Device and method for purification of exhaust gas in an internal combustion engine

Abstract

The present invention relates to an for apparatus and a method of cleaning exhaust gas from an internal combustion engine, in particular a Diesel engine. The apparatus has an exhaust gas line and an ozone source for enriching the exhaust gas stream of the engine with ozone. The ozone source generates a continuous ozone-containing gas stream, in such a way that particles flowing in the exhaust gas line are to a large extent oxidized, as a result of which the exhaust gas line can be kept free of particle filters.

1 . A method for cleaning the exhaust gas stream in the exhaust gas line ( 7 ) of an internal combustion engine ( 1 ), in particular a Diesel engine, of particles such as soot, the exhaust gas stream being enriched with ozone, characterized in that a continuous enrichment of the exhaust gas stream with ozone is effected such that particles that are present are to a great extent oxidized even during the flow through the exhaust gas line ( 7 ), and the concentration of the ozone is determined essentially as a function of the particle stream, and the concentration of the ozone is selected in particular such that the remaining particle content of the exhaust gas stream does not exceed a predetermined limit value.  
   
   
       2 . The method of  claim 1 , characterized in that for the ozone enrichment, oxygen present in the exhaust gas stream and/or water is used.  
   
   
       3 . The method of  claim 1 , characterized in that the generation of the ozone is effected in a reaction chamber ( 16 ) outside the exhaust gas stream.  
   
   
       4 . A method for regenerating a particle filter ( 3 ) in an apparatus for cleaning the exhaust gas from an internal combustion engine ( 1 ), having an ozone source ( 5 ) for enriching the exhaust gas stream in an exhaust gas line ( 7 ) upstream of the particle filter ( 3 ),  
     characterized in that 
 after the engine ( 1 ) has been shut off, ozone is generated in the ozone source ( 5 ) and introduced into the exhaust gas line ( 7 ) in the region of the particle filter ( 3 ).  
 
   
   
       5 . The method of  claim 4 , characterized in that the ozone concentration on or in the particle filter ( 3 ) is increased until the self-ignition of the deposited particles.  
   
   
       6 . The method of  claim 4  or  5 , characterized in that by means of a blower ( 17 ), an ozone-enriched gas flow through the particle filter ( 3 ) is generated.  
   
   
       7 . The method of one of claims  4  through  6 , characterized in that the ozone delivery is regulated on the basis of the temperature of the particle filter ( 3 ).  
   
   
       8 . A method for operating an apparatus for cleaning exhaust gases in an exhaust gas line ( 7 ) of an internal combustion engine ( 1 ), in which a gas stream enriched with ozone is generated in an ozone source ( 5 ),  
     characterized in that 
 the exhaust gas line ( 7 ) is rinsed at least partially with the gas enriched with ozone, before the engine ( 1 ) is started.  
 
   
   
       9 . The method of  claim 8 , characterized in that the gas stream is introduced into the exhaust gas line ( 7 ) upstream of an oxidizing catalytic converter ( 2 ), and at least the oxidizing catalytic converter ( 2 ) is rinsed with the ozone-enriched gas before the engine ( 1 ) is started.  
   
   
       10 . The method of  claim 9 , characterized in that immediately after the engine ( 1 ) is started, the combustion in the engine is controlled such that the exhaust gases still contain combustible hydrocarbons.  
   
   
       11 . The method of one of claims  8  through  10 , characterized in that until the operating temperature of the oxidizing catalytic converter ( 2 ) is reached, an enrichment, in particular a degressive enrichment, of the exhaust gas stream with ozone generated by the ozone source ( 5 ) is effected.  
   
   
       12 . The method of one of claims  8  through  11 , characterized in that the rinsing with ozone-enriched gas is effected during the preglow phase of the Diesel engine.  
   
   
       13 . A motor vehicle having an internal combustion engine, in particular a Diesel engine, having a control unit ( 6 ) for controlling at least the combustion process of the engine ( 1 ), with a computation device, in particular a microprocessor, for performing a method of one of claims  1  through  12 .