EGR Duct Virtual Wall Geometry for Return Flow Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing EGR systems face challenges in minimizing gas exchange work, maintaining a long service life, reducing manufacturing costs, and achieving low fuel consumption due to pulsating waste gas flows and pressure variations, which current solutions like reed valves fail to adequately address.
Innovation Solution
The EGR system employs a specially designed geometry with a sharp edge and transitional sections to create virtual walls through vortex formation, reducing return flow and drive pressure, thereby minimizing gas exchange work and fuel consumption without moving parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If reed valves are used in the EGR system to prevent return flow, then the directionality of waste gas flow is improved, but the pressure drop in the forward direction increases and the service life decreases due to the aggressive environment
Solution Approach 1:
The patent replaces the mechanical reed valve system with a passive geometric flow control system. The duct geometry includes a sharp edge and transitional sections that create vortex formation and virtual walls to prevent return flow without moving parts, eliminating the reliability issues of reed valves while maintaining flow directionality.
Solution Approach 2:
The patent introduces virtual walls formed by vortices as an intermediary mechanism. These virtual walls are created through carefully designed duct geometry with sharp edges and transitional sections that generate rotating flow patterns, acting as a mediator to block return flow without physical contact from moving parts.
2Stability of the object's composition
If reed valves are used in the EGR system to prevent return flow, then the directionality of waste gas flow is improved, but the pressure drop in the forward direction compounds
Solution Approach 1:
The patent replaces the mechanical reed valve system with a passive geometric flow control system. The duct geometry includes a sharp edge and transitional sections that create vortex formation and virtual walls to prevent return flow without moving parts, eliminating the reliability issues of reed valves while maintaining flow directionality.
Solution Approach 2:
The patent changes the geometric parameters of the duct, specifically incorporating a sharp edge with a defined radius and transitional sections with specific length-to-diameter ratios. These parameter changes optimize the vortex formation to achieve flow directionality while minimizing pressure drop through careful geometric tuning.
3Reliability
If a passive geometry solution with vortex formation is used, then the service life is extended and manufacturing cost is reduced, but the complexity of flow control geometry increases
Solution Approach 1:
The patent changes the geometric parameters of the duct, specifically incorporating a sharp edge with a defined radius and transitional sections with specific length-to-diameter ratios. These parameter changes optimize the vortex formation to achieve flow directionality while minimizing pressure drop through careful geometric tuning.
Solution Approach 2:
The patent employs self-service principles where the waste gas flow itself generates the vortex patterns and virtual walls through the designed geometry. The system uses the kinetic energy and pressure of the incoming waste gas to create the flow control mechanisms, eliminating the need for external actuators or complex control systems.
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 passive geometry solution effectively reduces the need for drive pressure, lowers fuel consumption, and extends the service life of the EGR system while maintaining low manufacturing costs and efficient gas exchange.
Implementation Method 1
specially designed geometry with a sharp edge and transitional sections to create virtual walls through vortex formation
Implementation Method 2
specially designed geometry with a sharp edge and transitional sections to create virtual walls through vortex formation
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to an EGR system, including a duct (48) with an inlet port (50) and an outlet port (56), which duct (48) includes a first duct section (54) with a first cross-sectional area (Al), a second duct section (56) with a second cross-sectional area (A2) and a transitional section (58) arranged between the first and second duct sections (54, 56). The transitional section (58) is designed so that a first virtual wall (60) is formed by EGR gases (25) in the transitional section (58) when the EGR gases (25) flow in the direction from the inlet port (50) to the outlet port (52) and a second virtual (74) wall is formed by a return flow (72) in the first duct section (54) when the return flow (72) flows from the outlet port (52) to the inlet port (50). The invention also relates to a combustion engine (2) with such an EGR system (4) and a vehicle (1) which includes such a combustion engine (2).