Helically coiled solar cavity receiver for micro-scale direct steam generation

Swanepoel, J.K.; Roux, W.G. Le; Lexmond, A.S.; Meyer, Josua P.

doi:10.1016/j.applthermaleng.2020.116427

Cited by 18 publications

(2 citation statements)

References 47 publications

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“…A self-developed Python code was used to read the cartesian coordinates and transform the shape to the respective origins of the cartesian plane [7]. This was done by obtaining three place markers positioned along the rim of the facet and determining the transformations required to align the normal unit of the displacement vectors of the place markers to be parallel to the z-axis.…”

Section: Methodology Photogrammetry Analysismentioning

confidence: 99%

“…The elliptical rim of the investigated satellite television antenna has a minor axis length of 757.5 mm and a major axis length of 820 mm. A pneumatic valve, comprising a 1/4-inch, threaded nipple, a quarter-turn valve and an 8 mm hose nipple was inserted into the back of the dish, through which a vacuum could be drawn [4,7]. All the connections at the back of the dish, including the dish mount and the pneumatic valve, were sealed with general-purpose silicone to prevent leaks.…”

Section: Facet Designmentioning

confidence: 99%

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Photogrammetry analysis of a vacuum-membrane solar dish using elliptical television antennas

Swanepoel¹,

Roosendaal²,

Roux³

2022

AIP Conference Proceedings

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The design of a solar dish usually involves the complex trade-off between cost and optical quality. The use of off-the-shelf elliptical television antennas in a vacuum-membrane solar dish array is investigated in this paper, in an effort to reduce the cost of solar concentration. Each facet comprised a 50-m-thick Mylar sheet membrane, stretched and sealed over the elliptical rim of an off-the-shelf satellite television antenna, forming a narrow cavity in which a vacuum could be drawn to pull the Mylar sheet into a concave shape. The shape of the facet concavity was investigated using photogrammetry. An elliptic paraboloid and a hemi-ellipsoid were fitted to the photogrammetry results, and it was determined that both fits could be used to represent the concave shape. The investigation allowed for the concave shape to be modelled in a ray tracing analysis, where the flux map was compared with the result from a lunar flux mapping analysis. Comparison of the intercept factor trends showed that further investigation into quantifying the contributions of individual facet alignment errors should be performed to further improve the model. With improvements in individual facet alignment, the use of off-the-shelf elliptical television antennas in a vacuum-membrane solar dish array can be a viable solution to reduce the cost of solar concentration.

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Section: Methodology Photogrammetry Analysismentioning

confidence: 99%

Section: Facet Designmentioning

confidence: 99%