Annular Catalytic Converter with Segmented Flow Paths
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Solution Overview
Problem
Existing exhaust-gas aftertreatment systems, particularly annular catalytic converters with tubular and annular flow paths, experience suboptimal flow distribution and temperature drops, leading to inefficient pollutant reaction at catalytic converter substrates.
Innovation Solution
An annular catalytic converter design with a tubular flow path, a diverting chamber, and an annular flow path, featuring structured metal foils with cutouts to reduce thermal mass and an electrically heatable heating disk or heating coil to accelerate heating, ensuring improved mixing and temperature maintenance or increase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If exhaust gas flows through a tubular flow path in an annular catalytic converter, then mixing of exhaust gas is improved, but exhaust-gas temperature decreases significantly
Solution Approach 1:
The flow path is segmented into distinct regions: a tubular flow path for mixing and a separate annular flow path for temperature maintenance. The substrate body is segmented with cutouts that create multiple flow channels, allowing different functional zones within the same component.
Solution Approach 2:
Different regions of the catalytic converter are assigned different functions: the tubular flow path optimizes for mixing quality, while the annular flow path optimizes for temperature maintenance. The substrate body has varying properties through its cutout structure, creating local zones for different flow characteristics.
2Loss of time
If catalytic converters are positioned close to the exhaust-gas source, then light-off temperature is reached faster, but flow distribution over the cross section becomes suboptimal
Solution Approach 1:
The flow path is divided into sequential segments: first the tubular flow path where exhaust gas mixes properly, then the diverting chamber, and finally the annular flow path where temperature is maintained. This segmentation allows the system to achieve both good flow distribution and fast heating.
Solution Approach 2:
The flow path transitions from a two-dimensional tubular section to a three-dimensional annular section with multiple flow channels created by cutouts in the substrate body. This dimensional change allows improved mixing in the tubular section while maintaining temperature in the annular section.
3Stability of the object's composition
If a tubular flow path is used in an annular catalytic converter, then exhaust gas mixing is enhanced, but temperature drop in the diverting chamber increases
Solution Approach 1:
The temperature maintenance function is extracted from the tubular flow path and placed in the separate annular flow path. The tubular flow path is dedicated to mixing, while the annular flow path with its multiple channels is dedicated to maintaining temperature through reduced thermal mass and improved heat distribution.
Solution Approach 2:
The diverting chamber acts as an intermediary between the tubular and annular flow paths, transitioning the flow while managing the temperature drop. The substrate body with cutouts serves as an intermediary structure that creates multiple flow channels, improving heat transfer efficiency.
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 design enhances exhaust-gas mixing and maintains or increases exhaust-gas temperature, facilitating quicker attainment of the light-off temperature for efficient pollutant reaction on catalytic converter substrates.
Implementation Method 1
an electrically heatable heating disk or heating coil to accelerate heating
Implementation Method 2
the catalytic converters advantageously arranged close to the source of the exhaust gases... the chemical reaction of the respective pollutants from the exhaust gases
Implementation Method 3
structured metal foils with cutouts to reduce thermal mass and an electrically heatable heating disk or heating coil to accelerate heating
Data Source
AI summary
A device for exhaust-gas aftertreatment, such as an annular catalytic converter, having a first, tubular flow path, having a diverting chamber and having a second, annular flow path, wherein the tubular flow path is delimited outwardly in the radial direction by an inner pipe and the second, annular flow path is delimited inwardly in the radial direction by the inner pipe and outwardly in the radial direction by an outer pipe, and the diverting chamber is designed to divert the exhaust-gas flow from the tubular flow path (8) into the annular flow path, wherein the annular catalytic converter has at least one annular substrate body which has a catalytically active coating applied to it and which is arranged in the annular flow path.