Next Generation Products
Meggitt Sensing Systems invests up to 12% of sales revenues back into engineering tomorrow’s products. Microwave sensors are just one of the many next generation products in development.
Microwave blade tip sensing for industrial and aero turbomachinery
Meggitt’s microwave phase based measurement system is being designed especially for un-shrouded blade tip measurements in turbomachinery. This innovative patented technology will allow measurement through steam and combustion gases.
Microwave sensors are exceptional for their ability to withstand permanent installation in the harsh environment of a gas turbine’s first stage, which is subject to vibration, fluctuating pressure and extreme temperatures. These sensors have an inherent tolerance to dirty environments because the microwave signal penetrates deposits on the sensors, such as the build-up of combustion byproducts.
The microwave blade tip sensing technology can provide measurements of blade tip clearance – which is the distance between the blades and the surrounding casing – and of blade tip timing – which is the times of arrivals of each blade in front of the sensor.
Tip clearance monitoring
Blade tip-clearance measurements in power generation gas turbines:
- provide measurements to be used in clearance control systems, which improves fuel efficiency as blade-casing clearance is reduced
- provide blade health monitoring by monitoring and detecting abnormal blade growth to alarm of an impending blade failure
Meggitt has extensive experience with blade tip clearance measurement in several gas turbines from aero engine ground test to large power generation gas turbines.
The following papers cover metrology aspects up to engine test results. Meggitt is continually working to improve the technology and measurement accuracy.
Blade vibration monitoring
Blade and disk failures often provide advanced warning through subtle changes in blade vibration characteristics. Meggitt’s microwave sensors prevent blade cyclic damage by providing a key measurement for warning of potentially dangerous blade vibrations due to flutter, static or dynamic blade deflections, resonance frequencies or foreign object damage.
The targeted applications are the compressor inlet stages of gas turbines and terminal stages of low pressure steam turbines where the blades are quite long and subject to high amplitude vibration which can lead to catastrophic blade failure with high down and repairs cost for the operator.
Blade tip-timing measurements in power generation gas or steam turbines:
- detect and monitor blade deflection and vibration, to optimize maintenance and prolong turbine life