Effective Absorber Area in Semispherical Solar Collectors With Spiral Cylindrical Absorber

This paper develops an advanced methodology to determine the real contribution of the incidence solar radiation components, direct, diffuse, and reflected, onto a semispherical solar collector with spirally rolled up cylindrical absorber, as a function of the intercepted area of the solar radiation components by the collector's receiver. Based on a previous work (2012, Study and Characterization of New Generation Semispherical Thermal Collectors, Ana Sofia Morillo Candas, Applied Physics Master, Master Thesis, UCM) in which the effective intercepted area for direct radiation was modeled, the present paper develops new algorithms for diffuse and reflected solar radiation and improves the existing one, with the aim at characterizing geometrical parameters of these types of collectors. The determination of the effective area intercepted by the receiver for the different components of the solar radiation is essential for the characterization of the collector's thermal performance, as the energy received by the absorber depends on the type of radiation and on the effective area covered by each type.