| 摘要 |
<p>A trap (23) for nitrogen oxides (NOx) is placed upstream of the particle filter so freeing the oxides during the regeneration of the trap encourages combustion of the particles. When the trap is full to preset values and the filter is full to preset values, the trap and filter are regenerated simultaneously to optimize the effectiveness of the treatment system System (10) of treating exhaust gas (G) from a combustion motor (12), in particular a diesel or petrol engine with poor mixture, with a particle filter (20). The particle filter is catalytic. A reducing agent is injected (22) upstream of the trap. The filter includes means of heating (18), for example an electrical resistance heater, or the means of heating is upstream of the filter. The system includes means (56) of measuring the nitrogen oxide concentration in the exhaust gas downstream of the trap which corresponds to the level indicating that the trap is full. There are also means (32) of determining when the particle filter is full. When the trap and the filter are full to between preset minimum and maximum values, the filter and trap are regenerated simultaneously. When the trap is full to above the preset maximum value and the filter is below the preset minimum value, an adequate quantity of reducing agent is injected to at least partially regenerate the trap. The rate of exhaust gas recirculation is then increased to reduce the quantity of reducing agent to be injected. When the filter is full to above the preset maximum value and the trap is below the preset minimum value, the filter is at least partially regenerated without the regeneration of the trap.</p> |
