Exhaust Gas After-Treatment System

Abstract

An exhaust gas after-treatment system includes an oxidation catalytic converter, a carbon-particulate filter, a device for burning off carbon-particulate matter within the carbon-particulate filter, and an exhaust gas cooling unit downstream of the filter for reducing the exhaust gas temperature in the exhaust gas flow. In order to reduce the fuel consumption overall, the device cooling unit can be deactivated.

1 . An exhaust gas after-treatment system through which flows exhaust gas from an internal combustion engine, the system having an oxidation catalytic converter, a carbon-particulate filter, a device for burning off carbon-particulate matter within the filter, and a cooler unit for cooling the exhaust gas, characterized in that:
 the cooler unit can be deactivated.   
     
     
         2 . The exhaust gas after-treatment system of  claim 1 , wherein:
 a cooling medium is fed through the cooler unit for reducing the exhaust gas temperature.   
     
     
         3 . The exhaust gas after-treatment system of  claim 2 , wherein:
 the cooling medium is ambient air.   
     
     
         4 . The exhaust gas after-treatment system of  claim 1 , wherein:
 the cooling unit comprises a diffuser through which the exhaust gas flows.   
     
     
         5 . The exhaust gas after-treatment system of  claim 4 , wherein:
 the diffuser has a variable geometry and a passage cross section of the diffuser can be adjusted by an adjustment mechanism.   
     
     
         6 . The exhaust gas after-treatment system of  claim 5 , wherein:
 the diffuser includes diffuser flaps for adjusting the passage cross section of the diffuser, wherein the diffuser flaps can be adjusted by the adjustment mechanism and by a remote-controllable actuator that is connected to the adjustment mechanism.   
     
     
         7 . The exhaust gas after-treatment system of  claim 4 , further comprising:
 a exhaust gas bypass line and a switch for directing exhaust gasses through the bypass line, the cooling unit being arranged in the bypass line.   
     
     
         8 . The exhaust gas after-treatment system of  claim 1 , wherein:
 the device for burning off the carbon-particulate matter within the carbon-particulate filter comprises a supply of fuel for combustion in the exhaust gas flow.