Particulate Filter Temperature Control for Regeneration

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Solution Overview

Problem

Conventional particulate filter regeneration methods in internal combustion engines consume excessive fuel, lead to undesirable engine lubricant dilution, and risk overheating, especially during low idle states and engine restarts, due to inefficient temperature control and fuel injection strategies.

Innovation Solution

A method for operating a particulate filter that includes a filtering phase and a regeneration phase with a main portion and an ignition portion, where the filter temperature is initially lowered at the beginning of the main portion to reduce fuel consumption and prevent overheating, and gradually increased to optimize combustion efficiency, with adaptive temperature control based on particulate load and engine state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the filter is heated to a high temperature to burn off accumulated particulate matter, then regeneration is achieved, but fuel consumption increases and the risk of overheating the filter rises

Engineering Contradiction:
Improveregeneration effectivenessVSAvoidfuel consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies periodic action by dividing the regeneration process into distinct phases: an ignition phase with higher temperature to start combustion, followed by a main regeneration phase with reduced temperature. This periodic temperature control allows the system to achieve regeneration effectiveness while reducing overall fuel consumption and preventing overheating damage.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent changes the temperature parameter dynamically during regeneration. The control unit lowers the temperature at the filter input port during the main regeneration phase compared to the ignition phase. This parameter change enables the combustion process to continue using heat from particulate matter oxidation while reducing external heating requirements, thereby lowering fuel consumption and preventing filter overheating.

Inventive Principle:
Principle #35Parameter changes

2Duration of action of stationary object

If a large amount of fuel is post-injected to maintain filter temperature during low idle, then regeneration continues, but engine lubricant becomes diluted by fuel

Engineering Contradiction:
Improveregeneration durationVSAvoidlubricant dilution
Core Design Contradiction:
Duration of action of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent changes the temperature parameter dynamically during regeneration. The control unit lowers the temperature at the filter input port during the main regeneration phase compared to the ignition phase. This parameter change enables the combustion process to continue using heat from particulate matter oxidation while reducing external heating requirements, thereby lowering fuel consumption and preventing filter overheating.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system uses the heat generated by particulate matter combustion itself to sustain the regeneration process during the main phase, rather than relying entirely on external fuel injection. This self-service approach reduces the amount of post-injected fuel needed, thereby minimizing lubricant dilution while maintaining regeneration effectiveness.

Inventive Principle:
Principle #25Self-service

3Use of energy by moving object

If the engine is turned off during filter regeneration, then fuel consumption is reduced, but the filter cools down and regeneration is interrupted

Engineering Contradiction:
Improvefuel consumptionVSAvoidregeneration completion
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies periodic action by dividing the regeneration process into distinct phases: an ignition phase with higher temperature to start combustion, followed by a main regeneration phase with reduced temperature. This periodic temperature control allows the system to achieve regeneration effectiveness while reducing overall fuel consumption and preventing overheating damage.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system uses the heat generated by particulate matter combustion itself to sustain the regeneration process during the main phase, rather than relying entirely on external fuel injection. This self-service approach reduces the amount of post-injected fuel needed, thereby minimizing lubricant dilution while maintaining regeneration effectiveness.

Inventive Principle:
Principle #25Self-service

4Productivity

If the filter temperature is maintained at a constant high level during regeneration, then particulate matter burns off efficiently, but the risk of filter damage from overheating increases

Engineering Contradiction:
Improveregeneration speedVSAvoidfilter overheating
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies periodic action by dividing the regeneration process into distinct phases: an ignition phase with higher temperature to start combustion, followed by a main regeneration phase with reduced temperature. This periodic temperature control allows the system to achieve regeneration effectiveness while reducing overall fuel consumption and preventing overheating damage.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent changes the temperature parameter dynamically during regeneration. The control unit lowers the temperature at the filter input port during the main regeneration phase compared to the ignition phase. This parameter change enables the combustion process to continue using heat from particulate matter oxidation while reducing external heating requirements, thereby lowering fuel consumption and preventing filter overheating.

Inventive Principle:
Principle #35Parameter changes

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 the energy required for filter regeneration, minimizes fuel consumption, prevents overheating, and ensures thorough particulate removal by adjusting the filter temperature according to the particulate load and engine conditions, maintaining filter effectiveness and reducing hydrocarbon emissions.

Implementation Method 1

The fuel injected after the top dead centre position, referred to as post-injected fuel in the following description, is ejected from the combustion chamber unburnt, and reaches an exhaust catalyst which is conventionally provided for degrading residual hydrocarbons and nitric oxides that are formed in the combustion process of the engine. Such a catalyst is also effective to oxidise the post-injected fuel. The catalytic oxidation of the post-injected fuel heats the exhaust gas which reaches the particulate filter, whereby the latter is heated.

Methodology Applied
Scientific EffectCatalytic oxidation: Catalysis

Implementation Method 2

regeneration is achieved by heating the filter to a temperature at which the accumulated particulate matter burns off

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP1918541B1Operating method for a particulate filter, data processor program product and control apparatus therefore
Publication Date: 2009.02.25 GM GLOBAL TECHNOLOGY OPERATIONS LLC
  • EP1918541B1 patent drawingFigure 1~2
  • EP1918541B1 patent drawingFigure 3~4

AI summary

A method for operating a particulate filter (12) in the exhaust system of an internal combustion engine comprises a filtering phase in which particles from exhaust gas of the combustion engine are collected in the filter, and a filter cleaning phase (t1-t5) in which the filter (12) is held in a temperature range in which particles collected in the filter (12) are burnt. The filter cleaning phase (t1-t5) comprises a main portion (t2-t5) and an ignition portion (t1-t2) prior to said main portion (t2-t5), and the temperature (Ts) at an input port of the filter (12) is controlled to be lower at the beginning (t2-t3) of the main portion (t2-t5) than in the ignition portion (t1-t2).