Annular EGR Flow Path for Uniform Gas Distribution
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Solution Overview
Problem
Existing exhaust gas recirculation systems face challenges in achieving uniform flow velocity distribution downstream of the connecting portion between the induction and recirculation passageways, leading to uneven mixing of fresh air and EGR gases, which can cause compressor wear and inefficiencies.
Innovation Solution
An exhaust gas recirculation system with an annular flow path extending circumferentially around the induction passageway, featuring a tapered inlet port with a constriction upstream and a wider downstream section, ensures even distribution of exhaust gases by adjusting the inner surface width and angles of the annular flow path to maintain uniform flow velocity distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If EGR gases are introduced from one side portion of the induction pipe, then the connecting construction is simple, but the flow velocity distribution becomes non-uniform and fresh air separates from EGR gases
Solution Approach 1:
The single side connection is segmented into multiple connection points arranged circumferentially around the induction pipe. This segmentation allows EGR gases to be introduced from multiple locations simultaneously, creating a more uniform flow velocity distribution and preventing fresh air separation while maintaining connection simplicity.
Solution Approach 2:
The connection arrangement transitions from a one-dimensional side connection to a two-dimensional circumferential distribution around the induction pipe. This dimensional change enables uniform EGR gas introduction across the cross-section, resolving the flow non-uniformity issue while keeping the connecting construction straightforward.
2Stability of the object's composition
If an annular path is formed to introduce EGR gases from circumferential direction, then flow velocity distribution becomes uniform, but the device complexity increases
Solution Approach 1:
The annular path construction is merged with the induction pipe structure, where the annular path is formed as an integrated feature of the induction pipe rather than as a separate component. This merging maintains uniform flow velocity distribution while reducing overall device complexity.
Solution Approach 2:
The induction pipe serves multiple functions: it guides fresh air flow and simultaneously provides the annular path for EGR gas introduction. This multi-functionality eliminates the need for separate annular path components, reducing device complexity while maintaining uniform flow distribution.
3Productivity
If EGR gases are introduced at high flow rate, then mixing efficiency improves, but induction resistance increases
Solution Approach 1:
The circumferential connection arrangement creates different local flow characteristics around the induction pipe. EGR gases are introduced at multiple locations with optimized local flow rates, achieving high overall mixing efficiency while distributing the induction resistance across multiple points rather than concentrating it at a single high-flow connection.
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 configuration ensures even mixing of fresh air and exhaust gases, reducing compressor wear and improving efficiency by maintaining uniform flow velocity distribution and minimizing induction resistance.
Implementation Method 1
the flow velocity distribution of the mixture of fresh air and EGR gases which flow within the induction passageway does not become uniform within the section of the same flow path
Data Source
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AI summary
An exhaust gas recirculation system includes an induction passageway (23) through which fresh air flows and an annular flow path (62) extending in a circumferential direction of the induction passageway (23) and formed in an annular shape. The annular flow path (62) encompasses the induction passageway (23) therein. An inlet port (63) is formed between the induction passageway (23) and the annular flow path (62) and communicates the induction passageway with the annular flow path. An exhaust gas introduction flow path (80) is communicated with the annular flow path (62) and introduces the exhaust gases into the annular flow path (62) so that the exhaust gases flow in one direction of the circumferential direction. The annular flow path (62) has an inner face facing the inlet port (63), and the inner face has a width (w2) in a direction crossing the one direction. An upstream side of the width (w2) is shorter than a downstream side of the width (w2) with respect to a flow of the exhaust gasses which flows into the annular flow path (62) from the exhaust gas introduction flow path (80).