Journal of Energy Engineering (에너지공학)

The Korean Society for Energy (한국에너지학회)
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A Study on Performance Improvement of Heat Pump Adopting the Hot Gas Bypass Method

고온냉매 우회방법을 적용한 열펌프의 성능 개선 연구

  • Kang, Shin-Hyung (Department of Mechanical Engineering, Konyang University) ;
  • Byun, Ju-Suk (Yonsei Center for Clean Technology, Yonsei University)
  • Published : 2006.12.31
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Abstract

This study experimentally investigates the performance improvement of the heat pump by adopting the hot gas bypass method and using the internal heat exchanger according to the automatic defrost test conditions of ISO 5151 This study compares the hot gas bypass method with the time step method, and investigates effect on outdoor coil fan speed when the hot gas of compressor outlet enter outdoor coil inlet after the frost formation. The tests were made for the fan speeds of the outdoor coil controlled at 90, 60 and 30% of the normal speed together with the case of the stationary fan. The performance of the heat pump is evaluated by variables such as COP, heat capacity, and the average COP during the 210 minutes heating mode. Results show that average COP of the hot gas bypass mettled is $2.2{\sim}6%$ higher than that of the time step method. When the outdoor coil fan speed is 60% (780 rpm) of the normal speed, it shows the best COP and heating capacity.

본 연구는 공기 열원 열펌프의 성능 향상을 위한 연구로써 제상 방법으로 고온냉매 우회방법을 사용하고 내부열교환기를 장착한 열펌프 시스템의 성능을 ISO5151의 표준제상 조건에서 실험하였다. 실험은 고온냉매 우회방법과 가장 일반적인 제상 방법인 시간주기 제상방법을 비교하였으며 착상 발생 후 압축기 출구의 고온냉매를 실외기 입구로 우회시킬 때 실외기 홴 속도를 정상속도에 대하여 0%, 30%, 60%, 90%로 변화 시키면서 열펌프의 성능변화를 관찰하였다. 연구결과 210분의 열펌프 가동시간 동안 고온냉매 우회방법은 시간주기 제상방법 보다 $2.2{\sim}6%$ 높은 평균 성능계수를 나타냈으며 고온냉매 우회방법에서는 실외기의 홴 속도가 60%일 때 가장 좋은 성능계수와 난방용량을 나타냈다.

Keywords

References

  1. Kondepudi, S.N.; O'Neal, D.L. 'The effect of different fin configuration on the performance of finnedtube heat exchanger under forsting conditions', ASHRAE Transactions, 1990, 96(2), 439-444
  2. Chen, H.; Thomas, L.; Besant, R.W. 'Measurement of frost characteristics on heat exchanger fins Part II : Data and Analysis', ASHRAE Transactions, 1999, 105(2), 294-304
  3. Watters, R.J.; O'Neal, D.L. 'Effect of fin staging on Frost/Defrost Performance of a Two-Row Heat Pump Evaporator at standard test conditions', ASHRAE Transaction, 2001, 240-249
  4. Mei, V.C.; Domitrovic, R.E. 'A Frost-Less Heat Pump', ASHRAE Transactions, 2002, 452-459
  5. 지성; 이관수. '휜-관 열교환기의 착.제상 거동에 대 한 표면처리의 영향에 관한 실험적 연구', 대한기계 학회논문집 B권, 2000, 24권(8), 1062-1068
  6. 황윤제; 이원희. 'A Frost-less Heat Pump', 설비저널, 2002, 31(3), 53-58
  7. O'Neal, D.L.; et al. 'Refrigeration system dynamics duringthe reverse cycle defrost', ASHRAE Transaction, 1989, 89(1), 689-698
  8. Yagub, M.; Zubair, S.M.; Khan, J. 'Performance evaluation of hot-gas by-pass capacity control scheme for refrigeration and air-conditioning systems', Energy, 2000, 25, 543-561 https://doi.org/10.1016/S0360-5442(00)00004-9
  9. Kirkman. 'Automatic hot gas bypass, Air conditioning, heating and ventilating', 1986, 65(1), 64-68
  10. Byun, J.-S.; Jeon, C.-D.; Jung, J.-H.; Lee, J. 'The application of photo-coupler for frost detecting in an air-source heat pump', International Journal of Refrigeration, 2006, 29(2), 191-198 https://doi.org/10.1016/j.ijrefrig.2005.06.008
  11. McLinden, M.O.; Klein, S.A.; Lemmon, E.W.; Peskin, A.P. 'NIST thermodynamic and transport properties of refrigerant and refrigerant mixtures (REFPROP V6.01)', NIST, Gaithersburg, MD, 1998
  12. ISO 5151. 'Non-ducted air conditioners and heat pumps-testing and rating for performance', 1994