This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Investigation of Diesel-CNG RCCI Combustion at Multiple Engine Operating Conditions
ISSN: 0148-7191, e-ISSN: 2688-3627
To be published on April 14, 2020 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
Past experimental studies conducted by the current authors on a 13 liter 16.7:1 compression ratio heavy-duty diesel engine have shown that diesel-Compressed Natural Gas (CNG) Reactivity Controlled Compression Ignition (RCCI) combustion targeting low NOx emissions becomes progressively difficult to control as the engine load is increased. This is mainly due to difficulty in controlling reactivity levels at higher loads. For the current study, CFD investigations were conducted in CONVERGE using the SAGE combustion solver with the application of the Rahimi mechanism. Studies were conducted at a load of 5 bar BMEP to validate the simulation results against RCCI experimental data. In the low load study, it was found that the Rahimi mechanism was not able to predict the RCCI combustion behavior for diesel injection timings advanced beyond 30 degCA bTDC. This poor prediction was found at multiple engine speed and load points. To resolve this, multiple reaction mechanisms were evaluated and a new reaction mechanism, that combines the GRI Mech 3.0 mechanism with the Chalmers mechanism, was proposed. This mechanism was shown to accurately predict the ignition delay and combustion behavior with early diesel injection timings (> 30 degCA bTDC), which is representative of the timing applied with low temperature RCCI combustion to achieve simultaneous low-NOx and PM emissions.
With the new combined mechanism, a number of simulation studies were conducted to quantify the in-cylinder conditions that are needed at 12 bar BMEP to effectively control a low-NOx RCCI combustion. A number of design parameters were examined in this study, including; exhaust gas recirculation rate, CNG substitution, fuel injection pressure, injector nozzle included angle and compression ratio. The study revealed that lowering the compression ratio was most effective in controlling a low NOx RCCI combustion. By lowering the base compression ratio by 4 points, to 12.7:1, a low-NOx RCCI combustion was achieved at 12 bar BMEP. Specifically, compared to the baseline diesel case, NOx and PM emissions were reduced by 70% and 67% respectively, while fuel consumption was improved by 5.5%.
As a next step, CFD studies were conducted at 20 bar BMEP and 1500 rpm using the combined mechanism along with the application of lower compression ratio. At this load point it was found that the peak cylinder pressures were much higher (>250 bar) with the lower compression ratio when compared to the baseline hardware. In order to limit the peak cylinder pressures, a spilt injection strategy was then investigated at 20 bar BMEP. Application of a spilt injection strategy along with lower compression ratio was successful in achieving the target of a low-NOx RCCI combustion at 20 bar BMEP and 1500 rpm. The final simulation results showed a 2% improvement in ISFC compared to the baseline diesel case, while NOx and PM emission were simultaneously reduced, by 87.5% and 95% respectively, compared to the baseline diesel case.
CitationDahodwala, M., Joshi, S., Koehler, E., Franke, M. et al., "Investigation of Diesel-CNG RCCI Combustion at Multiple Engine Operating Conditions," SAE Technical Paper 2020-01-0801, 2020.
Data Sets - Support Documents
|[Unnamed Dataset 1]|
|[Unnamed Dataset 2]|
|[Unnamed Dataset 3]|
|[Unnamed Dataset 4]|
|[Unnamed Dataset 5]|
|[Unnamed Dataset 6]|
|[Unnamed Dataset 7]|
|[Unnamed Dataset 8]|
- US Energy Information Administration , “Natural Gas,” http://www.eia.gov/naturalgas/, Aug 2013.
- Ribas, X. , “Heavy Duty Liquefied Natural Gas Engine Developments to Meet Future Emissions Requirements, Methodology and Real Application,” FISITA paper F2010F013, 2010.
- Ouellette, P. , “Cummins Westport Spark-Ignited (SI) and High Pressure Direct Injection (HPDI) Natural Gas Engines,” presented at in NGVTF 2003, USA, January 28-29, 2003.
- Guzman, P., Ribas, X., Garcia, J. Sr., and Pita, M. Sr. , “PM and CO2 Reduction in a Dual-fuel Heavy-duty Diesel Engine during the Freeway Part of Transient Worldwide Emission Tests,” SAE Technical Paper 2013-01-2759, 2013, doi:https://doi.org/10.4271/2013-01-2759.
