APPARATUS, SYSTEM, AND METHOD FOR CONTROLLING REDUCTANT DOSING IN AN SCR CATALYST SYSTEM
First Claim
1. An apparatus for controlling reductant dosing in an SCR catalyst system having a reductant injection system configured to inject reductant into an exhaust gas stream, the apparatus comprising:
- a controller configured to determine a reductant dosing rate command representing a desired reductant dosing rate;
an actual reductant dosing rate module configured to determine a predicted actual reductant dosing rate based at least partially on the reductant dosing rate command; and
a reductant doser compensation module configured to determine a modified reductant dosing rate command based at least partially on the predicted actual reductant dosing rate;
wherein the reductant injection system injects reductant into the exhaust gas stream at a rate corresponding to the modified reductant dosing rate command.
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Accused Products
Abstract
According to one representative embodiment, an apparatus for controlling reductant dosing in an SCR catalyst system having a reductant injection system configured to inject reductant into an exhaust gas stream includes a controller, an actual reductant dosing rate module, and a reductant doser compensation module. The controller is configured to determine a reductant dosing rate command representing a desired reductant dosing rate. The actual reductant dosing rate module is configured to determine a predicted actual reductant dosing rate based at least partially on the reductant dosing rate command. The reductant doser compensation module is configured to determine a modified reductant dosing rate command based at least partially on the predicted actual reductant dosing rate. The reductant injection system injects reductant into the exhaust gas stream at a rate corresponding to the modified reductant dosing rate command.
125 Citations
21 Claims
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1. An apparatus for controlling reductant dosing in an SCR catalyst system having a reductant injection system configured to inject reductant into an exhaust gas stream, the apparatus comprising:
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a controller configured to determine a reductant dosing rate command representing a desired reductant dosing rate; an actual reductant dosing rate module configured to determine a predicted actual reductant dosing rate based at least partially on the reductant dosing rate command; and a reductant doser compensation module configured to determine a modified reductant dosing rate command based at least partially on the predicted actual reductant dosing rate; wherein the reductant injection system injects reductant into the exhaust gas stream at a rate corresponding to the modified reductant dosing rate command. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for controlling reductant dosing in an SCR catalyst system having a reductant injector configured to inject reductant into an exhaust gas stream, the method comprising:
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determining a reductant dosing rate command representing a desired reductant dosing rate; determining a predicted actual reductant dosing rate corresponding to the reductant dosing rate command; determining a modified reductant dosing rate command based at least partially on the predicted actual reductant dosing rate; and injecting reductant into the exhaust gas stream at a rate corresponding to the modified reductant dosing rate command. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A system for controlling reductant dosing in an SCR catalyst system of an engine system, the system comprising:
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a selective catalytic reduction (SCR) catalyst that reduces NOx emissions in an exhaust gas stream in the presence of a reductant; a reductant injection system that injects reductant into the exhaust gas stream upstream of the SCR catalyst; a controller configured to command the reductant injection system to inject reductant into the exhaust gas stream at a commanded reductant dosing rate, the controller comprising; a reductant dosing rate command module configured to determine a reductant dosing rate command corresponding to a desired reductant dosing rate; an actual reductant dosing rate module configured to determine a predicted actual reductant dosing rate corresponding to the reductant dosing rate command, the predicted actual reductant dosing rate being a function of the natural delay of the reductant injection system; and a reductant doser compensation module configured to determine a modified reductant dosing rate command representing a modified reductant dosing rate, the modified reductant dosing rate being a function of an accuracy and a time delay of the injection system, the accuracy comprising the difference between a predetermined actual reductant dosing rate resulting from the reductant dosing rate command and the desired reductant dosing rate, and the time delay comprising a predetermined time constant between the reductant dosing rate command to inject reductant into the exhaust gas stream at the desired dosing rate and the actual injection of the reductant; wherein the reductant injection system is configured to inject reductant into the exhaust gas stream at the modified reductant dosing rate according to the modified reductant dosing rate command such that the actual reductant dosing rate is substantially equal to desired reductant dosing rate. - View Dependent Claims (18, 19, 20, 21)
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Specification