Method and device for diagnosing a particle filter
View Patent ↗A method for diagnosing a particle filter arranged in the waste gas line of an internal combustion engine has the steps of: executing at least one fuel injection, measuring HC emission in the waste gas line in the direction of flow of the waste gas behind the particle filter, and diagnosing a defect of the particle filter based on the measured HC emission.
1. A method for diagnosing a particle filter arranged in an exhaust gas line of an internal combustion engine, comprising the steps:
executing at least one fuel injection during an expansion phase or an expulsion phase of the combustion engine,
measuring a hydrocarbon (HC) emission using a single HC sensor arranged in the exhaust gas line in a direction of flow of the exhaust gas downstream of the particle filter,
predetermining a HC emission, limit value as a function of at least one of an injection fuel quantity, a temperature of the particle filter, and an exhaust gas mass flow,
comparing the measured HC emission to the predetermined HC emission limit value, and
diagnosing a defect of the particle filter if the measured HC emission exceeds the predetermined HC emission limit value.
2. The method according to claim 1 , wherein the fuel injection takes place into the exhaust gas line.
3. The method according to claim 1 , wherein the fuel injection is an after injection.
4. The method according to claim 1 , wherein the diagnosis is carried out in a regeneration phase of the particle filter.
5. A device for diagnosing a particle filter arranged in an exhaust gas line of an internal combustion engine, comprising:
a fuel injection unit,
a single hydrocarbon (HC) sensor arranged in the exhaust gas line in a direction of flow of the exhaust gas downstream of the particle filter, and
a diagnosis unit comprising instructions stored in a non-transitory computer-readable media which when executed by a processor:
predetermine a HC emission limit value as a function of at least one of: an injection fuel quantity, a temperature of the particle filter, and an exhaust gas mass flow,
compare an HC emission measured during a fuel injection of the fuel injection unit to the predetermined HC emission limit value, and
diagnose a defect of the particle filter if an HC emission measured by the HC sensor exceeds the predetermined HC emission limit value.
6. The device according to claim 5 , wherein the fuel injection unit is configured to execute a fuel injection into the exhaust gas line.
7. The device according to claim 5 , wherein the fuel injection unit is configured to execute an afterinjection.
8. The device according to claim 5 , wherein the diagnosis is carried out in a regeneration phase of the particle filter.