Aftertreatment Ash Accumulation Compensation via Flow Resistance Tracking

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Solution Overview

Problem

Existing systems for particulate filter regeneration do not adequately account for ash accumulation, leading to inefficiencies and inaccurate timing of servicing, which can result in adverse effects on fuel consumption and particulate matter emission control.

Innovation Solution

A method and system that determine and track minimum flow resistance values over time, correlate them with a model of engine oil consumption rate, and adjust predetermined values to compensate for ash accumulation, thereby optimizing regeneration frequency and filter efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If regeneration frequency is increased to compensate for ash accumulation, then particulate filter efficiency is maintained, but fuel consumption increases

Engineering Contradiction:

Improveparticulate filter efficiencyVSAvoidfuel consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system continuously monitors flow resistance through the particulate filter and uses this feedback to dynamically adjust regeneration frequency. Flow resistance serves as a direct indicator of ash accumulation level, allowing the control system to optimize regeneration timing based on actual filter conditions rather than following a fixed schedule, thereby maintaining filter efficiency while minimizing unnecessary fuel consumption

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system changes the regeneration frequency parameter based on monitored flow resistance values. By adjusting this operational parameter in response to actual ash accumulation levels, the system optimizes the balance between maintaining particulate filter efficiency and minimizing fuel consumption during regeneration events

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If predetermined oil consumption values are not adjusted for actual conditions, then the model remains simple, but ash accumulation is inaccurately determined

Engineering Contradiction:

Improvemodel simplicityVSAvoidash accumulation determination accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The system replaces complex direct measurement of ash accumulation with a flow resistance-based monitoring approach. By measuring flow resistance through the filter and correlating it with ash accumulation, the system achieves accurate determination of ash levels without requiring complex analytical instruments or direct sampling methods

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

Flow resistance serves as an intermediary parameter that indirectly indicates ash accumulation levels. Instead of directly measuring ash content, the system uses flow resistance as a proxy measurement that correlates with ash accumulation, simplifying the measurement process while maintaining accuracy

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If regeneration timing is not adjusted for ash accumulation, then the control system remains simple, but particulate trap volume determination becomes inaccurate

Engineering Contradiction:

Improvecontrol system complexityVSAvoidparticulate trap volume determination accuracy

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The control system uses flow resistance feedback to continuously monitor filter loading conditions and adjust regeneration timing accordingly. This feedback mechanism allows the system to maintain accurate determination of available particulate trap volume by basing regeneration decisions on actual filter conditions rather than fixed schedules or theoretical models

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 effectively maintains particulate filter efficiency by accurately predicting ash accumulation and adjusting regeneration cycles, ensuring optimal engine operation and reduced particulate emissions.

Implementation Method 1

A particulate filter may include filter material designed to capture particulate matter

Methodology Applied

Scientific EffectFiltration: Filter (physical)

Implementation Method 2

A large portion of the collected particulate matter, e.g. soot, may be removed from the filter material through a process called regeneration. One way that regeneration may be accomplished is by increasing the temperature of the filter material, and the particulate matter in the filter material, above the combustion temperature of the particulate matter. The soot may be consumed by the heat of the regeneration process.

Methodology Applied

Scientific EffectThermal oxidation/Combustion: Combustion

Data Source

PatentUS7841172B2Method and system for maintaining aftertreatment efficiency

Publication Date: 2010.11.30 CATERPILLAR INC

AI summary

A method is provided for compensating for variability in ash accumulation rates within an aftertreatment element of an engine exhaust system. The method includes determining flow resistance values through the aftertreatment element and tracking minimum flow resistance values over time. The method also includes correlating the tracked minimum flow resistance values over time, with a model of engine oil consumption rate that is based on predetermined values for model engine oil consumption. The method further includes adjusting the predetermined values based on the tracked minimum flow resistance values over time.