Journal of Advanced Marine Engineering and Technology

The Korean Society of Marine Engineering (한국마린엔지니어링학회)
권호 표지
DOI QR코드

DOI QR Code

Theoretical study on the performance improvement of refrigeration system installed with ejector entraining expansion gases after expansion process

이젝터를 적용한 팽창기체 흡입 냉동시스템의 성능향상 해석 연구

  • Yun, Sangkook (Division of Mechanical & Energy Systems Engineering, Korea Maritime Ocean University)
  • Received : 2014.07.07
  • Accepted : 2014.08.18
  • Published : 2014.09.30
Download PDF
⟨ Previous Next ⟩

Abstract

In this paper, the performance characteristics for newly developed ejector refrigeration system, which is that the part of saturated vapor from liquid-vapor separator after ejector expansion process is entrained in ejector, and the saturated liquid flows in the evaporator and compressed with the rest of vapor in separator, is studied. The reasons of the performance improvement of refrigeration system are that the refrigeration capacity is increased due to quality reduction after iso-entropic expansion process by ejector and the compression work is reduced because of the relatively high pressure of vapor refrigerant before compression process. The comparison results of the ejector system entraining expansion gases with the present residential freezer show that the COP increases to 27.8% maximum in case of the pressure drop to 65% of high pressure of freezer, and to 40.1% for 75% pressure drop of refrigerant R401A. The COP improvement rate with 20%~60% pressure lift in diffuser of ejector is only 2.6%~3%.

본 연구는 이젝터 팽창기를 적용한 냉동기에서 팽창한 냉매가 액기분리기에 포집된 후, 이 중 포화기체의 일부는 이젝터로 재흡입되고, 포화액체는 증발기에 유입되어 증발된 후 액기분리기의 잔여 기체와 혼합되어 압축되는 공정을 고안하여 특성을 해석하였다. 본 공정의 특성은 이젝터에서 등엔트로피 팽창 후 액체량의 증가로 냉동능력이 증가하고, 압축기에 유입되는 기체의 압력이 상승하게 되어 압축일이 감소함으로써 효율이 증가하게 된다. 냉매 R134a를 적용하는 냉장고 시스템과 본 고안 시스템을 비교한 결과, 이젝터에서 압력이 65% 저하될 때 COP는 27.8%가 증가된 최대값이 되었다. 다른 냉매의 경우 R401A가 75% 압력강하에서 40.1%의 COP 증가를 보였다. 이젝터의 디퓨져에서의 압력 상승율이 20%~60%까지 변화될 때, COP 증가율은 2.6%~3%로 영향이 매우 적었다.

Keywords

References

  1. M. Zhou, X. Wang, and J. Yu, "Theoretical study on a novel dual-nozzle ejector enhanced refrigeration cycle for household refrigeratorfreezers," Energy Conservation and Management, vol. 73, pp. 278-284, 2013. https://doi.org/10.1016/j.enconman.2013.04.028
  2. A. B. Little and S. Garimella, "A review of ejector technology for refrigeration applications." International Journal of Air-Conditioning and Refrigeration, vol. 19, no. 1, pp. 1-15, 2011. https://doi.org/10.1142/S2010132511000351
  3. K. Sumeru, H. Nasution, and F. N. Ani, "A review on two-phase ejector as an expansion device in vapor compression refrigeration cycle" Renewable and Sustainable Energy Reviews, vol. 16, pp. 4927-4937, 2012. https://doi.org/10.1016/j.rser.2012.04.058
  4. F. Liu and E. A. Groll, "Study of ejector efficiencies in refrigerant cycles," Applied Thermal Engineering, vol. 52, pp. 360-370, 2013. https://doi.org/10.1016/j.applthermaleng.2012.12.001
  5. A. Khalil, M. Fatouh, and E. Elgendy, "Ejector design and theoretical study of R134a ejector refrigeration cycle," International Journal of Refrigeration, vol. 34, pp. 1684-1698, 2011. https://doi.org/10.1016/j.ijrefrig.2011.01.005
  6. C. Lucas and J. Koehler, "Experimental investigation of the COP improvement of a refrigeration cycle by use of an ejector," International Journal of Refrigeration, vol. 35, 1595-1605, 2012. https://doi.org/10.1016/j.ijrefrig.2012.05.010
  7. Y. Jia and C. Wenjian, "Area ratio effects to the performance of air-cooled ejector refrigeration cycle with R134a refrigerant," Energy Conservation and Management, vol. 53, pp. 240-246, 2012. https://doi.org/10.1016/j.enconman.2011.09.002
  8. A. Khalil, M. Fatouh, and E. Elgendy, "Ejector design and theoretical study of R134a ejector refrigeration cycle," International Journal of Refrigeration, vol. 34, pp. 1684-1698, 2011. https://doi.org/10.1016/j.ijrefrig.2011.01.005
  9. M. Ikegami and K. Kayano, "Refrigeration cycle device." Japan Patent PCT/JP2012/004557, July. 17, 2012.
  10. Kabusakigaishya Denso, "Ejector and ejector cycle device", Korean Patent 1020060121757, Nov., 29, 2006.