- Dronniou, N., Kashdan, J., Lecointe, B., Sauve, K. et al. , “Optical Investigation of Dual-fuel CNG/Diesel Combustion Strategies to Reduce CO2 Emissions,” SAE Int. J. Engines 7(2):873-887, 2014, doi:https://doi.org/10.4271/2014-01-1313.
- Weaver, C. and Turner, S. , “Dual Fuel Natural Gas/Diesel Engines: Technology, Performance, and Emissions,” SAE Technical Paper 940548, 1994, doi:https://doi.org/10.4271/940548.
- Karim, G., Liu, Z., and Jones, W. , “Exhaust Emissions from Dual Fuel Engines at Light Load,” SAE Technical Paper 932822, 1993, doi:https://doi.org/10.4271/932822.
- Abd Alla, G.H., Soliman, H.A., Badr, O.A., and Abd Rabbo, M.F. , “Effect of Pilot Fuel Quantity on the Performance of a Dual Fuel Engine,” Energy Conversion and Management 41(6): 559-572, 2000, ISSN: 01968904
- Gebert, K., Beck, N., Barkhimer, R., and Wong, H. , “Strategies to Improve Combustion and Emission Characteristics of Dual-Fuel Pilot Ignited Natural Gas Engines,” SAE Technical Paper 971712, 1997, doi:https://doi.org/10.4271/971712.
- Abd Alla, G.H., Soliman, H.A., Badr, O.A., and Abd Rabbo, M.F. , “Effect of Injection Timing on the Performance of a Dual Fuel Engine,” Energy Conversion and Management 43:269-277, 2002.
- Dishy, A., You, T., Iwashiro, Y., Nakayama, S. et al. , “Controlling Combustion and Exhaust Emissions in a Direct-Injection Diesel Engine Dual-Fueled with Natural Gas,” SAE Technical Paper 952436, 1995, doi:https://doi.org/10.4271/952436.
- 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, doi:https://doi.org/10.4271/2014-01-1308.
- Nieman, D., Dempsey, A., and Reitz, R. , “Heavy-Duty RCCI Operation Using CNG and Diesel,” SAE Int. J. Engines 5(2):270-285, 2012, doi:https://doi.org/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, doi:https://doi.org/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, doi:https://doi.org/10.4271/2014-01-1318.
- Jia, Z. and Denbratt, I. , “Experimental Investigation of Natural Gas-Diesel Dual-Fuel RCCI in a Heavy-Duty Engine,” SAE Int. J. Engines 8(2):797-807, 2015, doi:https://doi.org/10.4271/2015-01-0838.
- 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, doi:https://doi.org/10.4271/2015-01-0849.
- Zoldak, P., Sobiesiak, A., Wickman, D., and Bergin, M. , “Combustion Simulation of Dual Fuel CNG Engine Using Direct Injection of Natural Gas and Diesel,” SAE Int. J. Engines 8(2):846-858, 2015, doi:https://doi.org/10.4271/2015-01-0851.
- Bekdemir, C., Baert, R., Willems, F., and Somers, B. , “Towards Control-Oriented Modeling of Natural Gas-Diesel RCCI Combustion,” SAE Technical Paper 2015-01-1745, 2015, doi:https://doi.org/10.4271/2015-01-1745.
- Garcia, P. and Tunestal, P. , “Experimental Investigation on CNG-Diesel Combustion Modes under Highly Diluted Conditions on a Light Duty Diesel Engine with Focus on Injection Strategy,” SAE Int. J. Engines 8(5):2177-2187, 2015, doi:https://doi.org/10.4271/2015-24-2439.
- Walker, R., Wissink, M. et al. , “Natural Gas for High Load Dual-Fuel Reactivity Controlled Compression Ignition in Heavy-Duty Engines,” Journal of Energy Resources Technology, 137, July 2015, 042202-1
- Kakaee, A., Rahnama, P., and Paykani, A. , “Influence of Fuel Composition on Combustion and Emissions Characteristics of Natural Gas/Diesel RCCI Engine,” Journal of Natural Gas Science and Engineering 25:58-65, 2015.
