Engine Injection Timing Control for NOx and Power Trade-off
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Solution Overview
Problem
Current engine control systems that adjust injection timing based on manifold air temperature to reduce NOx emissions often result in less-than-optimum engine performance, particularly at higher notch settings, due to stringent emission regulations.
Innovation Solution
Implementing a notch-specific method to dynamically adjust engine injection timing in response to increasing ambient or manifold air temperature, where the degree of retard is tailored to each notch setting, allowing for reduced NOx emissions at lower notches to compensate for higher NOx emissions at higher notches, thereby maintaining overall emission compliance while improving engine performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If injection timing is retarded to reduce NOx emissions, then exhaust NOx emissions are reduced, but engine performance deteriorates
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting injection timing based on manifold air temperature. As temperature increases, the injection timing is retarded in a proportionate manner to reduce NOx emissions while attempting to maintain engine performance. This continuous parameter adjustment allows the system to adapt to changing thermal conditions and balance emissions reduction with performance preservation.
Solution Approach 2:
The system implements dynamics by making injection timing adjustments dynamic rather than static. The injection timing is continuously modified in response to real-time manifold air temperature measurements, allowing the control system to adapt to varying operating conditions. This dynamic approach enables the system to optimize the trade-off between emissions reduction and performance maintenance under different thermal states.
2Object-generated harmful factors
If injection timing is retarded proportionally across all notches to meet emission thresholds, then overall emissions compliance is achieved, but engine performance at higher notches deteriorates significantly
Solution Approach 1:
The patent applies local quality by implementing notch-specific injection timing adjustments rather than a uniform approach across all notches. Each notch setting receives tailored timing adjustments based on its specific performance requirements and emissions characteristics. This localized control strategy allows higher notches to maintain better performance while still contributing to overall emissions compliance through coordinated adjustments across the duty cycle.
Solution Approach 2:
The system uses parameter changes by modifying injection timing proportions specific to each notch setting. The control system adjusts the degree of timing retardation differently for each notch based on manifold air temperature, allowing optimization of both performance and emissions for each operating point while ensuring the aggregate duty cycle emissions meet regulatory thresholds.
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 increased power at higher notch settings while maintaining NOx emissions within regulatory limits, reducing engine performance degradation and providing a larger margin for emissions compliance, thus enhancing engine performance and fuel economy.
Implementation Method 1
a temperature sensor included in the engine
Implementation Method 2
an engine controller may be configured to retard an engine injection timing. As such, by retarding injection timing, NOx formation may be reduced
Data Source
AI summary
Methods and systems are provided for operating an engine having a plurality of notch settings. One example method comprises, during a first notch setting, adjusting engine injection timing in a first proportion to an increasing temperature, and during a second notch setting higher than the first notch setting, adjusting engine injection timing in a second proportion to the increasing temperature, the second proportion lower than the first proportion.