Method for monitoring the pollutant coversion capacity in an exhaust gas after-treatment system

摘要

A method for monitoring a pollutant conversion capacity of a catalytically coated, oxidizing exhaust gas after-treatment component in an exhaust gas system of an internal combustion engine, wherein a capacity of the catalytic coating of the exhaust gas after-treatment component for oxidizing NO to NO2 is ascertained from the degree of efficiency of a downstream SCR catalytic converter, characterized in that operating conditions for said exhaust gas after-treatment component are set such that the effects on the SCR catalytic converter are maximized.

主权项

1. A method for monitoring a pollutant conversion capacity of a catalytically coated, oxidizing exhaust gas after-treatment component (36, 38) located upstream of a downstream SCR catalytic converter (44) in an exhaust gas system (12) of an internal combustion engine (10), the method comprising:
drawing conclusions, by an electronic control unit (16), about an operability the catalytic coating of the exhaust gas after-treatment component (36, 38) for oxidizing NO to NO2 based on the efficiency of the downstream SCR catalytic converter (44); setting operating conditions of the exhaust gas after-treatment component (36, 38) based on the conclusions about the operability of the catalytic coating of the exhaust gas after-treatment component (36, 38) to maximize the efficiency of the SCR catalytic converter; and shutting off an exhaust gas recirculation by the electronic control unit (16) based on the conclusions about the operability of the catalytic coating of the exhaust gas after-treatment component.