Method for regenerating a NOX storage catalytic converter and exhaust gas purification system with a NOX storage catalytic converter

摘要

For the discontinuous regeneration of a switched into the exhaust line 2 of an internal combustion engine, in particular a diesel engine NOX storage catalyst 4, the stored in an operation of the engine 1 in its exhaust NOX, are for the purpose of regeneration of the NOX storage catalyst 4 this from the operation of the Motors 1 entrained fuel supplied short-chain, unsaturated hydrocarbons (HCs). To generate the short-chain HCs required for the regeneration of the NOX storage catalytic converter 4 from the fuel, a flame burner 7 which is adjustable with regard to an excess HC in its exhaust gas is operated. Its burner exhaust gas is introduced into the exhaust line 2 in relation to the flow direction of the engine exhaust gas upstream of the NOX storage catalytic converter 4. This is passed together with the engine exhaust upstream of the NOX storage catalyst 4 via an oxidation catalyst 5, before it flows into the NOX storage catalyst 4. For regenerating the NOX storage catalytic converter 4, the residual oxygen contained in the engine exhaust gas is consumed before it flows into the NOX storage catalytic converter 4. An exhaust gas purification system comprises a NOX storage catalytic converter 4 for storing NOX entrained in the exhaust gas flow of an internal combustion engine, in particular a diesel engine 1, a post-engine HC supply for supplying HC needed for regeneration of the NOX storage catalytic converter 4, and a control device 8 for controlling an NOX -Speicherkatalysatorregeneration.