Numerical simulation and experimental research on combustion characteristics of compression-ignition engine under an O₂/CO₂ atmosphere

ABSTRACT

This study investigates the combustion characteristics of compression-ignition engines under an O₂/CO₂ atmosphere, through numerical simulation and experimental analysis methods, which will eventually provide a new solution of the “NOx-Soot” trade-off problem. The computational fluid dynamics (CFD) software FIRE is adopted to simulate in-cylinder combustion temperature and pressure, according to different O₂ volume ratio and different ignition advance angle. The dyno test including visualisation diagnostic is carried out under the above gas composition so that the emission and combustion characteristics can be analysed.

The simulation results of engine power performance show that when the ignition advance angle remains unchanged compared to the baseline engine, a combination of 65% O₂ with 35% CO₂ is the recommended gas composition. And the in-cylinder peak pressure of the engine is about 6.66 MPa, which is equivalent to that when the engine runs at normal air intake conditions. The results of the optical engine experiment show that, compared to the baseline engine under normal air, the ignition timing, the timing of maximum rate of pressure rise, the timing of maximum rate of heat release and peak pressure are 0.66°CA, 4.93°CA, 5°CA and 0.15°CA ahead, respectively.

KEYWORDS:

• Combustion characteristics
• compression-ignition engine
• O₂/CO₂ atmosphere
• optical visualisation test

Acknowledgements

Thanks are due to the Department of Energy Engineering of the Zhe Jiang University and the School of Energy and Power Engineering of Wuhan University of Technology.

Additional information

Funding

This research is substantially supported by “the Fundamental Research Funds for the Central Universities” (WUT: 163105001), “the Key Laboratory of Marine Power Engineering & Technology” (KLMPET2016-01) (Wuhan University of Technology), “the Ministry of Transport”, “the Specialized Research Fund for the Doctoral Program of Higher Education of China” (Grant No 20130111120021) and “the Science Foundation for Post-doctoral Scientists of China” (Grant No 2014M561757).

Notes on contributors

Hanyu Chen

Dr Hanyu Chen is a Lecturer of the School of Energy and Power Engineering, Wuhan University of Technology. His research areas include electronic control system development for engine, combustion and emissions for internal combustion engine.

Hai Shen

Mr Hai Shen is now studying for a master’s degree in Hefei University of Technology. His current research interest is combustion and emissions for internal combustion engine.

Tong Wu

Mr Tong Wu is now studying for a master’s degree in Hefei University of Technology. His current research interest is combustion and emissions for internal combustion engine.

Chengji Zuo

Prof Chengji Zuo is the Head and Professor of the Department of Thermal Energy and Power Engineering, Hefei University of Technology. He has authored and co-authored more than 100 papers. His main research interests include combustion and emissions for internal combustion engine, electronic control system development for engine, alternative fuel engine and biomass liquefaction.