scholarly journals Design and Evaluation of Polygonal Trough Solar Concentrator

2021 ◽  
Vol 34 (4) ◽  
pp. 10-16
Author(s):  
Yasser Yassin Khudair ◽  
Alaa Badr Hasan
Keyword(s):  
Concentration Ratio ◽  
Angle Of Incidence ◽  
Solar Concentrator ◽  
Acceptance Angle ◽  
Optical Efficiency ◽  
Cylindrical Mirror ◽  
Design For All ◽  
Reflecting Surfaces ◽  
Reflecting Surface ◽  
To Receive

     In this paper, a solar concentrator is designed in the form of a concave half-cylindrical mirror consisting of polygonal reflective surface plates. The plates are arranged to give a hemispherical shape to the design. These surfaces work to receive solar radiation and focusing by reflecting it to the receiver that is placed in front of the reflecting surfaces. The results are compared with a system consisting of a concave reflecting surface of the same dimensions to obtain a good criterion for evaluating the design performance. The results showed a low acceptance angle for the design for all the samples used due to the geometrical design nature. The optical efficiency affected by the angle of incidence greatly by all the samples used, which differ in the concentration ratio, width and location of the receiver.

A New Troughlike Nonimaging Solar Concentrator

2001 ◽  
Vol 124 (1) ◽  
pp. 51-54 ◽  
Author(s):  
Eduardo A. Rinco´n ◽  
Fidel A. Osorio
Keyword(s):  
Concentration Ratio ◽  
Glass Tube ◽  
Two Dimensional ◽  
Solar Concentrator ◽  
Steam Generation ◽  
Acceptance Angle ◽  
Practical Applications ◽  
Optimal Shapes ◽  
Heating Steam ◽  
East West

A new two-dimensional concentrator for solar energy collection has been developed. The concentrator has the following advantages, when compared with the classic Compound Parabolic Concentrators invented by Roland Winston, W. T. Welford, A. Rabl, Baranov, and other researchers: 1) It allows the use of parabolic mirrors, which have a reflecting area much smaller for a given concentration ratio and acceptance angle. 2) Between the mirror and the absorber, there is a large gap so that conduction losses are reduced. Convection losses can be reduced, too, if the absorber is enclosed within a glass tube. 3) It can be easily manufactured. Instead of seeking the shape of the mirrors for a given shape of the absorber, we have made the inverse statement of the problem, and we have obtained the optimal shapes of the absorbers with a prescribed acceptance angle, for parabolic mirrors, assuming that the intercept factor is unity, the mirrors are perfect, and the absorber surfaces are convex. The concentrator should be east-west oriented, and could be seasonal or monthly tilt adjusted. This concentrator could have many practical applications, such as fluid heating, steam generation, etc.

scholarly journals Design and Fabrication of Absorptive/Reflective Crossed CPC PV/T System

Designs ◽  
2018 ◽  
Vol 2 (3) ◽  
pp. 29
Author(s):  
Muhsin Aykapadathu ◽  
Mehdi Nazarinia ◽  
Nazmi Sellami
Keyword(s):  
Numerical Control ◽  
Solar Concentrator ◽  
Cnc Milling ◽  
Acceptance Angle ◽  
Optical Efficiency ◽  
Compound Parabolic Concentrator ◽  
Building Integrated Photovoltaic ◽  
New Generation ◽  
Experimental Rig ◽  
T System

A crossed compound parabolic concentrator (CCPC) is a non-imaging concentrator which is a modified form of a circular 3D compound parabolic concentrator (CPC) obtained by orthogonal intersection of two 2D CPCs that have an optical efficiency in line with that of 3D CPC. The present work is about the design and fabrication of a new generation of solar concentrator: the hybrid photovoltaic (PV)/thermal absorptive/reflective CCPC module. The module has a 4× CCPC structure truncated to have a concentration of 3.6× with a half acceptance angle of 30°. Furthermore, an experimental rig was also fabricated to test the performance of the module and its feasibility in real applications such as building-integrated photovoltaic (BIPV). 3D printing and Computer Numerical Control (CNC) milling technologies were utilized to manufacture the absorber and reflective parts of the module.

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.

Optical Analysis of a Heliostat Array With Linked Tracking

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
M. T. Dunham ◽  
R. Kasetty ◽  
A. Mathur ◽  
W. Lipiński
Keyword(s):  
Concentration Ratio ◽  
Tracking System ◽  
Average Concentration ◽  
Solar Concentrator ◽  
Optical Performance ◽  
Optical Analysis ◽  
Optical Efficiency ◽  
The North ◽  
The Individual ◽  
East West

The optical performance of a novel solar concentrator consisting of a 400 spherical heliostat array and a linked two-axis tracking system is analyzed using the Monte Carlo ray-tracing technique. The optical efficiency and concentration ratio are compared for four different heliostat linkage configurations, including linkages of 1 × 1, 1 × 2, 2 × 2, 4 × 4, and 5 × 5 heliostats for 7-hour operation and the selected months of June and December. The optical performance of the concentrator decreases with the increasing number of heliostats in the individual groups due to increasing optical inaccuracies. In June, the best-performing linked configuration, in which 1 heliostat in the east-west direction and 2 heliostats in the north-south direction are linked, provides a monthly-averaged 7-hour optical efficiency and average concentration ratio of 79% and 511 suns, respectively. In December, the optical efficiency and the average concentration ratio decreases to 61% and 315 suns, respectively.

