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

The Society of Air-Conditioning and Refrigerating Engineers of Korea (대한설비공학회)
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An Experimental Study on the Performance of Outdoor Heat Exchanger for Heat Pump Using $CO_{2}$

$CO_{2}$이용 열펌프의 실외열교환기 성능에 관한 실험적 연구

  • Chang Young Soo (Thermal/flowtrol Research Center, Korea institute of Science of Technology) ;
  • Lee Min Kyu (Thermal/flowtrol Research Center, Korea institute of Science of Technology) ;
  • Ahn Young San (Thermal/flowtrol Research Center, Korea institute of Science of Technology) ;
  • Kim Young Il (Thermal/flowtrol Research Center, Korea institute of Science of Technology)
  • 장영수 (한국과학기술연구원 열유동제어연구센터) ;
  • 이민규 (한국과학기술연구원 열유동제어연구센터) ;
  • 안영산 (한국과학기술연구원 열유동제어연구센터) ;
  • 김영일 (한국과학기술연구원 열유동제어연구센터)
  • Published : 2005.02.01
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Abstract

The purpose of this study is to investigate the performance of outdoor heat exchanger for heat pump using carbon dioxide. Two types of fin and tube heat exchangers (2 rows for type A and 3 rows for B) are tested. Both heat exchangers have counter-cross flow and 1-circuit arrangement. Test results such as heat transfer rate, pressure drop characteristics and temperature distribution in the heat exchanger are shown with respect to mass flow rate of refrigerant and frontal air velocity For cooling mode, the minimum temperature difference between air and refrigerant of type B is smaller than that of type A by $1^{circ}C$, but the pressure loss of air side is much higher for type B by $29\%$. It is found that a large temperature gradient of carbon dioxide during gas cooling Process Promotes thermal conduction through tube wall and fins which results in degradation of heat transfer performance. For heating mode operation, type B heat exchanger shows higher heat transfer performance compared to type A. However, because pressure loss of refrigerant side of type B is much greater than that of type A, the refrigerant outlet pressure of type B becomes lower than that of type A.

Keywords

References

  1. Yin, J. M., Bullard, C. W., and Hmjak, P. S., 2000, Design strategies for R744 gas cooler, Preliminary Proceedings of the 4th IIR-Gustav Lorentzen Conference on Natural Working Fluids at Purdue, July 25-28, USA, pp. 315-322
  2. Pettersen, J., Hafner, A., and Skaugen, G., 1998, Development of compact heat exchangers for $CO_2$ air-conditioning systems, International Journal of Refrigeration, Vol. 21, pp. 180-193 https://doi.org/10.1016/S0140-7007(98)00013-9
  3. Oh, S. K., Ko, C. S., Jang, D. Y., Sa Y. C., Oh, S. Y., and Chung, B. Y., 2003, An experimental study on the wet performance of flat tube heat exchangers, SAREK winter meeting, pp. 262-267
  4. KS C 9306, 1999, Air Conditioners, Korean Agency for Technology and Standards
  5. McLinden, M. O., Klein, S. A., Lemmon, E. W., and Peskin, A. P., 1998, NIST Thermodynamics Properties of Refrigerants and Refrigerant Mixtures Data Base(REFPROP), Version 6.01, NIST, Boulder
  6. Kline, S. J. and McClinetock, F., 1953, Describing uncertainty in single sample experiment, Mechanical Engineering, Vol. 75, pp. 3-8
  7. Heun, M. K. and Crawford, R. R., 1994, Longitudinal fin conduction in multipass cross-counterflow finned-tube heat exchangers, ASHRAE transactions, Vol. 100, no. 1, pp. 382-389
  8. Chiou, J. P., 1978, The effect of longitudinal heat conduction on crossflow heat exchanger, Transactions of the ASME, Vol. 100, pp. 346-351 https://doi.org/10.1115/1.3450807
  9. Ricardo, R. M., Mihir S., Yang, K. T., and Rodney, L. M., 1997, Effect of tube-to-tube conduction on plate-fin and tube heat exchanger performance, Int. J. Heat and Mass Transfer, Vol. 40, No. 16, pp. 3909-3916 https://doi.org/10.1016/S0017-9310(97)00015-X