| 摘要 |
Upstream of the reducing agent injector are controlled means of increasing the temperature of the exhaust gas and make it more reduced. When the trap is full to preset values and the filter is full to preset values, the trap and filter are regenerated simultaneously to minimize the consumption of reducing agent System (10) of treating exhaust gas (G) from a combustion motor (12), in particular a diesel or petrol engine with poor mixture, with a NOX trap (23) through which the exhaust gas flows. Upstream of the trap there is a system (22) for injecting a reducing agent. The means of increasing the temperature include a particle filter (20) and heater (18) to burn the particles filtered from the gas. The heater is an electrical resistance heater and is placed upstream of the filter so the gas is heated before it enters the filter. The filter is catalytic, covered with a catalytic layer which lowers the temperature of combustion of the particles. The system includes means of determining the fullness of the filter using a pressure gauge (32) measuring the pressure drop across the filter. An oxidation catalyst (30) is placed between the means of increasing the gas temperature and the trap. A tube (40) connects the exhaust line (14) to an air emission (42) from the motor so exhaust gases are introduced into the air intake. 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 injecting reducing agent upstream of the trap |
