New & Renewable Energy (신재생에너지)

Korean Society for New and Renewable Energy (한국신·재생에너지학회)
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Influence of Refrigerant Charge Amount on the Performance of a Water-to-Water Type Ground Source Heat Pump with a Variation of Compressor Speed and Water Flow Rate

용량 가변 및 유량변화에 따른 지열원 물대물 열펌프 유닛의 충전량 변화에 따른 성능 특성

  • 조찬용 (국립한밭대학교 기계공학과 대학원) ;
  • 최종민 (국립한밭대학교 기계공학과)
  • Received : 2011.11.21
  • Accepted : 2011.12.13
  • Published : 2011.12.25
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Abstract

The objective of this study is to investigate the effects of the refrigerant charge amount on the performance of a water-to-water ground source heat pump with a variation of compressor speed and the secondary fluid flow rate. The water-to-water ground source heat pump was tested by varying refrigerant charge amount from -40% to 20% of full charge. Compressor speed was changed from 30 Hz to 75 Hz and the secondary fluid flow rate was adjusted from 6 LPM to 14 LPM. For all test conditions, EWTs of an indoor heat exchanger and an outdoor heat exchanger were maintained at standard conditions of ISO 13256-2. The slope of the COP with the variation of charge amount is much steeper at undercharged conditions than that at overcharged conditions. For all compressor speed, the variation of the system performance according to charge amounts showed the similar trends. However, the optimum charge amount of the system increased a little with an increment of compressor speed. When the secondary fluid flow rate decreased, the system was optimized at higher refrigerant charge amount conditions.

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References

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  1. 신재생에너지 지열을 이용한 열펌프유닛의 성능에 관한 실험적 연구 vol.31, pp.6, 2011, https://doi.org/10.7316/khnes.2020.31.6.630