Toroidal Control Flaps for Swirling Exhaust Gas Mixtures
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Solution Overview
Problem
Existing systems for recycling exhaust gases in internal combustion engines fail to ensure a homogeneous mixture of air and recycled exhaust gases, leading to inefficient combustion and increased nitrogen oxides (NOx) due to incomplete mixing and reduced combustion temperature.
Innovation Solution
A device with two toroidal control flaps mounted rotatably on the intake duct, actuated by a mechanism that adjusts their position based on exhaust gas pressure, reducing the duct's cross-section to swirl and mix the gases, ensuring homogenization of the air-exhaust gas mixture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If control flaps are positioned to reduce intake duct cross-section for swirling and mixing, then homogeneity of air-exhaust gas mixture is improved, but pressure loss increases
Solution Approach 1:
The control flaps are designed to be movable between different positions: a retracted position where they align with the inner wall to minimize pressure loss, and an active position where they protrude to create swirling and mixing. This dynamic adjustment allows the system to optimize between pressure loss and mixing homogeneity based on operational requirements.
Solution Approach 2:
The mixing function is divided into multiple control flaps (at least two) that can be independently positioned. This segmentation allows for gradual creation of turbulence and mixing zones without completely blocking the flow, thereby reducing pressure loss while still achieving adequate homogeneity.
2Loss of energy
If control flaps are retracted to minimize pressure loss, then energy efficiency is improved, but mixing homogeneity deteriorates
Solution Approach 1:
The system dynamically adjusts control flap positions based on operating conditions. When high mixing is required, flaps are positioned to create turbulence; when pressure loss must be minimized, flaps are retracted. This dynamic control resolves the contradiction by allowing optimal performance in different operational scenarios.
Solution Approach 2:
The position parameter of the control flaps is changed to optimize system performance. By adjusting the flap position parameter between retracted and extended states, the system can change its characteristics to match different operational requirements, balancing pressure loss and mixing homogeneity.
3Temperature
If control flaps are positioned to swirl and mix gases, then combustion temperature uniformity is improved, but NOx emissions reduction becomes more complex
Solution Approach 1:
The mixing function is segmented into multiple control flaps that create distributed turbulence zones throughout the intake duct. This segmentation achieves better temperature uniformity compared to a single mixing element, while the modular nature of multiple simple flaps keeps the overall device complexity manageable.
Solution Approach 2:
The control flaps are designed with curved or toroidal shapes that efficiently generate swirling flow patterns. These curved geometries create effective mixing and temperature uniformity without requiring complex mechanical mechanisms, thus achieving good combustion temperature distribution while maintaining relatively simple device structure.
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
The device effectively homogenizes the air-exhaust gas mixture, reducing NOx emissions by optimizing combustion conditions, and maintains minimal pressure loss when exhaust gases are low, enhancing engine performance.
Implementation Method 1
In an active position, the control flaps act like the blades of a turbine to swirl the mixture of air and recycled burned gases and, consequently, enable this mixture to be homogenised quickly
Data Source
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AI summary
Device for swirling and mixing exhaust gases recycled in the intake duct (1) of an internal combustion engine via a recycling conduit (2). It is formed of two control flaps (3, 4) in the form of toroidal portions, mounted rotatably about axes of articulation (6, 7), said control flaps (3, 4) being displaceable in rotation between, on the one hand, a rest position in which they are retracted along the inner wall of the intake duct (1) so as to expose the entire cross-section of said duct and, on the other hand, an active position in which they are pulled towards one another so as to reduce said cross-section, and also formed of an actuator which makes it possible to control displacement of the control flaps (3, 4) between the active position and rest position thereof.