Method for monitoring function of particulate filter in exhaust gas after-treatment system of engine, involves closing defective filter when differential pressure or absolute pressure in gas flow direction is below minimum value

摘要

The method involves measuring and evaluating the differential pressure across the particulate filter or absolute pressure in the flow direction of the exhaust gas before the particulate filter. A butterfly valve is provided to increase exhaust gas volumetric flow into combustion engine during monitoring process of function of particulate filter. A defective particulate filter is closed when differential pressure across filter or absolute pressure in gas flow direction before the particulate filter is below preset minimum value. An independent claim is included for device for monitoring function of particulate filter in exhaust gas after-treatment system of internal combustion engine.