Systems and methods for reducing aftertreatment system NOx emissions
AssigneeCummins Emission Solutions Inc.
InventorsMatthew K. Volmerding, Simon Guest
Life of this patent
Estimating the term…
Abstract
A controller for an aftertreatment system coupled to an engine is configured to: in response to receiving an engine shutdown signal, determine an estimated amount of ammonia stored on a selective catalytic reduction (SCR) catalyst included in the aftertreatment system; in response to determining that the estimated amount of ammonia stored in the SCR catalyst is less than an ammonia storage threshold, cause flow of a heated gas towards the SCR catalyst; cause insertion of reductant into an exhaust gas flowing through the aftertreatment system; and in response to determining that the estimated amount of ammonia stored in the SCR catalyst is equal to or greater than the ammonia storage threshold, cause shutdown of the engine.
Claims16
A controller for an aftertreatment system coupled to an engine, the controller configured to:
- in response to receiving an engine shutdown signal, determine an estimated amount of ammonia stored on a selective catalytic reduction (SCR) catalyst included in the aftertreatment system;
- in response to determining that the estimated amount of ammonia stored in the SCR catalyst is less than an ammonia storage threshold, activate (i) an electric turbo or an air pump, and (ii) a heater, such that the electric turbo or the air pump causes a flow of gas through the heater and thereby causes a flow of a heated gas towards the SCR catalyst;
- cause insertion of a reductant into an exhaust gas flowing through the aftertreatment system;
- and
- in response to determining that the estimated amount of ammonia stored in the SCR catalyst is equal to or greater than the ammonia storage threshold, cause shutdown of the engine.
An aftertreatment system configured to be coupled to an engine, the aftertreatment system comprising:
- a selective catalytic reduction (SCR) catalyst;
- a reductant insertion assembly configured to insert a reductant into an exhaust gas flowing through the aftertreatment system;
- at least one of an electric turbo or an air pump;
- a heater;
- and
- a controller configured to:
- in response to receiving an engine shutdown signal, determine an estimated amount of ammonia stored on the SCR catalyst;
- in response to determining that the estimated amount of ammonia stored in the SCR catalyst is less than an ammonia storage threshold, activate (i) the electric turbo or the air pump, and (ii) a heater, such that the electric turbo or the air pump causes a flow of gas through the heater and thereby causes a flow of a heated gas towards the SCR catalyst;
- cause insertion of the reductant into the exhaust gas;
- and
- in response to determining that the estimated amount of ammonia stored in the SCR catalyst is equal to or greater than the ammonia storage threshold, cause shutdown of the engine.
Dependencies are inferred from the claim text.