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

  • 제39권1호
  • /
  • Pages.45-51
  • /
  • 2015
  • /
  • 1226-4881(pISSN)
  • /
  • 2288-5324(eISSN)
대한기계학회 (The Korean Society of Mechanical Engineers)
권호 표지
DOI QR코드

DOI QR Code

직접분사식 희박연소 LPG엔진에서 흡배기 밸브시기가 연소 및 배기특성에 미치는 영향

Effects of Intake and Exhaust Valve Timing on Combustion and Emission Characteristics of Lean-Burn Direct-Injection LPG Engine

  • 투고 : 2014.07.04
  • 심사 : 2014.09.22
  • 발행 : 2015.01.01
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

최근 강화되는 연료소비율과 배기 규제에 대응하기 위해 자동차용 엔진에 다양한 신기술들이 적용되고 있다. 직접분사식 희박연소 엔진은 안정적인 성층혼합기 연소를 통해 연료소비율 및 배출가스 개선이 가능하지만 과잉공기 조건에서 상대적으로 높은 수준은 질소산화물의 배출은 해결되어야 할 과제이다. 본 연구에서는 직접분사식 희박연소 LPG 엔진에서 가변 밸브 기구를 이용한 흡기 및 배기밸브 시기의 변경이 엔진의 성능 및 배출가스에 미치는 영향을 파악하고자 하였다. 스로틀링을 하지 않은 부분부하 운전 조건에서 흡기밸브 열림 시기의 진각은 공기과잉률의 증가에 의한 질소산화물 배출 증가에 원인으로 작용하였다. 배기밸브 열림 시기를 진각할 경우 팽창일 감소와 펌핑손실 증가에 의해 연료 소비율이 악화되었다.

In order to meet the enforced emission regulations and reduce fuel consumption, various new technologies are employed in engines. The problem of NOx emissions under a lean mixture condition should be solved, because a lean-burn direct-injection engine can realize stable lean combustion with a stratified mixture, which results in improvements in fuel economy and emissions. This study investigated the effects of intake and exhaust valve timing changes on the performance and emission characteristics of a lean-burn LPG direct-injection engine. Under a partial-load operating condition without throttling, an increase in the intake valve opening led to an increase in NOx emissions due to an increase in the amount of excess air. The fuel consumption deteriorated with an increase in the exhaust valve opening due to a decrease in the expansion work and an increase in the pumping loss.

키워드

참고문헌

  1. Schwarz, C., Schunemann, E., Durst, B., Fischer, J. and Witt, A., 2006, "Potentials of the Spray-guided BMW DI Combustion System," SAE Technical paper, 2006-01-1265.
  2. Van Basshuysen, R., 2007, "Gasoline Engine with Direct Injection," Vieweg+Teubner.
  3. Pauly, T., Franoschek, S., Hoyer R. and Echhoff, S., 2010, "Cost and Fuel Economy Driven Aftertreatment Solution for Lean GDI," SAE Technical paper, 2010-01-0363.
  4. Ramesh, A., 2003, "An Experimental Study of Cyclic Variations in a Lean Burn Natural Gas Fuelled Spark Ignition Engine," ASME ICEF2003-772.
  5. Chang, W.-S., Kim Y.-N. and Kong, J.-K., 2007, "Design and Development of a Spray-guided Gasoline DI Engine," SAE 2007-01-3531.
  6. Oh, H. C., Lee, M. S., Park, J. S. and Bae, C. S., 2011, "Effect of Injection Pressure and Injection Timing on Combustion Characteristics of Spray-Guided Direct-Injection Spark-Ignition Engine under Lean Stratified Combustion Operation," Trans. Korean Soc. Mech. Eng. B, Vol. 35, No. 10, pp. 981-987. https://doi.org/10.3795/KSME-B.2011.35.10.981
  7. Park, C., Park, Y., Oh, S., Lee, Y., Kim, T. Y., Kim, H., Choi, Y. and Kang, K.-Y., 2013, "Emission Characteristics of Gasoline and LPG in a Spray-Guided-Type Direct Injection Engine," SAE Technical paper, 2013-01-1323.
  8. Park, Y., Park, C., Kim, T. Y., Choi, Y., Lee, Y. and Oh, S., 2012, "Study of Performance and Emission Characteristics in a LPG Direct Injection Engine According to Multiple Injection," Proceedings of KIGAS fall conference, p. 4.
  9. Park, C., Park, Y., Oh, S., Lee Y. and Kim, T. Y., 2014, "A Study on the Combustion Characteristics with Control Strategy and Injector Position Changes in a Lean-burn LPG Direct Injection Engine," Trans. Korean Soc. Auto. Eng.,Vol. 22, No. 4, pp. 98-104. https://doi.org/10.7467/KSAE.2014.22.4.098
  10. Moriya, Y., Watanabe, A., Uda, H., Kawamura, H., Yoshioka, M. and Adachi, M., 1996, "A Newly Developed Intelligent Variable Valve Timing System -Continuously Controlled Cam Phasing as Applied to a New 3-Liter in-Line 6 Engine," SAE Technical paper, 960579.
  11. Klein, F., Kuhn, M., Weimann, H.-J., Wolpers, F., Kramer, M. and Abthoff, J., 1998, "The Influence of the Valve Stroke Design in Variable Valve Timing Systems on Load Cycle, Mixture Formantion and the Combustion Process in Conjunction with Throttle-Free Load Governing," SAE Technical paper, 981030.
  12. Nam, J. G., 2001, "A Study on the Residual Gas Fraction in Cylinder by the Adjustment of Variable Valve Timing with Volumetric Efficiency," Trans. Korean Soc. Auto. Eng., Vol. 9, No. 5, pp. 82-88.