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Water Injection to Improve Direct Injection Spark Ignition Engine Efficiency
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 02, 2019 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
The increasing use of downsized turbocharged gasoline engines for passengers cars and the new European homologation cycles (WLTC and RDE) both impose an optimization of the whole engine map. More weight is given to mid and high loads, thus enhancing knock and overfueling limitations. At low and moderate engine speeds, knock mitigation is one of the main issues, generally addressed by retarding spark advance thereby penalizing the combustion efficiency. At high engine speeds, knock still occurs but is less problematic. However, in order to comply with thermo-mechanical properties of the turbine, excess fuel is injected to limit the exhaust gas temperature while maximizing engine power, even with cooled exhaust manifolds. This also implies a decrease of the combustion efficiency and an increase in pollutant emissions.
Water injection is one way to overcome both limitations. With its high specific heat, water may be a solution to accurately control the temperature evolution in the cylinder. At low or medium speed, it can help to cool down the working gas and prevent knock occurrence. At high speed, water can replace overfueling and play a similar role but in a cheaper and cleaner way.
This study proposes to evaluate the potential of water injection to improve gasoline engine efficiency. The first part of this study is dedicated to a literature review of water injection concepts, in order to identify configurations already implemented on different gasoline engines, and to use these results to build our test program and improve our configuration. The second part is focused on single-cylinder engine tests. A downsized direct injection spark ignition single-cylinder engine was used with different water injection configurations, port or direct injection. Water and EGR (Exhaust Gas Recirculation) were also compared and combined.
This study highlights the positive impact of water injection on knock mitigation and overfueling limitation. Direct water injection is the preferred configuration for knock mitigation due to a greater fuel consumption reduction. Both port and direct water injection allowed to eliminate the need for overfueling, while respecting the maximum exhaust gas temperature. This allowed about 13% of fuel consumption reduction. Finally, EGR and water were compared and an in depth analysis carried out using the split of losses method. The results clearly show that the levers for fuel consumption reduction are different between these two diluents.
CitationCordier, M., Lecompte, M., Malbec, L., Reveille, B. et al., "Water Injection to Improve Direct Injection Spark Ignition Engine Efficiency," SAE Technical Paper 2019-01-1139, 2019, https://doi.org/10.4271/2019-01-1139.
Data Sets - Support Documents
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- Saliba , R. , Manns , J. , and von Essen , C. 2018
- de Bellis , V. , Bozza , F. , Teodosio , L. , and Valentino , G. Experimental and Numerical Study of the Water Injection to Improve the Fuel Economy of a Small Size Turbocharged SI Engine SAE Int. J. Engines 10 2 550 561 2017 10.4271/2017-01-0540
- Bohm , M. , Mahrle , W. , Bartelt , H.-C. , and Rubbert , S. Functional Integration of Water Injection into the Gasoline Engine MTZ 77 36 40 2017
- Bozza , F. , de Bellis , V. , and Teodosio , L. Potentials of Cooled EGR and Water Injection for Knock Resistance and Fuel Consumption Improvements of Gasoline Engines Applied Energy 169 112 125 2016 10.1016/j.apenergy.2016.01.129
- Breda , S. , Berni , F. , d’Adamo , A. , Testa , F. et al. Effects on Knock Intensity and Specific Fuel Consumption of Port Water/Methanol Injection in a Turbocharged GDI Engine: Comparative Analysis Energy Procedia 82 96 102 2015 10.1016/j.egypro.2015.11.888
- d'Adamo , A. , Berni , F. , Breda , S. , Lugli , M. et al. A Numerical Investigation on the Potentials of Water Injection as a Fuel Efficiency Enhancer in Highly Downsized GDI Engines 2015
- Hoppe , F. , Thewes , M. , Baumgarten , H. , and Dohmen , J. Water Injection for Gasoline Engines: Potentials, Challenges, and Solutions International Journal of Engine Research 17 1 86 96 2015 10.1177/1468087415599867
- Iacobacci , A. , Marchitto , L. , and Valentino , G. Water Injection to Enhance Performance and Emissions of a Turbocharged Gasoline Engine Under High Load Condition SAE Int. J. Engines 10 3 2017 10.4271/2017-01-0660
- Kim , J. , Park , H. , Bae , C. , Choi , M. et al. Effects of Water Direct Injection on the Torque Enhancement and Fuel Consumption Reduction of a Gasoline Engine under High-Load Conditions International Journal of Engine Research 17 7 795 808 2016 10.1177/1468087415613221
- Millo , F. , Mirzaeian , M. , and Porcu , D. Knock Mitigation Techniques for Highly Boosted Downsized SI Engines SIA Powertrain 2017
- Bevilacqua , V. , Jacobs , E. , Grauli , G. , and Wüst , J. Future of Downsizing: Fuel Consumption Improvement in SIA Powertrain 2017
- Worm , J. , Naber , J. , Duncan , J. , Barros , S. et al. Water Injection as an Enabler for Increased Efficiency at High-Load in a Direct Injected, Boosted, SI Engine SAE Int. J. Engines 10 3 2017 10.4271/2017-01-0663
- Thewes , M. , Baumgarten , H. , Scharf , J. , Birmes , G. et al. Water Injection - High Power and High Efficiency Combined 25th Aachen Colloquium Automobile and Engine Technology 2016
- Hoppe , F. , Thewes , M. , Seibel , J. , Balazs , A. et al. Evaluation of the Potential of Water Injection for Gasoline Engines SAE Int. J. Engines 10 5 2017 10.4271/2017-24-0149
- Brusca , S. and Lanzafame , R. 2003
- Tornatore , C. , Siano , D. , Marchitto , L. , Iacobacci , A. et al. Water Injection: A Technology to Improve Performance and Emissions of Downsized Turbocharged Spark Ignited Engines SAE Int. J. Engines 10 5 2017 10.4271/2017-24-0062
- Berni , F. , Breda , S. , Lugli , M. , and Cantore , G. A Numerical Investigation on the Potentials of Water Injection to Increase Knock Resistance and Reduce Fuel Consumption in Highly Downsized GDI Engines Energy Procedia 81 826 835 2015 10.1016/j.egypro.2015.12.091
- Thewes , M. , Hoppe , F. , Baumgarten , H. , and Seibel , J. Water Injection for Gasoline Combustion Systems MTZ 76 2015
- Bhagat , M. , Cung , K. , Johnson , J. , Lee , S.-Y. et al. Experimental and Numerical Study of Water Spray Injection at Engine-Relevant Conditions SAE 2013 World Congress & Exhibition Warrendale, PA, United States 2013
- Dauphin , R. , Gautrot , X. , and Malbec , L.-M. 2012
- Lecompte , M. , Malbec , L.-M. , Font , G. , and Walter , B. How to Improve Light Duty Diesel Based on Heavy Duty Diesel Thermodynamic Analysis? SAE 2013 World Congress & Exhibition 2013