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Induced Infrared Thermography: Flow visualizations under the extreme conditions of an open volumetric receiver of a solar tower
- Publication Year :
- 2017
- Publisher :
- Elsevier, 2017.
-
Abstract
- Current measurement techniques do not allow the visualization of the return air flow of open volumetric receivers in solar tower power plants. The reason is that the region of interest is irradiated by concentrated solar radiation and is located on top of a tower. Therefore, a novel method of measurement, the Induced Infrared Thermography (IIT) is introduced within this paper. With this method the return air can easily be observed with an infrared camera. As air has a very low emissivity in the infrared region the activity has to be induced by the addition of an infrared-active component, here carbon dioxide. The temperature of the infrared-active component has the greatest influence on the signal strength but the mole fraction of the component and the distance to the infrared camera are also important. Due to temperature restrictions, the measured signal to noise ratio is low and therefore several post-processing steps have to be conducted to visualize the return air. The most important step for the visualization is subtracting a background image. Furthermore, a video filter is employed in order to remove noise. A time series of ITT images can be used to obtain information on the velocity fields of the flow. The process, called Infrared Image Velocimetry (IRIV) here, is similar to Particle Image Velocimetry (PIV) and is applied in this paper to external fluid flows of the open volumetric receiver. As IRIV is in an early stage of development the depicted results are treated as qualitative vector fields.
- Subjects :
- Fluid Flow and Transfer Processes
Flow visualization
Materials science
Infrared Image Velocimetry (IRIV)
Noise (signal processing)
business.industry
020209 energy
Mechanical Engineering
Airflow
Solar air receiver
02 engineering and technology
Qualifizierung
Velocimetry
Condensed Matter Physics
Low emissivity
Signal-to-noise ratio
Optics
Particle image velocimetry
Air return ratio
Thermography
Tracer gas
0202 electrical engineering, electronic engineering, information engineering
business
Induced Infrared Thermography (IIT)
Subjects
Details
- Language :
- German
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....52a1989cf869bc4a9d752fc21205b5b0