This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Characteristics of CNG Direct Injection with Auto-Ignition
ISSN: 0148-7191, e-ISSN: 2688-3627
Published October 23, 2005 by The Automotive Research Association of India in India
Annotation ability available
Event: International Mobility Engineering Congress & Exposition 2005 - SAE India Technology for Emerging Markets
Characteristics of compressed natural gas (CNG) direct injection auto-ignition were investigated experimentally. A rapid compression machine (RCM) with the compression ratio of 10 was used. The diameter and thickness of the combustion chamber are 80 mm and 20 mm, respectively. After the compression start, fuel was directly injected with a single hole injector at the injection pressure of 7.0 MPa, and auto-ignition takes place. The fuel injection timing was varied from 50 ms to 60 ms from the compression start. Two kinds of natural gasses were tested; 12A (CH4: 99.1 %) and 13A (CH4: 86.3 %, C2H6: 5.2 %, C3H8: 1.9 % and others). A glow plug was installed in the cylinder in order to assist the ignition, which was set at 30 mm downstream from the fuel injector nozzle exit. Two kinds of auto-ignition processes were observed. For CNG 12A, auto-ignition always takes place after the end of the fuel injection. The ignition delay is relatively long (40 to 80 ms) and the fluctuation is large. For CNG 13A, under some conditions, auto-ignition takes place just after the start of fuel injection (designated as ‘early ignition’), and the combustion continues during the fuel injection duration. The ignition delay is much shorter when compared to the case of 12A, and the fluctuation is small. This suggests that the components of C2H6 and C3H8 in 13A are quite important in the auto-ignition process of natural gas.
- Mikiya Araki - Department of Mechanical Engineering, Gunma University, Kiryu, Gunma, 376-8515 Japan
- Hui Dong - Department of Mechanical Engineering, Gunma University, Kiryu, Gunma, 376-8515 Japan
- Tomio Obokata - Department of Mechanical Engineering, Gunma University, Kiryu, Gunma, 376-8515 Japan
- Seiichi Shiga - Department of Mechanical Engineering, Gunma University, Kiryu, Gunma, 376-8515 Japan
- Tsuneaki Ishima - Department of Mechanical Engineering, Gunma University, Kiryu, Gunma, 376-8515 Japan
- Kiyohira Aoki
CitationAraki, M., Dong, H., Obokata, T., Shiga, S. et al., "Characteristics of CNG Direct Injection with Auto-Ignition," SAE Technical Paper 2005-26-358, 2005, https://doi.org/10.4271/2005-26-358.
- Heywood J. B. Internal Combustion Engine Fundamentals McGraw-Hill Education 1989
- Lewis B. Von Elbe G. Combustion, Flames and Explosions of Gases Academic Press Inc. 1961
- Huang Z. Shiga S. Ueda T. Jingu N. Nakamura H. Ishima T. Obokata T. Tsue M. Kono M. A Basic Behavior of CNG DI Combustion in a Spark-Ignited Rapid Compression Machine JSME Int. J. (Series B) 45 4 2002
- Huang Z. Shiga S. Ueda T. Nakamura H. Ishima T. Obokata T. Tsue M. Kono M. Effect of Fuel Injection Timing Relative to Ignition Timing on the Natural-Gas Direct-Injection Combustion J. Eng. Gas Turbines Power 125 783 2003