Exhaust Device Offset Ports Reduce Flow Resistance
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Solution Overview
Problem
Conventional exhaust-gas purifying devices with EGR systems face increased flow resistance due to interference between exhaust gas flows in the main exhaust path and the EGR path, which can lead to inefficient pipe arrangements and increased resistance.
Innovation Solution
The exhaust device design includes an offset exhaust-gas discharge port and EGR-gas takeout port at the downstream end of the purifying device, with an L-shaped exhaust pipe configuration that directs exhaust gas flow to minimize interference and enhance EGR performance, while also allowing for compact pipe arrangements by overlapping upstream and downstream purifying devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the EGR path is branched from a cone portion or flange continuous to the main exhaust path, then the EGR device can be connected to the exhaust-gas purifying device, but the flow resistance increases due to interference between exhaust gas flow and EGR gas flow
Solution Approach 1:
The EGR-gas takeout port is positioned on the outer-peripheral side of the L-shaped bending, utilizing the spatial dimension created by the bent exhaust pipe configuration. This dimensional approach separates the EGR gas extraction location from the main exhaust flow path, allowing EGR gas to be taken out without interfering with the exhaust gas flow to the discharge port, thereby reducing flow resistance while maintaining EGR functionality
2Volume of moving object
If the exhaust-gas discharge port and EGR-gas takeout port are positioned at the downstream end of the purifying device, then the pipe arrangement can be made compact, but flow interference occurs between the two gas flows
Solution Approach 1:
The exhaust-gas discharge port and EGR-gas takeout port are positioned asymmetrically relative to each other on the downstream end face of the purifying device case. Specifically, the EGR-gas takeout port is offset to the outer-peripheral side of the L-shaped bending while the exhaust-gas discharge port is positioned elsewhere on the downstream end face. This asymmetric arrangement allows both ports to be located at the downstream end for compact pipe arrangement while preventing flow interference between the two gas streams
3Productivity
If the EGR-gas takeout port is positioned on the outer-peripheral side of L-shaped bending, then EGR performance is enhanced due to higher exhaust gas flow amount, but the port position must be precisely optimized
Solution Approach 1:
The invention optimizes the position of the EGR-gas takeout port by changing the spatial parameters of the exhaust-gas purifying device configuration. Specifically, the port is positioned on the outer-peripheral side of the L-shaped bending where the exhaust gas flow amount is naturally higher due to the bending geometry and exhaust gas inertia. This parameter optimization enhances EGR performance by utilizing the higher flow amount region without requiring complex additional structures
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 effectively reduces flow resistance, secures efficient EGR performance, and maintains high use efficiency of the exhaust-gas purifying devices by directing exhaust gas flow to minimize interference and optimize pipe layout.
Implementation Method 1
when the exhaust gas passes through the L-shaped exhaust pipe, a lot of exhaust gas flows into the exhaust-gas purifying device, passing through the outer-peripheral side of the L-shaped bending of the L-shaped exhaust pipe because of its inertia
Data Source
AI summary
An exhaust-gas discharge port to discharge a main flow of exhaust gas passing through an exhaust-gas purifying device is provided at a position which is offset, on one side, from a center axis of the purifying-device body, and an EGR-gas takeout port is provided at a position which is offset, on an opposite side to the exhaust-gas discharge port, from the center axis of the purifying-device body.