Sensor for Detecting the Amount of a Reducing Agent and the Amount of a Pollutant in an Exhaust Gas
AssigneeBayerische Motoren Werke Aktiengesellschaft
InventorBernhard AICHHORN
Life of this patent
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Abstract
A system assembly detects the amount of reducing agent and the amount of pollutant in an exhaust gas. The system assembly has a first pollutant sensor, which is cross-sensitive to the reducing agent, and is provided for emitting a first measuring signal proportional to the amount of pollutant in the exhaust gas for use in front of a filtering device for the selective reducing of the reducing agent or the pollutant in the exhaust gas. A second pollutant sensor, which is also cross-sensitive to the reducing agent, emits a second measuring signal proportional to the amount of pollutant in the exhaust gas for use behind the filtering device.
Claims20
A system for use in detecting an amount of reducing agent and an amount of pollutant in an exhaust gas, the system comprising:
- a filtering device for a selective reduction of one of the reducing agent and the pollutant in the exhaust gas;
- a first pollutant sensor arranged upstream of the filtering device, the first pollutant sensor being cross-sensitive to the reducing agent and emitting a first measuring signal proportional to the amount of pollutant in the exhaust gas;
- and
- a second pollutant sensor arranged downstream of the filtering device, the second pollutant sensor being cross-sensitive to the reducing agent and emitting a second measuring signal proportional to the amount of pollutant in the exhaust gas.
An arrangement for selective catalytic reduction of pollutants in an exhaust gas, the arrangement comprising:
- a system for use in detecting an amount of reducing agent and an amount of pollutant in the exhaust gas, the system comprising a first pollutant sensor arranged upstream of a filtering device and a second pollutant sensor arranged downstream of the filtering device, the first and second pollutant sensors being cross-sensitive to the reducing agent and emitting, respectively, first and second measuring signals proportional to the amount of pollutant in the exhaust gas;
- a catalyst arranged upstream of the first pollutant sensor, the catalyst reducing pollutants in the exhaust gas based on the reducing agent;
- and
- an injection mechanism for injecting the reducing agent into the exhaust gas at an input of the catalyst based on a dosing amount determined as a function of the first and second measuring signals of the pollutant sensors.
A process for detecting at least one of an amount of reducing agent and an amount of pollutant in an exhaust gas, the process comprising the acts of:
- emitting a first measuring signal proportional to the amount of the reducing agent and to the amount of the pollutant in the exhaust gas;
- filtering the exhaust gas by reducing one of the reducing agent and the pollutant in the exhaust gas;
- emitting a second measuring signal proportional to the amount of the reducing agent and to the amount of pollutant in the filtered exhaust gas;
- and
- determining at least one of the amount of the reducing agent and the amount of the pollutant in the exhaust gas based on the first and second measuring signals.
Dependencies are inferred from the claim text.