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A Study of Efficiency and Emissions for a 4-Stroke SI and a CAI Engine with EEGR and Light Boost
Technical Paper
2006-32-0042
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
A single-cylinder, 500cc research engine was tested under Spark-Ignition (SI) and Controlled Auto-Ignition (CAI) operation with similar load and speed conditions. Camshafts with low-lift and short duration, run with a negative valve overlap, were used to obtain CAI at wide open throttle. Two different camshaft profiles were tested in order to get a wide span of loads at 1200 and 2000rpm. The SI engine was Port Fuel-Injected (PFI) while the CAI engine was tested with both PFI and an Orbital Air-Assist Direct-Injection (DI) system.
To reduce the high Indicated Specific Nitrogen Oxide (ISNOx) emissions at λ=1, 10% External Exhaust Gas Residuals (EEGR) was applied to the SI engine. EEGR reduced ISNOx emissions and there was slight reduction in ISFC. However, when the engine was tested in CAI mode, both ISNOx and ISFC were lower than the SI engine. To reduce the high Pressure Rise Rates (Prise) associated with higher loads, 5 and 10% EEGR was applied to the DI CAI engine at λ values between 1 and 1.3 with fixed valve timing. At λ=1, the decrease in Indicated Mean Effective Pressure (IMEP) was minimal as the EEGR level was increased. The EEGR reduced the Prise, ISFC and ISNOx. However, when the mixture was leaner, the IMEP reduced as more EEGR was applied. At lean mixtures with EEGR, the ISFC and ISNOx were both very low. The application of EEGR also reduced the Indicated Specific Carbon Monoxide (I SC O) and Indicated Specific Carbon Dioxide (ISCO2) emissions.
To reduce ISFC and ISNOx at low load, a 0.18bar boost was applied to the engine intake. The boost allowed the exhaust valve to be closed earlier, which meant a larger amount of Internal Exhaust Gas Residuals (IEGR) was trapped. As the airflow had increased from the boost, leaner mixtures were used to keep the Prise to a minimum. λ values between 1.1 and 1.3 were tested. At leaner mixtures and early exhaust valve closing, the ISNOx emissions were almost eliminated. The leaner mixture ensured that the ISFC was minimised and the ISCO and ISCO2 emissions were substantially decreased.
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Gaynor, J., Fleck, R., Kee, R., Kenny, R. et al., "A Study of Efficiency and Emissions for a 4-Stroke SI and a CAI Engine with EEGR and Light Boost," SAE Technical Paper 2006-32-0042, 2006, https://doi.org/10.4271/2006-32-0042.Also In
References
- Noguhi, M. Tanaka, Y. Tanaka, T. Takeuchi, Y. “A Study on Gasoline Engine Combustion by Observation of Intermediate Reactive Products during Combustion” SAE paper 790840 1979
- Onishi, S. Jo, S.H. Shoda, K. Jo, P.D. Kato, S. “Active Thermo-Atmosphere Combustion (ATAC) - A New Combustion Process for Internal Combustion Engines” SAE paper 790501 1979
- Najt, P.M. Foster, D.E. “Compression-Ignited Homogenous Charge Combustion” SAE paper 830264 1983
- Thring, R.H. “Homogenous-Charge Compression (HCCI) Engines” SAE paper 892068 1989
- Aoyama, T. Hattori, Y. Sato, Y. Mizuta, J. “An Experimental Study on Premixed-C harge Compression Ignition Gasoline Engine” SAE paper 960081 1996
- Law, D. Kemp, D. Allen, J. Kirkpatrick, G. Copland, T. “Controlled Combustion in an IC-Engine with a Fully Variable Valve Train” SAE paper 2001-01-0251 2000
- Allen, J. Law, D. “Variable Valve Actuated Controlled Auto-Ignition: Speed and Load Maps and Strategic Regimes of Operation” SAE paper 2002-01-0422 2002
- Koopmans, L. Denbratt, I. “A Four Stroke Camless Engine, Operated in Homogeneous Charge Compression Ignition Mode with Commercial Gasoline” SAE paper 2001-01-3610 2001
- Chen, R. Milovanovic, N. Turner, J. Blundell, D. “The Thermal Effect of Internal Exhaust Gas Recirculation on Controlled Auto-Ignition” SAE paper 2003-01-0751 2003
- Kontarakis, G. Collings, N. Ma, T. “Demonstration of HCCI Using a Single Cylinder Four-stroke SI Engine with Modified Valve Timing” SAE paper 2000-01-2870 2000
- Urushihara, T. Hiraya, K. Kakuhou, A. Itoh, T. “Expansion of HCCI Operation Region by the Combination of Direct Fuel Injection, Negative Valve Overlap and Internal Fuel Reformation” SAE paper 2003-01-0749 2003
- Marriott, C. Reitz, R. “Experimental Investigation of Direct Injection-Gasoline for Premixed Compression Ignited Combustion Phasing Control” SAE paper 2002-01-0418 2002
- Aleiferis, P. Charalambides, A. Hardalupas, Y. Taylor, A. Urata, Y. “Modelling and Experiments of HCCI Engine Combustion with Charge Stratification and Internal EGR” SAE paper 2005-01-3725 2005
- Sjöberg, M. Edling, L.-O. Eliassen, T. Magnusson, L. Ångström, H.-E. “GDI HCCI: Effects of Injection Timing and Air-Swirl on Fuel Stratification, Combustion and Emissions Formation” SAE paper 2002-01-0106 2002
- Cairns, A. Blaxill, H. “The Effects of Combined Internal and External Exhaust Gas Recirculation on Gasoline Controlled Auto-Ignition” SAE paper 2005-01-0133 2005
- Gentili, R. Frigo, S. “Further Insight on ATAC and GDI Combination in Two-Stroke Engines” SAE paper 2000-01-0897 2000
- Leach, B. Zhao, H. Li, Y. Ma, T. “Control of CAI Combustion Through Injection Timing in a GDI Engine With an Air-Assisted Injector” SAE paper 2005-01-0134 2005
- Cairns, A. Blaxill, H. “Lean Boost and External Exhaust Gas Recirculation for High Load Controlled Auto-Ignition” SAE paper 2005-01-3744 2005
- Yap, D. Wyszynski, M. Megaritis, A. Xu, H. “Applying boosting to gasoline HCCI operation with residual gas trapping” SAE paper 2005-01-2121 2005
- 4stHEAD Design Software Prof. Blair and Associates Belfast, Northern Ireland www.profblairandassociates.com
- Heywood, J.B. “Internal Combustion Engine Fundamentals” McGraw-Hill 1988
- Aroonsrisopon, T. Werner, P. Waldman, J. Sohm, V. Foster, D. Morikawa, T. Iida, M. “Expanding the HCCI Operation With the Charge Stratification” SAE paper 2004-01-1756 2004
- Persson, H. Agrell, M. Olsson, J-O Johansson, B Ström, H. “The Effect of Intake Temperature on HCCI Operation Using Negative Valve Overlap” SAE paper 2004-01-0944 2004
- Zhao, H. Ladommatos, N. “Engine Combustion and Diagnostics” SAE publication R-264 2001