Method for operating an exhaust gas system for an internal combustion engine

摘要

A method for operating an exhaust gas system for an internal combustion engine, in which the exhaust gas system includes at least one first catalytic coating and at least one second catalytic coating, the second catalytic coating being situated in the exhaust gas flow downstream from the first catalytic coating. An additional quantity of hydrocarbons is occasionally introduced into the exhaust gas upstream from the first catalytic coating so that a heat-generating reaction may take place in the second catalytic coating. With the aid of at least one temperature sensor and/or at least one hydrocarbon sensor and/or at least one lambda sensor upstream and/or downstream from the second catalytic coating, at least one property of the exhaust gas is ascertained which characterizes a reaction of the second catalytic coating due to the additional quantity of hydrocarbons.

主权项

1. A method for operating an exhaust gas system for an internal combustion engine, the method comprising:
occasionally introducing an additional quantity of hydrocarbons into the exhaust gas, of an exhaust gas system, upstream from at least one first catalytic coating so that a heat-generating reaction can occur in the second catalytic coating, wherein the exhaust gas system includes the at least one first catalytic coating and at least one second catalytic coating, the second catalytic coating being situated in the exhaust gas flow downstream from the first catalytic coating; and ascertaining, with the aid of at least one of (i) at least one temperature sensor, (ii) at least one hydrocarbon sensor, (iii) at least one lambda sensor upstream and/or downstream from the second catalytic coating, at least one property of the exhaust gas which characterizes a reaction of the second catalytic coating due to the additional quantity of hydrocarbons, wherein the property is ascertained: when a volume flow of the exhaust gas is greater than a threshold value; and/or when an exhaust gas temperature is lower than a threshold value, and the second catalytic coating has a temperature that is higher than a threshold value.