APPARATUS, SYSTEM, AND METHOD FOR REDUCING NOx EMISSIONS ON AN SCR CATALYST
First Claim
1. An apparatus for reducing no, emissions in an engine exhaust gas stream of an engine system, comprising:
- a NOx reduction target module configured to determine a NOx reduction requirement, the NOx reduction requirement comprising an amount of NOx in the exhaust gas stream to be reduced on a selective catalytic reduction (SCR) catalyst;
an ammonia target module configured to determine an ammonia addition requirement, the ammonia addition requirement comprising an amount of ammonia added to the exhaust gas stream to achieve the NOx reduction requirement;
a reductant target module configured to determine a reductant injection requirement, the reductant injection requirement comprising an amount of reductant added to the exhaust gas stream to achieve the ammonia addition requirement; and
a reductant limiting module configured to determine a reductant limiting requirement representing whether at least one reductant limiting condition has been met;
wherein the reductant target module is communicable in data receiving communication with the reductant limiting module to receive the reductant limiting requirement, the reductant target module being configured to limit the amount of reductant added in response to the reductant limiting requirement.
1 Assignment
0 Petitions
Accused Products
Abstract
Various embodiments of an apparatus, system, and method are disclosed for reducing NOx emissions on an SCR catalyst. For example, according to one representative embodiment, an apparatus for reducing NOx emissions in an engine exhaust includes a NOx reduction target module that is configured to determine a NOx reduction requirement that includes an amount of NOx in the exhaust gas stream to be reduced on a selective catalytic reduction (SCR) catalyst. The apparatus also includes an ammonia target module that is configured to determine an ammonia addition requirement that includes an amount of ammonia added to the exhaust gas stream to achieve the NOx reduction requirement. The apparatus also includes a reductant target module that is configured to determine a reductant injection requirement that includes an amount of reductant added to the exhaust gas stream to achieve the ammonia addition requirement. The apparatus further includes a reductant limiting module that is configured to determine whether at least one reductant limiting condition is met and to limit the amount of reductant added in response to the at least one reductant limiting condition if the at least one reductant limiting condition has been met.
-
Citations
25 Claims
-
1. An apparatus for reducing no, emissions in an engine exhaust gas stream of an engine system, comprising:
-
a NOx reduction target module configured to determine a NOx reduction requirement, the NOx reduction requirement comprising an amount of NOx in the exhaust gas stream to be reduced on a selective catalytic reduction (SCR) catalyst; an ammonia target module configured to determine an ammonia addition requirement, the ammonia addition requirement comprising an amount of ammonia added to the exhaust gas stream to achieve the NOx reduction requirement; a reductant target module configured to determine a reductant injection requirement, the reductant injection requirement comprising an amount of reductant added to the exhaust gas stream to achieve the ammonia addition requirement; and a reductant limiting module configured to determine a reductant limiting requirement representing whether at least one reductant limiting condition has been met; wherein the reductant target module is communicable in data receiving communication with the reductant limiting module to receive the reductant limiting requirement, the reductant target module being configured to limit the amount of reductant added in response to the reductant limiting requirement. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. A method for reducing NOx emissions in an engine exhaust gas stream of an engine system, the method comprising:
-
determining a NOx reduction requirement, the NOx reduction requirement comprising an amount of NOx in the exhaust gas stream to be reduced on a selective catalytic reduction (SCR) catalyst; determining an ammonia addition requirement, the ammonia addition requirement comprising an amount of ammonia added to the exhaust gas stream to achieve the NOx reduction requirement; determining a reductant injection requirement, the reductant injection requirement comprising an amount of reductant added to the exhaust gas stream to achieve the ammonia addition requirement; and determining whether at least one reductant limiting condition is met, and if the at least one reductant limiting condition is met, limiting the amount of reductant added in response to the reductant limiting condition. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22)
-
-
23. A system for reducing NOx emissions in an engine exhaust, the system comprising:
-
an internal combustion engine producing an exhaust gas stream; a selective catalytic reduction (SCR) catalyst that reduces NOx emissions in the exhaust gas stream in the presence of a reductant; a reductant injector that injects reductant into the exhaust gas stream upstream of the SCR catalyst; a controller comprising; a NOx reduction target module configured to determine a NOx reduction requirement, the NOx reduction requirement comprising an amount of NOx in the exhaust gas stream to be reduced on the SCR catalyst; an ammonia target module configured to determine an ammonia addition requirement, the ammonia addition requirement comprising an amount of ammonia added to the exhaust gas stream to achieve the NOx reduction requirement; a reductant target module configured to determine a reductant injection requirement, the reductant injection requirement comprising an amount of reductant added to the exhaust gas stream to achieve the ammonia addition requirement; and a reductant limiting module configured to determine whether at least one reductant limiting condition is met, and to limit the amount of reductant added in response to the at least one reductant limiting condition if the at least one reductant limiting condition is met. - View Dependent Claims (24, 25)
-
Specification