Particulate Filter Temperature Set Point Control for Regeneration

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Solution Overview

Problem

Existing systems face challenges in controlling exhaust gas fuel levels and temperatures at particulate filters to facilitate effective regeneration, risking heat damage or incomplete oxidation due to inadequate temperature set points and thermal inertia considerations.

Innovation Solution

A controller determines a particulate filter temperature set point (Tset) by combining a critical temperature (Tc) value, which accounts for maximum safe exposure, and a temperature adjustment (Ta) value representing thermal inertia, to manage exhaust gas temperatures and fuel levels, ensuring optimal regeneration without damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the temperature at the particulate filter is raised to facilitate regeneration, then the oxidation rate of captured particulates is improved, but the risk of heat damage to the filter increases

Engineering Contradiction:

Improveoxidation rateVSAvoidheat damage

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the temperature set point based on thermal inertia calculations. The system modifies the target temperature parameter in real-time, considering the filter's thermal mass and heating rate, to achieve optimal oxidation while preventing heat damage through controlled parameter variation.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback control by continuously monitoring the actual temperature at the particulate filter and comparing it to the calculated set point. The controller adjusts exhaust gas fuel levels and temperatures based on this feedback, ensuring the system maintains temperatures that maximize oxidation while preventing harmful overheating.

Inventive Principle:

Principle #23Feedback

2Reliability

If the temperature set point is set high to ensure complete regeneration, then the reliability of particulate removal is improved, but the thermal inertia may cause overheating and damage

Engineering Contradiction:

Improveparticulate removalVSAvoidoverheating

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent applies preliminary action by calculating the temperature set point in advance of the actual heating process. The controller determines the appropriate set point based on thermal inertia considerations before initiating temperature increases, preventing overheating by pre-planning the temperature trajectory to account for the filter's thermal mass and heating characteristics.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If exhaust gas fuel levels are increased to raise temperature for regeneration, then the regeneration effectiveness is improved, but the risk of uncontrolled temperature rise increases

Engineering Contradiction:

Improveregeneration effectivenessVSAvoidtemperature control

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent implements feedback control by continuously monitoring actual temperature and adjusting exhaust gas fuel levels accordingly. The controller modifies fuel injection based on the difference between actual and target temperatures, ensuring regeneration effectiveness while maintaining reliable temperature control and preventing uncontrolled temperature rises.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent applies parameter changes by dynamically adjusting exhaust gas fuel levels based on calculated temperature set points. The system varies the fuel parameter in real-time to achieve the desired temperature for effective regeneration while maintaining control through continuous parameter adaptation.

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 allows for controlled regeneration, preventing heat damage and maximizing oxidation rates while minimizing overheating, thereby maintaining filter efficiency and extending its lifespan.

Implementation Method 1

oxidize or burn the capture particulates in a process commonly referred to as regeneration

Methodology Applied

Scientific EffectOxidation: Oxidation

Implementation Method 2

burn the capture particulates in a process commonly referred to as regeneration

Methodology Applied

Scientific EffectCombustion: Combustion

Implementation Method 3

raising temperatures at the particulate filter to those specified by the Tset value

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentUS7441403B2Method and system for determining temperature set points in systems having particulate filters with regeneration capabilities

Publication Date: 2008.10.28 DETROIT DIESEL CORP

AI summary

Method, system, and controller for determining a temperature set point for use in controlling regeneration of a particulate filter. The method, system, and controller being applicable in systems having an engine which emits exhaust gases having particulates which are captured by the particulate filter.