Diesel Particulate Filter NOx Sensor Placement for CRT Monitoring
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Solution Overview
Problem
Precise determination of the Continuous Regeneration Trap (CRT) effect in diesel particulate filters is challenging due to fluctuations in NOX levels under real driving conditions, affecting regeneration efficiency and filter aging.
Innovation Solution
The implementation of NO and NO2 sensors strategically placed in the exhaust gas line upstream and downstream of the diesel particulate filter allows for precise measurement of nitrogen monoxide and dioxide concentrations, enabling accurate determination of CRT efficiency and controlling regeneration processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If regeneration frequency is increased to maintain filter efficiency, then particulate filter performance is improved, but CO2 emissions increase and filter aging accelerates
Solution Approach 1:
The system uses NO and NO2 sensors to continuously monitor exhaust gas composition and provides feedback to the control unit. The control unit adjusts regeneration timing and intensity based on real-time CRT effect measurements, enabling precise control that prevents both premature and delayed regeneration, thereby reducing unnecessary CO2 emissions while maintaining filter performance.
Solution Approach 2:
The system monitors changes in NO and NO2 concentrations as key parameters to determine optimal regeneration timing. By tracking these parameter changes and their relationship to the CRT effect, the system dynamically adjusts regeneration strategies to achieve minimum necessary regeneration frequency while maintaining particulate filter efficiency.
2Loss of substance
If regeneration frequency is decreased to reduce CO2 emissions, then CO2 emissions are reduced, but particulate filter performance deteriorates
Solution Approach 1:
The control unit receives continuous feedback from NO and NO2 sensors about exhaust gas composition and CRT effect strength. This feedback enables the system to delay regeneration only when the CRT effect is sufficiently strong and natural regeneration is occurring, while triggering regeneration when the CRT effect weakens, thus maintaining filter performance while minimizing CO2 emissions.
Solution Approach 2:
The system uses NO and NO2 concentration ratios as dynamic parameters to determine regeneration timing. By monitoring how these parameters change over time and correlating them with CRT effect strength, the system optimizes regeneration frequency to match actual filter needs, preventing both premature and delayed regeneration.
3Measurement precision
If NOX levels are monitored continuously to optimize regeneration, then regeneration precision is improved, but measurement complexity increases
Solution Approach 1:
The system uses NO and NO2 gases as intermediary indicators to indirectly measure CRT effect strength. Instead of directly measuring soot combustion, the sensors detect NO and NO2 concentration changes that correlate with CRT activity, providing a simplified yet precise measurement approach that avoids complex direct soot measurement systems.
Solution Approach 2:
The system replaces complex mechanical or direct chemical measurement systems with electronic gas concentration sensors. By using electrochemical or semiconductor-based NO and NO2 sensors, the system achieves precise CRT effect measurement through electrical signals rather than complex mechanical or direct chemical analysis systems.
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 enhances the precision of CRT effect detection, reduces regeneration frequency, minimizes CO2 emissions, and delays filter aging by optimizing regeneration strategies based on real-time NOX concentration data.
Implementation Method 1
an NO2 sensor (4) is arranged in the exhaust gas line (1) upstream of the diesel particulate filter (2) and an NO2 sensor (5) is arranged in the exhaust gas line (1) downstream of the diesel particulate filter (2)
Implementation Method 2
an upstream oxidation catalyst or the catalytically active filter coating converts the nitrogen monoxide (NO) present in the exhaust gases together with the residual oxygen (O2) into nitrogen dioxide (NO2)
Implementation Method 3
This nitrogen dioxide then allows continuous combustion of the soot which has collected in the particulate filter into carbon dioxide (CO2) and nitrogen monoxide (NO)
Data Source
AI summary
Various embodiments include a diesel engine comprising: an exhaust gas line; a diesel particulate filter arranged in the exhaust gas line; a first NO sensor arranged in the exhaust gas line upstream of the diesel particulate filter; and a second NO sensor arranged in the exhaust gas line downstream of the diesel particulate filter.