Turbine Tip Clearance Measurement Using Passage Event Integration
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Solution Overview
Problem
Existing methods for measuring tip clearance in turbines face challenges due to noise in sensor output, which leads to errors in measurements and requires increased data sampling rates, resulting in high data volumes that hinder real-time processing and response to emergency situations, and may necessitate additional sensors, increasing weight and cost.
Innovation Solution
The integration of sensor output over a passage event reduces random noise, allowing for real-time signal generation without the need for complex electronics, enabling accurate timing signals and reducing the need for separate apparatus for clearance and timing measurements, thus providing a cost-effective and lightweight solution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If data sampling rate is increased to reduce noise in sensor output, then measurement precision is improved, but device complexity and data processing requirements increase
Solution Approach 1:
The patent applies preliminary action by performing integration of sensor signals over complete passage events before analysis. By accumulating signal data across multiple blade passages and integrating over defined time windows corresponding to blade tip passage, the system pre-processes noisy sensor output into averaged clearance values. This preliminary integration reduces random noise and measurement variability before the data requires further processing or decision-making, thereby improving measurement precision without requiring increased sampling rates or complex post-processing algorithms
2Measurement precision
If separate sensing system is provided for tip clearance detection, then measurement precision is improved, but weight and cost increase
Solution Approach 1:
The patent applies universality by enabling existing turbine blade passage sensors to serve dual purposes: generating timing signals for vibration monitoring and providing clearance measurement data through integration processing. By implementing passage event integration algorithms on standard sensor output, the system extracts both timing information (for rotational speed and vibration analysis) and clearance information (through signal amplitude integration over blade passage events). This multi-functional use of existing sensors eliminates the need for separate clearance measurement devices, thereby maintaining measurement precision while avoiding additional weight and cost
3Measurement precision
If large volumes of data are processed for noise reduction, then measurement precision is improved, but response time to emergency situations worsens
Solution Approach 1:
The patent applies preliminary action by continuously integrating sensor signals over complete passage events in real-time, maintaining running averages of clearance values as blades pass the sensor. This continuous pre-processing approach reduces noise and improves measurement precision incrementally with each blade passage without requiring batch processing of large historical data sets. The integrated clearance values become available immediately after each passage event, enabling rapid detection of clearance excursions beyond acceptable limits and triggering timely emergency responses without the computational burden of processing extensive historical data
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 provides accurate and reliable timing signals, enhances detection of fault conditions, and allows for rapid response to malfunctions while minimizing noise and data processing demands, improving resolution and reducing the sensitivity to component distortions and variations in rotation speed.
Implementation Method 1
a sensor (4) having an output dependent on a separation between a moving component (6) and a reference structure (10)
Implementation Method 2
a sensor (4) having an output dependent on a separation between a moving component (6) and a reference structure (10)
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
Apparatus and methods for measuring clearance are disclosed. In one arrangement, a sensor is used to output a signal that is dependent on a separation between the component and the reference structure. A passage event integration comprising integrating an output from the sensor over at least a portion of a passage event of the component past the sensor is performed. Information about a clearance between the component and the reference structure is determined using a result of the passage event integration.