Systems and Methods for Monitoring Catalyst Deactivation and Controlling an Air/Fuel Ratio
AssigneeGeneral Electric Company
InventorMaruthi Devarakonda
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Abstract
A system for controlling an air/fuel ratio in an engine based on catalyst deactivation includes an NH3 detector disposed downstream from the three way catalyst, and a subsystem that compares measured values of NH3 concentration with a nominal value of NH3 concentration at rich operating conditions. A subsystem adjusts the air/fuel ratio based on the measured value of NH3 concentration and estimated CO concentration.
Claims20
A method for controlling an air/fuel ratio in an engine, the method comprising:
- determining whether an actual value of NH3 concentration downstream from a three way catalyst is lower than a nominal value for NH3 concentrations produced at rich operating conditions;
- if the actual value of NH3 concentration is lower than the nominal value for NH3 concentrations produced at rich operating conditions then adjusting the air/fuel ratio based on estimated CO concentrations.
A method for detecting deactivation of a catalyst, the method comprising:
- determining whether an actual value of NH3 concentration downstream from a three way catalyst is lower than a nominal value for NH3 concentrations produced at rich operating conditions;
- if the actual value of NH3 concentration is lower than the nominal value for NH3 concentrations produced at rich operating conditions then determining an estimated CO concentration value;
- and comparing the estimated CO concentration value to a reference CO concentration value.
A system for controlling an air/fuel ratio in an engine, the system comprising:
- a three way catalyst;
- an NH3 detector disposed downstream from the three way catalyst;
- a subsystem that compares a measured value of NH3 concentration with a nominal value of NH3 concentration at rich operating conditions;
- and
- a subsystem that adjusts the air/fuel ratio based on the measured value of NH3 concentration and estimated CO concentrations.
Dependencies are inferred from the claim text.