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Hybrid Plants for Thermal Energy Production
Published in Dimitris Al. Katsaprakakis, Power Plant Synthesis, 2020
The most usual form of CPC is the 2D collector of trough type, presented in Figure 4.11. As seen in this figure, each side of the collector follows the pattern of a parabola. Both parabolas are extended until they are parallel to the axis of symmetry of the CPC. The angle configured by the CPC axis and the line connecting the focus of the one parabola with the opposite edge of the collector's aperture is called acceptance half angle θc. If the parabolic reflective surfaces are optically perfect, then the incident solar radiation inside the collector's aperture with an angle θ: –θc < θ < θc is reflected towards the receiver, located at the base of the CPC. For θ < –θc or θ > θc the solar radiation cannot reach the receiver. The angle range [–θc, θc] is called acceptance angle and determines the incident angles for which the solar radiation is exploited.
Holographic Optical Elements and Instrument Applications
Published in Raymond K. Kostuk, Holography, 2019
The theoretical limit for the conversion efficiency of a single bandgap PV cell is approximately 33% as determined by detailed energy balance between the temperature of the sun and the PV cell [59]. In order to increase conversion efficiency, multiple PV cells with different energy bandgaps are needed that span the solar emission spectrum. This can be accomplished using a broadband concentrator and a stacked or tandem multi-junction PV cell. While a number of systems of this type have been demonstrated [60], the individual cells are series connected which limits the total output current to the lowest output cell. In addition, the cells are typically manufactured by epitaxial growth methods that deposit one bandgap material on top of the other. This requires precise lattice matching and limits the choice of materials that can be used. Another issue is that the high cost of the cells per unit area limits the size of the cell, and they are typically used with large high concentration ratio collectors. As discussed earlier, this limits the acceptance angle of the concentrator and prevents the collection of diffuse illumination that makes up a significant fraction of the available solar energy.
Why Use Nonimaging Optics
Published in Julio Chaves, Introduction to Nonimaging Optics, 2017
Under parallel radiation, the concentrator has a half-acceptance angle θ. Under sunlight with finite angular aperture, the concentrator has a (reduced) real half-acceptance angle θR commonly defined as the angle for which the transmission (efficiency) of the concentrator drops to 90% of its maximum.3,5
Effective removal of fecal coliforms from river water in a rural community using low-cost CPC
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2022
Teresa Hernández-Ortíz, Iván Salgado-Tránsito, Carlos A. Pineda-Arellano, Josefina Vergara-Sánchez, Moisés Montiel-González
Conventional SODIS involves disinfecting contaminated water by placing it in a transparent polyethylene terephthalate (PET) bottle and exposing it to the Sun between 6 and 12 h. However, the efficiency and velocity of SODIS process can be radically improved using solar concentrators. These devices harness the energy from the Sun as the compound parabolic concentrator (CPC), whose main advantage is capturing incident radiation in a wide range of acceptance angles (Zheng et al. 2016). CPCs are considered low concentration and can collect direct and diffuse solar radiation, despite remaining static, achieving a thermal efficiency of up to 60% (Duffie and Beckman 2013).
A review on compound parabolic solar concentrator for sustainable development
Published in International Journal of Ambient Energy, 2018
D. K. Patel, P. K. Brahmbhatt, Hitesh Panchal
Rincón and Osorio (2002) made a new design of a trough-like non-imaging solar concentrator for increment in concentration ratio and thermal performance based on numerical computations for acceptance angle variations. They compared the trough-like solar concentrator with a conventional CPC by experimental analysis and found the former to be better in performance. They also concluded that the trough-like concentrator can be easily used in applications such as steam generation and direct fluid heating. Figure 10 shows a sketch of the new trough-like concept with a 15° acceptance angle.
Parabolic trough collector with rhombus tube absorber for higher concentration ratio
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2018
The half acceptance angle (θ) can be defined as the maximum deviation of the ray that can be allowed in the collector while the absorber is receiving whole energy reflected from the concentrator as shown in Figure 2 (Rodriguez-Sanchez and Rosengarten 2015). It is calculated by using the absorber tube radius (r), aperture width (w), and focal length (F) in Equation (5) (Rodriguez-Sanchez and Rosengarten 2015) obtained from the triangle ‘doa’ in Figure 3.