EGR Accumulator with Segmented Outlets for Cylinder Distribution
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Solution Overview
Problem
Existing systems face challenges in achieving a proper mix and distribution of exhaust gas recirculation (EGR) flow with intake air flow in internal combustion engines, which affects combustion efficiency and NOx emissions.
Innovation Solution
The implementation of an EGR system that includes an accumulator with multiple outlets connected to the intake manifold, allowing for the temporary storage and controlled release of EGR flow, ensuring even distribution and mixing with intake air, and optionally utilizing a porous media to enhance hydrogen content and reduce pressure drop losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If exhaust gas is recirculated from dedicated cylinders to reduce NOx emissions, then combustion temperature is reduced and NOx formation decreases, but proper mixing and distribution of EGR flow with intake air becomes difficult
Solution Approach 1:
The EGR flow from dedicated cylinders is divided into multiple separate flow paths, with each path leading to a different intake manifold or cylinder group. This segmentation allows independent control and optimization of EGR distribution to different cylinders, solving the mixing and distribution problem while maintaining the NOx reduction benefit
Solution Approach 2:
An intermediary mixing chamber or manifold is introduced between the EGR source and the intake air supply. This intermediary component facilitates proper mixing of EGR with fresh intake air before the mixture enters the combustion chambers, ensuring homogeneous distribution while maintaining the temperature reduction effect
2Adaptability or versatility
If a variable geometry turbocharger is used to drive EGR flow, then EGR flow control is improved, but device complexity and cost increase
Solution Approach 1:
The system utilizes the engine's own intake manifold pressure and cylinder suction to draw EGR flow from the dedicated cylinders. The engine's natural intake process serves as the driving force for EGR circulation, eliminating the need for external turbochargers or complex mechanical EGR pumps while maintaining effective EGR flow control
3Quantity of substance
If EGR flow is increased to maintain target air-fuel ratios, then combustion temperature control is improved, but mixing efficiency and distribution uniformity decrease
Solution Approach 1:
High EGR flow rates are achieved by segmenting the total EGR quantity into multiple parallel flow paths, each delivering controlled amounts to different intake manifolds or cylinder groups. This maintains high overall EGR rates while ensuring uniform distribution across all cylinders through the segmented delivery system
Solution Approach 2:
Different cylinders or cylinder groups receive customized EGR flow rates tailored to their specific combustion requirements. The system provides local optimization of EGR quantity and mixing characteristics for each cylinder group, maintaining uniform distribution quality even at high overall EGR flow rates
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 solution improves the distribution of EGR flow, ensuring a constant and even supply of recirculated exhaust gas to all engine cylinders, reducing NOx emissions and enhancing combustion efficiency by maintaining optimal air-exhaust gas mixtures.
Implementation Method 1
optionally utilizing a porous media to enhance hydrogen content
Data Source
AI summary
Systems, methods and techniques for exhaust gas recirculation are provided. The system includes mixing exhaust flow from at least one cylinder of an engine with air in an air intake system prior to combustion. The exhaust flow from the at least one cylinder is accumulated prior to mixing and distributed into the intake air system in a controlled manner.