Method for monitoring ammonia storage in an exhaust aftertreatment system
AssigneeGM Global Technology Operations LLC
InventorMin Sun
Life of this patent
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Abstract
A method for monitoring the ammonia-selective catalyst reduction device includes monitoring states of parameters of the exhaust gas feedstream upstream of the ammonia-selective catalyst reduction device, analytically segmenting the ammonia-selective catalyst reduction device into a plurality of discrete substrate elements, sequentially calculating a change in ammonia storage for each of the discrete substrate elements, and determining a total ammonia storage concentration on the ammonia-selective catalyst reduction device based upon the sequentially calculated change in ammonia storage for each of the discrete substrate elements.
Claims19
Method for monitoring an ammonia-selective catalyst reduction device configured to treat an exhaust gas feedstream of an internal combustion engine, comprising:
- monitoring states of parameters of the exhaust gas feedstream upstream of the ammonia-selective catalyst reduction device;
- analytically segmenting the ammonia-selective catalyst reduction device into a plurality of discrete substrate elements;
- sequentially calculating a change in ammonia storage for each of the discrete substrate elements;
- and
- determining a total ammonia storage concentration on the ammonia-selective catalyst reduction device based upon the sequentially calculated change in ammonia storage for each of the discrete substrate elements.
Method for controlling dosing of ammonia into an exhaust gas feedstream upstream of an ammonia-selective catalyst reduction device, the exhaust gas feedstream originating from an internal combustion engine operating lean of stoichiometry, the method comprising:
- determining an amount of NOx gas in the exhaust gas feedstream upstream of the ammonia-selective catalyst reduction device;
- segmenting a substrate of the ammonia-selective catalyst reduction device into a plurality of discrete substrate elements oriented in series;
- calculating a change in ammonia storage for each of the discrete substrate elements;
- determining an ammonia storage concentration on the ammonia-selective catalyst reduction device based upon the calculated changes in ammonia storage for all the discrete substrate elements;
- and
- controlling dosing of ammonia into the exhaust gas feedstream upstream of the ammonia-selective catalyst reduction device in response to a total ammonia storage concentration on the ammonia-selective catalyst reduction device and the amount of NOx gas in the exhaust gas feedstream upstream of the ammonia-selective catalyst reduction device.
Dependencies are inferred from the claim text.