Compact Exhaust Gas Aftertreatment System with Integrated Compensator

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Solution Overview

Problem

Current exhaust gas aftertreatment systems in internal combustion engines face challenges in minimizing installation space, efficiently reducing nitrogen oxides and solid particles, and preventing corrosion due to ammonia backflow, especially under varying operating conditions.

Innovation Solution

Integrating catalytic converters and particle filters within compensators that allow for relative movement, utilizing a combination of oxidation and SCR catalytic converters, and a hydrolysis catalyst to optimize nitrogen oxide reduction and ammonia handling, while preventing ammonia backflow and corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If catalytic converters and particle filters are integrated within compensators, then installation space is minimized, but the device complexity increases

Engineering Contradiction:
Improveinstallation spaceVSAvoiddevice complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The patent integrates catalytic converters and particle filters within the compensator structure, merging multiple exhaust treatment functions into a single component. This consolidation minimizes installation space by utilizing the existing compensator volume rather than adding separate devices, while the modular integration approach manages the increased device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The compensator is designed to serve multiple functions: it compensates for relative movements in the exhaust tract and simultaneously houses catalytic converters for nitrogen oxide reduction and particle filters for solid particle removal. This multi-functionality reduces the overall system volume by eliminating the need for separate dedicated spaces for each function.

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

2Productivity

If oxidation catalytic converter is added upstream of SCR catalytic converter, then nitrogen oxide conversion efficiency is enhanced, but device complexity increases

Engineering Contradiction:
Improvenitrogen oxide conversion efficiencyVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The oxidation catalytic converter is positioned upstream of the SCR catalytic converter to perform preliminary oxidation of nitrogen monoxide to nitrogen dioxide. This preliminary action enhances the subsequent SCR reduction efficiency by providing nitrogen dioxide, which reacts more readily with ammonia than nitrogen monoxide does, thereby improving overall nitrogen oxide conversion efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a continuous exhaust gas treatment process where oxidation and SCR reduction occur in sequence without interruption. The oxidation catalytic converter continuously converts nitrogen monoxide to nitrogen dioxide, which then continuously flows to the SCR catalytic converter for reduction, maintaining continuous useful action throughout the treatment process.

Inventive Principle:
Principle #20Continuity of useful action

3Adaptability or versatility

If compensators with relative movement capability are used, then adaptability to varying operating conditions is improved, but device complexity increases

Engineering Contradiction:
Improveadaptability to varying operating conditionsVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The compensator incorporates dynamic elements that allow relative movements between different parts of the exhaust tract. This dynamic capability enables the system to adapt to varying operating conditions such as thermal expansion, vibrations, and misalignments that occur during different engine operating states, while the compensator maintains its function of housing the catalytic converters and particle filters.

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 approach minimizes installation space, enhances nitrogen oxide conversion efficiency, prevents ammonia-related corrosion, and ensures continuous particle filtration without additional control complexity, thereby meeting stringent emission standards.

Implementation Method 1

a device for converting exhaust gas components of an internal combustion engine by means of at least one catalytic converter

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

Nitrogen oxides are usually reduced with the help of catalytic converters; in oxygen-rich exhaust gas, a reducing agent is also required to increase selectivity and NO x conversion. These methods have become known under the collective term SCR method, where SCR stands for 'selective catalytic reduction'.

Methodology Applied
Scientific EffectSelective catalytic reduction: Catalysis

Implementation Method 3

If the SCR catalysts are preceded by a platinum-containing NO oxidation catalyst for the formation of NO 2 2NO+O 2 ⇔ 2NO 2

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 4

a hydrolysis catalyst to optimize nitrogen oxide reduction and ammonia handling

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Implementation Method 5

particle filters are prone to clogging, which increases exhaust back pressure and reduces engine performance

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 6

an ammonia blocking catalytic converter is often used downstream of the SCR catalytic converter, which converts excess ammonia into nitrogen and water vapor

Methodology Applied
Scientific EffectCatalytic conversion: Catalysis

Data Source

PatentEP2101049B1Compact exhaust gas after treatment system
Publication Date: 2015.12.23 MAN TRUCK & BUS SE
  • EP2101049B1 patent drawingFigure 1~2
  • EP2101049B1 patent drawingFigure 3~4
  • EP2101049B1 patent drawingFigure 5~6

AI summary

Device for converting exhaust gas components of an internal combustion engine by means of at least one catalyst and/or particulate filter and/or particulate separator, and for compensating for relative movements between the internal combustion engine and the exhaust system and/or for compensating for relative movements of different parts of the exhaust system by means of at least one compensator that allows for such relative movements. It is provided that the at least one catalyst for converting exhaust gas components and/or the at least one particulate filter and/or the at least one particulate separator is arranged within the compensator (20.1 - 20.8, 20.X, 20.Y, 20.Z) and/or within a part of the exhaust system that is permanently connected to the compensator (20.1 - 20.8, 20.X, 20.Y, 20.Z). The outer diameter of the catalyst and/or the particulate filter and/or the particulate separator is less than or equal to the inner diameter of the compensator (20.1 - 20.8, 20.X, 20.Y, 20.Z).