DOI QR코드

DOI QR Code

인버터 주파수 제어에 따른 CO2용 수냉식 열펌프의 성능 특성

Performance Characteristics of Water-Chilling Heat Pump Using CO2 on Control of Inverter Frequency

  • 손창효 (부경대학교 냉동공조공학과)
  • Son, Chang-Hyo (Division of Refrigeration and Air-Conditioning, Pukyong National University)
  • 투고 : 2010.11.15
  • 심사 : 2010.12.17
  • 발행 : 2010.12.31

초록

본 논문은 압축기 인버터 주파수 제어에 따른 CO2용 수냉식 열펌프의 성능 특성에 대해서 실험적으로 조사하였다. 실험장치는 압축기, 가스냉각기, 팽창밸브, 증발기, 내부 열교환기, 수액기로 구성된다. 실험장치에 사용된 모든 열교환기는 동관으로 제작된 이중관식 대향류형이다. 가스냉각기와 증발기는 2.4 m인 소시험부 6개와 4개로 각각 구성된다. 실험결과를 요약하면, 우선 증발기와 가스냉각기의 입구온도와 냉매유량이 일정한 조건하에서 압축기 인버터 주파수가 증가할수록 압축비와 토출압력이 증가한다. 또한 인버터 주파수가 증가할수록 난방능력과 압축일량은 증가하는 반면 성능계수는 감소한다. 그리고 증발기 입구 2차유체의 온도가 $15^{\circ}C$에서 $25^{\circ}C$로 증가함에 따라 압축비와 압축일량은 감소하지만 질량유량, 난방능력, 성능계수는 증가한다. 위의 이러한 경향은 종래의 프레온계 냉매 시스템의 성능 변화와 유사하다.

The performance characteristics of water-chilling heat pump using CO2 for the control of inverter frequency was investigated experimentally. An experimental apparatus is consisted of a compressor, a gas cooler, an expansion valve, an evaporator and a liquid receiver. All heat exchangers used in the test rig are counter flow type heat exchangers with concentric dual tubes, which are made of copper. The gas cooler and the evaporator consist of 6 and 4 straight sections respectively arranged in parallel, each has 2.4m length. The experimental results summarize as the following: for constant inlet temperature of evaporator and gas cooler, as mass flow rate, compression ratio and discharge pressure increases with the inverter frequency. And heating capacity and compressor work increases, but coefficient of performance(COP) decreases with the inverter frequency of compressor. As inlet temperature of secondary fluid in the evaporator increases from $15^{\circ}C$ to $25^{\circ}C$, compression ratio and compressor work decreases, but mass flow rate, heating capacity and COP increases with the inverter frequency of compressor. The above tendency is similar with performance variation with respect to the variation of inverter frequency in the conventional vapor compression refrigeration cycle.

키워드

참고문헌

  1. Neksa, P., Rekstad, H., Zakeri, G. R. and Schiefloe, P. A., "CO2 heat pump water heater: characteristics, system design and experimental results.", International Journal of refrigeration, Vol. 21, No. 3, pp.172-179, 1988.
  2. Hwang, Y., and Radermacher, R., "Theoretical evaluation of carbon dioxide refrigeration cycle", HAVC&R Research, Vol. 4, No. 3, pp. 245∼263, 1998.
  3. Liao, S., Jakobsen, A., "Optimal heat rejection pressure in transcritical carbon dioxide air conditioning and heat pump system.", IIF-IIR-Sections B and E-Oslo, Norway, 1998. pp. 301-310, 1998.
  4. Brown, S. J., Yana-Motta, F. S., Domanski, A. P., "comparative analysis of an auto motive air conditioning systems operating with CO2 and R134a.", International Journal of refrigeration, 25(2002), pp. 19-32, 2002. https://doi.org/10.1016/S0140-7007(01)00011-1
  5. Halozan, H, and Rieberer, R., CO2 as refrigerant -possible applications, 4th IIR-Gustav Lorentzen Conference, pp. 43-50, 2000.
  6. Hafner, A., 2000, Experimental study on heat pump operation of prototype CO2 mobile air conditionins system, 4th IIR-Gustav Lorentzen Conference, pp. 177-184.
  7. Kim, M., Pettersen, J. and Bullard, C., "Fundamental process and system design issues in CO2 vapor compression systems", Progress in Energy and Combustion Science, Vol. 30, pp. 119-174, 2004. https://doi.org/10.1016/j.pecs.2003.09.002
  8. McLinden, M. O., Klein, S. A., Lemmon, E. W., Peskin, A. P., "NIST Thermodynamic Properties and Refrigerant Mixtures Database (REFPROP)", Version 6.01, National Institute of Standards and Technology, Gaithersburg, MD, U.S.A, 1998.
  9. Cho, H., Ryu, C. and Kim, Y., "Experimental study on the cooling performance of a CO2 cycle with internal heat exchanger", Proceeding of the SAREK "04 Winter Annual Conference, pp. 571-576, 2004.
  10. Rieberer, R., Neksa, P. and Schiefloe, P.A., CO2 heat pumps for space heating and tap water heating, 20th International Congress of Refrigeration, IIR/IIF, Sydney, 1999.
  11. Rieberer, R., Gassler, M. and Halozan, H., "Control of CO2 heat pumps", Proceedings of the 4th IIR-Gustav Lorentzen Conference on Natural Working Fluids at Purdue, 2000 July 25-28; West Lafayette, USA, pp. 75-82, 2000.
  12. McEnaney R. P., Boewe D. E., Yin JM, Park Y. C., Bullard C. W., Hrnjak P. S., "Experimental comparison of mobile A/C systems when operated with transcritical CO2 versus conventional R134a". In Proceedings of the Seventh International Refrigeration Conference at Purdue University, WestLafaytte, Indiana, pp. 145-150, 1998.