Particulate Filter Regeneration via Dynamic Oxygen Control

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Solution Overview

Problem

Current methods for regenerating particulate filters in diesel engines are inefficient, leading to prolonged regeneration times and increased risks of clogged filters and premature alerts, as they lack variability in oxygen levels during the regeneration process, which can result in uncontrolled combustion and damage to the filter.

Innovation Solution

A process that varies the average oxygen level by alternating phases rich in oxygen and phases poor in oxygen throughout the regeneration cycle, with specific temperature and oxygen setpoints adjusted based on soot mass thresholds to optimize combustion efficiency and prevent runaway regeneration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed oxygen level setting is used during regeneration, then runaway regeneration is avoided, but regeneration efficiency is reduced and time is prolonged

Engineering Contradiction:
Improvecontrol of regeneration processVSAvoidregeneration efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies dynamics by transitioning from a static oxygen level setting to a dynamic control system that continuously adjusts the oxygen concentration based on real-time temperature measurements. The control unit modifies the oxygen level throughout the regeneration process, allowing the system to adapt to changing conditions and optimize both safety and efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by varying the oxygen concentration parameter during regeneration. The control unit adjusts the oxygen level based on temperature thresholds: maintaining a first oxygen level when temperature is below a threshold, and switching to a second (different) oxygen level when the temperature exceeds the threshold, thereby optimizing combustion efficiency at different stages.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If oxygen level is reduced throughout regeneration, then runaway combustion is prevented, but combustion efficiency and temperature rise are reduced

Engineering Contradiction:
Improveprevention of uncontrolled combustionVSAvoidexhaust gas temperature
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent uses parameter changes by implementing temperature-dependent oxygen level adjustment. When the exhaust gas temperature is below the threshold, a first oxygen level is maintained to ensure safe combustion control. When the temperature exceeds the threshold, the control unit switches to a second oxygen level parameter, enabling more efficient combustion and higher temperature rise while maintaining safety through continuous monitoring.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If regeneration time is prolonged to ensure controlled combustion, then filter damage is prevented, but vehicle performance and productivity are reduced

Engineering Contradiction:
Improvefilter integrityVSAvoidregeneration duration
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements feedback control by continuously monitoring the exhaust gas temperature during regeneration and using this information to adjust the oxygen level in real-time. The control unit receives temperature data and dynamically modifies the oxygen concentration to maintain controlled combustion, allowing for faster regeneration while ensuring filter safety through closed-loop control.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system applies dynamics by making the regeneration process adaptive rather than static. The oxygen level is dynamically adjusted based on real-time temperature feedback, allowing the system to accelerate combustion when safe and maintain control when necessary, thereby reducing overall regeneration time while preserving filter integrity.

Inventive Principle:
Principle #15Dynamics

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 reduces regeneration time, prevents filter damage, and extends oil change intervals by ensuring controlled combustion and efficient particulate filter regeneration.

Implementation Method 1

During normal engine operation, the particulate filter traps polluting particles, such as soot particles emitted in the engine's combustion gases

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 2

Periodically during regeneration phases of the particle filter, for example when the mass of soot reaches a threshold, these stored particles are burned, by the production of a controlled exotherm in the exhaust line

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 3

these stored particles are burned, by the production of a controlled exotherm in the exhaust line

Methodology Applied
Scientific EffectExothermic reaction: Exothermic Reaction

Implementation Method 4

The method is then able to trigger a regeneration and to implement it by controlling the injection of fuel and the opening and closing of the air intake valve

Methodology Applied
Scientific EffectFuel injection: Injector

Data Source

PatentEP3546716B1Method and device for controlling the regeneration of a particulate filter
Publication Date: 2020.12.09 RENAULT SA
  • EP3546716B1 patent drawingFigure 1
  • EP3546716B1 patent drawingFigure 2
  • EP3546716B1 patent drawingFigure 3

AI summary

Method (40) of controlling the regeneration of a particulate filter in which the average oxygen level is varied by alternating oxygen-rich phases and oxygen-poor phases throughout the duration of a regeneration cycle of the particulate filter.