Realization of a test rig for small solar collectors and preliminary test

Pierucci, Giacomo; Hosouli, Sahand; Messeri, Matteo; Salvestroni, Michele; Fagioli, Federico; Taddei, Francesco; Pourreza, Atabak; Rashidi, Hamid; Lucia, Maurizio De

doi:10.1063/1.5117634

Cited by 4 publications

(3 citation statements)

References 10 publications

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“…A new prototype of micro-PTC was optically designed, realized, and tested [30][31][32][33]. The micro-PTC was successively utilized for the realization of a concentrated solar power plant.…”

Section: Introductionmentioning

confidence: 99%

Laser Profilometry on Micro-PTC

et al. 2022

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Profilometry is useful in detecting surface faults on solar concentrators, which can be imperfectly manufactured, thus affecting system performance. Profilometric analyses are performed on a micro-parabolic trough collector (m-PTC), with reduced sizes and greater mirror curvature than a usual PTC. The peculiar dimensions and shape of this micro-PTC request to develop a specific configuration of laser profilometry. It includes a laser diode with a converging lens placed in front of it, ensuring that the mirror curvature does not affect the beam reflection. A new method to calculate the spot position furnishes the reflected beam center even if it lies outside the target, giving it a virtual expansion. The profile is assessed with an iterative calculation, starting from a first point, physically measured. The results are the 3D profile reconstruction of the parabolic mirror and a map of the slope error for each mirror point. It also estimates the intercept factor, a parameter fundamental to optimize the m-PTC system, whose value is in agreement with a structured light measurement on the same object. This intercept factor was obtained averaging the local intercept factor calculated for each mirror point, which individuates the mirror portions not focusing the sunrays on the tube.

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Section: Introductionmentioning

confidence: 99%

Laser Profilometry on Micro-PTC

et al. 2022

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“…In fact, considering a defect of the same size on the surface of a micro-PTC collector and on a conventional PTC mirror will result in a greater loss of energy on the smaller concentrator, because it affects a larger fraction of the total area of the receiver. In the current testing phase for this technology [14][15][16][17], a fundamental parameter to be experimentally determined and calculated is the optical efficiency of the system. It represents the upper limit that overall efficiency can be reached in the absence of thermal losses.…”

Section: Introductionmentioning

confidence: 99%

“…In the current testing phase for this technology [14][15][16][17], a fundamental parameter to be experimentally determined and calculated is the optical efficiency of the system. It represents the upper limit that overall efficiency can be reached in the absence of thermal losses.…”

Section: Introductionmentioning

confidence: 99%

Structured Light Profilometry on m-PTC

et al. 2020

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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.

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