Effects of natural gas composition on ignition delay under diesel conditions

Conference · Mon Oct 31 23:00:00 EST 1994 · Combustion and Flame; (United States)

OSTI ID:6571098

Naber, J D; Siebers, D L ^[1]; Di Julio, S S ^[2]; Westbrook, C K ^[3]

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1. Sandia National Labs., Livermore, CA (United States). Combustion Research Facility
2. California State Univ., Northridge, CA (United States). Dept. of Mechanical Engineering
3. Lawrence Livermore National Lab., CA (United States)

Effects of variations in natural gas composition on the autoignition of natural gas under direct-injection (DI) diesel engine conditions were studied experimentally in a constant-volume combustion vessel and computationally using a chemical kinetic model. Four fuel blends were investigated: pure methane, a capacity-weighted mean natural gas, a high-ethane-content natural gas, and a natural gas with added propane typical of peak shaving conditions. Experimentally measured ignition delays were longest for pure methane and became progressively shorter as ethane and propane concentrations increased. At conditions characteristic of a DI compression ignition natural gas engine at Top Dead Center (CR = 23:1, p = 6.8 MPa, T = 1,150 K), measured ignition delays for the four fuels varied from 1.8 ms for the peak shaving and high ethane gases to 2.7 ms for pure methane. A computational model, incorporating detailed chemical kinetics of oxidation of methane, ethane, propane and other small hydrocarbons was used to predict the influences of fuel composition on ignition, focusing on the four fuel types considered in the experimental study. Numerically predicted variations in ignition delay as a function of natural gas composition agreed with these measurements. The model results are used to interpret the kinetic factors responsible for the observations.

• OSTI ID: 6571098
• Report Number(s): CONF-940711--
• Journal Information: Combustion and Flame; (United States), Journal Name: Combustion and Flame; (United States) Vol. 99:2; ISSN CBFMAO; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
034000* -- Natural Gas-- Combustion
33 ADVANCED PROPULSION SYSTEMS
330800 -- Emission Control-- Alternative Fuels
ALKANES
CHEMICAL COMPOSITION
CHEMICAL REACTION KINETICS
COMBUSTION KINETICS
COMPRESSION RATIO
CONCENTRATION RATIO
DIESEL ENGINES
ENERGY SOURCES
ENGINES
ETHANE
FLUIDS
FOSSIL FUELS
FUEL GAS
FUEL SUBSTITUTION
FUELS
GAS FUELS
GASES
HEAT ENGINES
HYDROCARBONS
IGNITION
INTERNAL COMBUSTION ENGINES
KINETICS
MATHEMATICAL MODELS
NATURAL GAS
ORGANIC COMPOUNDS
PROPANE
REACTION KINETICS
TIME DELAY