Method for manually regenerating particulate filter

Abstract

Related is a method for regeneration of a particulate filter 6 wherein manual regeneration of the particulate filter 6 started with a vehicle being stopped causes an exhaust brake 14 to throttle an exhaust passage. This increases an engine load and a fuel injection amount to elevate in temperature an exhaust gas 3; then, fuel addition is started by post injection with a fuel injection device 10, and the particulate filter 6 is regenerated by heat of an oxidation reaction of the added fuel on an oxidation catalyst 5 . After the starting of the manual regeneration, whether a fuel injection amount exceeds a reference value or not is judged. Only if the judgment is affirmative, throttling of the exhaust passage by the exhaust brake 14 is released provided exhaust temperature exceeds a reference temperature on an entry side of the particulate filter 6.

Description

TECHNICAL FIELD[0001]The present invention relates to a method for manually regenerating a particulate filter.BACKGROUND ART [0002]Particulates or particulate matter from a diesel engine is mainly constituted by carbonic soot and a soluble organic fraction (SOF) of high-boiling hydrocarbon and contains a trace of sulfate (misty sulfuric acid fraction). In order to reduce the particulates, it has been carried out to incorporate a particulate filter in an exhaust pipe through which an exhaust gas flows.[0003]Such kind of particulate filter has a porous honeycomb structure made of ceramics such as cordierite and having lattice-like compartmentalized passages; alternate ones of the passages have plugged inlets and the remaining passages with unplugged open inlets are plugged at outlets thereof. Thus, only the exhaust gas passing through thin porous walls compartmentalizing the respective passages is discharged downstream while the particulates in the exhaust gas are captured on inner su...

AI Technical Summary

Benefits of technology

The method described in the patent can effectively and quickly regenerate a particulate filter in a vehicle's exhaust system. By using an auxiliary machine and monitoring fuel injection, the method can increase the temperature of the filter and activate the oxidation catalyst, reducing the time needed for regeneration. Additionally, this method reduces the amount of fuel required for regeneration and improves overall efficiency.

Problems solved by technology

However, the exhaust gas from the diesel engine in a normal operation status rarely has a chance to reach a temperature level at which the particulates ignite by themselves, so that an oxidation catalyst with active species of, e.g., Pt or Pd is integrally carried by the particulate filter.

However, even in the employment of the particulate filter, a captured amount may exceed a treated amount of the particulates in an operation area having a lower exhaust temperature level.

Continued operation at such lower exhaust temperature level may hinder sufficient regeneration of the particulate filter, resulting in excessive accumulation of the captured particulates in the particulate filter.

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