초록 ▼

A method is disclosed for regenerating a diesel particulate filter without excessively increasing NO2 emissions. The system includes a fuel delivery device, an oxidation catalyst, and a diesel particulate filter. During a first operational mode, the fuel injection device injects a relatively smaller

A method is disclosed for regenerating a diesel particulate filter without excessively increasing NO2 emissions. The system includes a fuel delivery device, an oxidation catalyst, and a diesel particulate filter. During a first operational mode, the fuel injection device injects a relatively smaller amount of fuel into the exhaust stream to reduce the capacity of the oxidation catalyst to oxidize NO in the exhaust stream to NO2. At a determined time, a second operational mode is initiated where a relatively larger amount of fuel is injected into the exhaust stream and is oxidized within the oxidation catalyst, thereby raising the exhaust temperature sufficiently to combust substantially all of the soot trapped on the diesel particulate filter.

대표청구항 ▼

What is claimed is: 1. A method for injecting fuel into an exhaust system of a diesel engine, the exhaust system including a catalytic converter including a catalyst that promotes oxidation at the catalytic converter, the exhaust system also including a diesel particulate filter positioned downstrea

What is claimed is: 1. A method for injecting fuel into an exhaust system of a diesel engine, the exhaust system including a catalytic converter including a catalyst that promotes oxidation at the catalytic converter, the exhaust system also including a diesel particulate filter positioned downstream from the catalytic converter, the method comprising:injecting fuel at a first fuel injection rate a majority of the engine operational time to limit the oxidation of NO to NO2 at the catalytic converter, the fuel being injected into the exhaust system from an injection location located upstream from the catalytic converter and downstream from the diesel engine; andinjecting fuel from the injection location at a second fuel injection rate a minority of the engine operational time, the second fuel injection rate being higher than the first fuel injection rate, wherein the fuel injected at the second fuel injection rate is combusted at the catalytic converter to provide sufficient heat to cause regeneration of the diesel particulate filter.