Vehicle Exhaust Pipe Expanded Portion Gas Diffusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vehicle exhaust pipes fail to adequately purify exhaust gases when the flow velocity of exhaust gas increases, as the gas flow is not sufficiently diffused, leading to inadequate functioning of the catalyst carrier in the peripheral areas.
Innovation Solution
The exhaust pipe design includes expanded portions on both the front and rear sides of the storage space, with larger cross-sectional areas than the storage space, to reduce exhaust gas velocity and ensure even distribution across the catalyst carrier, enhancing purification efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the diameter of the storage space is increased to reduce exhaust gas flow velocity, then the exhaust gas can be sufficiently diffused and purified, but the device complexity and space requirements increase
Solution Approach 1:
The storage space is divided into multiple compartments by partition walls, with catalyst carriers arranged in different layers. This segmentation allows the exhaust gas to flow through multiple catalyst surfaces, increasing purification efficiency without requiring a single large-diameter storage space, thus reducing overall device complexity.
Solution Approach 2:
Multiple catalyst carriers are nested within the storage space at different levels and positions, including inner and outer circumferential arrangements. This nested configuration maximizes the catalyst surface area exposed to exhaust gas flow within a compact storage space, improving purification efficiency without increasing the overall device size.
2Productivity
If the flow velocity of exhaust gas is increased to improve productivity, then the exhaust gas purification is insufficient because the gas is not sufficiently diffused
Solution Approach 1:
The partition walls divide the storage space into multiple flow paths, forcing the high-velocity exhaust gas to split and flow through multiple catalyst carrier surfaces. This segmentation extends the effective contact time between exhaust gas and catalyst, ensuring sufficient purification even at high flow rates.
Solution Approach 2:
Catalyst carriers are arranged in multiple dimensions including inner and outer circumferential positions, and multiple layers separated by partition walls. This multi-dimensional arrangement increases the total catalyst surface area exposed to exhaust gas, allowing efficient purification at higher flow velocities by providing parallel purification paths.
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 ensures that exhaust gases are evenly distributed across the catalyst carrier, effectively purifying the exhaust gases even at increased flow velocities, thereby improving the overall purification efficiency.
Implementation Method 1
a sufficient amount of the exhaust gas which flows into the expanded portion is fully diffused while the flow velocity is decreasing therein
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
An exhaust pipe (1) having a circular cross section is connected to a circular cylindrical housing (2) which creates part of pipe conduit. The housing (2) forms a storage space (21) having a diameter larger than the diameter of the exhaust pipe (1) and connecting to the rear connection part (22). The connection part (22) is tapered toward the downstream exhaust pipe (12) and the diameter of the connection part (22) is gradually reduced and its opening is welded into the opening of the downstream exhaust pipe (12). And a cylindrical honeycomb catalyst carrier (3) is stored in the storage space (21) so that the outer surface of the catalyst carrier is in contact with the inner surface of the storage space (21). An expanded portion (23) having a diameter larger than the diameter of the storage space (21) is outwardly expanded from the outer circumference of the housing (2) and connectingly provided on the front face of the storage space (21). The diameter of the expanded portion (23) is gradually reduced toward the upstream exhaust pipe (11) and welded into the opening of the outer wall of the exhaust pipe (11).