Engine Control via Catalytic Converter Oxygen Storage Capability
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Solution Overview
Problem
As catalytic converters age, their oxygen storage capability diminishes, leading to reduced emission reduction effectiveness, especially during cold starts or fuel cutoff events, resulting in increased hydrocarbon and nitrogen oxide emissions.
Innovation Solution
A system that includes an oxygen storage capability module to determine the catalytic converter's oxygen storage capacity, allowing for engine speed control and spark timing adjustments based on this capability to optimize engine operation and reduce emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the catalytic converter ages, then its oxygen storage capability diminishes, but emission reduction effectiveness decreases
Solution Approach 1:
The system performs preliminary assessment of the catalytic converter's oxygen storage capability using sensors and control modules. By evaluating the converter's state before emission control events (such as cold starts or fuel cutoff), the system can prepare appropriate control strategies in advance to compensate for reduced oxygen storage capability and maintain emission reduction effectiveness.
Solution Approach 2:
The system dynamically adjusts engine operating parameters based on the measured oxygen storage capability. When the catalytic converter's capability diminishes, the control system modifies parameters such as idle speed, spark timing, and fuel enrichment to compensate for reduced oxygen storage, thereby maintaining effective emission control despite converter aging.
2Reliability
If engine idle speed is increased during cold starts, then emission reduction efficiency is maintained, but fuel consumption increases
Solution Approach 1:
The system dynamically adjusts idle speed based on real-time assessment of the catalytic converter's oxygen storage capability. Rather than maintaining a fixed high idle speed during cold starts, the control module modulates the speed according to the converter's actual state, allowing the engine to operate at the minimum necessary speed to maintain emission control effectiveness while minimizing fuel consumption.
Solution Approach 2:
The system changes the idle speed parameter dynamically based on the oxygen storage capability measurement. When the catalytic converter has reduced capability, the system increases idle speed to maintain emission control; when capability is sufficient, it allows lower idle speed, thereby optimizing the balance between emission reduction and fuel consumption.
3Reliability
If spark timing is retarded, then emission control is improved, but engine power output decreases
Solution Approach 1:
The system adjusts spark timing as a controllable parameter based on the catalytic converter's oxygen storage capability. When the converter's capability is reduced, the system retards spark timing to enhance emission control through more complete combustion. The control module monitors the balance between emission control benefits and power output penalties, adjusting the timing retardment accordingly.
Solution Approach 2:
The spark timing is dynamically adjusted rather than fixed, allowing the system to optimize emission control while maintaining acceptable power output. The control system continuously monitors engine operating conditions and converter capability, making real-time adjustments to spark timing that balance emission reduction effectiveness with power output requirements.
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
The system effectively increases engine idle speed and retards spark timing during cold starts and adjusts fuel enrichment post-fuel cutoff to minimize emissions, maintaining emission reduction efficiency even as the catalytic converter ages.
Implementation Method 1
The catalyst may store oxygen when the engine operates at a lean air/fuel ratio, and the catalyst may release oxygen when the engine operates at a rich air/fuel ratio.
Implementation Method 2
A catalytic converter contains a catalyst that reacts with exhaust gas from an engine to reduce emissions such as nitrogen oxide, carbon monoxide, and hydrocarbon.
Implementation Method 3
The oxygen released may react with exhaust gas to reduce emissions such as carbon monoxide and hydrocarbon.
Data Source
AI summary
A system according to the principles of the present disclosure includes a storage capability module and at least one of an engine speed control module and a spark control module. The storage capability module determines a capability of a catalytic converter to store oxygen. The engine speed control module controls a speed of an engine based on the oxygen storage capability of the catalytic converter. The spark control module controls a spark timing of the engine based on the oxygen storage capability of the catalytic converter.