Segmented Particle Filter for Cold Start Emission Control
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Solution Overview
Problem
Existing particle filters for internal combustion engines, particularly those in spark-ignited Otto engines, face challenges in efficiently separating particles during the cold start phase, leading to increased exhaust back pressure, emissions, and reduced performance due to insufficient particle separation and regeneration issues.
Innovation Solution
A particle filter design featuring first filter channels closed on the outlet side by low-porosity closures and second filter channels closed on the inlet side by impermeable closures, with highly porous closures on the outlet side to allow exhaust gas to flow through, enhancing particle separation and filter efficiency by depositing soot on the filter walls, which increases the filter effect over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If exhaust gas flows through one filter wall of the particulate filter, then the structure is simple, but particle separation efficiency is insufficient during cold start phase
Solution Approach 1:
The filter body is divided into multiple filter channels (first and second groups) with different closure configurations. Some channels are closed at the inlet side, others at the outlet side, creating segmented flow paths that enhance particle separation efficiency while maintaining a manageable structural complexity through modular organization.
Solution Approach 2:
Different regions of the filter body are assigned different functions: inlet-side closed channels provide primary filtration, outlet-side closed channels provide secondary filtration and soot storage, and open channels allow direct exhaust flow. This local differentiation of filter wall porosity and channel closure positions optimizes particle separation without uniformly increasing complexity throughout the entire structure.
2Reliability
If filter channels are closed with impermeable plugs on both inlet and outlet sides, then soot combustion is controlled, but exhaust gas flow paths are blocked creating dead zones
Solution Approach 1:
Filter channels are segmented into different functional groups: some closed at the inlet side for primary filtration, others closed at the outlet side for secondary filtration and soot storage. This segmentation ensures that not all channels are completely blocked, maintaining exhaust gas flow efficiency while still providing controlled soot combustion zones where needed.
Solution Approach 2:
Porous filter walls act as intermediaries between the inlet-side closed channels and outlet-side closed channels, allowing controlled gas flow and heat transfer. This intermediary structure enables soot combustion control through thermal coupling while maintaining overall exhaust gas flow efficiency by providing alternative pathways through the porous medium.
3Reliability
If GPF is regenerated continuously or periodically through thermal oxidation, then soot is removed, but exhaust backpressure increases leading to fuel consumption increase
Solution Approach 1:
The filter body is segmented into multiple channels with different closure configurations, creating distributed soot storage zones and flow paths. This segmentation allows exhaust gas to flow through multiple pathways, reducing overall backpressure while still providing sufficient residence time and surface area for thermal oxidation of soot, thereby reducing fuel consumption penalties.
Solution Approach 2:
Different channels are assigned different porosity characteristics and closure positions to create local variations in flow resistance and soot accumulation. Outlet-side closed channels with specific porosity provide localized soot storage and oxidation zones that are optimized for regeneration while maintaining overall system backpressure at acceptable levels.
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 improves particle separation and filter efficiency, reducing exhaust back pressure, emissions, and maintaining engine performance by allowing exhaust gas to flow through porous materials multiple times, while minimizing the increase in back pressure and enhancing the filtering effect as soot deposits form on the filter walls.
Implementation Method 1
exhaust gas from the internal combustion engine enters the first filter channels of the particulate filter during operation, passes through the filter walls, and exits through the second filter channels
Implementation Method 2
During operation, soot particles are deposited on both the filter walls and the highly porous seals, which, over time, reduce the pore size and thus increase the filtering effect
Implementation Method 3
The improved filtering effect is achieved by the exhaust gas flowing through a porous material multiple times
Implementation Method 4
Thermal oxidation of the soot trapped in the GPF with oxygen requires a sufficiently high temperature combined with the presence of oxygen in the exhaust system of the gasoline engine
Data Source
Figure 1
Figure 2~3
AI summary
The invention relates to a particulate filter (30) for exhaust aftertreatment of an internal combustion engine (10). The particulate filter (30) has a housing (34) on which an inlet (40) and an outlet (42) are formed on opposite end faces. The particulate filter (30) further comprises a filter body (60) arranged in the housing (34), which has a plurality of filter channels (46, 48) running substantially parallel to one another. The filter channels (46, 48) are alternately closed on the inlet or outlet side by a closure (50) to prevent direct gas passage through the filter body (60). The filter channels (46, 48) can be divided into a first group of filter channels (46), which are closed on the outlet side by a closure (50, 52), and a second group of filter channels (48), which are each closed on the inlet side by a gas-tight closure (50).It is provided that the filter channels (48) of the second group are additionally closed on the outlet side by a highly porous seal (54) in order to improve the cleaning effect of the particulate filter (30). According to the invention, a method for manufacturing such a particulate filter (30) for an internal combustion engine (10) is further proposed.