International Journal of Air-Conditioning and Refrigeration

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

Effects of Gas Injection on the Heating Performance of a Two-Stage Heat Pump Using a Twin Rotary Compressor with Refrigerant Charge Amount

  • Heo, Jae-Hyeok (Graduate School of Mechanical Engineering, Korea University) ;
  • Jeong, Min-Woo (Graduate School of Mechanical Engineering, Korea University) ;
  • Jeon, Jong-Ug (Graduate School of Mechanical Engineering, Korea University) ;
  • Kim, Yong-Chan (Department of Mechanical Engineering, Korea University)
  • Published : 2008.09.30
Download PDF
⟨ Previous Next ⟩

Abstract

For heat pumps used in a cold region, it is very important to obtain appropriate heating capacity. Several studies using a variable speed compressor and an additional heater have been performed to enhance heating capacity at low ambient temperatures. However, for outdoor temperature conditions below $-15^{\circ}C$, it is still difficult to obtain enough heating capacity above the rated value. In recent studies, the application of gas injection technique into a two-stage heat pump yielded noticeable heating performance improvement at low temperature conditions. In this study, the heating performance of a two-stage gas injection heat pump with a rated capacity of 3.5 kW was measured and analyzed by varying refrigerant charge amount and EEV opening at the standard heating condition. The heating performance of the two-stage gas injection heat pump was compared with that of a two-stage non-injection heat pump. The heating capacity and COP of the two-stage gas injection heat pump were improved by 2-10% at the optimal charging condition over those of the two-stage non-injection heat pump.

Keywords

References

  1. Kim, B. H., 2001, An experimental investigation on the variation of heating performance due to the refrigerant flow control in a variable-speed heat pump, Korea Journal of Air-conditioning and Refrigeration, Vol. 13, No. 8, pp. 746-756
  2. Hwang, Y. J., 1998, A technical prospects and trends in small size heat pump, The Magazine of the Society of Air-conditioning and Refrigerating Engineers of Korea, Vol. 27, No. 2, pp. 165-175
  3. Korean Standard C 9306, 1999, Airconditioner, Korean Standards Association, Korea
  4. ASHRAE Standard 116, 1993, Methods of testing for seasonal efficiency of unitary air-conditioner and heat pumps, ASHRAE Standard 116, Atlanta (GA), ASHRAE, USA
  5. ANSI/AMCA 210, 1985, Laboratory methods of testing fans for rating, Arlington (VA), ANSI, USA
  6. ASHRAE Guideline 2, 1986, Engineering analysis of experimental data, Atlanta (GA), ASHRAE, USA
  7. Cho, H., Ryu, C., Kim, Y., Kim, H. Y., 2005, Effects of refrigerant charge amount on the performance of a transcritical $CO_2$ heat pump, International Journal of Refrigeration, Vol. 28, pp. 1266-1273 https://doi.org/10.1016/j.ijrefrig.2005.09.011
  8. Chikahisa, T., Ichikawa, H., Murayama, T., 1996, Investigations on compact and high-performance heat pumps for cold regions, Transaction B of the Japan Society of Mechanical Engineers, Vol. 62, No. 593, pp. 340-346 https://doi.org/10.1299/kikaib.62.340
  9. Ju, J. D., Bae, K. S., Hwang, Y. K., Lee, Y. Y, Jeong, G. H., Oh, S. K., 2005, An experimental study on the performance of a heat pump for the cold climate, Korea Journal of Air-conditioning and Refrigeration, Vol. 17, No. 1, pp. 39-46
  10. Choi, J., Kim, Y., Ha, J., 2001, Experimental study on superheat control of a variable speed heat pump, Korea Journal of Air-conditioning and Refrigeration, Vol. 13, No. 4, pp. 233-241
  11. Ma, G., Chai, Q., 2004, Characteristics of an improved heat-pump cycle for cold regions, Applied Energy, Vol. 77, pp. 235-247 https://doi.org/10.1016/S0306-2619(03)00123-5
  12. Park, T. J., Lee, M. K., Jeong, J. H., Chang, K. S., 2003, Comparison of performance variation between R-22 and R-410A refrigeration systems, Korea Journal of Air-conditioning and Refrigeration, Vol. 15, No. 3, pp. 166-176