용량 가변 및 유량변화에 따른 지열원 물대물 열펌프 유닛의 충전량 변화에 따른 성능 특성
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
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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.
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.
참고문헌 (7)
- und, J., "Ground-Source Heat Pumps-A World Overview", Renewable Energy World, pp.218~227 (2003)
- 최종민, "지열원 물대공기 멀티 히트펌프의 일일 난방 운전 특성에 관한 실증 연구", 설비공학 논문집, 21(9), pp.527~535 (2009), 대한설비공학회
- 최은수, "냉매충전량이 모세관 팽창장치를 가진 공기조화기의 성능에 미치는 영향", 설비공학 논문집, 14(5), pp.1~364 (2002), 대한설비공학회
- Houcek, J., "A research into a new method of refrigeration charging and the effects of improper charging", Proceedings of 1st Annual Sym. on Efficient Utilization of Energy in Residential and Commercial Buildings (1984)
- Stoecker, W.F., "Influence of the expansion device on the seasonal energy requirements of a residential air conditioner", ASHRAE Trans, 87(1), pp.349~360 (1981)
- Choi, J.M., "Influence of the expansion device on the performance of a heat pump using R407C under a range of charging conditions", INTERNATIONAL JOURNAL OF REFRIGERATION-REVUE INTERNATIONALE DU FROID, 27(4), pp.378~384 (2004), Elsevier Ltd.
- ISO, "“Water-source heat pumps- Testing and rating for performance ; Part 2: Water-to-water and brine-to-water heat pumps”, ISO 13256-2", ~ (1998)