- May, I., Pedrozo, V., Zhao, H., Cairns, A. et al. , “Characterization and Potential of Premixed Dual-Fuel Combustion in a Heavy Duty Natural Gas/Diesel Engine,” SAE Technical Paper 2016-01-0790, 2016, doi:https://doi.org/10.4271/2016-01-0790.
- Hanson, R., Ickes, A., and Wallner, T. , “Comparison of RCCI Operation with and without EGR over the Full Operating Map of a Heavy-Duty Diesel Engine,” SAE Technical Paper 2016-01-0794, 2016, doi:https://doi.org/10.4271/2016-01-0794.
- Hanson, R., Ickes, A., and Wallner, T. , “Use of Adaptive Injection Strategies to Increase the Full Load Limit of RCCI Operation,” Journal of Engineering for Gas Turbines and Power, GTP-16-1034.
- Kakaee, A., Nasiri-Toosi, A., Partovi, B., and Paykani, A. , “Effects of Piston Bowl Geometry on Combustion and Emissions Characteristics of a Natural Gas/Diesel RCCI Engine,” Applied Thermal Engineering 102:1462-1472, 2016.
- Khatamnejad, H., Khalilarya, S., Jafarmadar, S., Mirsalim, M. et al. , “Influence of Blend Ratio and Injection Parameters on Combustion and Emissions Characteristics of Natural Gas-Diesel RCCI Engine,” SAE Technical Paper 2017-24-0083, 2017, doi:https://doi.org/10.4271/2017-24-0083.
- Poorghasemi, K. et al. , “Effect of Diesel Injection Strategies on Natural Gas/Diesel RCCI Combustion Characteristics in a Light Duty Diesel Engine,” Journal of Applied Energy, May 2017, http://dx.doi.org/10.1016/j.apenergy.2017.05.011.
- 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, doi:https://doi.org/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, doi:https://doi.org/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, doi:https://doi.org/10.4271/2011-01-0363.
- Maxey, C., Kalaskar, V., Kang, D., and Boehman, A. , “Impact of Supplemental CNG on Engine Efficiency, Performance, and Emissions,” SAE Technical Paper 2013-01-0847, 2013, doi:https://doi.org/10.4271/2013-01-0847.
- Sun, L., Liu, Y., Zhou, L., and Zeng, K. , “Experimental Investigation of Cycle-by-Cycle Variations in a CNG/Diesel Dual Fuel Engine with EGR,” SAE Technical Paper 2013-01-0853, 2013, doi:https://doi.org/10.4271/2013-01-0853.
- 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, doi:https://doi.org/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. , “Experimental and Theoretical Analysis of the Combustion and Pollutants Formation Mechanisms in Dual Fuel DI Diesel Engines,” SAE Technical Paper 2005-01-1726, 2005, doi:https://doi.org/10.4271/2005-01-1726.
- Papagiannakis, R., Hountalas, D., and Kotsiopoulos, P. , “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, doi:https://doi.org/10.4271/2008-01-1392.
- 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 224:1141, 2010, doi:10.1243/09544070JAUTO1343.
- Gregory, P.S., Golden, D.M., Frenklach, M., Moriarty, N.W., Eiteneer, B., Goldenberg, M., Bowman, C.T., Hanson, R.K., Song, S., Gardiner, W.C., Lissianski, V.V., and Qin, Z. http://www.me.berkeley.edu/gri_mech/.
- Edman, J. , “3D Modeling of Conventional and HCCI Diesel Combustion,” Chalmers University of Technology, PhD dissertation, 2005.
- Joshi, S., Dahodwala, M., Koehler, E., and Franke, M. , “Engine Strategies to Meet Phase-2 Greenhouse Gas Emission Legislation for Heavy-Duty Diesel Engines,” ICEF2017-3552.
- Federal Register/Vol. 81, No. 206/Tuesday, October 25, 2016/Rules and Regulations Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles- Phase 2
- Memorandum in Response to Petition for Rulemaking to Adopt Ultra-Low NOx Standards for On-Highway Heavy-Duty Trucks and Engines, EPA, December 2016
- Dahodwala, M. , “Experimental and Computational Investigation of Dual Fuel Diesel-Natural Gas RCCI Combustion in a Heavy-Duty Diesel Engine,” PhD Dissertation, Michigan Technological University, 2018.