OPTICAL, THERMAL, AND EXERGETIC PERFORMANCE OF A NOVEL SPHERICAL SOLAR
CONCENTRATOR WITH DIFFERENT CAVITY RECEIVER SHAPES
Abstract
While a variety of solar concentrators have been studied for decades,
the study of the spherical glass concentrator has never been reported,
to the best of our knowledge. For that, this paper examines the optical
characteristics of the novel solar spherical glass concentrator and
identifies its performance and features. In addition, the thermal and
exergetic performance of the concentrator are studied with three cavity
receiver designs under various operating temperatures and different mass
flow rates. More specifically, the examined receiver shapes: spiral,
conical, and cylindrical. All the cavities are analyzed in order to
determine the best design which maximizes the thermal efficiency of the
solar collector. According to the results, the spherical collector can
concentrate the heat flux up to 25 times the incident flux value. Also,
the study is defined the best receiver dimensions that achieve optimum
optical performance. Then, the optical analysis is conducted with an
optical simulation in COMSOL Ray Optics to validate this work’s
findings. Moreover, the best design is found to be the one with a spiral
shape, while the conical is the next choice. The cylindrical is the
third design in the performance sequence.