NO TO NO2 CONVERSION CONTROL IN A COMPRESSION INJECTION ENGINE BY HYDROCARBON INJECTION DURING THE EXPANSION STROKE

摘要

The invention is directed towards a method for adjusting the NO2 to NO conte nt of a diesel engine's exhaust without affecting engine performance. The NO2 to NO ratio is adjusted by varying the amount and timin g of secondary hydrocarbon injection during the engine's expansion stroke. The appropriate amount of secondary injected hydrocarbon a nd the appropriate injection timing are determined from calibration values obtained by direct engine measurements and the desired NO2:NO ratio.