Apparatus and method for exhaust gas posttreatment

Abstract

The invention relates to an exhaust gas aftertreatment device for an internal combustion engine supercharged in two stages, having an oxidation catalyst, a particle filter, and a metering device for introducing a regeneration agent into an exhaust gas system, and to an associated method for exhaust gas aftertreatment. According to the invention, the metering device is arranged in the exhaust gas system between a high-pressure turbine and a low-pressure turbine which produce two-stage supercharging of the internal combustion engine.

1 - 6 . (canceled) 
     
     
         7 . An exhaust gas posttreatment apparatus for an internal combustion engine, supercharged in two stages, comprising:
 an oxidation catalytic converter;   a particle filter;   a high-pressure turbine and a low-pressure turbine that effect the two-stage supercharging of the engine; and   a metering device introducing a regeneration agent into an exhaust gas system, wherein the metering device is disposed in the exhaust gas system between the high-pressure turbine and the low-pressure turbine.   
     
     
         8 . The apparatus as defined by  claim 7 , wherein the metering device is disposed upstream of the low-pressure turbine in such a way that the low-pressure turbine effects uniform thorough mixing of the regeneration agent and the exhaust gas in the exhaust gas system. 
     
     
         9 . The apparatus as defined by  claim 7 , further comprising at least one temperature sensor which is disposed in the exhaust gas system and is evaluated for the adjustment of the metering device. 
     
     
         10 . The apparatus as defined by  claim 8 , further comprising at least one temperature sensor which is disposed in the exhaust gas system and is evaluated for the adjustment of the metering device. 
     
     
         11 . The apparatus as defined by  claim 7 , further comprising a pressure difference sensor which determines a pressure difference in the particle filter, from which difference a load state of the particle filter can be ascertained. 
     
     
         12 . The apparatus as defined by  claim 8 , further comprising a pressure difference sensor which determines a pressure difference in the particle filter, from which difference a load state of the particle filter can be ascertained. 
     
     
         13 . The apparatus as defined by  claim 9 , further comprising a pressure difference sensor which determines a pressure difference in the particle filter, from which difference a load state of the particle filter can be ascertained. 
     
     
         14 . The apparatus as defined by  claim 10 , further comprising a pressure difference sensor which determines a pressure difference in the particle filter, from which difference a load state of the particle filter can be ascertained. 
     
     
         15 . A method for exhaust gas posttreatment of an internal combustion engine supercharged in two stages, comprising the step of introducing a regeneration agent for thermal regeneration of a soot-laden particle filter into an exhaust gas system between a high-pressure turbine and a low-pressure turbine disposed therein. 
     
     
         16 . The method as defined by  claim 15 , wherein the introduction of the regeneration agent into the exhaust gas system is effected in such a way that the low-pressure turbine effects uniform thorough mixing of the regeneration agent and the exhaust gas in the exhaust gas system, and an oxidation catalytic converter disposed in the exhaust gas system is uniformly subjected to reducing agent.