Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Comparison of Combustion Characteristics On the Basis of the Dilution Ratio in Diesel Engines with LPL EGR

저압 EGR을 적용한 디젤엔진의 희석비에 따른 연소 특성 비교

  • Lim, Gi-Hun (Dept. of Environmental System Engineering, Univ. of Science and Technology) ;
  • Park, Jun-Hyuk (Dept. of Mechanical Engineering, Kyungwon Univ.) ;
  • Choi, Young (Engine Research Team, Korea Institute of Machinery and Materials) ;
  • Lee, Sun-Youp (Engine Research Team, Korea Institute of Machinery and Materials) ;
  • Kim, Yong-Min (Engine Research Team, Korea Institute of Machinery and Materials)
  • 임기훈 (과학기술연합대학원대학교 청정환경시스템공학과 대학원) ;
  • 박준혁 (경원대학교 기계공학과 대학원) ;
  • 최영 (한국기계연구원 그린환경에너지기계연구본부 그린동력연구실) ;
  • 이선엽 (한국기계연구원 그린환경에너지기계연구본부 그린동력연구실) ;
  • 김영민 (한국기계연구원 그린환경에너지기계연구본부 그린동력연구실)
  • Received : 2010.12.10
  • Accepted : 2011.02.22
  • Published : 2011.05.01
Download PDF
⟨ Previous Next ⟩

Abstract

Exhaust gas recirculation (EGR) is more effective than selective catalytic reduction (SCR) or lean $NO_x$ trap (LNT) for the reduction of $NO_x$ emissions in diesel engines. A large amount of EGR gas is necessary to satisfy the stringent regulations on $NO_x$ emissions. Low pressure loop (LPL) EGR is almost independent of the variable geometry turbocharger (VGT) at a specific boost pressure, so LPL EGR is better than conventional high pressure loop (HPL) EGR in terms of EGR supply. We compare the influence of HPL EGR and LPL EGR on the combustion characteristics at a constant boost pressure in a diesel engine. The dilution ratio was employed as an independent parameter to analyze the effect of the dilution of the intake charge for each EGR loop. At the same level of $NO_x$ emissions, the fuel consumption and smoke opacity were slightly lower for LPL EGR than for HPL EGR.

디젤엔진에서 배기가스 재순환(EGR; Exhaust Gas Recirculation)은 선택적 환원 촉매나 $NO_x$ 흡장 촉 매에 비해 $NO_x$ 배출 저감을 위한 가장 효과적인 기술이다. 점점 더 강화되어 가는 $NO_x$ 배출 규제를 만족시키기 위해서는 많은 양의 EGR 가스 공급이 필요하다. 저압 EGR은 일정한 과급 압력에서 가변형상 터보차져의 제어와 거의 독립적이기 때문에 EGR 공급 측면에서 보면 저압 EGR이 기존의 고압 EGR에 비해서 더 많은 장점을 갖는다. 본 연구에서는 저압 EGR이 연소 특성에 미치는 영향을 고압 EGR을 적용했을 때와 비교하였다. 각 EGR 루프에 대해 혼합기의 희석 정도에 따른 영향을 분석하기 위해 독립변수로써 희석비를 사용하였다. 저압 EGR을 적용하였을 때, 고압 EGR을 적용했을 때와 동등한 $NO_x$ 배출량을 유지하면서 연료 소비율과 매연 배출은 고압 EGR의 경우보다 좀 더 낮은 결과를 보였다.

Keywords

References

  1. Maiboom, A., Tauzia, X. and Hétet, J. -F.,2008, "Influence of High Rates of Supplemental Cooled EGR on NOx and PM Emissions of an Automotive HSDI Diesel Engine Using an LP EGR Loop," International Journal of Energy Research, Vol. 32, No. 15, pp. 1383-1398. https://doi.org/10.1002/er.1455
  2. Lee, K. S., Baek, M. Y. and Park, H. B.,2007, "Study on Low Pressure Loop EGR System for Heavy-duty Diesel Engine to Meet EURO-5 $NO_x$ Regulation," Journal of the Korea Society For Power System Engineering, Vol. 11, No. 4, pp. 12-17.
  3. Lim, G. H., Park, C. W., Choi, Y. and Park, J.H., 2010, "Comparison of Emission Characteristics with Respect to High Pressure Loop and Low Pressure Loop EGR in 2.0 L Diesel Engine," 2010 Spring conference of the Korea Society of Mechanical Engineering, pp. 94-95.
  4. Ladommatos, N., Abdelhalim, S. M., Zhao, H.and Hu, Z., 1997, "The Dilution, Chemical, and Thermal Effects of Exhaust Gas Recirculation on Diesel Engine Emissions-Part 4: Effects of Carbon Dioxide and Water Vapor," SAE Technical paper, 971660.
  5. Sohn, H. S. and Kim, H. Y., 2002, "Effects of Oxygen Concentration on the NOx Emission of Non-Premixed Flame in Hot Exhaust Gas," The Korea Society of Mechanical Engineering B, Vol. 26, No. 6, pp. 833-841. https://doi.org/10.3795/KSME-B.2002.26.6.833