Method for use in connection with an exhaust gas post-treatment system
AssigneeMan Truck & Bus AG
InventorAndreas DOERING
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Abstract
A method for use with an exhaust gas post-treatment system on an internal combustion engine operated with aft surplus includes reducing nitrous oxides in that an ammonia-separating reducing agent is added to the exhaust gas flow upstream of a catalyst which is charged with a catalyst material for selective catalytic reduction of nitrous oxides. The method further provides that the NH3 to NOx ratio (feed ratio α) is varied in phases by changing the untreated nitrous oxide emissions of the internal combustion engine such that the feed ratio α oscillates in phases about a predefined value.
Claims13
A method for an exhaust gas post-treatment system used with an internal combustion engine operated with air surplus, the method comprising:
- reducing nitrous oxides by adding an ammonia-separating reducing agent to an exhaust gas flow upstream of an SCR catalyst which is charged with a catalyst material for selective catalytic reduction of nitrous oxides, and
- varying a NH3 to NOx ratio (feed ratio α) in phases by periodically changing untreated NOx emissions of the internal combustion engine between phases of high untreated NOx emissions and low untreated NOx emissions such that the feed ratio oscillates in phases about a predefined value.
Dependencies are inferred from the claim text.