RAY-TRACING ANALYSIS OF A TWO-STAGE SOLAR CONCENTRATOR

2010 ◽  
Vol 34 (2) ◽  
pp. 263-275 ◽  
Author(s):  
Dominic Groulx ◽  
Benjamin Sponagle
Keyword(s):  
Solar Energy ◽  
Ray Tracing ◽  
Energy Flux ◽  
Incident Energy ◽  
Focal Length ◽  
Target Position ◽  
The Sun ◽  
Solar Concentrator ◽  
Secondary Mirror ◽  
Solar Energy Flux

A ray-tracing analysis was conducted on a 2-stage solar concentrator made of two parabolic mirrors created by Lunenburg Industrial Foundry & Engineering (LIFE). The effects of the secondary mirror’s focal length, the distance between the secondary mirror and the target, and the misalignment with the sun were studied. The focal length of the secondary mirror determines the maximum local solar energy flux Φ that can be achieve on the target. For the optimal focal length of 157.9ʺ, a maximum Φ = 1.2 x 104 MW/m2 was achieve compare to Φ = 1680 MW/m2 for the initial LIFE’s focal length of 158.8125ʺ. The concentrator concentrates all the incident energy from the sun on the target, and that independently of the secondary mirror’s focal length (within the range studied), as long as the target position is within an 11 cm zone. Small misalignments in the order of ±0.2° would bring the concentration efficiency to zero.

Design and test of an annular fresnel solar concentrator to obtain a high-concentration solar energy flux

Energy ◽  
2021 ◽  
Vol 214 ◽  
pp. 118947
Author(s):  
Kai Liang ◽  
Heng Zhang ◽  
Haiping Chen ◽  
Dan Gao ◽  
Yang Liu
Keyword(s):  
Solar Energy ◽  
Energy Flux ◽  
Solar Concentrator ◽  
High Concentration ◽  
Solar Energy Flux

Behavior of a Heat-Protective Material Based on Al2O3 and SiO2 Fibers under Exposure to Concentrated Solar Energy Flux

2021 ◽  
Author(s):  
S. Kh. Suleimanov ◽  
V. G. Babashov ◽  
M. U. Dzhanklich ◽  
V. G. Dyskin ◽  
M. I. Daskovskii ◽  
...  
Keyword(s):  
Solar Energy ◽  
Energy Flux ◽  
Protective Material ◽  
Concentrated Solar Energy ◽  
Solar Energy Flux

scholarly journals Monte Carlo Ray-Tracing Simulation of a Cassegrain Solar Concentrator Module for CPV

2021 ◽  
Vol 9 ◽  
Author(s):  
Seung Jin Oh ◽  
Hyungchan Kim ◽  
Youngsun Hong
Keyword(s):  
Monte Carlo ◽  
Ray Tracing ◽  
Concentration Ratio ◽  
Collection Efficiency ◽  
Focal Length ◽  
Tracking Error ◽  
Target Area ◽  
Solar Concentrator ◽  
Acceptance Angle ◽  
Energy Applications

The concentration ratio is one of the most important characteristics in designing a Cassegrain solar concentrator since it directly affects the performance of high-density solar energy applications such as concentrated photovoltaics (CPVs). In this study, solar concentrator modules that have different configurations were proposed and their performances were compared by means of a Monte Carlo ray-tracing algorithm to identify the optimal configurations. The first solar concentrator design includes a primary parabolic concentrator, a parabolic secondary reflector, and a homogenizer. The second design, on the other hand, includes a parabolic primary concentrator, a secondary hyperbolic concentrator, and a homogenizer. Two different reflectance were applied to find the ideal concentration ratio and the actual concentration ratio. In addition, uniform rays and solar rays also were compared to estimate their efficiency. Results revealed that both modules show identical concentration ratios of 610 when the tracking error is not considered. However, the concentration ratio of the first design rapidly drops when the sun tracking error overshoots even 0.1°, whereas the concentration ratio of the second design remained constant within the range of the 0.8° tracking error. It was concluded that a paraboloidal reflector is not appropriate for the second mirror in a Cassegrain concentrator due to its low acceptance angle. The maximum collection efficiency was achieved when the f-number is smaller and the rim angle is bigger and when the secondary reflector is in a hyperboloid shape. The target area has to be rather bigger with a shorter focal length for the secondary reflector to obtain a wider acceptance angle.

