Aircraft Engine Controller Cylinder Fuel-Air Ratio Adjustment
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Solution Overview
Problem
Conventional methods for adjusting the air-fuel mixture in aircraft engines are operator-dependent and lack precision, leading to suboptimal fuel economy and potential engine damage due to inaccurate detection of peak exhaust gas temperature, which can result in detonation or excessive turbine inlet temperatures.
Innovation Solution
An aircraft engine controller detects actual peak exhaust gas temperature for each cylinder independently and adjusts the fuel-air ratio by finding the intersection between rich and lean exhaust gas temperature signals, ensuring each cylinder receives an accurate fuel-air mixture for optimal fuel economy, avoiding detrimental fuel mixtures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual visual monitoring and adjustment of air-fuel mixture is used, then operator control flexibility is maintained, but measurement precision and reliability of peak EGT detection deteriorate
Solution Approach 1:
The patent replaces manual visual monitoring and mechanical adjustment with an automated electronic control system that uses sensors to detect EGT and a microprocessor to calculate and adjust the air-fuel mixture ratio, thereby improving measurement precision while maintaining operational control
Solution Approach 2:
The system implements continuous feedback by monitoring EGT signals from sensors, comparing actual values with target values, and automatically adjusting the fuel injection quantity based on the deviation, ensuring accurate peak EGT detection and optimal air-fuel mixture maintenance
2Power
If rich air-fuel mixture is used during takeoff, then engine power output is improved, but fuel consumption increases
Solution Approach 1:
The system dynamically adjusts the air-fuel mixture ratio based on real-time operating conditions, using a rich mixture during high-power takeoff operations and automatically transitioning to a leaner mixture during cruising conditions to optimize both power output and fuel efficiency
Solution Approach 2:
The control system changes the air-fuel mixture ratio parameter according to flight phases and engine load conditions, maintaining optimal performance across different operating regimes by adjusting the fuel injection quantity based on detected EGT and calculated target ratios
3Loss of energy
If lean air-fuel mixture is used for fuel economy, then fuel consumption decreases, but risk of detonation and excessive turbine temperatures increases
Solution Approach 1:
The system continuously monitors EGT and automatically adjusts the air-fuel mixture to maintain it within the optimal range, preventing both overly rich and overly lean conditions that could cause detonation or excessive temperatures, thereby enabling safe operation with improved fuel economy
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 solution provides each cylinder with an optimal fuel-air mixture, enhancing fuel economy and preventing engine damage by accurately determining the peak exhaust gas temperature and adjusting the fuel-air ratio accordingly, thus optimizing engine performance.
Implementation Method 1
an exhaust gas temperature sensor...configured to generate gas temperature signals associated with an aircraft engine cylinder
Data Source
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AI summary
An aircraft engine includes an aircraft engine controller configured to detect an actual peak exhaust gas temperature of a cylinder assembly. The aircraft engine controller detects an intersection between a first function representing a relationship between a set of rich exhaust gas temperature signals and a corresponding set of rich fuel-air ratio values and a second function representing a relationship between a set of lean exhaust gas temperature signals and a set of lean fuel-air ratio values. Based upon the intersection between the first and second functions, the engine controller detects an actual peak fuel-air ratio value for the cylinder assembly and can determine if a correction in the fuel-air ratio of a fuel-air mixture provided to the cylinder assembly is required.