This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Experimental and Computational Analysis of Diesel-Natural Gas RCCI Combustion in Heavy-Duty Engines
Technical Paper
2015-01-0849
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Substitution of diesel fuel with natural gas in heavy-duty diesel engines offers significant advantages in terms of operating cost, as well as NOx, PM emissions and greenhouse gas emissions. However, the challenges of high THC and CO emissions, combustion stability, exhaust temperatures and pressure rise rates limit the substitution levels across the engine operating map and necessitate an optimized combustion strategy.
Reactivity controlled compression ignition (RCCI) combustion has shown promise in regard to improving combustion efficiency at low and medium loads and simultaneously reducing NOx emissions at higher loads. RCCI combustion exploits the difference in reactivity between two fuels by introducing a less reactive fuel, such as natural gas, along with air during the intake stroke and igniting the air-CNG mixture by injecting a higher reactivity fuel, such as diesel, later in the compression stroke. Recent studies to optimize dual fuel diesel-CNG RCCI combustion have primarily focused on the simultaneous reduction of NOx and soot emissions. However, further investigation is needed to outline the in-cylinder conditions that are required in order for RCCI combustion to proceed. In addition, the THC emissions produced under dual fuel diesel-CNG RCCI operation need to be analyzed to better understand how to address this limitation of the technology.
The current study builds on the dual fuel diesel-CNG study previously presented by the same set of authors by analyzing the experimental RCCI combustion results achieved on a heavy-duty diesel engine at 6 bar BMEP and multiple engine speeds. The study evaluates the impact of various control variables, such as CNG substitution, EGR rate and injection strategy on achieving RCCI combustion at 6 bar BMEP, thereby establishing a general framework for in-cylinder mixture properties required in realizing RCCI combustion. The conclusions at 6 bar BMEP are supported by 3D simulations of the complete combustion chamber using Converge CFD software. CFD results are also used to highlight the causes of high CH4 and CO emissions with dual fuel diesel-CNG RCCI operation. Further, the paper analyzes the experimental RCCI combustion results at 14 bar BMEP and multiple engine speeds to lay out the challenges in achieving RCCI combustion at increased engine load.
Recommended Content
Authors
Topic
Citation
Dahodwala, M., Joshi, S., Koehler, E., Franke, M. et al., "Experimental and Computational Analysis of Diesel-Natural Gas RCCI Combustion in Heavy-Duty Engines," SAE Technical Paper 2015-01-0849, 2015, https://doi.org/10.4271/2015-01-0849.Also In
References
- US Energy Information Administration Natural Gas http://www.eia.gov/naturalgas/ Aug 2013
- Aroonsrisopon , T. , Salad , M. , Wirojsakunchai , E. , Wannatong , K. et al. Injection Strategies for Operational Improvement of Diesel Dual Fuel Engines under Low Load Conditions SAE Technical Paper 2009-01-1855 2009 10.4271/2009-01-1855
- Kowalewicz A. , and Woloszyn R. Comparison of performance end emissions of turbocharged CI engine fuelled either with diesel fuel or CNG and diesel fuel Combustion Engines, PTNSS-2011-SC-117 2011
- Papagiannakis , R. , Hountalas , D. , Rakopoulos , C. , and Rakopoulos , D. Combustion and Performance Characteristics of a DI Diesel Engine Operating from Low to High Natural Gas Supplement Ratios at Various Operating Conditions SAE Technical Paper 2008-01-1392 2008 10.4271/2008-01-1392
- Dahodwala , M. , Joshi , S. , Koehler , E. , and Franke , M. Investigation of Diesel and CNG Combustion in a Dual Fuel Regime and as an Enabler to Achieve RCCI Combustion SAE Technical Paper 2014-01-1308 2014 10.4271/2014-01-1308
- Zhang , Y. , Sagalovich , I. , De Ojeda , W. , Ickes , A. et al. Development of Dual-Fuel Low Temperature Combustion Strategy in a Multi-Cylinder Heavy-Duty Compression Ignition Engine Using Conventional and Alternative Fuels SAE Int. J. Engines 6 3 1481 1489 2013 10.4271/2013-01-2422
- Joo , S. , Alger , T. , Chadwell , C. , De Ojeda , W. et al. A High Efficiency, Dilute Gasoline Engine for the Heavy-Duty Market SAE Int. J. Engines 5 4 1768 1789 2012 10.4271/2012-01-1979
- Splitter , D. , Hanson , R. , Kokjohn , S. , and Reitz , R. Reactivity Controlled Compression Ignition (RCCI) Heavy-Duty Engine Operation at Mid-and High-Loads with Conventional and Alternative Fuels SAE Technical Paper 2011-01-0363 2011 10.4271/2011-01-0363
- Nieman , D. , Dempsey , A. , and Reitz , R. Heavy-Duty RCCI Operation Using Natural Gas and Diesel SAE Int. J. Engines 5 2 270 285 2012 10.4271/2012-01-0379
- Zoldak , P. , Sobiesiak , A. , Bergin , M. , and Wickman , D. Computational Study of Reactivity Controlled Compression Ignition (RCCI) Combustion in a Heavy-Duty Diesel Engine Using Natural Gas SAE Technical Paper 2014-01-1321 2014 10.4271/2014-01-1321
- Doosje , E. , Willems , F. , and Baert , R. Experimental Demonstration of RCCI in Heavy-Duty Engines using Diesel and Natural Gas SAE Technical Paper 2014-01-1318 2014 10.4271/2014-01-1318
- Rahimi , A. , Fatehifar , E. , and Khoshbakhti Saray , R. Development of an optimized chemical kinetic mechanism for homogeneous charge compression ignition combustion of a fuel blend of n-heptane and natural gas using a genetic algorithm Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 2010 224 1141 10.1243/09544070JAUTO1343