Circular Truncated Conical Mirror with Cavity Shape and Inner Reflection for Concentrating Diffused Light to Collector Mouth from a Half Celestial Sphere
In this study, we designed a circular truncated conical mirror to concentrate diffused light to the collector mouth from a half celestial sphere and evaluated its performance. The conical mirror has a circular truncated cone-shaped cavity, which reflects light on the cavity’s inner surface. The top of the truncated cone shape is the incident mouth, the bottom is the collector mouth, and the sides are the mirror surfaces. The incident mouth size is smaller than the collector mouth size. All light incident on the incident mouth is either reflected or not reflected on the mirror surface to reach the collector mouth. Light incident at a shallow angle to the central axis of the conical mirror is not reflected on the mirror surface, while light incident at a deep angle is reflected on the mirror surface. The conical mirror can concentrate all diffused light incident at the incident mouth from a half celestial sphere of 360◦ in the horizontal direction and 180◦ in the vertical direction to the collector mouth. A coordinate system is established for the conical mirror, and a design method is proposed. Using our design method, the conical mirror is manufactured from the determined design values. A plane mirror, concave mirror, compound parabolic mirror, and Fresnel lens, comprising the conical mirror, are used as the measured objects to compare the manufactured conical mirror performance. An experimental setup is constructed to evaluate the performance of the measured objects. Using the constructed experimental setup, diffused light is irradiated to the measured objects as scattered light. The illuminance of the light concentrated in the collector mouth of the measured objects is measured for the irradiated diffused light. The measured illuminance is then used to compare and evaluate the light-concentrating efficiency of the measured objects.
Japan Solar Energy Society ed., “New Solar Energy Utiliza- tion Handbook”, Japan Solar Energy Society, pp.123-128, Tokyo, 2015 (in Japanese).
Japan Solar Energy Society ed., “Solar Energy Utilization Technology”, Japan Solar Energy Society, p.66, Tokyo, 2006 (in Japanese).
Geospatial Information Authority of Japan ed., “National Atlas of Japan”, Japan Map Center, p.47, Tokyo, 1990 (in Japanese).
R. Winston, “Principles of Solar Concentrators of a Novel Design”, Solar Energy, Vol.16, No.2, pp.89-95, 1974.
G. H. Derrick, I. M. Bassett and D. R. Mills, “Comparison of Reflector Designs for Stationary Tubular Solar Collectors”, Solar Energy, Vol.37, No.3, pp.195-203, 1986.
S.S.Rao,H.LeeandY.Hu,“OptimalDesignofCompound Parabolic Concentrator Solar Collector System”, Transac- tions of the ASME, Journal of Mechanical Design, Vol.136, No.9, pp.091402-1-091402-10, 2014.
G. R. Mather and D. C. Beekley, “Performance of an Evacu- ated Tubular Collector Using Non-imaging Reflectors”, Pro- ceedings of the Joint Conference International Solar Energy Society, No.2, pp.64-78, 1976.
D. R. Mills and J. E. Giutronich, “Symmetrical and Asym- metrical Ideal Cylindrical Radiation Transformers and Concentrators”, Journal of the Optical Society of America, Vol.69, No.2, pp.325-328, 1979.
I. M. Bassett and G. H. Derrick, “Diffuse Reflectors in Non- imaging Optics”, Proceedings of the International Solar En- ergy Society Silver Jubilee Congress, Vol.1, pp.557-560, 1979.
D. P. Grimmer, “A Comparison of Compound Parabolic and Simple Parabolic Concentrating Solar Collectors”, Solar En- ergy, Vol.22, No.1, pp.21-25, 1979.
J.R.FrissoraandD.M.Platt,“DrainableEvacuatedCollec- tor with Compound Parabolic Cusp Reflector”, Solar Energy and Conservation, Vol.1, pp.113-140, 1980.
B. Norton, P. C. Eames and Y. P. Yadav, “Symmetric and Asymmetric Linear Compound Parabolic Concentrating So- lar Energy Collectors - The State-of-the-art in Optical and Thermo-physical Analysis -”, International Journal of Am- bient Energy, Vol.12, No.4, pp.171-190, 1991.
P. C. Eames and B. Norton, “The Effect of Sky Conditions on the Partition of Incident Solar Energy between the Com- ponents of a CPC Solar Energy Collector”, Proceedings of the Solar World Congress 1991 (SWC1991), Vol.2, pp.1884- 1889, 1992.
A. Suzuki, “Optimum Design for Non-imaging Solar Con- centrators with Reference to Scattering Insolation Fraction”, Proceedings of the Japan Solar Energy Society Japan Wind Energy Association Joint Conference, pp.37-40, 1993 (in Japanese).
P. C. Eames, B. Norton, Y. Tripagnostopoulos and P. Yianoulis, “Modelling Line-axis Solar Concentrators in the Medium Temperature Range”, Renewable Energy, Vol.16, No.1, pp.743-748, 1999.
J. Wang, L. Yu, C. Jiang, S. Yang and T. Liu,“Optical Analysis of Solar Collector with New V-shaped CPC”, Solar En- ergy, Vol.135, pp.780-785, 2016.
N. Yamada and Y. Honda, “Optical Analysis of High Con- centrating Optical Geometry Coupled with Diffuse Solar Ra- diation Absorber”, Journal of Japan Solar Energy Society, Vol.36, No.3, pp.45-50, 2010 (in Japanese).
N. Sellami, T. K. Mallick and D. A. Mcneil, “Optical Char- acterisation of 3-D Static Solar Concentrator”, Energy Con- version and Management, Vol.64, pp.579-586, 2012.
M. Matsumoto, “Multi-part Mirror for Focusing Diffuse Light”, Mechanical Engineering Journal, Vol.4, No.3, 2017, DOI:10.1299/mej.16-00520.
S. Onizuka, “Light Funnel as a Teaching Material - A Con- ical Device for Collecting or Projecting Light -”, Journal of the Physics Education Society of Japan, Vol.42, No.1, pp.26- 29, 1994 (in Japanese).
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