A Study on Combustion Process of Biodiesel Fuel with Pilot Injection in a Common-rail Diesel Engine

파일럿분사에 의한 바이오디젤유의 연소과정에 관한 연구

  • Bang, Joong-Cheol (School of Mechanical Engineering, Kumoh National Institute of Technology) ;
  • Kim, Sung-Hoon (Department of Mechanical Engineering, Graduate School, Kumoh National Institute of Technology)
  • 방중철 (금오공과대학교 기계공학부) ;
  • 김성훈 (금오공과대학교 대학원 기계공학과)
  • Received : 2010.10.12
  • Accepted : 2010.12.27
  • Published : 2011.05.01

Abstract

American NREL (National Renewable Energy Laboratory) reported that BDF20 could reduce PM, CO, SOx, and cancerogenic matters by 13.6%, 9.3%, 17.6%, and 13% respectively, compared to diesel fuel. BDF20 has been being tested on garbage trucks and official vehicles at Seoul City, which is positive on air environment, but negative on combustion by higher viscosity in winter season. This study investigated the combustion characteristics by applying pilot injection for improving the deterioration of combustibility caused by the higher viscosity of the BDF20 with the combustion flames taken by a high-speed camera and the cylinder pressure diagram. A 4-cycle single-cylinder diesel engine was remodeled to a visible 2-cycle engine taking the flame photographs, which has a common-rail injection system. The test was done laboratory temperature at $5{\sim}6^{\circ}C$. The results obtained are summarized as follows, (1) In the case of without pilot injection, the flame propagation speed was slowed and the maximum combustion pressure became lower. The phenomena became further aggravated as the fuel viscosity gets higher. (2) In the case of with pilot injection, early stage of combustion such as rapid ignition timing and flame propagation was activated since intermediate products formed by pilot injection act as a catalyst for combustion of main fuel.

Keywords

References

  1. D. S. Baik and S. W. Lee, "A Study on Spray and Combustion Characteristics by Temperature of Biodiesel Fuel," Transactions of KSAE, Vol.16, No.1, pp.152-157, 2008.
  2. S. H. Yoon, M. Y. Kim, S. I. Kwon, H. S. Jeon and C. S. Lee, "Combustion Characteristics of Biodiesel Fuel Derived from Soybean in a Common-rail Diesel Engine," Spring Conference Proceedings, KSAE, pp.1922-1928, 2006.
  3. S. H. Choi and Y. T. Oh, "A Simultaneous Reduction of Smoke and NOx with Biodiesel Fuel in a D.I. Diesel Engine," Transactions of KSAE, Vol.13, No.2, pp.65-71, 2005.
  4. K. H. Ryu, Y. J. Yun and Y. T. Oh, "The Combustion Characteristics of Agricultural Diesel Engine using Biodiesel Fuel (Ester of Rice Bran Oil)," Transactions of the Korean Society of Mechanical Engineer, Vol.27, No.2, pp.181-187, 2003. https://doi.org/10.3795/KSME-B.2003.27.2.181
  5. Y. Hirako and M. T. Ohta, "Effect of Lean Pre-mixture on the Combustion in Diesel Engine (1st Report)," Bulletin of JSME, Vol.16, No.101, pp.1750-1757, 1973. https://doi.org/10.1299/jsme1958.16.1750
  6. Y. Hirako and M. T. Ohta, "Effect of Lean Pre-mixture on the Combustion in Diesel Engine (2nd Report)," Bulletin of JSME, Vol.17, No.104, pp.256-263, 1973.
  7. Y. Hirako and M. T. Ohta, "Effect of Lean Pre-mixture on the Combustion in Diesel Engine (3rd Report)," Bulletin of JSME, Vol.17, No.109, pp.936-943, 1973.
  8. W. Choi, C. W. Park, S. H. Kook and C. S. Bae, "The Effect of Triple Injection on Engine Performance and Emission in a HSDI Diesel Engine," Transactions of KSAE, Vol.12, No.5, pp.40-57, 2004.
  9. M. Y. Kim, D. J. Lee, H. G. Roh, J. H. Lee and C. S. Lee, "Effect of Injection Parameters on Combustion and Flame Characteristics in a Small Common-rail Diesel Engine," Fall Conference Proceedings, KSAE, pp.397-404, 2003.
  10. H. G. Roh and C. S. Lee, "The Effect of Multiple Injection on the Stability of Combustion and Emission Characteristics in a Passenger Car Common-rail Diesel Engine," Spring Conference Proceedings, KSAE, pp.330-335, 2006.
  11. C. W. Park, S. H. Kook and C. S. Bae, "The Effect of Pilot Injection on the Engine Performance and Emissions in a HSDI Diesel Engine," Spring Conference Proceedings, KSAE, pp.286-291, 2003.
  12. I. S. Choi and J. C. Bang, "The Flame Characteristics by Combustion Chamber Shape in 2 Stroke D. I. Diesel Engine," Transactions of KSAE, Vol.11, No.1, pp.55-63, 2003.