Internal combustion engine

摘要

A diesel engine comprises a turbocharger, an intercooler 4, a particulate filtering unit 10 and an EGR cooler 12. EGR ratio of intake air, injection timing of an injection nozzle and excess air ratio lambda to fuel are controlled depending upon engine-operating load. Lean premixed compression ignition is performed at low engine load; low temperature combustion at low excess air ratio with high EGR ratio is performed at medium engine load; and normal EGR combustion is performed at high engine load.