Experimental Study of Emission Characteristics for CNG Passenger Car

CNG 승용 자동차의 배출가스 특성에 관한 실험적 연구

Kim, Hyun-jun;Lee, Ho-kil

  • Received : 2015.11.24
  • Accepted : 2015.12.24
  • Published : 2015.12.31


Recently, most of the energy consumed in vehicle is derived from fossil fuels. For this reason, the demand for clean, renewable and affordable alternative energy is forcing the automotive industry to look beyond the conventional fossil fuels. Natural gas represents today a promising alternative to conventional fuels for vehicles propulsion, because it is characterized by a relatively low cost, better geopolitical distribution than oil, lower environmental impact, higher octane number and a higher self ignition temperature. Above all, CNG is an environmentally clean alternative to the existing spark ignition engines with the advantages of minimum change. In this study was installed bi-fuel system that a conventional 2 liters gasoline engine was modified to run on natural gas by a gas injection system. Experiments were mainly carried on the optimization of an ECU control strategy affecting the emission characteristics of CNG/Gasoline bi-fule vehicle. The test results shown that CO2 emission in bi-fuel mode was reduced 16% compared to gasoline fuel in the NEDC mode. Also the amount of CO and HC emissions in bi-fuel and gasoline modes were found to equality. But Compared to gasoline, the bi-fuel mode resulted in higher NOx emissions.


CNG;Bi-fuel vehicle;mono-fuel vehicle;emission;electronic control unit(ECU);NEDC mode


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