An investigation of lean combustion in a natural gas-fueled spark-ignited engine

Journal Article · Sat Jun 01 04:00:00 EDT 1996 · Journal of Energy Resources Technology

DOI:https://doi.org/10.1115/1.2792706· OSTI ID:253696

Gupta, M; Bell, S R; Tillman, S T ^[1]

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1. Univ. of Alabama, Tuscaloosa, AL (United States). Dept. of Mechanical Engineering

The objective of this work was to investigate the performance and emission characteristics of natural gas in an original equipment manufacturer (OEM), light-duty, spark-ignited engine being operated in the lean fueling regime and compare the operation with gasoline fueling cases. Data were acquired for several operating conditions of speed, throttle position, air-fuel equivalence ratio, and spark timing for both fuels. Results showed that for stoichiometric fueling, with a naturally aspirated engine, a power loss of 10 to 15 percent can be expected for natural gas over gasoline fueling. For lean operation, however, power increases can be expected for equivalence ratios below about {phi} = 0.80 with natural gas fueling as compared to gasoline. Higher brake thermal efficiencies can also be expected with natural gas fueling with maximum brake torque (MBT) timings over the range of equivalence ratios investigated in this work. Coefficient of variation (COV) data based on the indicated mean effective pressure (IMEP) demonstrated that the engine is much less sensitive to equivalence ratio leaning for natural gas fueling as compared to gasoline cases. The lean limit for a COV of 10 percent was about {phi} = 0.72 for gasoline and {phi} = 0.63 for natural gas. Lean fueling resulted in significantly reduced NO{sub x} levels where a lower plateau for NO{sub x} concentrations was reached at {phi} near or below 0.70, which corresponded to about 220 ppm. For natural gas fueling, this corresponded to about 1.21 gm/kW-h. Finally, with MBT timings, relatively short heat release durations were obtained for lean fueling with natural gas compared to gasoline.

• Sponsoring Organization: USDOE
• OSTI ID: 253696
• Journal Information: Journal of Energy Resources Technology, Journal Name: Journal of Energy Resources Technology Journal Issue: 2 Vol. 118; ISSN 0195-0738; ISSN JERTD2
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
33 ADVANCED PROPULSION SYSTEMS
AIR POLLUTION ABATEMENT
COMBUSTION KINETICS
COMPARATIVE EVALUATIONS
FUEL SUBSTITUTION
FUEL-AIR RATIO
NATURAL GAS
NITROGEN OXIDES
PERFORMANCE
SPARK IGNITION ENGINES
UNLEADED GASOLINE