Method of operating a diesel engine system having LNT and SCR aftertreatment devices
AssigneeFord Global Technologies, LLC
InventorsKhizer Tufail, Mark Stephen Brogan, Haiwen Song, Martin John Ledger, Peter Graham Eastwood
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Abstract
A method of operating a diesel engine 10 having LNT 11 and SCR 13 aftertreatment devices arranged in series to receive exhaust gas from the engine is disclosed in which the engine is operated in a rich early injection mode to generate ammonia in the LNT for storage in the SCR located downstream from the LNT. This reduces the amount of soot produced permitting longer operation of the engine in rich early injection mode and further may reduce the use of PGM material in the LNT and increase the amount of ammonia for use in the SCR.
Claims7
An engine control method, comprising:
- adjusting fuel injection to the engine to perform lean stratified combustion in the engine during a first lean stratified combustion mode;
- adjusting fuel injection to the engine to perform repeated lean stratified combustion and rich stratified combustion during a second ammonia generation mode;
- and
- adjusting fuel injection to the engine to perform repeated lean pre-mixed compression ignition and rich pre-mixed compression ignition during a third ammonia generation mode.
An engine control method, comprising:
- adjusting fuel injection to the engine to perform lean stratified compression-ignition combustion during a first lean stratified compression-ignition combustion mode;
- adjusting fuel injection to the engine to perform repeated lean stratified compression-ignition combustion and rich stratified compression-ignition combustion during a second ammonia generation mode;
- and
- adjusting fuel injection to the engine to perform repeated lean pre-mixed compression-ignition and rich pre-mixed compression-ignition during a third ammonia generation mode, the second and third modes selected based on ammonia storage levels of an exhaust SCR catalyst.
Dependencies are inferred from the claim text.