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US 10,371,031 B2Granted
Methods and systems for introducing reductant into an exhaust passage
AssigneeFord Global Technologies, LLC
InventorsFrederik De Smet, Monika Angst
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for an exhaust passage having a plurality of catalysts. In one example, a method may include injecting reductant via one or more injectors of the exhaust passage and monitoring injection conditions by flowing exhaust gas to the engine.
Claims13
A method comprising:
- flowing low-pressure exhaust gas to an engine while a first injector is injecting, where the first injector is positioned to inject into an exhaust passage upstream of a first selective catalytic reduction device for treating NOx and a low-pressure exhaust gas recirculation passage branches from the exhaust passage downstream of the first selective catalytic reduction device;
- sensing reductant slip through the first selective catalytic reduction device via an exhaust gas sensor located in the exhaust passage upstream of the first injector;
- and
- adjusting injection conditions in response to a comparison between a sensed NOx value and a threshold NOx value.
1 more element
A method comprising:
- injecting reductant into an exhaust passage via first and second injectors, where the first injector is upstream of a first selective catalytic reduction device for treating NOx and the second injector is upstream of a second selective catalytic reduction device for treating NOx, further comprising an exhaust gas recirculation passage coming off the exhaust passage between the first selective catalytic reduction device and the second injector;
- and
- injecting reductant via both injectors during a first condition, where a ratio between the injectors is adjusted responsive to sensing recirculated reductant slip coming around through an EGR passage, and where the sensing occurs at an exhaust gas sensor located in the exhaust passage upstream of the first injector.
Dependencies are inferred from the claim text.