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Performance and Efficiency Assessment of a Production CNG Vehicle Compared to Its Gasoline Counterpart
ISSN: 0148-7191, e-ISSN: 2688-3627
Published October 13, 2014 by SAE International in United States
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Two modern light-duty passenger vehicles were selected for chassis dynamometer testing to evaluate differences in performance end efficiency resulting from CNG and gasoline combustion in a vehicle-based context. The vehicles were chosen to be as similar as possible apart from fuel type, sharing similar test weights and identical driveline configurations.
Both vehicles were tested over several chassis dynamometer driving cycles, where it was found that the CNG vehicle exhibited 3-9% lower fuel economy than the gasoline-fueled subject. Performance tests were also conducted, where the CNG vehicle's lower tractive effort capability and longer acceleration times were consistent with the lower rated torque and power of its engine as compared to the gasoline model.
The vehicles were also tested using quasi-steady-state chassis dynamometer techniques, wherein a series of engine operating points were studied. When the indicated thermal efficiency at each point was calculated, it was found that the CNG vehicle typically exhibited lower thermal efficiency.
Several operating points were chosen for further characterization of engine efficiency and combustion behavior, including an analysis of losses. Though the CNG engine had better theoretical efficiency potential, the losses suffered by this engine were repeatedly more significant than those suffered by the gasoline engine. As a result, the CNG engine was typically less efficient. There were a number of factors contributing to this phenomenon, including compression ratio, fuel properties, ignition and combustion timing and phasing, as well as EGR rates.
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CitationAnderson, J., Miers, S., Wallner, T., Stutenberg, K. et al., "Performance and Efficiency Assessment of a Production CNG Vehicle Compared to Its Gasoline Counterpart," SAE Technical Paper 2014-01-2694, 2014, https://doi.org/10.4271/2014-01-2694.
- U.S. Department of Energy Alternative Fuels Data Center - Natural Gas http://www.afdc.energy.gov/fuels/natural_gas.html Jan 6 2014
- Kubesh , J. , King , S. , and Liss , W. Effect of Gas Composition on Octane Number of Natural Gas Fuels SAE Technical Paper 922359 1992 10.4271/922359
- Kubesh , John T. Effect of Gas Composition on Octane Number of Natural Gas Fuels SwRI-3178-4.4, GETA 92-01, GRI-92/0150 May 1992
- Methane Number and Fuel Composition California Air Resources Board 21 Feb. 2002 03 Apr. 2014
- Eichlseder , H. , Wallner , T. , Freymann , R. , and Ringler , J. The Potential of Hydrogen Internal Combustion Engines in a Future Mobility Scenario SAE Technical Paper 2003-01-2267 2003 10.4271/2003-01-2267
- Akima , K. , Seko , K. , Taga , W. , Torii , K. et al. Development of New Low Fuel Consumption 1.8L i-VTEC Gasoline Engine with Delayed Intake Valve Closing SAE Technical Paper 2006-01-0192 2006 10.4271/2006-01-0192
- Watanabe , O. , Nakajima , S. , Goto , H. , and Matsunaga , T. Development of CNG Engine with Variable Valve Timing Electronic Control SAE Technical Paper 2007-01-3615 2007 10.4271/2007-01-3615
- U.S. Environmental Protection Agency CFR 600.13-93(h EPA Natural Gas Fuel Economy http://www.epa.gov Jan 9 2014
- CNG050 Coriolis Meters CNG050 Coriolis Flow and Density Meters 01 Apr. 2014 http://www2.emersonprocess.com/en-US/brands/micromotion/coriolis-flow-density-meters/CNG050-meter/Pages/index.aspx
- PLU 126 Positive Displacement Flowmeter 01 Apr. 2014 https://www.avl.com/web/avl-north-america-inc.-its/plu-126-positive-displacement-flowmeter
- Anderson , J. , Rask , E. , Lohse-Busch , H. , and Miers , S. A Comparison of Cold-Start Behavior and its Impact on Fuel Economy for Advanced Technology Vehicles SAE Int. J. Fuels Lubr. 7 2 427 435 2014 10.4271/2014-01-1375
- Matthias , N. , Wallner , T. , and Scarcelli , R. A Hydrogen Direct Injection Engine Concept that Exceeds U.S. DOE Light-Duty Efficiency Targets SAE Int. J. Engines 5 3 838 849 2012 10.4271/2012-01-0653
- Woschni , G. A Universally Applicable Equation for the Instantaneous Heat Transfer Coefficient in the Internal Combustion Engine SAE Technical Paper 670931 1967 10.4271/670931