| Patent application number | Description | Published |
|---|
| 20100024389 | NITROGEN OXIDE ESTIMATION DOWNSTREAM OF A SELECTIVE CATALYTIC REDUCTION CATALYST - A dosing control system comprises a selective catalytic reduction (SCR) analysis module, a dosing management module, an adjustment module, and an error module. The SCR analysis module estimates ammonia (NH3) stored by an SCR catalyst, a maximum NH3 storage capacity of the SCR catalyst, and a nitrogen oxides (NOx) measurement for a NOx sensor downstream of the SCR catalyst. The dosing management module controls dosing agent injection upstream of the SCR catalyst based on the maximum NH3 storage capacity and the NH3 stored. The adjustment module outputs an adjusted estimate of the NOx measurement based on the estimate of the NOx measurement, cross-sensitivity of the NOx sensor, and a delay period for exhaust flow. The error module selectively adjusts at least one of the NH3 stored and the maximum NH3 storage capacity based on a difference between the adjusted estimate and NOx measured by the NOx sensor. | 02-04-2010 |
| 20100028228 | CURRENT STORAGE ESTIMATION FOR SELECTIVE CATALYTIC REDUCTION CATALYSTS - A dosing control system comprises a selective catalytic reduction (SCR) analysis module and a dosing management module. The SCR analysis module estimates an ammonia (NH3) slip rate downstream of an SCR catalyst, an NH3 conversion rate, an NH3 supply rate, and an NH3 oxidation rate. The SCR analysis module estimates an NH3 rate of change based on the NH3 slip, conversion, supply, and oxidation rates and estimates an NH3 storage change based on the NH3 rate of change. The SCR analysis module estimates NH3 stored by the SCR catalyst based on the NH3 storage change. The dosing management module controls dosing agent injection into an exhaust system upstream of the SCR catalyst based on the NH3 stored by the SCR catalyst. | 02-04-2010 |
| 20100028230 | DOSING AGENT INJECTION CONTROL FOR SELECTIVE CATALYTIC REDUCTION CATALYSTS - A dosing control system comprises a selective catalytic reduction (SCR) analysis module and a dosing management module. The SCR analysis module estimates ammonia (NH3) stored by an SCR catalyst, maximum NH3 storage capacity of the SCR catalyst, NH3 slip downstream of the SCR catalyst, NH3 oxidation, and NH3 conversion through reaction with nitrogen oxides (NOx). The NH3 stored is estimated based an amount of dosing agent injected, the NH3 slip, the NH3 oxidation, and the NH3 conversion. The dosing management module controls dosing agent injection into an exhaust system upstream of the SCR catalyst based on the NH3 stored by the SCR catalyst and the maximum NH3 storage capacity. | 02-04-2010 |
| 20100199644 | Exhaust treatment diagnostic system and method - A method and system for monitoring operation of an exhaust treatment system of a diesel engine includes a dosing system for injecting an injection fluid and a temperature sensor generating temperature signals corresponding to exhaust temperatures. A control module determines a temperature change after an injection of injection fluid based on the temperature signals, compares the temperature change to a threshold, and generates a fault signal in response thereto. | 08-12-2010 |
| 20110005202 | IDENTIFYING AMMONIA SLIP CONDITIONS IN A SELECTIVE CATALYTIC REDUCTION APPLICATION - A system includes a filtering module that filters a first signal that indicates an amount of nitrogen oxides (NOx) in exhaust gas upstream from a catalyst, and that filters a second signal that indicates amounts of NOx and ammonia (NH3) in exhaust gas downstream from the catalyst. A slip determination module determines whether NH3 is present in exhaust gas downstream from the catalyst based on a frequency response of the first and second signals. | 01-13-2011 |
| 20110005203 | IDENTIFYING AMMONIA NON-SLIP CONDITIONS IN A SELECTIVE CATLYTIC REDUCTION APPLICATION - A system includes a sampling module, a correlation determination module, and an injector control module. The sampling module samples first and second signals that indicate an amount of nitrogen oxides (NOx) upstream and downstream from a selective catalytic reduction (SCR) catalyst, respectively. The second signal further indicates an amount of ammonia downstream from the SCR catalyst when ammonia is released from the SCR catalyst. The correlation determination module determines an amount of correlation between the first and second signals, wherein the amount of correlation indicates a probability that ammonia is released from the SCR catalyst. The injector control module controls an amount of reducing agent injected into the exhaust gas upstream from the SCR catalyst based on the amount of correlation. | 01-13-2011 |
| 20110005209 | AMMONIA STORAGE SET-POINT CONTROL FOR SELECTIVE CATALYTIC REDUCTION APPLICATIONS - A system includes an injector control module and an SCR optimization module. The injector control module controls an amount of ammonia (NH | 01-13-2011 |
| 20120000189 | ADAPTIVE CONTROL OF SCR UREA INJECTION TO COMPENSATE ERRORS - A method for controlling a selective catalytic reduction injection system having a storage tank, a pump, a delivery line, and an injection nozzle includes monitoring the selective catalytic reduction injection system, determining a selective catalytic reduction injector system effective area ratio, comparing the selective catalytic reduction injector system effective area ratio to a threshold, calculating a compensation factor upon surpassing the threshold, and modifying the commanded injected mass according to the calculated compensation factor. | 01-05-2012 |
