Particulate Filter Regeneration via Intake-Exhaust Valve Overlap

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Solution Overview

Problem

Direct injection gasoline engines produce particulates due to incomplete vaporization of fuel before combustion, leading to soot formation, which existing technologies struggle to address effectively without external air supplies for particulate filter regeneration.

Innovation Solution

Increasing the overlap between intake and exhaust valves to supply excess oxygen for particulate filter regeneration, adjusting boost pressure and fuel amounts to match soot levels, and controlling valve positions to optimize oxygen supply and combustion conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If an external air supply is used for particulate filter regeneration, then soot combustion efficiency is improved, but device complexity and cost increase due to auxiliary air pump requirements

Engineering Contradiction:

Improvesoot combustion efficiencyVSAvoidauxiliary air pump requirements

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The engine's own intake air is redirected through the exhaust system during regeneration, allowing the system to regenerate the particulate filter using its own operational resources without external air supply equipment

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The intake air serves dual purposes: normal engine operation and particulate filter regeneration, eliminating the need for separate air supply systems for regeneration

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Productivity

If air is supplied to exhaust system for regeneration, then particulate filter regeneration is enabled, but NOX production increases due to lean combustion conditions

Engineering Contradiction:

Improveparticulate filter regenerationVSAvoidNOX production

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The air-fuel mixture is enriched locally in the cylinder during regeneration to maintain stoichiometric or rich conditions, preventing NOX formation while still allowing oxygen supply to the exhaust system for soot combustion

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The system dynamically adjusts fuel injection amounts during regeneration to match the oxygen supply rate, maintaining optimal combustion conditions and preventing NOX production while enabling continuous soot combustion

Inventive Principle:

Principle #15Dynamics

3Productivity

If valve overlap is increased to supply oxygen for regeneration, then soot combustion is enhanced, but cylinder air-fuel mixture is affected

Engineering Contradiction:

Improvesoot combustion rateVSAvoidcylinder air-fuel mixture

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

Fuel is injected into the cylinder before the exhaust valve closes during the overlap period, ensuring the cylinder air-fuel mixture is enriched before the oxygen supply begins, thus maintaining stable combustion conditions while enabling soot combustion

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The fuel injection continues during the valve overlap period to maintain continuous enrichment of the air-fuel mixture, ensuring stable combustion while providing continuous oxygen supply for soot combustion throughout the regeneration process

Inventive Principle:

Principle #20Continuity of useful action

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

Enables efficient particulate filter regeneration at stoichiometric conditions, reducing NOX production and eliminating the need for an auxiliary air pump, while effectively combusting soot with varying oxygen supply.

Implementation Method 1

air may pass from the intake system to the exhaust system so that excess oxygen is available to regenerate a particulate filter

Methodology Applied

Scientific EffectGas flow through valve overlap:

Implementation Method 2

excess oxygen is available to regenerate a particulate filter... the amount of excess oxygen supplied to oxidize soot held by the particulate trap may be varied so that the soot is combusted efficiently

Methodology Applied

Scientific EffectOxidation: Oxidation

Implementation Method 3

the cylinder may be operated at stoichiometric or rich conditions so that less NOX is produced by the cylinder during regeneration of the particulate filter

Methodology Applied

Scientific EffectStoichiometric combustion: Combustion

Data Source

PatentUS8464514B2Method for regenerating a particulate filter for a boosted direct injection engine

Publication Date: 2013.06.18 FORD GLOBAL TECH LLC

AI summary

A method for regenerating a particulate filter is disclosed. In one example, oxygen is pumped from the intake system of a direct injection turobocharged gasoline engine through a cylinder and into the exhaust system by a compressor. In this way, regeneration of a particulate filter may be accomplished without an auxiliary air supply.