Flux Density Distribution in the Focal Region of a Solar Concentrator System

1991 ◽  
Vol 113 (2) ◽  
pp. 112-116 ◽  
Author(s):  
M. Schubnell ◽  
J. Keller ◽  
A. Imhof
Keyword(s):  
Density Distribution ◽  
Flux Density ◽  
Ray Tracing ◽  
Radiation Flux ◽  
Focal Length ◽  
Solar Furnace ◽  
Focal Region ◽  
The Sun ◽  
Parabolic Dish ◽  
Flux Density Distribution

In high temperature solar energy applications highly concentrating optical systems, such as, e.g., parabolic dishes, achieve typical radiation flux densities >2 MW/m2. In order to investigate thermo and photochemical reactions at temperatures >1500 K and radiation flux densities >2 MW/m2 a solar furnace was built at Paul Scherrer Institute (PSI). This furnace is a two-stage concentrator. The first stage is a prefocusing glass heliostat with a focal length of 100 m. The second stage is a highly concentrating parabolic dish with a focal length of 1.93 m. To design experiments to be carried out in the focal region of the parabolic dish, the radiation flux as well as its density distribution have to be known. This distribution is usually measured by radiometric methods. However, these methods are generally rather troublesome because of the high temperatures involved. In this paper we present a simple method to estimate the characteristic features of the radiation flux density distribution in the focal region of a concentrator system. It is well known from solar eclipses that the mean angular diameter of the moon is almost equal to that of the sun (9.1 mrad versus 9.3 mrad). Hence, the lunar disk is well suited to be used as a light source to investigate the flux distribution in a solar furnace. Compared to the sun the flux density is reduced by 4·105 and the flux density distribution can be inspected on a sheet of paper located in the plane of interest, e.g., the focal plane. This distribution was photographed and analyzed by means of an image processing system. The density distribution was also simulated using a Monte Carlo ray tracing program. Based on this comparison, and on further ray tracing computations, we show that the peak flux density decreases from 8.9 MW/m2 in December to values below 4 MW/m2 in June and the net radiation flux from 25 kW to 15 kW, respectively.

Parametric Analysis of the Fixed Mirror Solar Concentrator for Medium Temperature Applications

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Ramon Pujol-Nadal ◽  
Víctor Martínez-Moll ◽  
Andreu Moià-Pol
Keyword(s):  
Ray Tracing ◽  
Focal Length ◽  
Design Parameters ◽  
Solar Concentrator ◽  
Medium Temperature ◽  
Thermal Output ◽  
Optimal Values ◽  
Palma De Mallorca ◽  
Trans Asme ◽  
Optical Ray Tracing

The fixed mirror solar concentrator (FMSC) possesses a geometry that can produce thermal energy in medium temperature range. Due to its static reflector, the FMSC has several advantages when compared to other designs, such as being one of the best adapted for integration onto building roofs. An optical ray-tracing analysis of its geometry was presented in a previous paper (Pujol Nadal and Martínez Moll, 2012, “Optical Analysis of the Fixed Mirror Solar Concentrator by Forward Ray-Tracing Procedure,” Trans ASME J. Solar Energy Eng., 134(3), pp. 031009-1-14). The optical results were obtained in function of three design parameters: the number of mirrors N, the ratio of focal length and reflector width F/W, and the intercept factor γ (in order to represent different receiver widths). In this communication, the integrated thermal output of the same parameter combinations has been determined in order to find optimal values of the design parameters at a working temperature of 200 °C. The results were obtained for three different climates and two orientations (North-South and East-West). The results show that FMSC can produce heat at 200 °C with an annual thermal efficiency of 39, 44, and 48%, dependent of the location considered (Munich, Palma de Mallorca, and Cairo). The best FMSC geometries in function of the design parameters are exhibited for medium range applications.

The influence of concentrated solar energy flux on the structure and properties of stainless steel brazed joints

2019 ◽  
Vol 141 (4) ◽  
pp. 1291-1304
Author(s):  
Mihai Alexandru Luca ◽  
Mircea Horia Tierean ◽  
Teodor Machedon Pisu ◽  
Jose Rodriguez ◽  
Catalin Croitoru
Keyword(s):  
Stainless Steel ◽  
Solar Energy ◽  
Energy Flux ◽  
Structure And Properties ◽  
Concentrated Solar Energy ◽  
Brazed Joints ◽  
Solar Energy Flux
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