A Novel Lens-Walled Compound Parabolic Concentrator for Photovoltaic Applications

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Yuehong Su ◽  
Gang Pei ◽  
Saffa B. Riffat ◽  
Hulin Huang
Keyword(s):  
Concentration Ratio ◽  
Incidence Angle ◽  
Small Degree ◽  
Photovoltaic System ◽  
Acceptance Angle ◽  
Optical Efficiency ◽  
Concentrate Solar Radiation ◽  
Compound Parabolic Concentrator ◽  
Photovoltaic Applications ◽  
The Common

A compound parabolic concentrator (CPC) is a nonimaging concentrator that can concentrate solar radiation coming within its acceptance angle. A low concentration CPC photovoltaic system has the advantages of reduced Photovoltaics (PVs) cell size, increased efficiency and stationary operation. The acceptance angle of a CPC is associated with its geometrical concentration ratio, by which the size of PV cell could be reduced. Truncation is a way to increase the actual acceptance angle of a mirror CPC, but it also reduces the geometrical concentration ratio. On the other hand, a solid dielectric CPC can have a much larger acceptance angle, but it has a larger weight. To overcome these drawbacks, this study presents a novel lens-walled CPC that has a thin lens attached to the inside of a common mirror CPC or has the lens to be mirror coated on its outside surface. The shape of the lens is formed by rotating the parabolic curves of a CPC by a small degree internally around the top end points of the curves. The refraction of the lens allows the lens-walled CPC to concentrate light from wider incidence angle. The commercial optical analysis software PHOTOPIA is used to verify the principle of the presented lens-walled CPC and examine its optical performance against the common CPCs. As an example, the simulation is aimed to evaluate whether a lens-walled CPC with a geometrical concentration ratio of 4 has any advantage over a common CPC with a geometrical concentration ratio of 2.5 in terms of actual acceptance angle, optical efficiency and optical concentration ratio.

scholarly journals Experimental investigation of solar compound parabolic collector using Al2O3/H2O nanofluid in a subtropical climate

2020 ◽  
pp. 201-201
Author(s):  
Faria Akhtar ◽  
Muzaffar Ali ◽  
Nadeem Sheikh ◽  
Muhammad Shehryar
Keyword(s):  
Base Fluid ◽  
Concentration Ratio ◽  
Heat Transfer Fluid ◽  
Subtropical Climate ◽  
Solar Concentrator ◽  
Acceptance Angle ◽  
Flow Rates ◽  
Climate Conditions ◽  
Medium Range ◽  
Parabolic Collector

Different solar concentrator technologies are used for low-medium range temperature applications. In this paper, a non-tracking compound parabolic collector with a nanofluid is experimentally analyzed under real climate conditions of a typical sub-tropical climate Taxila, Pakistan. The collector used for the experimentation has concentration ratio of 4.17, collector area of 0.828 m2 and half acceptance angle of 24?. The heat transfer fluid used for the study is water based nanofluid with particles of Al2O3. The investigation is carried out at three different volumetric concentrations (0.025%, 0.05%,0.075%) of nanofluids at flowrates of 0.01 kg/s, 0.02 kg/s, 0.05 kg/s and 0.07 kg/s are compared with base fluid (water). Comparison of system thermal efficiency, solar heat gain, and temperature difference is presented for different selected days in real climate conditions during months of March to May. It is observed that performance of the compound parabolic collector is improved by 8%, 11%, 14% and 19%, respectively at considered flow rates compared to water.

Optimization of Parabolic Heliostat Focal Lengths in a Mini-Tower Solar Concentrator System

2011 ◽  
Author(s):  
Karim Hamza ◽  
Umesh Gandhi ◽  
Kazuhiro Saitou
Keyword(s):  
High Temperature ◽  
Concentration Ratio ◽  
Focal Length ◽  
Low Cost ◽  
Small Scale ◽  
Angle Of Incidence ◽  
Solar Concentrator ◽  
Effective Focal Length ◽  
Unit Energy ◽  
Utility Scale

