SCR Catalyst Aging Control for Engine Emission Compliance
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Solution Overview
Problem
Internal combustion engines with SCR catalytic converters face inefficiencies due to the initial high nitrogen oxide emission levels, leading to increased fuel consumption and environmental impact, as the converters' performance decreases over time, necessitating a method to optimize engine operation based on the converter's aging state.
Innovation Solution
A method that involves controlling process parameters to reduce nitrogen oxide emissions when the SCR catalytic converter ages, utilizing a control device to adjust operating parameters such as injection timing, boost pressure, and fuel ratio, and continuously monitoring the converter's aging to maintain optimal performance and minimize fuel consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a design reserve (aging reserve) is incorporated to account for SCR catalyst performance degradation, then the system maintains compliance with emission limits throughout the catalyst service life, but the internal combustion engine operates with significantly lower raw nitrogen oxide emissions than necessary, leading to increased fuel consumption
Solution Approach 1:
The system dynamically adjusts the raw nitrogen oxide emission target value based on the actual age of the SCR catalyst. Instead of using a static design reserve approach, the control device modifies the emission target according to the catalyst's service life, allowing the engine to operate with optimized fuel consumption at each stage of catalyst aging while ensuring continuous compliance with emission limits.
Solution Approach 2:
The system incorporates feedback regarding the catalyst's actual performance degradation over time. By monitoring the catalyst's age and conversion rate, the control device adjusts the raw emission target value accordingly, creating a closed-loop system that optimizes fuel consumption while maintaining emission compliance throughout the catalyst's service life.
2Use of energy by moving object
If the engine operates with high raw nitrogen oxide emissions to reduce fuel consumption, then fuel efficiency improves, but the SCR catalyst must maintain high conversion rates throughout its service life, which becomes impossible as the catalyst ages
Solution Approach 1:
The system dynamically adjusts the raw nitrogen oxide emission target value based on the actual age of the SCR catalyst. Instead of using a static design reserve approach, the control device modifies the emission target according to the catalyst's service life, allowing the engine to operate with optimized fuel consumption at each stage of catalyst aging while ensuring continuous compliance with emission limits.
Solution Approach 2:
The system changes the emission target parameter as a function of catalyst age. By continuously or periodically updating the raw nitrogen oxide emission target value based on the catalyst's actual degradation, the system allows higher emissions when the catalyst is new and efficient, while progressively lowering the target as the catalyst ages, thereby maintaining compliance throughout the service life.
3Reliability
If aging detection is implemented to adjust emissions, then emission compliance is maintained throughout catalyst service life, but the system complexity increases due to additional sensors and control mechanisms
Solution Approach 1:
The system uses the catalyst's own aging characteristics as the basis for adjustment. By leveraging the naturally occurring degradation of the catalyst over time as the triggering mechanism, the system avoids the need for complex additional sensors or active diagnostic systems. The aging detection is performed based on the catalyst's inherent performance changes, simplifying the overall system architecture.
Solution Approach 2:
The system performs preliminary determination of the catalyst's age and conversion rate before making emission adjustments. By calculating the catalyst's service life and estimating its current conversion rate in advance, the control device can proactively set appropriate raw emission target values, avoiding the need for complex real-time feedback mechanisms and simplifying the control architecture.
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 approach allows for efficient operation of the internal combustion engine by utilizing the high conversion rate of a new SCR catalytic converter, reducing fuel consumption, and maintaining compliance with emission limits, thereby optimizing both cost and environmental impact.
Implementation Method 1
exhaust aftertreatment system with an SCR catalyst... for the selective catalytic reduction of nitrogen oxides
Implementation Method 2
Aging detection is performed for the SCR catalyst... if aging of the SCR catalyst is detected
Implementation Method 3
The internal combustion engine is controlled based on at least one process parameter influencing raw nitrogen oxide emissions... operating parameters of the combustion engine are modified
Data Source
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AI summary
The invention relates to a method for operating a system comprising an internal combustion engine (1) and an exhaust aftertreatment system (3) having an SCR catalyst (7), wherein the internal combustion engine (1) is controlled on the basis of at least one process parameter that influences a nitrogen oxide raw emission (57), wherein aging detection is performed for the SCR catalyst (7), wherein in a first operating mode of the internal combustion engine (1), if aging of the SCR catalyst (7) is detected, the at least one process parameter is changed in the direction of a reduced nitrogen oxide raw emission (57), wherein the internal combustion engine (1) is controlled on the basis of the changed at least one process parameter.