Skip Fire Control for Particulate Filter Soot Management

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Solution Overview

Problem

Particulate filters in internal combustion engines face reduced performance and fuel economy due to pore blockage from soot and ash accumulation, leading to decreased gas flow and emissions issues.

Innovation Solution

Implementing skip fire engine control to dynamically adjust the firing sequence and exhaust gas temperature, allowing for maintaining a desired soot quantity in the particulate filter, thereby optimizing filtration efficiency and preventing ash from entering the filter pores.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If particles continue to collect in the filter material over time, then filtration effectiveness is improved, but gas flow through the filter decreases due to pore blockage

Engineering Contradiction:

Improvefiltration effectivenessVSAvoidgas flow

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The system performs preliminary oxidation of soot particles during deceleration fuel-cut events before they can accumulate to problematic levels in the filter. By proactively burning off soot at these specific moments, the system prevents pore blockage rather than addressing it after it occurs, maintaining gas flow while preserving filtration effectiveness.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system converts the harmful accumulation of soot in the filter into a beneficial process by using deceleration fuel-cut events to oxidize and burn off the soot. The soot that would normally be seen as a blocking contaminant is instead utilized as fuel for the oxidation process, transforming it from a harmful substance into a useful energy source for maintaining filter performance.

Inventive Principle:

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

2Quantity of substance

If exhaust gas temperature is increased to oxidize soot, then soot quantity is reduced, but engine performance and fuel economy are affected

Engineering Contradiction:

Improvesoot quantity in filterVSAvoidengine performance

Core Design Contradiction:

Quantity of substanceVSProductivity

Solution Approach 1:

The system employs periodic oxidation events during deceleration fuel-cut events rather than continuous high-temperature operation. By spacing out the thermal oxidation processes to coincide with specific engine operating conditions (deceleration events), the system achieves soot reduction without subjecting the engine to sustained high temperatures that would harm performance and fuel economy.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system changes the thermal parameters of the exhaust system dynamically based on engine operating conditions. During deceleration fuel-cut events, the system allows temperature to rise sufficiently for soot oxidation, but only temporarily and only when engine performance is not compromised. This dynamic parameter adjustment enables soot management while preserving overall engine efficiency.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If fuel injection is continued during deceleration, then engine performance is maintained, but soot oxidation is prevented

Engineering Contradiction:

Improveengine performanceVSAvoidsoot oxidation

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The system periodically interrupts fuel injection during deceleration events to create oxidation conditions in the exhaust system. By timing the fuel cut-off to coincide with specific deceleration moments, the system creates periodic windows where soot oxidation can occur without compromising overall engine performance, balancing performance maintenance with soot management.

Inventive Principle:

Principle #19Periodic 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

This approach enhances particulate capture efficiency, reduces engine backpressure, and improves fuel economy by maintaining optimal soot levels within the filter, extending its lifespan and reducing emissions.

Implementation Method 1

elevating the exhaust gas temperature to oxidize the soot

Methodology Applied

Scientific EffectOxidation: Oxidation

Implementation Method 2

elevating the exhaust gas temperature

Methodology Applied

Scientific EffectThermal heating: Heating

Implementation Method 3

The filter exhaust gas to pass through a porous filter material and, in doing so, larger particulate, such as larger soot and ash particles, cannot pass through the pores and are captured by the filter material

Methodology Applied

Scientific EffectPhysical filtration: Filter (physical)

Implementation Method 4

pass through a porous filter material

Methodology Applied

Scientific EffectPorosity: Porosity

Implementation Method 5

adjusting a skip fire firing sequence based at least in part on maintaining the quantity of soot within a desired soot quantity range

Methodology Applied

Scientific EffectThermal control:

Implementation Method 6

both spark ignition and compression ignition engines produce an amount of soot and ash as byproducts of the combustion process

Methodology Applied

Scientific EffectCombustion: Combustion

Data Source

PatentUS11560822B2Particulate filter soot management for internal combustion engines

Publication Date: 2023.01.24 TULA TECHNOLOGY INC

AI summary

Methods, systems, and devices for particulate filter soot management for internal combustion engines are described herein. A method for particulate filter soot management for internal combustion engines includes determining a quantity of soot on a particulate filter and adjusting a skip fire firing sequence based at least in part on maintaining the quantity of soot on the particulate filter within a desired soot quantity range.