Structured Light Profilometry on m-PTC
Authors: Marotta G., Sansoni P., Francini F., Jafrancesco D., De Lucia M., Fontani D.
Autors Affiliation: Natl Inst Opt CNR INO, I-50125 Florence, Italy; Univ Florence, Dept Ind Engn, I-50139 Florence, Italy
Abstract: In concentrating solar systems, it is essential to study the optical losses of the collectors. A fundamental parameter is the intercept factor, namely, the fraction of sunrays reflected by the concentrator that reaches the receiver. Optical profilometry studies the relationship between the collector profile and the intercept factor, which influences the collection efficiency. Profilometric analyses were performed on a micro-parabolic trough collector (m-PTC), with reduced sizes and greater mirror curvature than a usual PTC. The proposed technique projects a luminous pattern (structured light) both on the collector with an opaque covering and on a flat reference plane. Measurement set-up and calibration technique were developed for m-PTC. A program coded in Python analyzed the images and reconstructs the mirror profile. The tilted reference plane was reconstructed using an original geometric model and a calibration procedure. The focal length of each parabolic section was calculated, providing information on surface defects in the mirror. An
important parameter obtained was the displacement of the focus of the parabola with respect to the ideal position. Using this value, the intercept factor was estimated to be 0.89. The proposed technique was validated by comparing the results with an independent profilometric study applied to the same m-PTC.
Volume: 13 (21) Pages from: 5671-1 to: 5671-17
KeyWords: parabolic trough collectors; profilometry; structured light; intercept factor; optical measurement; solar energyDOI: 10.3390/en13215671Citations: 1data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2022-01-23References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here