Robert Bosch

William Krein

Christian Disch

Max Braunbeck

Dietmar Uhlenbrock

Chao Zhang

Patrick Hoff

Torsten Kunz

A method for ascertaining an operating state an exhaust gas burner in an exhaust system of an internal combustion engine. The burner is supplied with air by means of a secondary air system and with fuel by means of a fuel system. Exhaust gas generated in the burner is discharged into the exhaust system of the internal combustion engine. The method includes: detecting a sensor signal of at least one pressure sensor arranged in an air path upstream and/or downstream of the burner; ascertaining an amplitude of at least one periodic partial signal contained in the sensor signal and having a predeterminable frequency; and ascertaining the operating state of the burner depending on the ascertained amplitude. A computing unit, an exhaust system, and a computer program for carrying out the method are also provided.

Method for ascertaining an operating state of a burner

A method for operating an exhaust burner, which is situated in an exhaust system downstream from an internal combustion engine of a motor vehicle. Prior to and during a start phase of the exhaust burner, an air-mass flow supplied to a combustion chamber of the exhaust burner is increased, in particular in a strictly monotonical manner, between a start time in a starting air-mass flow and a further time in a further air-mass flow. Prior to the further time, fuel is supplied to the combustion chamber. A fuel-air mixture is produced in the combustion chamber from the fuel and air of the air-mass flow. The fuel-air mixture is ignited with the aid of an ignition device which is continuously hot or forms ignition sparks intermittently.

Method for operating an exhaust burner, device for executing such a method, and motor vehicle

A method for operating an exhaust burner with a secondary air system downstream of a combustion engine of a motor vehicle. The method includes: activating an ignition device as a function of a release condition, the ignition device being heated up to a specifiable target temperature; metering fuel at a first time point into a combustion chamber of the exhaust burner at a first injection frequency using an injection valve, and the combustion chamber not being actively supplied with air; setting a first target air-mass flow using a secondary air system at a further, second time point, wherein the air-mass flow is increased strictly monotonically; controlling the air-fuel ratio to a first target air-fuel ratio as a function of a lambda sensor starting from the second time point, and metering fuel at a second injection frequency; setting a second target air-mass flow at a further, third time point.

Method for operating an exhaust burner, apparatus for performing such a method, and motor vehicle

A method for operating an exhaust gas burner that is situated in an exhaust gas system downstream from an internal combustion engine of a motor vehicle during a start phase of the exhaust gas burner, in which the internal combustion engine is not fired. The method includes an incremental increasing of the air mass flow supplied to the exhaust gas burner and an incremental varying of a fuel mass flow supplied to the exhaust gas burner.

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Neckarzimmern, Germany

William Krein