| 摘要 |
In a method for exhaust cleaning at a combustion engine, exhaust gases are caused to pass through a particulate filter which is part of a filter configuration and in which particles from the exhaust gases are oxidised. The method comprises the step of continuously assessing (S1 ) amounts of particles accumulated in the filter as a basis for preventing their uncontrollable exothermic oxidation in it, and the filter is provided with catalytic material for varying the rate of said oxidation. The step of continuously assessing amounts of particles accumulated in the filter comprises using a particulate prefilter which is part of the filter configuration and is provided with catalytic material for a lower oxidation rate in said prefilter. The method further comprises the step, as a basis for said assessment, of determining (S2) the occurrence of said uncontrollable exothermic oxidation by determination of temperatures of the prefilter, which oxidation will take place in the prefilter before it takes place in the filter. A device for exhaust cleaning of a combustion engine comprises similar parts to those mentioned above. |
