Exhaust Catalytic Converter Detection via Temperature Profiles

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Solution Overview

Problem

Existing methods for monitoring the functionality of exhaust systems, particularly in applications with SCR catalytic converters, often require additional sensors and incur extra costs, as they rely on differential pressure sensors to detect the presence or absence of catalytic converters, which is inefficient and costly.

Innovation Solution

A method utilizing existing temperature sensors upstream and downstream of the catalytic converter to determine temperature profiles during a temperature jump, comparing these profiles to detect if a catalytic converter is present, eliminating the need for differential pressure sensors and reducing costs by simplifying the exhaust aftertreatment system design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If differential pressure sensors are used to detect the presence or absence of catalytic converters, then the functionality of the exhaust system can be monitored, but additional sensors and extra costs are required

Engineering Contradiction:
Improvefunctionality monitoringVSAvoidsensor quantity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The temperature sensors originally intended for other monitoring purposes are made to serve dual functions: their primary function and the additional function of detecting catalytic converter presence through temperature profile analysis during transient operations. This eliminates the need for separate differential pressure sensors while maintaining monitoring capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The exhaust system uses its own thermal characteristics and existing temperature sensors to perform self-diagnosis regarding catalytic converter presence. The system monitors its own temperature profiles during transient operations and automatically detects anomalies indicating converter removal, without requiring external specialized sensors.

Inventive Principle:
Principle #25Self-service

2Reliability

If differential pressure sensors are installed to detect empty pipes, then catalytic converter removal can be detected, but sensor, cabling, hose and maintenance costs increase

Engineering Contradiction:
Improveconverter presence detectionVSAvoidsystem cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Existing temperature sensors are repurposed to perform dual functions: their original monitoring role and the new role of detecting catalytic converter presence. By analyzing temperature profiles during transient operations, the system achieves converter detection capability without requiring additional specialized sensors, thereby reducing sensor, cabling, hose, and maintenance costs.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention uses inexpensive temperature data that is already being collected by the system rather than relying on expensive specialized differential pressure sensors. The temperature profiles are derived from normal operational data, avoiding the need for costly dedicated detection hardware.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Device complexity

If temperature sensors are used to determine temperature profiles, then the presence of catalytic converter can be detected without additional sensors, but the method requires temperature jump conditions

Engineering Contradiction:
Improvesensor quantityVSAvoidoperating condition requirement
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The detection method utilizes periodic transient operations (temperature jumps) that occur naturally during engine operation. By analyzing temperature profiles during these periodic transient events, the system can detect catalytic converter presence without requiring continuous special measurement conditions, as transient operations occur regularly in normal engine cycles.

Inventive Principle:
Principle #19Periodic action

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 checks for the presence of a catalytic converter without additional sensors, saving costs and maintaining emissions compliance by accurately identifying removal scenarios through temperature profile analysis, thus ensuring efficient monitoring of exhaust systems.

Implementation Method 1

A first temperature sensor 20 is arranged in the direction of flow 14 in front of the installation location 16 and thus in front of the catalytic converter 18, and a second temperature sensor 22 is provided in the direction of flow 14 behind the installation location 16

Methodology Applied
Scientific EffectTemperature measurement:

Data Source

PatentEP2764220B1Method for monitoring an exhaust system
Publication Date: 2018.07.25 ROLLS ROYCE SOLUTIONS GMBH
  • EP2764220B1 patent drawingFigure 1
  • EP2764220B1 patent drawingFigure 2
  • EP2764220B1 patent drawingFigure 3

AI summary

A method and an arrangement for monitoring an exhaust system (10) of an internal combustion engine are disclosed. In said method and arrangement, temperature variations are measured upstream and downstream of an installation location (16) of a catalytic converter (18) in order to determine whether or not said catalytic converter (18) is installed.