Operating procedure for Diesel engine with catalytic particle filter includes brief periods of operation with fuel/air ratio and reducing agent concentration above stoichiometric levels

摘要

The procedure, designed to achieve combustion of exhaust gas particles, consists of operating the engine for brief periods - preferably at least one second at a time - with a fuel/air ratio below normal but above the 1 : 1 stoichiometric ratio, and/or with an increased concentration of reducing agent in the exhaust gases. The reduced fuel/air ratio is preferably between 1.025 and 1.075 : 1, and the concentration of reducing agent in the exhaust gases is preferably at least 6 times the normal level.