Analysis of the Impact of High-Pressure EGR on Gasoline Partially Premixed Combustion
2022-01-0550
03/29/2022
- Event
- Content
- Due to the increasingly stringent emission regulations for Internal Combustion Engines (ICE), a great amount of research has been carried out, over the past years, in the field of innovative combustion approaches characterized by high efficiency and low emissions. Previous research demonstrates that such promising techniques, named Low Temperature Combustion (LTC), combine the benefits of compression-ignited engines, especially high compression ratio and unthrottled lean mixture, with low engine-out emissions using a properly premixed air-fuel mixture. Due to longer ignition delay and high volatility compared to diesel, gasoline-like fuels show a good potential for the generation of a highly-premixed charge, needed to reach LTC characteristics. In this scenario, gasoline Partially Premixed Combustion (PPC), obtained through the direct injection of gasoline at high pressure (up to 1000 bar), showed a good potential for the simultaneous reduction of pollutants and emissions in CI engines. However, a key factor to achieve the optimal trade-off between efficiency and pollutants is the proper management of Exhaust Gas Recirculation (EGR). This work presents the experimental investigation performed running a light-duty compression ignited engine, operated with gasoline PPC, and varying the mass of recirculated gases trapped in the combustion chamber. To guarantee the stability of gasoline auto-ignition in all the tested conditions, a specific experimental layout has been developed to accurately quantify the amount of trapped residual gases due to internal and external EGR. The obtained results clearly highlight the impact of EGR on combustion process and emissions, demonstrating that the optimization of charge dilution with EGR is fundamental to guarantee the optimal compromise between efficiency and emissions.
- Citation
- Ravaglioli, V., Ponti, F., Silvagni, G., Moro, D. et al., "Analysis of the Impact of High-Pressure EGR on Gasoline Partially Premixed Combustion," SAE Technical Paper 2022-01-0550, 2022, .