US 7,458,206 B2 · Exhaust gas purification system of internal combustion engine

Abstract

An exhaust gas purification system determines a deposited state of particulate matters based on a differential pressure across a diesel particulate filter (DPF) sensed by a differential pressure sensor. An electronic control unit (ECU) of the system prohibits the determination of the deposited state of the particulate matters, which is performed based on the differential pressure, when uniformity of temperature distribution inside the DPF is low. The ECU estimates temperatures at multiple points inside the DPF distant from an inlet along a direction of a flow of exhaust gas based on the temperature at the inlet sensed by an exhaust gas temperature sensor disposed immediately upstream of the DPF. The ECU determines the uniformity of the temperature distribution inside the DPF based on a range of the temperatures at the multiple points.

Claims15

Dependent claims

A method of purifying exhaust gas of an internal combustion engine, which includes a particulate filter disposed in an exhaust passage for collecting particulate matters contained in exhaust gas, the method comprising:

calculating a value of a deposited amount of the particulate matters deposited on the particulate filter based on a state of the exhaust gas including a differential pressure between an inlet and an outlet of the particulate filter;
measuring a temperature distribution inside the particulate filter;
and
invalidating the calculated value of the deposited amount of the particulate matters when uniformity of the temperature distribution inside the particulate filter is low;
wherein the uniformity of the temperature distribution decreases as a range of temperatures at multiple points inside the particulate filter increases, and the multiple points are arranged on a central axis of the particulate filter or on a plane perpendicular to the central axis.

2 more elements

An exhaust gas purification system of an internal combustion engine, which includes a particulate filter disposed in an exhaust passage for collecting particulate matters contained in exhaust gas and calculates a deposited amount of the particulate matters deposited on the particulate filter based on a state of the exhaust gas including a differential pressure between an inlet and an outlet of the particulate filter, the exhaust gas purification system comprising:

measuring means for measuring temperature distribution inside the particulate filter;
and
invalidating means for invalidating the calculated value of the deposited amount of the particulate matters when uniformity of the temperature distribution inside the particulate filter is low;
wherein the measuring means determines that the uniformity of the temperature distribution decreases as a range of temperatures at multiple points inside the particulate filter increases, and the multiple points are arranged on a central axis of the particulate filter or on a plane perpendicular to the central axis.

1 more element

measuring means for measuring temperature distribution inside the particulate filter;
and
invalidating means for invalidating the calculated value of the deposited amount of the particulate matter when uniformity of the temperature distribution inside the particulate filter is low, wherein
the measuring means determines that the uniformity of the temperature distribution decreases as a difference between temperatures as multiple points inside the particulate filter increases, and
the temperature difference inside the particulate filter is larger than a temperature difference caused by a heat capacity difference of the particulate matters unevenly existing inside the particulate filter.

2 more elements

Dependencies are inferred from the claim text.

Exhaust gas purification system of internal combustion engine

Life of this patent

Exhaust gas purification system of internal combustion engine

Life of this patent

Abstract

Claims15