Directly injected and externally ignited IC engine has catalyst system in exhaust gas line, and measuring, evaluating and controlling device for controlling operation of engine and influencing exhaust gas composition

摘要

A directly injected and externally ignited IC engine (10) has a catalyst system (14) in the exhaust gas line; and a measuring, evaluating and controlling device (20) for controlling the operation of the engine and influencing the exhaust gas composition. The exhaust gas of the engine in the operating phase has a rotary frequency of at least 3000 U/minute, an effective pressure of the engine of at least 9 bar and under a mixture composition in the region of lambda = 0.9-1.0 a residual oxygen content of not more than 0.4 vol.% upstream of the nitrogen oxide (NOx) storage catalyst (18) or a catalyst connected to it. An Independent claim is also included for a process for reducing the residual oxygen content of the exhaust gas of a directly injected and externally ignited IC engine. Preferred Features: The residual oxygen content is at least 80%. The rotary frequency of the gas is at least 5000 U/minute. The mixture composition lies in the region of lambda = 0.92-0.95.