The Engine Performance and Emission Characteristics of CNG/Diesel Dual-fuel Engine by CNG Mixing Ratio

CNG/Diesel Dual-fuel 엔진의 CNG 혼합율에 따른 엔진성능 및 배출가스 특성에 관한 연구

  • Choi, Gun-Ho (Graduate School of Mechanical and Automotive Engineering, Ulsan University) ;
  • Lim, Ock-Taeck (Department of Mechanical and Automotive Engineering, Ulsan University)
  • 최건호 (울산대학교 대학원 기계자동차공학과) ;
  • 임옥택 (울산대학교 기계자동차공학부)
  • Received : 2010.03.15
  • Accepted : 2010.11.08
  • Published : 2011.05.01


A CNG/diesel dual-fuel engine uses CNG as the main fuel and injects a small amount of diesel as an ignition priming. This study proposed the modification of the existing diesel engine into a dual-fuel engine that injects diesel with a high pressure by common rail direct injection (CRDI) and by injecting CNG at the intake port for premixing. And experiment was progressed for understanding about effect of CNG mixing ratio. The CNG/diesel dual-fuel engine showed equally satisfactory coordinate torque and power regardless of CNG mixing ratio. The PM emission was low at any CNG mixing ratio because of very small diesel pilot injection. In case of NOx and HC, high CNG mixing ratio showed low NOx and HC emissions at low speed. At medium & high speed, low CNG mixing ratio showed low NOx and HC emissions. Therefore, it would be optimized by controlling CNG mixing ratio.


Supported by : 울산대학교


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