Beam Characterization and Improvement With a Flux Mapping System for Dish Concentrators

Solar Energy ◽  
2002 ◽  
Author(s):  
Steffen Ulmer ◽  
Wolfgang Reinalter ◽  
Peter Heller ◽  
Eckhard Lu¨pfert ◽  
Diego Martinez
Keyword(s):  
Flux Distribution ◽  
Ccd Camera ◽  
Measuring Method ◽  
Brightness Distribution ◽  
Total Power ◽  
Beam Path ◽  
Mapping System ◽  
Beam Characterization ◽  
Measurement Area ◽  
Flux Mapping

A flux mapping system able to measure the flux distribution of dish/Stirling systems in planes perpendicular to the optical axis was built and operated at the Plataforma Solar de Almeri´a (PSA). It uses the indirect measuring method with a water-cooled Lambertian target placed in the beam path and a CCD-camera mounted on the concentrator taking images of the brightness distribution of the focal spot. The calibration is made by calculating the total power coming from the dish and relating it to the integrated gray value over the whole measurement area. The system was successfully operated in a DISTAL II stretched membrane dish and in the new EURODISH in order to characterize their beams and improve the flux distribution on their receivers.

Beam Characterization and Improvement with a Flux Mapping System for Dish Concentrators

2002 ◽  
Vol 124 (2) ◽  
pp. 182-188 ◽  
Author(s):  
Steffen Ulmer ◽  
Wolfgang Reinalter ◽  
Peter Heller ◽  
Eckhard Lu¨pfert ◽  
Diego Martı´nez
Keyword(s):  
Flux Distribution ◽  
Ccd Camera ◽  
Measuring Method ◽  
Brightness Distribution ◽  
Total Power ◽  
Beam Path ◽  
Mapping System ◽  
Beam Characterization ◽  
Measurement Area ◽  
Flux Mapping

A flux mapping system able to measure the flux distribution of dish/Stirling systems in planes perpendicular to the optical axis was built and operated at the Plataforma Solar de Almerı´a (PSA). It uses the indirect measuring method with a water-cooled Lambertian target placed in the beam path and a CCD-camera mounted on the concentrator taking images of the brightness distribution of the focal spot. The calibration is made by calculating the total power coming from the dish and relating it to the integrated gray value over the whole measurement area. The system was successfully operated in a DISTAL II stretched membrane dish and in the new EURODISH in order to characterize their beams and improve the flux distribution on their receivers.

scholarly journals A Flux Mapping Method for Central Receiver Systems

2011 ◽  
Author(s):  
Clifford K. Ho ◽  
Siri S. Khalsa
Keyword(s):  
Ccd Camera ◽  
Mapping Method ◽  
Test Facility ◽  
The Novel ◽  
Additional Information ◽  
Thermal Test ◽  
Central Receiver ◽  
Direct Normal Irradiance ◽  
Beam Characterization ◽  
Pixel Value

A new method is described to determine irradiance distributions on receivers and targets from heliostats or other collectors for concentrating solar power applications. The method uses a CCD camera, and, unlike previous beam characterization systems, it does not require additional sensors, calorimeters, or flux gauges on the receiver or target. In addition, spillage can exist (the beam does not need to be contained within the target). The only additional information required besides the digital images recorded from the CCD camera is the direct normal irradiance and the reflectivity of the receiver. Methods are described to calculate either an average reflectivity or a reflectivity distribution for the receiver using the CCD camera. The novel feature of this new PHLUX method is the use of recorded images of the sun to scale both the magnitude of each pixel value and the subtended angle of each pixel. A test was performed to evaluate the PHLUX method using a heliostat beam on the central receiver tower at the National Solar Thermal Test Facility in Albuquerque, NM. Results showed that the PHLUX method was capable of producing an accurate flux map of the heliostat beam with a relative error in the peak flux of 2%.

Design of a modified indirect flux mapping system for high-flux solar simulators

Energy ◽  
2021 ◽  
pp. 121311
Author(s):  
Qing Li ◽  
Jikang Wang ◽  
Yu Qiu ◽  
Mingpan Xu ◽  
Xiudong Wei
Keyword(s):  
High Flux ◽  
Mapping System ◽  
Flux Mapping

Study on the Composite Measuring Method for Small Module Gears

2008 ◽  
Vol 381-382 ◽  
pp. 83-86
Author(s):  
Jian Jun Ding ◽  
Zhuang De Jiang ◽  
Bing Li ◽  
Jun Jie Guo
Keyword(s):  
Imaging System ◽  
Ccd Camera ◽  
Measuring Method ◽  
Important Research ◽  
Mechanical Contact ◽  
Ccd Imaging ◽  
Contact Measurement ◽  
Extraction Algorithm ◽  
Probe System ◽  
Micro Sphere

The detection technique of small module gears has a very important research and application value. In this paper, a composite measuring method is presented based on combining traditional mechanical contact measurement with optical image non-contact measurement. First of all, this paper analyzes the basic principle of composite probe composed of optical fiber stylus and CCD imaging system. The tail-end of the stylus is shaped into a micro-sphere, where a small refection mirror is designed. When the laser is transmitted through the fiber, a round facula can be seen from the CCD camera. The micro-sphere is kept contact with the surface of the measured gear at the time of measuring and the error of the measured gear will be reflected by the offset of the facula center. Meanwhile, the sub-pixel extraction algorithm for the center of facula image is presented. Then the calibration principle and method of probe system is analyzed in detail. Finally, the data processing principle of the presented method is discussed for gear measurement.

