Method for cleaning a particle filter and a vehicle for utilizing said method

Abstract

Method and arrangement for regenerating a particle filter ( 15 ) arranged in thermal proximity to a catalyst unit ( 16 ) in an exhaust duct ( 10 ) connected to an internal combustion engine ( 2 ). The particle filter is located downstream of an adjustable exhaust pressure regulator ( 20 ) for regulating an exhaust flow through the exhaust duct. When the internal combustion engine is driven at low engine load, the exhaust pressure regulator ( 20 ) is activated with a predetermined regulating pressure. Fuel is then supplied to the exhaust duct ( 10 ) by means of an injection unit, the catalyst unit ( 16 ) being exposed to the fuel, which is oxidized, and the particle filter ( 15 ) being heated to such a temperature that soot particles are converted into carbon dioxide in reaction with oxygen contained in the exhaust flow.

1 . A method for regenerating a particle filter ( 15 ) arranged in thermal proximity to a catalyst unit ( 16 ) in an exhaust duct ( 10 ) connected to an internal combustion engine ( 2 ), said particle filter being located downstream of an adjustable exhaust pressure regulator ( 20 ) for regulating an exhaust flow through the exhaust duct, said method comprising: 
 establishing by means of a control unit ( 24 ) that the internal combustion engine is being driven at low engine load;    activating the exhaust pressure regulator ( 20 ) with a predetermined regulating pressure; and    supplying fuel to the exhaust duct ( 10 ) by means of an injection unit, the catalyst unit ( 16 ) being exposed to said fuel, which is oxidized, and the particle filter ( 15 ) being heated to a temperature at which soot particles are converted into carbon dioxide in reaction with oxygen contained in the exhaust flow.    
   
   
       2 . The regenerating method as recited in  claim 1 , wherein said injection unit supplies fuel to a combustion chamber arranged in the internal combustion engine ( 2 ) at such a stage of the working cycle of the internal combustion engine that fuel is allowed to pass through the combustion chamber into the exhaust duct ( 10 ) in a non-combusted or partly combusted state, said non-combusted or partly combusted fuel being oxidized on contact with the catalyst unit ( 16 ) and the particle filter ( 15 ) being heated to such a temperature that soot particles are converted into carbon monoxide in reaction with oxygen contained in said exhaust flow.  
   
   
       3 . The regenerating method as recited in  claim 2 , wherein said fuel is supplied during one of ( 1 ) the expansion stroke and ( 2 ) the exhaust stroke of the internal combustion engine.  
   
   
       4 . The regenerating method as recited in  claim 1 , wherein fuel is supplied directly to the exhaust duct ( 10 ) via an injection unit assigned to the exhaust duct.  
   
   
       5 . The regenerating method as recited in  claim 1 , wherein fuel is supplied when the exhaust gas temperature at the particle filter ( 15 ), under low load and with the exhaust pressure regulator activated, is at least 250° C.  
   
   
       6 . A vehicle ( 1 ) comprising: 
 an internal combustion engine ( 2 ) and a particle filter ( 15 ) in thermal proximity to a catalyst unit ( 16 ) in an exhaust duct ( 10 ) connected to the internal combustion engine, the particle filter being located downstream of an adjustable exhaust pressure regulator ( 20 ) for regulating an exhaust flow through the exhaust duct; and    an injection system configured so that when regeneration of the particle filter ( 15 ) is necessary, fuel is supplied to the exhaust duct ( 10 ) with simultaneous activation of the exhaust pressure regulator ( 20 ), the catalyst unit ( 16 ) is exposed to the fuel which is oxidized, and the particle filter is heated to such a temperature that soot particles are converted into carbon dioxide in reaction with oxygen contained in said exhaust flow.    
   
   
       7 . The vehicle as recited in  claim 6 , wherein the injection system is configured to supply fuel to combustion chambers arranged in the internal combustion engine ( 2 ) at such a stage of the working cycle of the internal combustion engine that fuel is allowed to pass through the combustion chamber into the exhaust duct ( 10 ) in a non-combusted or partly combusted state.  
   
   
       8 . The vehicle as recited in  claim 7 , wherein said injection system is configured to supply fuel during one of ( 1 ) the expansion stroke and ( 2 ) the exhaust stroke of the internal combustion engine.  
   
   
       9 . The vehicle as recited in  claim 6 , wherein the vehicle further comprises an injection unit assigned to the exhaust duct ( 10 ), said injection unit being arranged to supply fuel directly to the exhaust duct.  
   
   
       10 . The vehicle as recited in  claim 6 , wherein the exhaust pressure regulator ( 20 ) comprises a pneumatically operated piston ( 22 ) that is connected to a valve disk ( 23 ) which, when moved in the direction of a seat, forms a throttle for the exhaust flow of the engine.