Reducing Agent Injector Feedback for Degraded Catalytic Systems
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Solution Overview
Problem
Conventional methods for controlling ammonia buffer levels in catalytic reduction arrangements are inadequate in handling unexpected changes, particularly in degraded systems, leading to inefficient emission control and potential harmful emissions.
Innovation Solution
A method and system that dynamically adjusts the mass flow rate of the reducing agent injector based on real-time toxic substance levels, updating the pre-set flow rate to optimize ammonia buffer levels and maintain efficient conversion of harmful exhaust components, even in degraded catalytic reduction arrangements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a predefined injection model with a pre-set mass flow rate is used to control the reducing agent injector, then the system operation is simple, but the system cannot compensate for hardware degradation and component deviations leading to inefficient emission control
Solution Approach 1:
The patent implements a feedback mechanism where the actual mass flow rate of the reducing agent is continuously measured and compared with the desired mass flow rate. Based on this comparison, the control system automatically adjusts the injection parameters to compensate for hardware degradation and component deviations, thereby maintaining reliable emission control without requiring complex manual calibration or system redesign
Solution Approach 2:
The control system performs self-adjustment by automatically detecting deviations in the reducing agent injection performance and correcting them without external intervention. The system monitors its own operation through sensors and autonomously modifies injection parameters to maintain optimal performance, eliminating the need for frequent manual maintenance or recalibration
2Productivity
If the ammonia buffer level is controlled to be high to ensure sufficient conversion capacity, then the conversion of harmful exhaust is improved, but ammonia emissions increase causing undesirable harmful exhaust
Solution Approach 1:
The patent dynamically adjusts the ammonia buffer level based on real-time operating conditions such as exhaust flow rate, temperature, and detected conversion efficiency. Rather than maintaining a static high buffer level, the system continuously adapts the reducing agent injection rate to provide sufficient conversion capacity only when needed, thereby preventing excessive ammonia accumulation and subsequent ammonia slip emissions
Solution Approach 2:
The system changes operational parameters including the mass flow rate of the reducing agent and the ammonia buffer level based on monitored performance metrics. By adjusting these parameters dynamically rather than maintaining fixed high values, the system achieves high conversion efficiency when required while minimizing ammonia emissions during normal operation
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
Ensures efficient operation of catalytic reduction arrangements by compensating for hardware degradation and component deviations, optimizing ammonia buffer levels to minimize toxic emissions and reduce the need for maintenance.
Implementation Method 1
a reducing agent is injected into an engine exhaust and hydrolyzes into ammonia
Implementation Method 2
A chemical reaction involving the ammonia and the unwanted exhaust components within the catalytic reduction arrangement substrate reduces the unwanted exhaust component into Nitrogen gas and water
Data Source
Figure 1
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AI summary
The inventive concept relates to a method of operating a reducing agent injector, the method comprising: determining a reference level of toxic substances exhausted from a catalytic reduction arrangement when injecting reducing agent at the pre-set mass flow rate; controlling a reducing agent injector to inject reducing agent at a first mass flow rate, the first mass flow rate being different from the pre-set mass flow rate; determining a first level of toxic substances exhausted from the catalytic reduction arrangement after injecting reducing agent at the first mass flow rate; determining which one of the reference level of toxic substances and the first level of toxic substances being a lowest level of toxic substances; updating the pre-set mass flow rate of the predefined injection model to an updated pre-set mass flow rate as the mass flow rate causing the catalytic reduction arrangement to exhaust the lowest level of toxic substances; and controlling the reducing agent injector to inject reducing agent at the updated pre-set mass flow rate.