Method and apparatus for monitoring a particulate filter
AssigneeGM Global Technology Operations LLC
InventorMin Sun
Life of this patent
Estimating the term…
Abstract
A method to monitor a particulate filter includes determining an equivalent bypass area corresponding to a difference between a mass flowrate of an exhaust gas feedstream flowing to the particulate filter and a mass flowrate of the exhaust gas feedstream flowing through porous walls of a substrate.
Claims13
A method to monitor a particulate filter having an inlet, an outlet, and a substrate having porous walls disposed intermediate the inlet and the outlet, wherein a control module performs the following steps comprising:
- determining a mass flowrate of an exhaust gas feedstream flowing to the particulate filter;
- determining a mass flowrate of the exhaust gas feedstream flowing through the porous walls of the substrate subsequent to executing a regenerative operation to purge the substrate;
- determining an equivalent bypass area corresponding to a difference between the mass flowrate of the exhaust gas feedstream flowing to the particulate filter and the mass flowrate of the exhaust gas feedstream flowing through the porous walls of the substrate;
- comparing the equivalent bypass area to a threshold bypass area;
- and
- detecting a fault when the equivalent bypass area exceeds the threshold bypass area and continuing operation when no fault is detected.
A method to monitor integrity of a particulate filter having an inlet, an outlet, and a filtering substrate disposed intermediate the inlet and outlet, the filtering substrate having a multiplicity of alternately closed parallel flow passages having porous walls oriented parallel to an axis between the inlet and outlet, wherein a control module performs the following steps comprising:
- regenerating the particulate filter;
- and
- subsequent to the regeneration,
- determining a mass flowrate of an exhaust gas feedstream flowing to the particulate filter;
- determining a mass flowrate of the exhaust gas feedstream flowing through the porous walls of the filtering substrate;
- determining an equivalent bypass area corresponding to a difference between the mass flowrate of the exhaust gas feedstream flowing to the particulate filter and the mass flowrate of the exhaust gas feedstream flowing through the porous walls of the filtering substrate;
- comparing the equivalent bypass area to a threshold bypass area;
- and
- detecting a fault when the equivalent bypass area exceeds the threshold bypass area and continuing operation when no fault is detected.
A method to monitor a regenerated particulate filter including a substrate, said substrate configured to filter exhaust gas, wherein a control module performs the following steps comprising:
- determining a mass flowrate of exhaust gas flowing to the particulate filter;
- determining a temperature of the exhaust gas and a pressure differential across the particulate filter subsequent to executing a regenerative operation to purge the substrate;
- determining a mass flowrate of the exhaust gas flowing through the substrate corresponding to the temperature of the exhaust gas and the pressure differential across the particulate filter;
- determining an equivalent bypass area corresponding to a difference between the mass flowrate of the exhaust gas flowing to the particulate filter and the mass flowrate of the exhaust gas flowing through the substrate;
- comparing the equivalent bypass area to a threshold bypass area;
- and
- detecting a fault when the equivalent bypass area exceeds the threshold bypass area and continuing operation when no fault is detected.
Dependencies are inferred from the claim text.