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 Characteristics of Hot-gas and Liquid Bypass Heat Pump Systems for Capacity Modulation

고온가스 및 액체 바이패스 적용 용량가변 히트펌프의 성능특성에 관한 실험적 연구

  • Ahn, Jae Hwan (Department of Mechanical Engineering, Graduate School of Korea University) ;
  • Joo, Youngju (Digital Appliance Division, Samsung Electronics Inc.) ;
  • Yoon, Won Jae (Department of Mechanical Engineering, Graduate School of Korea University) ;
  • Kang, Hoon (Department of Mechanical Engineering, Korea University) ;
  • Kim, Yongchan (Department of Mechanical Engineering, Korea University)
  • 안재환 (고려대학교 기계공학부 대학원) ;
  • 주영주 (삼성전자 생활가전사업부) ;
  • 윤원재 (고려대학교 기계공학부 대학원) ;
  • 강훈 (고려대학교 기계공학부) ;
  • 김용찬 (고려대학교 기계공학부)
  • Received : 2012.12.05
  • Published : 2013.03.10
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Abstract

A small air-conditioner or chiller for a constant temperature bath normally uses a constant speed compressor. The constant speed compressor is relatively inexpensive, but it uses on/off control for capacity modulation. The on/off control has several disadvantages, specifically energy loss and large temperature fluctuation. Continuous operation with a bypass system can be an alternative to on/off control, for capacity modulation. In this study, a heat pump system having a hot-gas bypass and a liquid bypass was adopted. The performance of the bypass-type heat pump was measured, by varying the bypass valve opening. The differences of the COP between the hot-gas bypass and the liquid bypass, in the cooling and heating operations, were within 2% and 1%, respectively. The liquid bypass showed a wider range of capacity control in the cooling operation but the hot-gas bypass showed a wider range of capacity control in the heating operation.

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References

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