HOMOGENEOUS CHARGE COMPRESSION IGNITION IN A COMPRESSED NATURAL GAS ENGINE WITH A GASOLINE PILOT

Homogeneous Charge Compression Ignition (HCCI) is an autoignition
combustion that is very promising in reducing the nitrogen oxides emissions. HCCI
uses a very lean mixture that contributes to good fuel economy and produces high
thermal efficiency. This is one of the solutions of the atmospheric air pollution and
depleting fossil fuel resources. HCCIengines are still at the researchstage as there are
no establish means for controlling the autoignition combustion. Under a very lean
condition, the engine misfires while at high loads, often there will be an extremely
loud and strong acoustic oscillations resembling knocking. This project proposed a
method to control the HCCI combustion by direct injection of a secondary fuel, A
homogeneous chargeof gasoline is injected in the inlet port and CNGdirect injection
flow rates and degrees of stratification were identified as the potential parameters for
HCCI combustion control.