Exhaust gas recirculation system with a NOx sensor
AssigneeFord Global Technologies, LLC
InventorsDave Charles Weber, Michiel J. Van Nieuwstadt, Daniel Joseph Styles, Daniel Joseph Rinkevich
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Abstract
Various systems and methods are described for operating an engine system having a sensor coupled to an exhaust gas recirculation system in a motor vehicle. One example method comprises during a first operating condition, directing at least some exhaust gas from an exhaust of the engine through the exhaust gas recirculation system and past the sensor to an intake of the engine and, during a second operating condition, directing at least some fresh air through the exhaust gas recirculation system and past the sensor.
Claims18
A method of operating an engine system having a sensor coupled to an exhaust gas recirculation system (EGR), comprising:
- during a first operating condition, directing exhaust gas past the sensor to an engine intake;
- and
- during a second operating condition where an EGR valve is closed, opening an EGR bypass valve in response to the closed EGR valve and boost greater than a threshold boost amount, and directing fresh air past the sensor, wherein the sensor is a NOx sensor, where during the second operating condition the fresh air is directed through the EGR system, and where the NOx sensor is coupled to a passage in the EGR system at a location between a catalyst and an exhaust as recirculation cooler.
A method of operating an engine exhaust gas recirculation system (EGR) system coupled to an ammonia sensor, comprising:
- during a first condition, directing exhaust gas past the ammonia sensor to an engine intake;
- and
- during a second condition where an EGR valve is closed, generating a gain, opening an EGR bypass valve in response to the closed EGR valve and boost greater than a threshold amount, and directing fresh air past the ammonia sensor.
A system for an engine in a vehicle, the system comprising:
- an exhaust gas recirculation system, the exhaust gas recirculation system having an exhaust gas recirculation passage coupled at a first end to an exhaust manifold of the engine downstream of one or more catalysts and a second end of the passage coupled to an intake manifold of the engine upstream of a compressor;
- a bypass coupled at one end to the exhaust gas recirculation passage and coupled at an opposite end to the intake manifold downstream of the compressor;
- an exhaust gas recirculation valve coupled to the exhaust gas recirculation passage between the second end of the passage and the bypass;
- an exhaust gas recirculation purge valve coupled to the bypass between the exhaust gas recirculation passage and the intake manifold;
- and
- a NOx sensor coupled to the exhaust gas recirculation passage between the first end of the exhaust gas recirculation passage and an exhaust gas recirculation cooler.
Dependencies are inferred from the claim text.