Multi-Layer Exhaust Catalyst Oxygen Storage Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing exhaust emission control devices face challenges in maintaining effective oxygen absorption and release by the catalytically active coating, especially during faults, which can lead to inadequate reaction time for lambda control and non-compliance with stringent emission regulations.
Innovation Solution
A catalytically active coating with three distinct oxygen storage units, each composed of different materials that change their oxidation stages at specific lambda values, allowing for staggered oxygen absorption and release to buffer oxygen demand, ensuring continuous emission control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single-layer catalytic coating is used, then manufacturing cost is reduced, but oxygen storage capacity and reliability during faults are insufficient
Solution Approach 1:
The catalytic coating is segmented into multiple functional layers, each with specific oxygen storage capacities. The first layer (downstream) has lower oxygen storage capacity and changes oxidation stage at lambda λ1, while the second layer (upstream) has higher oxygen storage capacity. This segmentation allows the system to maintain reliability during faults by distributing oxygen storage functions across layers.
2Reliability
If complex multi-layer catalytic converters are used, then catalyst activity and service life are improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The invention extracts and isolates the oxygen storage function into specific layers with distinct characteristics. The first layer is specifically designed with lower oxygen storage capacity and different oxidation stage change behavior compared to conventional designs. This extraction allows for simplified control and predictable behavior during faults, reducing overall system complexity.
Solution Approach 2:
Different regions of the catalytic coating are assigned different oxygen storage capacities and oxidation stage change characteristics. The downstream layer (first layer) has lower oxygen storage capacity and changes at lambda λ1, while the upstream layer (second layer) has higher capacity. This local differentiation optimizes overall system performance and reliability.
3Measurement precision
If lambda control responds immediately at lambda=1, then control precision is improved, but response time for fault correction is insufficient due to lack of buffer capacity
Solution Approach 1:
The first catalytic layer is pre-configured with lower oxygen storage capacity and is designed to change oxidation stage at lambda λ1 (close to 1). This preliminary arrangement creates a buffer that allows lambda control to respond precisely at lambda=1 while the first layer provides temporary oxygen storage, buying time for fault correction before the second layer is depleted.
Solution Approach 2:
The first layer acts as a cushion or buffer for oxygen storage, positioned downstream and designed to be depleted first during faults. This beforehand cushioning protects the second layer (with higher oxygen storage capacity) from immediate depletion, providing time for lambda control to react and correct faults before complete oxygen depletion occurs.
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 provides a time delay for lambda control to react effectively, ensuring improved air/fuel mixture control and compliance with strict emission regulations by allowing the catalytic converter to maintain efficient oxygen storage and release capabilities, even during faults.
Implementation Method 1
a catalytically active coating for absorbing oxygen in the reduction of the exhaust gas and for releasing oxygen in the oxidation of the exhaust gas
Implementation Method 2
the first material at lambda λ1 changing its oxidation stage and constituting a third component storage unit for oxygen
Data Source
AI summary
For an exhaust emission control device of an internal combustion engine with a support which has a catalytically active coating for absorbing oxygen (O2) in the reduction of the exhaust gas and for releasing oxygen in the oxidation of the exhaust gas, it is proposed that the catalytically active coating comprises different materials (A, B, C) which can store oxygen and which each form a component storage unit (MA, MB, MC) for the oxygen (O2), the first material (A) at lambda λ<1 changing its oxidation stage and constituting a first component storage unit (MA) for oxygen (O2), the second material (B) at lambda λ=1 changing its oxidation stage and constituting a second component storage unit (MB) for oxygen (O2), and the third material (C) at lambda λ>1 changing its oxidation stage and constituting a third component storage unit (MC) for oxygen (O2).