Dynamic NOx Adsorber Regeneration Threshold Control
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Solution Overview
Problem
The efficiency of NOx adsorber catalysts deteriorates over time, leading to increased NOx emissions and wastage of reductant due to improper tracking of regeneration needs in traditional emission control systems for internal combustion engines.
Innovation Solution
A method that adjusts the engine operating condition threshold for NOx adsorber regeneration based on fuel consumption and adsorber efficiency, using sensors to determine deterioration and modify the regeneration triggering value to maintain system performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional fixed threshold regeneration control is used, then the system is simple to operate, but NOx adsorption efficiency deteriorates over time and reductant is wasted
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed regeneration threshold to a dynamic threshold that adapts based on adsorber efficiency. The system continuously monitors NOx adsorption performance and adjusts the regeneration trigger point accordingly, allowing the control parameter to evolve rather than remain static. This resolves the contradiction by making the system responsive to deteriorating efficiency while maintaining operational simplicity.
Solution Approach 2:
The patent implements feedback control by monitoring actual NOx adsorption efficiency and using this information to modify the regeneration threshold. The system creates a closed-loop where performance data feeds back into the control decision-making process, enabling the threshold to be adjusted based on real-time or historical efficiency measurements. This feedback mechanism addresses the contradiction by automatically adapting to efficiency changes without requiring complex manual intervention.
2Object-generated harmful factors
If regeneration cycles are triggered based on fixed fuel consumption threshold, then reductant usage is controlled, but NOx emissions increase due to improper tracking of adsorber deterioration
Solution Approach 1:
The patent applies parameter changes by modifying the regeneration threshold parameter based on adsorber efficiency deterioration. Instead of using a fixed fuel consumption threshold, the system adjusts the trigger parameter dynamically as the adsorber ages and efficiency decreases. This allows the system to optimize the balance between NOx emissions control and reductant consumption, resolving the contradiction by adapting the control parameter to current system conditions.
3Object-generated harmful factors
If regeneration is performed frequently to maintain NOx adsorption, then emission control is effective, but reductant consumption increases
Solution Approach 1:
The patent applies preliminary action by proactively adjusting the regeneration threshold before significant efficiency deterioration occurs. The system monitors adsorber performance trends and modifies the trigger point in advance, allowing regeneration to be scheduled optimally rather than reactively. This enables effective emission control while minimizing unnecessary regeneration cycles and associated reductant consumption.
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 ensures optimal NOx adsorption and reduces reductant wastage by aligning regeneration cycles with actual NOx adsorption capacity, thereby meeting stringent emission regulations.
Implementation Method 1
a NOx adsorber in fluid communication with the exhaust gas for adsorbing at least a portion of the exhaust gas
Implementation Method 2
catalytic technology that converts the NOx species to diatomic nitrogen (N2) using a reductant
Data Source
AI summary
A method for modifying a NOx adsorber regeneration triggering variable. Engine operating conditions are monitored until the regeneration triggering variable is met. The adsorber is regenerated and the adsorbtion efficiency of the adsorber is subsequently determined. The regeneration triggering variable is modified to correspond with the decline in adsorber efficiency. The adsorber efficiency may be determined using an empirically predetermined set of values or by using a pair of oxygen sensors to determine the oxygen response delay across the sensors.