Exhaust Purification Substrate Hole Area Optimization
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Solution Overview
Problem
Exhaust gas purification devices using perforated metal substrates achieve high purification performance but suffer from high pressure loss, which negatively affects fuel consumption in internal combustion engines.
Innovation Solution
A perforated metal substrate with a corrugated and flat foil lamination, featuring specific ranges of cell density and hole sizes, where the corrugated foil has first holes 2.0 to 50 times the average opening area of the cells, and the flat foil has second holes 3.0 to 100 times the average opening area, with the total area of first holes being 60% or greater of the corrugated foil and second holes being 60% or greater of the flat foil, optimizing both pressure loss and purification performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If holes are present in the corrugated foil and flat foil to improve purification performance, then purification performance is improved, but pressure loss becomes high
Solution Approach 1:
The patent applies parameter changes by optimizing the hole area ratios of the corrugated foil (6-20%) and flat foil (6-20%), and controlling the cell density (7.75-23.0 cells/cm²). These specific parameter ranges balance the competing requirements: sufficient holes for improved purification performance while limiting pressure loss increase. The patent discovered through experimentation that these particular parameter ranges achieve both low pressure loss and high purification performance, resolving the technical contradiction.
2Reliability
If the total area of holes is increased to improve gas flow distribution, then purification performance is enhanced, but pressure loss increases
Solution Approach 1:
The patent applies local quality by creating different hole area ratios in different parts of the structure: the corrugated foil has holes occupying 6-20% of its total area, while the flat foil has holes occupying 6-20% of its total area. This differentiated local structure allows each layer to contribute differently to gas flow distribution and purification, optimizing overall performance while controlling pressure loss.
Solution Approach 2:
The patent uses a composite structure of corrugated foil and flat foil laminated together to form the metal substrate. This composite structure combines the advantages of both layers: the corrugated foil provides structural integrity and some purification function, while the flat foil with its hole pattern enhances gas flow distribution. The composite design achieves both low pressure loss and high purification performance that neither layer could achieve alone.
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 solution enables both low pressure loss and high purification performance by balancing the influence of hole sizes in the corrugated and flat foils, improving gas flow distribution and contact area with the catalyst layer, thereby reducing pressure loss while maintaining effective purification.
Implementation Method 1
improving gas flow distribution and contact area with the catalyst layer
Implementation Method 2
the diffusion of exhaust gas between neighboring cells
Implementation Method 3
exhaust gas passes through the cells and is purified by contacting the catalyst layer present on the wall surfaces of the cells
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention provides: an exhaust-gas-purifying metal substrate capable of achieving both low pressure loss and high purification performance; and an exhaust gas purification device using the metal substrate. The invention relates to an exhaust-gas-purifying perforated metal substrate in which a corrugated foil and a flat foil are layered and made into a cylindrical shape, wherein: the perforated metal substrate includes from 50/in2 to 800/in2 of cells; the corrugated foil includes a plurality of first holes having an area that is from 2.0 to 50 times the average opening area of the cells; the flat foil includes a plurality of second holes having an area that is from 3.0 to 100 times the average opening area of the cells; and the average value of the area of the first holes in the corrugated foil is smaller than the average value of the area of the second holes in the flat foil.