LINEAR ARRAY IR CAMERA FOR MONITORING AND DIAGNOSTICS IMAGING OF TURBMOMACHINE COMPONENTS
Publication Date: 2014-Sep-03
The IP.com Prior Art Database
A technique using a commercially available small profile, fast linear array camera enables wider band, multiple wavelength infrared imaging of hot turbomachine components. This allows handling wavelength dependent emissivity changes and reduces costs by reducing the cooling flows and sizes compared to available two dimensional mid-IR broadband cameras. It allows selective choosing of specific wavelengths where intensity is expected to be highest, depending on component temperature, thus enabling shorter integration time, and reducing motion blur for rotating components
This material is based upon work supported by the Department of Energy under Award Number DE-FC26-05NT42643. This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
This innovative technique works by triggering the linear detector to acquire images of the specific lines of interest on the buckets, e.g., the leading edge or the trailing edge or mid-span or the root or the tip. The camera line-of-view (LOV) can also be scanned to acquire 2-d images from root to tip by either scanning the lens or other optical elements in the sight tube. Alternately, LOV can be set to go radially (along root-tip) and triggering can be staggered such that composite images of the buckets can be obtained. In addition, by choosing the best possible or optimum wavelength where highest intensity occurs, this technique can also be used as a fast single color method that enables obtaining sharpest possible, motion blur free images of the rotating components.
This method can obtain accurate temperature and emissivity mapping of turbomachine hot components with as few assumptions as possible. This method can eliminate having to guess/assume the emissivity of the component surfaces which could change with prolonged operation of the turbomachine. It also can eliminate having to make artificial assumptions, such as a constant emissivity as a function of wavelength. Changes in emissivity of the hot component surfaces and surface coatings with operating hours accumulated on the turbomachine can be used to calculate remaining useful life of the components. In addition, with the thermal history information that can be obtained using this im...