Method and device for monitoring the regeneration of a pollution-removal system

Abstract

A method for monitoring regeneration of a pollution-removal system, relying on introduction of fuel into exhaust gases by delayed injections of fuel into certain combustion chambers of an engine and/or direct injections into an exhaust system upstream of a filter depending on an inlet temperature of the system. Introduced fuel delivery is assigned to direct injections into the exhaust system and/or to delayed injections into the combustion chamber according to the value of the wall temperature of the exhaust system.

1 - 20 . (canceled) 
   
   
       21 . A method for controlling regeneration of a depollution system including an oxidation catalyst and a filter, based on introduction of fuel into exhaust gases via delayed injections of fuel into certain combustion chambers of an engine and/or by direct injections into an exhaust line upstream from the filter by virtue of an injector dedicated to the exhaust line, as a function of temperature at an inlet of the system, wherein the introduced fuel flow is assigned to the direct injections into the exhaust line and/or to the delayed injections into certain combustion chambers according to a value of a wall temperature of the exhaust line. 
   
   
       22 . A control method according to  claim 21 , wherein the injection of fuel into the exhaust line is used only in certain ranges of operation of the engine. 
   
   
       23 . A control method according to  claim 21 , wherein the injection of fuel into the exhaust line is limited to one zone of relatively low loads and to one zone of relatively high loads of the engine. 
   
   
       24 . A control method according to  claim 21 , wherein the wall temperature is determined by a transducer. 
   
   
       25 . A control method according to  claim 21 , wherein the wall temperature is determined by an algorithm integrated into the engine calculator, as a function of parameters that include the temperature of the exhaust gases upstream from a turbine of a turbocompressor, water temperature, exhaust-gas flow, and air flow. 
   
   
       26 . A control method according to  claim 21 , wherein the fuel flow injected into the exhaust line is limited to a maximum flow, beyond which the injected fuel would not be completely oxidized therein by the oxidation catalyst. 
   
   
       27 . A control method according to  claim 21 , wherein the fuel is injected prioritarily into the exhaust line as long as the injected flow is smaller than a maximum flow that can be completely oxidized therein. 
   
   
       28 . A control method according to  claim 27 , wherein a surplus of fuel relative to the flow that can be oxidized in the exhaust line is introduced by delayed injections into the combustion chambers of the engine. 
   
   
       29 . A control method according to  claim 21 , wherein a total fuel flow is corrected at each engine operating point by a factor that depends on the difference between the filter inlet temperature and a regeneration setpoint temperature. 
   
   
       30 . A control method according to  claim 21 , wherein an engine calculator directs fuel flow into a dedicated injector of the exhaust line until a saturation level of the oxidation catalyst, before passing on surplus ordered by regeneration of the filter to delayed injections of fuel into the combustion chambers of the engine. 
   
   
       31 . A control method according to  claim 30 , wherein flow of the exhaust injector varies prioritarily in response to a variation of a setpoint for total flow. 
   
   
       32 . A control method according to  claim 21 , wherein the depollution system includes a particulate filter. 
   
   
       33 . A device for implementation of a method according to  claim 21 , comprising:
 an injector dedicated to the exhaust;   a first temperature transducer upstream from a turbine of a turbocompressor;   an oxidation catalyst;   a second temperature transducer that measures the temperature at the inlet of the depollution system;   the depollution system; and   means for determining the wall temperature of the exhaust line.   
   
   
       34 . A control device according to  claim 33 , wherein the wall-temperature determining means includes a calculating algorithm integrated into a calculator. 
   
   
       35 . A control device according to  claim 33 , wherein the fuel injector is disposed upstream from a turbocompressor turbine. 
   
   
       36 . A control device according to  claim 33 , wherein the fuel injector is disposed downstream from the turbocompressor turbine. 
   
   
       37 . A control device according to  claim 33 , wherein the first temperature transducer is disposed upstream from the turbocompressor turbine. 
   
   
       38 . A control device according to  claim 33 , further comprising a fourth transducer for determining temperature at an outlet of the depollution system. 
   
   
       39 . A control device according to  claim 33 , wherein the depollution system includes a particulate filter. 
   
   
       40 . A control device according to  claim 33 , wherein the depollution system includes a nitrogen oxides trap.