Exhaust After-Treatment System with Configurable Flow Path
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Solution Overview
Problem
Current exhaust after-treatment systems face challenges in mitigating NOx emissions during low temperatures and risk damage to storage catalysts during high temperature regeneration, leading to inefficient emission conversion and prolonged warm-up times.
Innovation Solution
An exhaust after-treatment system with a configurable valve and conduit arrangement that routes exhaust gases through different sets of components based on operating conditions, allowing for quick warming of high-temperature components and minimizing exposure to damaging temperatures, using sensors and a controller to automatically adjust the flow path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If storage catalysts are arranged upstream of conversion catalysts, then NOx conversion efficiency is improved, but warm-up time is prolonged
Solution Approach 1:
The patent implements a dynamic flow path configuration system with valves and conduits that can switch between different exhaust gas routing modes. The system dynamically adjusts the flow path based on operating conditions, allowing the storage catalyst to be bypassed during warm-up phases while maintaining proper sequencing during normal operation, thus resolving the contradiction between conversion efficiency and warm-up time
Solution Approach 2:
The exhaust after-treatment system is segmented into distinct functional zones with controllable flow paths. The storage catalyst and conversion catalyst are separated by adjustable flow path segments controlled by valves, allowing independent optimization of their operating conditions and timing, thereby enabling quick warm-up of conversion catalyst while preserving NOx conversion efficiency
2Reliability
If high temperature exhaust gas is passed through storage catalyst for regeneration, then storage catalyst performance is improved, but risk of catalyst damage is increased
Solution Approach 1:
The system dynamically controls the flow path to regulate the duration and intensity of high-temperature exposure to the storage catalyst. By using valves to adjust the flow path configuration, the system can provide controlled thermal exposure for regeneration while preventing excessive temperature exposure that would damage the catalyst, thus balancing performance improvement with damage prevention
Solution Approach 2:
The patent implements periodic regeneration cycles where the storage catalyst is exposed to high-temperature exhaust gas in controlled intervals. The flow path configuration is periodically adjusted to route hot exhaust through the storage catalyst for regeneration, then switched back to normal operation mode, providing regular performance maintenance while limiting cumulative thermal stress through rhythmic, controlled exposure
3Reliability
If storage catalyst stores NOx during cold operation, then low temperature emissions are mitigated, but NOx spike emissions occur during warm-up
Solution Approach 1:
The dynamic flow path control system monitors operating temperature and adjusts the flow path configuration in real-time. During cold operation, the system routes exhaust through the storage catalyst to capture NOx. During warm-up when the conversion catalyst is not yet operational, the system dynamically switches the flow path to bypass the storage catalyst or prevent NOx release, thereby eliminating NOx spike emissions while preserving cold-start emission mitigation
Solution Approach 2:
The system performs preliminary actions by pre-warming the conversion catalyst or pre-configuring the flow path before the storage catalyst releases stored NOx. This ensures the conversion catalyst is ready to immediately process released NOx, preventing spike emissions. The flow path is preliminarily adjusted to maintain storage catalyst functionality during cold operation while preparing for seamless transition to conversion mode
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
Facilitates effective emission mitigation during low temperatures, rapid warming of high-temperature components, and safe regeneration of storage catalysts, reducing the risk of damage and optimizing NOx conversion efficiency.
Implementation Method 1
exhaust gases are cooled by, among other things, the storage catalyst before they reach the conversion catalyst
Implementation Method 2
As exhaust temperature heats up, the NOx trap or absorber receives exhaust heat
Implementation Method 3
current combinations of storage and conversion catalysts are at risk of releasing the NOx stored in NOx traps or absorbers before the conversion catalyst reaches its operating temperature
Data Source
Figure 1~3
AI summary
An exhaust after-treatment system includes a first set of exhaust after-treatment components, a second set of exhaust after-treatment components, an inlet to the exhaust after-treatment system, an outlet from the exhaust after-treatment system, and a valve and conduit arrangement configurable in a plurality of modes, in a first mode, exhaust gas entering the inlet flows through the second set of exhaust after-treatment components, then through the first set of exhaust after-treatment components, and then through the outlet. In a second mode, exhaust gas entering the inlet flows through the second set of exhaust after-treatment components without flowing through the first set of exhaust after-treatment components, and then through the outlet in a third mode, exhaust gas entering the inlet flows through the first set of exhaust after-treatment components, then through the second set of exhaust after-treatment components, and then through the outlet.