Excess NH3 storage control for SCR catalysts
AssigneeGM Global Technology Operations LLC
InventorCharles E. Solbrig
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Abstract
A method of regulating an amount of NH3 stored in a catalyst of an exhaust after-treatment system includes determining a mass of NH3 into the catalyst based on a dosing rate of a dosing agent that is injected into an exhaust stream upstream of the catalyst and determining a mass of NH3 out of the catalyst. An accumulated mass of NH3 within the catalyst is calculated based on the mass of NH3 into the catalyst and the mass of NH3 out of the catalyst. The dosing rate is regulated based on the accumulated mass of NH3 within the catalyst.
Claims22
A method of regulating an amount of NH3 stored in a catalyst of an exhaust after-treatment system, comprising:
- determining a mass of NH3 into the catalyst based on a dosing rate of a dosing agent that is injected into an exhaust stream upstream of the catalyst;
- determining a mass of NH3 out of the catalyst;
- calculating an accumulated mass of NH3 within the catalyst based on said mass of NH3 into the catalyst and said mass of NH3 out of the catalyst;
- and
- regulating said dosing rate based on said accumulated mass of NH3 within the catalyst.
An exhaust after-treatment system that regulates an amount of NH3 stored in a catalyst thereof, comprising:
- a first module that determines a mass of NH3 into the catalyst based on a dosing rate of a dosing agent that is injected into an exhaust stream upstream of the catalyst;
- a second module that determines a mass of NH3 out of the catalyst;
- a third module that calculates an accumulated mass of NH3 within the catalyst based on said mass of NH3 into the catalyst and said mass of NH3 out of the catalyst;
- and
- a fourth module that regulates said dosing rate based on said accumulated mass of NH3 within the catalyst.
A method of regulating an amount of NH3 stored in a catalyst of an exhaust after-treatment system, comprising:
- determining a mass of NH3 into the catalyst based on a dosing rate of a dosing agent that is injected into an exhaust stream upstream of the catalyst;
- determining a mass of NH3 out of the catalyst;
- calculating an accumulated mass of NH3 within the catalyst based on said mass of NH3 into the catalyst and said mass of NH3 out of the catalyst;
- determining a maximum NH3 storage mass of the catalyst;
- calculating an excess NH3 storage ratio based on said maximum NH3 storage mass and said accumulated mass of NH3 within the catalyst;
- and
- regulating said dosing rate based on said excess NH3 storage ratio to maintain said excess NH3 storage ratio to be less than 1.
Dependencies are inferred from the claim text.