scholarly journals On-Sun Evaluation of the PHLUX Method for Heliostat Beam Characterization

2016 ◽  
Author(s):  
Julius Yellowhair ◽  
Clifford K. Ho
Keyword(s):  
Focal Length ◽  
Digital Camera ◽  
Total Power ◽  
Neutral Density ◽  
Additional Information ◽  
Direct Normal Irradiance ◽  
Beam Characterization ◽  
Peak Flux ◽  
And Performance ◽  
Solar Field

Flux distributions from solar field collectors are typically evaluated using a beam characterization system, which consists of a digital camera with neutral density filters, flux gauge or calorimeter, and water-cooled Lambertian target panel. The pixels in camera image of the flux distribution are scaled by the flux peak value measured with the flux gauge or the total power value measured with the calorimeter. An alternative method, called PHLUX developed at Sandia National Laboratories, can serve the same purpose using a digital camera but without auxiliary instrumentation. The only additional information required besides the digital images recorded from the camera are the direct normal irradiance, an image of the sun using the same camera, and the reflectivity of the receiver or target panel surface. The PHLUX method was evaluated using two digital cameras (Nikon D90 and D3300) at different flux levels on a target panel. The performances of the two cameras were compared to each other and to measurements from a Kendall radiometer. For consistency in comparison of the two cameras, the same focal length lenses and same number of neutral density filters were used. Other camera settings (e.g., shutter speed, f-stop, etc.) were set based on the aperture size and performance of the cameras. The Nikon D3300 has twice the number of pixels as the D90. D3300 provided higher resolution, however, due to the smaller pixel sizes the images were noisier, and the D90 with larger pixels had better response to low light levels. The noise in the D3300, if not corrected, could result in gross overestimation of the irradiance calculations. After corrections to the D3300 flux images, the PHLUX results from the two cameras showed they agreed to within 8% for a peak flux level of 1000 suns on the target, and less than 10% error in the peak flux when compared to the Kendall radiometer.

Operational Performance of the University of Minnesota 45kWe High-Flux Solar Simulator

2012 ◽  
Author(s):  
Katherine R. Krueger ◽  
Wojciech Lipiński ◽  
Jane H. Davidson
Keyword(s):  
Heat Flux ◽  
Focal Plane ◽  
Flux Distribution ◽  
Spectral Characteristics ◽  
Ccd Camera ◽  
Optical Filters ◽  
High Flux ◽  
University Of Minnesota ◽  
Solar Simulator ◽  
The University

This paper presents measured performance of the University of Minnesota’s 45 kWe indoor high-flux solar simulator. The simulator consists of seven radiation units, each comprised of a 6.5 kWe xenon short arc lamp coupled to a reflector in the shape of a truncated ellipsoid of revolution. Data include flux distribution at the focal plane for all seven radiation units operating in tandem and for individual radiation units. The flux distribution is measured optically by acquiring the image of radiation reflected from a Lambertian target with a CCD camera equipped with neutral density optical filters. The CCD camera output is calibrated to irradiation using a circular foil heat flux gage. It is shown that accurate calibration of the heat flux gage must account for its response to the spectral characteristics of the radiation source. The simulator delivers radiative power of approximately 9.2 kW over a 60-mm diameter circular area located in the focal plane, corresponding to an average flux of 3.2 MW m−2, with a peak flux of 7.3 MW m−2.

scholarly journals 3D Wide FOV Scanning Measurement System Based on Multiline Structured-Light Sensors

2014 ◽  
Vol 6 ◽  
pp. 758679 ◽  
Author(s):  
He Gao ◽  
Fuqiang Zhou ◽  
Bin Peng ◽  
Yexin Wang ◽  
Haishu Tan
Keyword(s):  
Measurement System ◽  
High Efficiency ◽  
Structured Light ◽  
Ccd Camera ◽  
Measurement Range ◽  
Object Surface ◽  
3D Vision ◽  
Vision Measurement ◽  
Measurement Area ◽  
Wide Fov

Structured-light three-dimensional (3D) vision measurement is currently one of the most common approaches to obtain 3D surface data. However, the existing structured-light scanning measurement systems are primarily constructed on the basis of single sensor, which inevitably generates three obvious problems: limited measurement range, blind measurement area, and low scanning efficiency. To solve these problems, we developed a novel 3D wide FOV scanning measurement system which adopted two multiline structured-light sensors. Each sensor is composed of a digital CCD camera and three line-structured-light projectors. During the measurement process, the measured object is scanned by the two sensors from two different angles at a certain speed. Consequently, the measurement range is expanded and the blind measurement area is reduced. More importantly, since six light stripes are simultaneously projected on the object surface, the scanning efficiency is greatly improved. The Multiline Structured-light Sensors Scanning Measurement System (MSSS) is calibrated on site by a 2D pattern. The experimental results show that the RMS errors of the system for calibration and measurement are less than 0.092 mm and 0.168 mm, respectively, which proves that the MSSS is applicable for obtaining 3D object surface with high efficiency and accuracy.

A Microprocessor Based Automatic Flux Mapping System for Pressurized Water Reactors

1979 ◽  
Vol 26 (1) ◽  
pp. 796-801
Author(s):  
William W. Wassel ◽  
Gilbert W. Remley ◽  
James A. Neuner ◽  
Robert M. Oates
Keyword(s):  
Pressurized Water Reactors ◽  
Pressurized Water ◽  
Mapping System ◽  
Water Reactors ◽  
Flux Mapping
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