Shaft Shear Detection Using Dynamic Torque Reduction Thresholds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing shaft shear mitigation techniques in gas turbine engines face challenges in achieving a balance between quick reaction times and minimizing false detection occurrences, particularly due to imperfect sensor representations of engine configurations, which can lead to undesirable turbine over-speeding and potential engine damage.
Innovation Solution
A method involving an engine controller that monitors the rate of torque reduction of the shaft, generates a signal for shaft shear detection when the current value exceeds a threshold value, and includes a confirmation step to reduce false detection likelihood, with dynamically adjusted threshold values based on current operating conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional shaft shear mitigation techniques are used with fixed thresholds, then the system can detect shaft shear events, but false detection occurrences increase due to imperfect sensor representations of engine configurations
Solution Approach 1:
The patent applies dynamics by transitioning from fixed threshold values to dynamically adjustable threshold values that adapt to current engine operating conditions. The engine controller continuously monitors operating parameters and adjusts the threshold accordingly, allowing the detection system to remain reliable across varying engine configurations and operational states without requiring multiple fixed threshold sets.
Solution Approach 2:
The patent implements parameter changes by modifying the threshold parameter based on operating conditions. Instead of using a static threshold, the system varies the threshold value dynamically according to real-time engine parameters such as speed, load, and temperature, thereby maintaining optimal detection accuracy across different operating regimes while avoiding false detections.
2Reliability
If the reaction time is extended to allow pilot intervention, then false detection can be verified, but turbine over-speeding risk increases during the extended period
Solution Approach 1:
The patent applies feedback by implementing a confirmation mechanism that provides additional verification before triggering engine shutdown. The system monitors multiple parameters and uses feedback loops to confirm shaft shear detection before executing mitigation actions, thereby reducing false detections while maintaining rapid response capability to prevent turbine over-speeding.
Solution Approach 2:
The patent implements preliminary action by performing confirmation checks and additional verification steps before final shutdown execution. The system prepares mitigation actions in advance but delays their execution until confirmation is obtained, allowing rapid response to genuine shaft shear events while preventing premature shutdowns due to false detections.
3Measurement precision
If multiple sensors are added to improve engine configuration representation, then detection accuracy improves, but device complexity and cost increase
Solution Approach 1:
The patent applies universality by enabling the existing torque sensor to serve multiple functions: it not only measures torque for engine control but also provides the basis for shaft shear detection and threshold determination. This multi-functional use of existing sensors improves measurement precision without requiring additional dedicated sensors for shaft shear detection.
Solution Approach 2:
The patent implements self-service by using the engine's existing sensor infrastructure and operating parameter data to perform shaft shear detection. The system leverages data already being collected for engine control purposes, eliminating the need for additional specialized sensors and reducing overall system complexity while maintaining detection accuracy.
Data Source
AI summary
The method can include: monitoring a current value of a rate of reduction of torque of the shaft; providing a threshold value for the rate of reduction of torque of the shaft; and generating a signal indicative of the shaft shear event when the current value exceeds the threshold value.