Particulate Filter Cooling Control During Downhill Engine Cutoff

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Solution Overview

Problem

Heavy-duty vehicles equipped with diesel particulate filters face a risk of soot ignition when the filter becomes full and temperature increases, potentially damaging the filter and surrounding components.

Innovation Solution

A computer system that determines if a downhill condition and a soot or temperature threshold is met, controlling the vehicle to either turn off the engine or supply fuel while disconnecting it from drive members to generate exhaust gas flow through the filter, cooling it and preventing ignition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the combustion engine is turned off during downhill conditions, then fuel consumption is reduced, but the risk of soot ignition in the particulate filter increases

Engineering Contradiction:
Improvefuel consumptionVSAvoidrisk of soot ignition
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The control system performs preliminary assessment of soot load and temperature conditions before turning off the engine during downhill driving. By checking whether soot amount and temperature thresholds are exceeded in advance, the system prevents soot ignition from occurring, thereby eliminating the harmful effect before it can manifest.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The system continuously monitors soot amount in the particulate filter and temperature conditions, using this feedback information to make real-time decisions about engine operation. When thresholds are exceeded, the system adjusts engine operation to maintain cooling exhaust gas flow, preventing soot ignition while managing fuel consumption.

Inventive Principle:
Principle #23Feedback

2Reliability

If the combustion engine is kept running to cool the particulate filter, then soot ignition risk is reduced, but fuel consumption increases

Engineering Contradiction:
Improverisk of soot ignitionVSAvoidfuel consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system changes the operational parameters of the combustion engine based on monitored conditions. When soot load and temperature thresholds are not exceeded, the engine is turned off to save fuel. When thresholds are exceeded, the engine is kept running at specific parameters to generate cooling exhaust gas flow, thus resolving the contradiction between fuel consumption and soot ignition prevention.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the engine is drivingly disconnected from drive members, then the vehicle can coast downhill, but exhaust gas flow through the filter is reduced

Engineering Contradiction:
Improvedownhill coasting efficiencyVSAvoidexhaust gas flow for cooling
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system dynamically adjusts the connection between the combustion engine and drive members based on real-time conditions. When soot ignition risk is high, the engine remains connected to maintain sufficient exhaust gas flow for cooling the particulate filter. When risk is low, the engine can be disconnected to enable efficient downhill coasting, thus optimizing both productivity and reliability dynamically.

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 method reduces the risk of soot ignition in the particulate filter by ensuring a controlled exhaust gas flow cools the filter, thereby protecting it from damage.

Implementation Method 1

The exhaust gas mass flow is thereby able to cool the particulate filter

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

The heat energy may damage the filter, and/or surrounding components within the aftertreatment system

Methodology Applied
Scientific EffectThermal energy transfer: Conduction (thermal)

Data Source

PatentEP4417803A1A method and a system for controlling a vehicle comprising an engine exhaust system
Publication Date: 2024.08.21 VOLVO TRUCK CORP
  • EP4417803A1 patent drawingFigure 1~2
  • EP4417803A1 patent drawingFigure 3
  • EP4417803A1 patent drawingFigure 4

AI summary

A computer-implemented method for controlling a vehicle (100) comprising a combustion engine, drive members, and an engine exhaust system comprising a particulate filter, the method comprising: determining that a first condition is fulfilled, such as when a downhill condition applies, determining if a second condition is fulfilled, wherein the second condition is considered fulfilled if an amount of soot in the particulate filter exceeds a threshold amount, and/or if a temperature at the particulate filter exceeds a temperature threshold level (TTH), in response to determining that the first condition is fulfilled, and the second condition is not fulfilled, controlling the vehicle to turn off the combustion engine, in response to determining that the first and second conditions are fulfilled, controlling the vehicle to supply fuel to the combustion engine, the engine being drivingly disconnected from the drive members.