Solar tower with heliostat mirrors is one of the established setups for utility-scale solar energy harvesting. Advantages of the setup include the capability to reach high temperature, modularity and ease of maintenance for the heliostats, containment of the high temperature zone atop the tower, as well as overall low cost per unit energy. However, downscaling to medium or small scale applications often does not turn out economically feasible with flat mirror heliostats that are the norm in utility-scale systems. This is mainly due to the need to preserve the solar concentration ratio, which in turn means the number of flat mirrors cannot be reduced. Use of parabolic mirrors instead can significantly reduce the required number of mirrors for smaller scale systems, but comes with new challenges. Unlike flat mirrors that have infinite effective focal length, the effective focal length of parabolic mirrors changes with the angle of incidence, which in turn, changes throughout the day and season. The design challenge tackled in this paper is that of optimal selection of the focal lengths of the heliostats in order to maximize the yearly harvested energy while maintaining the concentration ratio within desirable limits. A parameterized system model is developed and a genetic algorithm is implemented for the optimization task. The model is then applied to a demonstration case study of a 10 kW solar concentrator. Results of the study demonstrate the proposed design approach as well as show the promise for effective downscaling of tower and heliostat systems.

scholarly journals Optimal Design of a Secondary Optical Element for a Noncoplanar Two-Reflector Solar Concentrator

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Yi-Cheng Chen ◽  
Chia-Chi You
Keyword(s):  
Design Process ◽  
Parametric Design ◽  
Optical Element ◽  
Solar Concentrator ◽  
Optical Performance ◽  
Parabolic Mirror ◽  
Acceptance Angle ◽  
Optical Efficiency ◽  
Two Phases ◽  
Ray Tracing Simulation

This paper presents the results of a parametric design process used to achieve an optimal secondary optical element (SOE) in a noncoplanar solar concentrator composed of two reflectors. The noncoplanar solar concentrator comprises a primary parabolic mirror (M1) and a secondary hyperbolic mirror (M2). The optical performance (i.e., acceptance angle, optical efficiency, and irradiance distribution) of concentrators with various SOEs was compared using ray-tracing simulation. The parametric design process for the SOE was divided into two phases, and an optimal SOE was obtained. The sensitivity to assembly errors of the solar concentrator when using the optimal SOE was studied and the findings are discussed.

An Outdoor Experiment of a Lens-Walled Compound Parabolic Concentrator Photovoltaic Module on a Sunny Day in Nottingham

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Guiqiang Li ◽  
Yuehong Su ◽  
Gang Pei ◽  
Hang Zhou ◽  
Xu Yu ◽  
...  
Keyword(s):  
Concentration Ratio ◽  
Good Choice ◽  
Experimental Results ◽  
Photovoltaic Module ◽  
Solar Concentrator ◽  
Acceptance Angle ◽  
Compound Parabolic Concentrator ◽  
Pv Module ◽  
Outdoor Experiment ◽  
East West

A lens-walled compound parabolic concentrator (lens-walled CPC) has a larger half acceptance angle than a mirror CPC for the same geometrical concentration ratio of 2.5X, so it would be more suitable for the building-integrated application as a stationary solar concentrator. Based on our previous work, an outdoor experimental study of a sample trough lens-walled CPC PV module under sunny condition in Nottingham is described. The experimental results provide the verification of actual larger half acceptance angle obtained by the lens-walled CPC in comparison with a mirror CPC of the same size. Along with the analysis of the projected incidence angles, the experimental results also indicate that the lens-walled CPC of 2.5X orientated east–west may be a good choice for high latitude area as a stationary solar concentrator to give a satisfactory whole year performance.

scholarly journals High Concentration Photovoltaics (HCPV) with Diffractive Secondary Optical Elements

Photonics ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 68 ◽  
Author(s):  
Furkan Sahin ◽  
Musa Yılmaz
Keyword(s):  
Low Cost ◽  
Optical Design ◽  
Chromatic Aberration ◽  
High Energy ◽  
Solar Concentrator ◽  
High Concentration ◽  
Acceptance Angle ◽  
Optical Elements ◽  
Optical Efficiency ◽  
Single Material

Multi-junction solar cells can be economically viable for terrestrial applications when operated under concentrated illuminations. The optimal design of concentrator optics in high concentration photovoltaics (HCPV) systems is crucial for achieving high energy conversion. At a high geometric concentration, chromatic aberration of the primary lens can restrict the optical efficiency and acceptance angle. In order to correct chromatic aberration, multi-material, multi-element refractive elements, hybrid refractive/diffractive elements, or multi-element refractive and diffractive systems can be designed. In this paper, the effect of introducing a diffractive surface in the optical path is analyzed. An example two-stage refractive and diffractive optical system is shown to have an optical efficiency of up to 0.87, and an acceptance angle of up to ±0.55° with a 1600× geometric concentration ratio, which is a significant improvement compared to a single-stage concentrator system with a single material. This optical design can be mass-produced with conventional fabrication methods, thus providing a low-cost alternative to other approaches, and the design approach can be generalized to many other solar concentrator systems with different cell sizes and geometric concentration ratios.

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