society of Air-Conditioning and Refrigerating Engineers of Korea (대한설비공학회)
권호 표지

R-22 and R-410A Condensation in Flat Aluminum Multi-Channel Tubes

알루미늄 다채널 평판관내 R-22 및 R-410A 응축에 관한 연구

  • Jung, Ho-Jong (Graduate School of Mechanical Engineering, Incheon University) ;
  • Kim, Nae-Hyun (Department of Mechanical Engineering, Incheon University) ;
  • Yoon, Baek (Air-conditioning Div., Samsung Electronics) ;
  • Kim, Man-Hoi (Air-conditioning Div., Samsung Electronics)
  • Published : 2002.07.01
Download PDF
⟨ Previous Next ⟩

Abstract

In this study, condensation heat transfer tests were conducted in flat aluminum multi-channel tubes using R-410A, and the results are compared with those of R-22. Two internal geometries were tested; one with a smooth inner surface and the other with micro-fins. Data are presented for the following range of variables; vapor quality (0.1~0.9), mass flux (200~600 kg/$m^2$s) and heat flux (5~15 ㎾/$m^2$). Results show that the effect of surface tension drainage on the fin surface is more pronounced for R-22 than R-410A. The smaller Weber number for R-22 may be responsible. For the smooth tube, the heat transfer coefficient of R-410A is slightly larger than that of R-22. For the micro-fin tube, however, the reverse is true. Possible reasoning is provided considering the physical properties of the refrigerants. For the smooth tube, a correlation of Akers et at. type predicts the data reasonably well. For the micro-fin tube, the Yang and Webb model was modified to correlate the present data.

Keywords

References

  1. Yang, C.-Y. and Webb, R. L., 1996, Condensation of R-12 in Small Hydraulic Diameter Extruded Aluminum Tubes with and without Microfins, Int. J. Heat Mass Trans., Vol. 39, No. 4, pp. 791-800
  2. Webb, R L. and Yang, C.-Y., 1995, A Comparison of R-12 and R-134a Condensation inside Small Extruded Aluminum Plain and Micro-Fin Tubes, C4961053195, IMechE, pp. 77-86
  3. Shah, M. M., 1979, A General Correlation for Heat Transfer during Film Condensation in Tubes, Int. J. Heat Mass Transfer, Vol. 22, No. 4, pp. 547-556
  4. Akers, W. W., Deans, H. A and Crosser, O. K, 1959, Condensation Heat Transfer within Horizontal Tubes, Chem. Eng. Prog. Symp. Series, Vol. 55, No. 29, pp. 171-176.
  5. Nae-Hyun Kim, Jin-Pyo Cho and Jung-Oh Kim, 2000, R-22 Condensation in Flat Aluminum Multi Channel Tubes, J. Enhanced Heat Transfer, Vol. 7, pp. 427-438
  6. Ermis, K and Webb, R L., 1998, Effect of Hydraulic Diameter on Condensation of R134a in Flat Extruded Aluminum Tubes, submitted to J. Heat Transfer
  7. Katsuda, M., 1994, The Effect of A Cross-sectional Geometry on The Condensation Heat Transfer inside Multi-pass Tubes, Proc of WTPF, Vol. 2, pp. 146-157, AFERC, POSTECH
  8. Webb, R L., Zhang, M. and Narayanamurthy, R, 1998, Condensation Heat Transfer in Small Diameter Tubes, Heat Transfer 1998, Proceedings of 11th IHTC, Vol. 6, Aug. 23-28, Kyongju, Korea
  9. Dobson, M. K, Chato, J. C., Hinde P. K and Wang, S. P., 1994, Experimental Evaluation of Internal Condensation of R-12 and R-134a, ASHRAE Trans., No-94-5-3, pp. 744-754
  10. Hong, J. W., Rho, G. S., Jeong, J. C., Oh, H. K., 2001, Condensing heat transfer characteristics of R-22 and R-134a in small diameter tubes, KSME J. Vol. 25, No.1, pp. 54-61
  11. Cavallini, A. and Zecchin, R., 1971, High Velocity Condensation of Organic Refrigerants inside Tubes, Proceeding of 8th International Congress of Refrigeration, Brussels, Belgium, Vol. 2, pp. 193-200
  12. Kline, S.J. and McClintock, F. A, 1953, The Description of Uncertainties in Single Sample Experiments, Mechanical Engineering, Vol. 75, pp. 3-9
  13. Carnavos, T. C., 1979. Cooling Air in Turbulent Flow with Internally Finned Tubes, Heat Transfer Engineering, Vol. 1 (2), pp. 41-46
  14. Yang, C.-Y. and Webb, R L., 1997, A Predicted Model for Condensation in Small Hydraulic Diameter Tubes Having Axial Micro-fins, J. Heat Trans., Vol. 119, pp. 776-782 https://doi.org/10.1115/1.2824182