Korean Journal of Air-Conditioning and Refrigeration Engineering (설비공학논문집)

The Society of Air-Conditioning and Refrigerating Engineers of Korea (대한설비공학회)
권호 표지

The Performance of a Simultaneous Heat and Cooling Heat Pump at Various Charging Conditions

동시냉난방 히트펌프의 냉매 충전량과 운전모드 변화에 따른 성능특성에 관한 연구

  • Song, In-Sik (Graduate School of Mechanical Engineering, Hanbat National University) ;
  • Choi, Jong-Min (Department of Mechanical Engineering, Hanbat National University) ;
  • Joo, Young-Ju (Graduate School of Mechanical Engineering, Korea University) ;
  • Chung, Hyun-Joon (Graduate School of Mechanical Engineering, Korea University) ;
  • Kang, Hoon (Graduate School of Mechanical Engineering, Korea University) ;
  • Kim, Yong-Chan (Department of Mechanical Engineering, Korea University)
  • 송인식 (한밭대학교 기계공학과 대학원) ;
  • 최종민 (한밭대학교 기계공학과) ;
  • 주영주 (고려대학교 기계공학과 대학원) ;
  • 정현준 (고려대학교 기계공학과 대학원) ;
  • 강훈 (고려대학교 기계공학과 대학원) ;
  • 김용찬 (고려대학교 기계공학과)
  • Published : 2008.07.10
Download PDF
⟨ Previous Next ⟩

Abstract

The cooling load in winter is significant in many commercial buildings and hotels because of the usage of office equipments and the high efficiency of wall insulation. The development of a multi-heat pump that can cover heating and cooling simultaneously for each indoor unit is required. In this study, the performance of a multi-heat pump with 3-piping system was investigated as a function of refrigerant charge and its performance was analyzed in cooling mode, heating mode, and heat recovery mode. COP in the heating or cooling mode showed little dependence on refrigerant charge at overcharge conditions, while those were strongly dependent on refrigerant charge at undercharge conditions and outdoor inlet temperature. In the heat recovery mode, the performance of the system was very sensitive to charge amount at all conditions. Optimum charge amount in the heat recovery mode was 14% lower than that in the cooling mode at the standard condition because the refrigerant only passed the indoor units. It is required to store the excessive refrigerant charge in a storage tank to optimize the system performance at operating modes.

Keywords

References

  1. Houcek, J. and Thedford, M., 1984, 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, Texas
  2. Stoecker, W. F., Smith III, L. D., and Emde, B. N., 1981, Influence of the expansion device on the seasonal energy requirements of a residential air conditioner, ASHRAE Trans., Vol. 87, No. 1, pp. 349-360
  3. Jung, D. S., Kim, M. and Kim, M. S., 1999, PID control of multi-type heat pump system, Proceedings of the SAREK, pp. 541-545
  4. Choi, E. and Kim, J., 2002, The effects of the refrigerant charge on the performance of an air conditioner with capillary tube expansions, Korean Journal of Air-Conditioning and Refrigeration Engineering, Vol. 14, No. 5, pp. 359-364
  5. Kang, H., Lee, S., Joo, Y., Chung, H., Kim, Y. and Choi, J., 2007, Experimental study on the performance characteristics of a simultaneous heating and cooling heat pump system at each operating mode, Korean Journal of Air-Conditioning and Refrigeration Engineering, Vol. 19, No. 10, pp. 679-686
  6. ANSI/AMCA 210, 1985, Laboratory Methods of Testing Fans for Rating, Arlington(VA), ANSI
  7. ARI 210/240, 1986, Unitary Air-conditioning and Air-source Heat Pump Equipment, Arlington( VA), ARI
  8. ISO/DIS 15042, 2005, Multi-split Air conditioners and Air-to-air Heat Pumps-Testing and Rating for Performance
  9. Farzard, M. and O'Neal, D. L., 1994, The effect of improper refrigerant charging on the performance of a residential heat pump with fixed expansion devices(capillary tube and short tube orifice), Proceedings, The 29th Intersociety Energy-Conversion Engineering Conference, California, Part 2, pp. 921-926