Method for detecting excessive burn
AssigneeDenso Corporation
InventorKazuhiro Higuchi
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Abstract
In an excessive burn detection method for detecting an excessive burn during a regeneration process, in which particulates accumulated in a particulate filter arranged in an exhaust passage of a diesel engine are burned and removed for regenerating the particulate filter, an oxygen concentration in exhaust gas in the exhaust passage downstream of the particulate filter is measured in predetermined time intervals after the regeneration process starts and it is determined whether the excessive burn occurs by determining whether the measured oxygen concentration decreases with a predetermined tendency.
Claims16
An excessive burn detection method for detecting an excessive burn during a regeneration process, in which particulates accumulated in a particulate filter arranged in an exhaust passage of a diesel engine are burned and removed for regenerating the particulate filter, the method comprising:
- measuring an oxygen concentration in exhaust gas in the exhaust passage downstream of the particulate filter in predetermined time intervals after the regeneration process starts;
- and
- determining whether the excessive burn occurs by determining whether the oxygen concentration, which is measured by the measuring of the oxygen concentration, decreases with a predetermined tendency wherein:
- the determining of whether the oxygen concentration decreases with the predetermined tendency includes:
- computing an oxygen concentration change rate, which is a change rate from a previously measured value to a currently measured value of the oxygen concentration measured by the measuring of the oxygen concentration;
- and
- determining whether the oxygen concentration decreases with the predetermined tendency based on the oxygen concentration change rate.
An excessive burn detection method for detecting an excessive burn during a regeneration process, in which particulates accumulated in a particulate filter arranged in an exhaust passage of a diesel engine are burned and removed for regenerating the particulate filter, the method comprising:
- measuring an oxygen concentration in exhaust gas in the exhaust passage downstream of the particulate filter in predetermined time intervals after the regeneration process starts:
- and
- determining whether the excessive burn occurs by determining whether the oxygen concentration, which is measured by the measuring of the oxygen concentration, decreases with a predetermined tendency:
- wherein the regeneration process is started by performing a post injection of unburned gas into the exhaust passage.
An apparatus for detecting an excessive burn during a regeneration process, in which particulates accumulated in a particulate filter arranged in an exhaust passage of a diesel engine are burned and removed for regenerating the particulate filter, the apparatus comprising:
- a sensor that measures an oxygen concentration in exhaust gas in the exhaust passage downstream of the particulate filter in predetermined time intervals after the regeneration process starts;
- and
- a controller that determines whether the excessive burn occurs by determining whether the oxygen concentration measured by the sensor decreases with a predetermined tendency, wherein the controller determines whether the oxygen concentration decreases with the predetermined tendency by:
- computing an oxygen concentration change rate, which is a change rate from a previously measured value to a currently measured value of the oxygen concentration measured by the sensor;
- and
- determining whether the oxygen concentration decreases with the predetermined tendency based on the oxygen concentration change rate.
An apparatus for detecting an excessive burn during a regeneration process, in which particulates accumulated in a particulate filter arranged in an exhaust passage of a diesel engine are burned and removed for regenerating the particulate filter, the apparatus comprising:
- a sensor that measures an oxygen concentration in exhaust gas in the exhaust passage downstream of the particulate filter in predetermined time intervals after the regeneration process starts;
- and
- a controller that determines whether the excessive burn occurs by determining whether the oxygen concentration measured by the sensor decreases with a predetermined tendency;
- wherein the regeneration process is started by performing a post injection of unburned gas into the exhaust passage.
Dependencies are inferred from the claim text.