Injection timing effects of diesel-ignited methane dual fuel combustion in a single cylinder research engine.

摘要

Diesel-ignited methane dual fuel combustion experiments were performed in a single cylinder research engine (SCRE). Methane was fumigated into the intake manifold and injection of diesel was used to initiate combustion. The engine was operated at a constant speed of 1500 rev/min, and diesel rail pressure was maintained at 500 bar. Diesel injection timing (SOI) was varied to quantify its impact on engine performance and engine-out ISNOx, ISHC, ISCO, and smoke emissions. The SOI sweeps were performed at different net indicated mean effective pressures (IMEPs) of 4.1, 6.5, 9.5, and 12.1 bar. Intake manifold pressure was maintained at 1.5 bar for the 4.1 and 6.5 bar IMEP SOI sweeps and 1.8 bar for the 9.5 and 12.1 bar IMEP SOI sweeps. Advancing SOI to 310º and earlier resulted in reduced ISNOx. However, high methane percent energy substitution (PES) resulted in high ISHC emissions especially at low IMEP.