The Effects of Low Ambient Temperatures on the Combustion of Natural Gas in a Single-Cylinder Spark Ignition Engine

Operating characteristics including ignition limits, cyclic variability, and exhaust emissions were studied in the combustion of natural gas in a spark ignition, single-cylinder, variable compression ratio engine, operated at intake mixture temperatures ranging between 120 and -60 F.

The work confirmed in general the feasibility of using natural gas in a spark ignition engine operated under extremely cold intake temperature conditions. It was learned that both the maximum peak cylinder pressures and the mass of mixture inducted by the engine increased as the intake mixture temperature was lowered, and that the emissions of pollutants were not significantly increased.

These findings are thought to be particularly relevant to the use of natural gas in spark ignition engines, either as LNG or under very cold wintry conditions.