Particulate Filter Regeneration via Stored Vacuum

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Solution Overview

Problem

Direct injection engines face challenges in maintaining accurate emission control during particulate filter regeneration due to inadequate air-fuel mixing, leading to soot generation, especially under high load and speed conditions, making it difficult to regenerate the filter effectively without increasing emissions.

Innovation Solution

A method is introduced to regenerate the particulate filter during or after engine shutdown by generating and storing a vacuum, which is used to draw fresh air through the filter in a reverse direction, increasing oxygen flow and avoiding increased emissions from the three-way catalyst, allowing for delayed or advanced regeneration based on filter conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If particulate filter regeneration is performed during engine operation, then soot removal is achieved, but emission control accuracy deteriorates due to three-way catalyst emissions increase

Engineering Contradiction:

Improvesoot removalVSAvoidemissions from three-way catalyst

Core Design Contradiction:

Loss of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent reverses the conventional regeneration approach by performing filter regeneration during engine shutdown rather than during operation. This inversion allows the engine to breathe through the filter in reverse direction, drawing fresh air through the exhaust system and across the particulate filter, thereby regenerating the filter without operating the three-way catalyst and avoiding associated emission increases

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The system stores vacuum pressure in the intake manifold during engine operation as a preliminary action. This stored vacuum is then utilized during engine shutdown to drive the reverse flow of air through the filter for regeneration, preparing the necessary driving force before the actual regeneration event occurs

Inventive Principle:

Principle #10Preliminary action

2Power

If direct injection engines operate under high load and speed conditions, then power output increases, but soot generation increases due to inadequate air-fuel mixing

Engineering Contradiction:

Improveengine power outputVSAvoidsoot generation

Core Design Contradiction:

PowerVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful effect of soot accumulation during high-power operation into a beneficial regeneration process. By utilizing the stored vacuum and reverse airflow during shutdown, the system oxidizes and removes the soot that accumulated during high-load operation, transforming the problem of soot generation into an opportunity for filter regeneration without compromising power output

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Object-generated harmful factors

If engine shutdown is used for filter regeneration, then emission control is maintained, but regeneration timing must be delayed until optimal temperature conditions occur

Engineering Contradiction:

Improveemission controlVSAvoidregeneration timing delay

Core Design Contradiction:

Object-generated harmful factorsVSLoss of time

Solution Approach 1:

The system performs preliminary heating of the particulate filter during engine operation or immediately before shutdown to reach optimal regeneration temperature. This preliminary action ensures that when the reverse flow regeneration begins during shutdown, the filter is already at the necessary temperature for effective soot oxidation, minimizing the delay while maintaining emission control

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control system monitors filter temperature and regeneration progress to determine the optimal moment to initiate reverse flow regeneration. This feedback mechanism ensures that regeneration begins only when temperature conditions are appropriate, balancing emission control requirements with regeneration effectiveness and timing

Inventive Principle:

Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables improved soot removal and selective regeneration of the particulate filter during engine shutdown, maintaining emission control while avoiding increased emissions, and allows for regeneration under optimal temperature conditions.

Implementation Method 1

generating a vacuum during engine operation and storing the generated vacuum

Methodology Applied

Scientific EffectVacuum: Vacuum

Implementation Method 2

the vacuum may be stored until the particulate filter temperature becomes hot enough to carry out the regeneration reaction

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentUS8516797B2Control of exhaust flow in an engine including a particulate filter

Publication Date: 2013.08.27 FORD GLOBAL TECH LLC

AI summary

Methods and systems for controlling operation of exhaust of an engine including a particulate filter are provided. One example method includes generating vacuum during engine operation, and storing the vacuum. The method further includes, during or after engine shutdown, drawing ambient air through the particulate filter via the vacuum.