초록 ▼

Excessive NO.sub.x emission in a diesel internal combustionengine with SCR exhaust gas treatment is detected by a control unit. The excessive NO.sub.x emission value is determined from the catalytic-converter efficiency calculated for the metering of the reducing agent. In response, measures are tak

Excessive NO.sub.x emission in a diesel internal combustionengine with SCR exhaust gas treatment is detected by a control unit. The excessive NO.sub.x emission value is determined from the catalytic-converter efficiency calculated for the metering of the reducing agent. In response, measures are taken, such as delayed start of the fuel injection, deactivation of a coasting cutoff, reducing an exhaust gas recirculation rate and/or increasing the idling speed. As a result, the NO.sub.x content in the untreated exhaust gas drops, the catalytic-converter temperature increases more quickly after a cold start, and the NO.sub.x emission is reduced.

대표청구항 ▼

[We claim:] [1.]treating exhaust gas of a diesel internal combustion engine in an SCR catalytic converter, the exhaust gas having an exhaust gas mass flow;feeding reducing agent into the exhaust gas upstream of the catalytic converter in a flow direction of the exhaust gas;determining, with a contro

[We claim:] [1.]treating exhaust gas of a diesel internal combustion engine in an SCR catalytic converter, the exhaust gas having an exhaust gas mass flow;feeding reducing agent into the exhaust gas upstream of the catalytic converter in a flow direction of the exhaust gas;determining, with a control unit, control parameters of the diesel internal combustion engine and a respective catalytic-converter efficiency, the respective catalytic converter efficiency determined from control parameters of the diesel internal combustion engine including the exhaust gas mass flow and a measured exhaust gas temperature;calculating a setpoint value for a reducing agent feed in dependence on the catalytic-converter efficiency; andif the catalytic-converter efficiency drops below a predetermined value, changing the control parameters of the diesel internal combustion engine with the control unit as a function of the catalytic-converter efficiency such that NO.sub.x in the exhaust gas upstream of the catalytic converter is reduced and the exhaust gas temperature is increased.