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Exploiting SI Engine Efficiency Through Lean Burn Operation in Combination with Stroke Extension, Miller Timings and High Compression Ratios
Technical Paper
2021-24-0034
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Individual transport plays a considerable role in global greenhouse gas emissions. Hence, worldwide legislation increases the demands on the automotive industry with regard to emissions. Because internal combustion engines will likely play an important role in the future transport, particularly in hybrid propulsion systems, further improvement of the combustion system is necessary. Therefore, the potential of lean burn combustion in combination with other technologies is investigated. The primary focus is on the improvement of SI engine efficiency.
For the investigations conducted, an extremely downsized SI single cylinder research engine is upgraded with various engine technologies. The stroke-to-bore ratio is increased to 1.5, leading to higher piston speeds. The resulting increase in tumble and hence turbulent flame speed supports the combustion performance of highly diluted mixtures. In order to further increase the thermodynamic efficiency, miller timings are realised in the form of late intake valve closing. Additionally, the compression ratio is increased to ε = 15.
The investigations reveal that relative air/fuel ratios of up to λ = 1.6 are achievable while maintaining reasonable combustion stability. The use of late intake valve closing limits the maximum dilution. But similar efficiencies compared to reference timings with higher dilution can be achieved. Increasing the compression ratio allows further increase in indicated efficiency, especially when combined with the miller timings. Lean operation enables an increase of engine efficiency at low load as well as high load operation. Best values are achieved in mid loads, where an indicated efficiency of ηi = 44.1% is possible.
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Wenz, E., Pauls, A., Thielen, M., Todt, A. et al., "Exploiting SI Engine Efficiency Through Lean Burn Operation in Combination with Stroke Extension, Miller Timings and High Compression Ratios," SAE Technical Paper 2021-24-0034, 2021, https://doi.org/10.4271/2021-24-0034.Data Sets - Support Documents
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References
- IPCC
- European Commission https://ec.europa.eu/clima/policies/transport/vehicles/regulation_en#tab-0-0
- Pischinger , S. , Mally , M. , Bergmann , D. , Thewes , M. , et al. Gasoline Engines with Highest Efficiency - What Large and Small Bore Engines Can Learn from Each Other 16th Conference ‘The Working Process of the Internal Combustion Engine’ Graz 2017
- Ayala , F.A. , Gerty , M.D. , and Heywood , J.B. Effects of Combustion Phasing, Relative Air-fuel Ratio, Compression Ratio, and Load on SI Engine Efficiency SAE Technical Paper 2006-01-0229 2006 https://doi.org/10.4271/2006-01-0229
- Stokes , J. , Lake , T.H. , and Osborne , R.J. A Gasoline Engine Concept for Improved Fuel Economy -The Lean Boost System SAE Technical Paper 2000-01-2902 2000 https://doi.org/10.4271/2000-01-2902
- Eilts , P. Das Miller- und das Atkinsonverfahren an Verbrennungsmotoren MTZ Conference Ladungswechsel im Verbrennungsmotor Stuttgart 2014
- Scheidt , M. , Brands , C. , Kratzsch , M. , and Günther , M. Kombinierte Miller-AtkinsonStrategie für Downsizing-Konzepte MTZ - Motortechnische Zeitschrift 75 5 Apr.2014 14 21
- Cordier , M. , Laget , O. , Duffour , F. , Gautrot , X. et al. Increasing Modern Spark Ignition Engine Efficiency: A Comprehension Study of High CR and Atkinson Cycle SAE Technical Paper 2016-01-2172 2016 https://doi.org/10.4271/2016-01-2172
- Luisi , S. , Doria , V. , Stroppiana , A. , Millo , F. et al. Experimental Investigation on Early and Late Intake Valve Closuresfor Knock Mitigation through Miller Cycle in a Downsized Turbocharged Engine SAE Technical Paper 2015-01-0760 2015 https://doi.org/10.4271/2015-01-0760
- Martins , J. , Uzuneanu , K. , Ribeiro , B.S. , and Jasasky , O. Thermodynamic Analysis of an Over-Expanded Engine SAE Technical Paper 2004-01-0617 2004 https://doi.org/10.4271/2004-01-0617
- Clasen , K. and Koopmans , L. Investigation of Homogeneous Lean SI Combustion in High Load Operating Conditions SAE Int. J. Advances & Curr. Prac. in Mobility 2 4 2020 2051 2066 10.4271/2020-01-0959
- Todt , A. , Schech , J. , Wiebe , A. , and Bradenstahl , A.
- Kuznik , A. , Negüs , F. , Kelich , V. , Thielen , M. et al. 2021
- Durst , B. , Unterweger , G. , Rubbert , S. , Witt , A. et al. 2015
- Landerl , C. , Schwarz , C. , Durst , B. , Böhm , M. et al. 2017
- Doornbos , G. , Hemdal , S. , Denbratt , I. , and Dahl , D. Knock Phenomena under Very Lean Conditions in Gasoline Powered SI-Engines SAE Int. J. Engines 11 1 2018 10.4271/03-11-01-0003
- Albrecht , M. , Deeg , H.-P. , Schwarzenthal , D. , and Eilts , P. The Influence of Fuel Composition and Renewable Fuel Components on the Emissions of a GDI Engine SAE Technical Paper 2020-37-0025 2020 https://doi.org/10.4271/2020-37-0025
- Pauls , A. and Eilts , P. Optical Investigation of Mixture Formation in a Small Bore DISI Engine by Laser Induced Exciplex Fluorescence (LIEF) SAE Technical Paper 2019-24-0133 2019 https://doi.org/10.4271/2019-24-0133
- Eilts , P. and Klare , L. Investigations on the Determination of the Service Methane Number of LNG SAE Technical Paper 2018-01-1143 2018 https://doi.org/10.4271/2018-01-1143
- Huß , M. 2012