Method of monitoring pollutant emissions of a combustion engine

Abstract

The invention relates to a method for monitoring the pollutant emissions of a combustion engine comprising at least one piston, the translatable movement of which defines a combustion chamber, said engine being combined with an exhaust line that, in the direction of exhaust gas flow, comprises an oxidation catalyst, an NOx reduction catalyst, and a particle filter, the method being characterized by the use of a fuel comprising an additive assisting in soot combustion when re-refined by the particle filter, and according to at least one operating mode of the engine, the fuel is injected in accordance with a calibration minimizing carbon dioxide discharges by the engine.

1 . A method for controlling the emissions of pollutants by a combustion engine comprising at least one piston of which the displacement in translation defines a combustion chamber, said engine associated with an exhaust line comprising, in the direction of the exhaust gas flow, an oxidation catalyst, a NOx reduction catalyst and a particle filter, wherein the method comprises:
 providing a fuel containing an additive promoting the combustion of soot during the regenerations of the particle filter;   operating the engine in a selected operating mode; and   injecting the fuel containing the additive into a combustion chamber of the engine according to a selected CO 2  calibration, thereby minimizing the discharge of carbon dioxide by the engine.   
     
     
         2 . The method according to  claim 1 , wherein said operating mode minimizing the discharge of carbon dioxide is obtained by injecting a main injection of fuel between 20° and 0° crankshaft before the upper dead point, at any torque speed and effective average pressure of the engine. 
     
     
         3 . The method according to  claim 2 , wherein the main injection is preceded by a pilot injection. 
     
     
         4 . The method according to  claim 3 , wherein said pilot injection takes place between 2 and 10° crankshaft prior to the main injection. 
     
     
         5 . The method according to  claim 1  wherein the injection of fuel is performed with a mixture with richness between 0.6 and 0.8. 
     
     
         6 . The method according to  claim 1  wherein the operating mode of the engine minimizing the discharge of carbon dioxide is activated as soon as a NOx reduction means is active. 
     
     
         7 . The method according to  claim 1  wherein the catalytic reduction of NOx is obtained by means of a reducing agent injected in the exhaust line upstream of the NOx reduction catalyst. 
     
     
         8 . The method according to  claim 1  wherein the NOx reduction catalyst and the particle filter are located side by side. 
     
     
         9 . The method according  claim 1  wherein the oxidization catalyst is impregnated with one of platinum and palladium. 
     
     
         10 . The method according to  claim 9 , wherein a molar relationship of the one of platinum and palladium is 2 to 1.