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.

Optical Analysis of a New Point Focus Fresnel Concentrator

2015 ◽  
Author(s):  
Hany Al-Ansary ◽  
Shaker Alaqel ◽  
Eldwin Djajadiwinata ◽  
Abdullah Mohammed
Keyword(s):  
Concentration Ratio ◽  
Focal Point ◽  
Tracking System ◽  
Average Concentration ◽  
The Sun ◽  
Optical Performance ◽  
Optical Analysis ◽  
King Saud University ◽  
Stirling Engines ◽  
Current Design

This study describes preliminary optical analysis performed regarding a new collector called the Point Focus Fresnel Concentrator (PFFC). This collector combines the concepts of the linear Fresnel collector and central receiver systems to form a new concept of a focal point Fresnel concentrator with a dual-axis sun tracking system. It concentrates direct solar radiation using a number of flat mirrors positioned over a rotating frame. The frame tracks the sun in the azimuth direction, while each row of mirrors tracks the sun in the elevation direction, thereby allowing sunlight to be concentrated on the same point above the collector throughout the day. PFFC is considered suitable for a number of applications, such as power generation by concentrating photovoltaics (CPV) and Stirling engines, and process heat applications. In this study, the first attempt to characterize the optical performance of the collector is made. A prototype of the collector has already been built on the campus of King Saud University. It has a total footprint of 9 m2, and includes 900 mirrors, each of which is 7 cm × 7 cm. The receiver has a diameter of 10 cm. Optical performance is studied by ray tracing methods to obtain flux maps and intercept factors of the receiver. Results show that the average concentration ratio is in the order of 220 to 300 suns when mirrors with a 6-mrad optical error are used. For the same mirrors, the highest attainable average intercept factor (0.674) occurs in the winter due to the low particle loading in the atmosphere. When the optical error is reduced to 2 mrad, the average concentration ratio increases to 290 to 400 suns, and the average intercept factor increases to 0.892. In any case, if the current design of PFFC is to be used in conjunction with CPV, a secondary concentrator would be needed to achieve required concentration ratios in the order of 500 suns.

scholarly journals Optimal design of the solar tracking system of parabolic trough concentrating collectors

2020 ◽  
Vol 15 (4) ◽  
pp. 613-619
Author(s):  
Li Kong ◽  
Yunpeng Zhang ◽  
Zhijian Lin ◽  
Zhongzhu Qiu ◽  
Chunying Li ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Solar Radiation ◽  
Tracking System ◽  
Low Cost ◽  
Parabolic Trough ◽  
The North ◽  
Tracking Mode ◽  
Solar Tracking ◽  
East West

Abstract The present work aimed to select the optimum solar tracking mode for parabolic trough concentrating collectors using numerical simulation. The current work involved: (1) the calculation of daily solar radiation on the Earth’s surface, (2) the comparison of annual direct solar radiation received under different tracking modes and (3) the determination of optimum tilt angle for the north-south tilt tracking mode. It was found that the order of solar radiation received in Shanghai under the available tracking modes was: dual-axis tracking > north-south Earth’s axis tracking > north-south tilt tracking (β = 15°) > north-south tilt tracking (β = 45) > north-south horizontal tracking > east-west horizontal tracking. Single-axis solar tracking modes feature simple structures and low cost. This study also found that the solar radiation received under the north-south tilt tracking mode was higher than that of the north-south Earth’s axis tracking mode in 7 out of 12 months. Therefore, the north-south tilt tracking mode was studied separately to determine the corresponding optimum tilt angles in Haikou, Lhasa, Shanghai, Beijing and Hohhot, respectively, which were shown as follows: 18.81°, 27.29°, 28.67°, 36.21° and 37.97°.

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.

Optical Analysis of Solar Concentrators Using Photogrammetry Process

2017 ◽  
pp. 175-201
Author(s):  
Safa Skouri ◽  
Salwa Bouadila
Keyword(s):  
Measurement Technique ◽  
Measurement Techniques ◽  
High Impact ◽  
Geometric Errors ◽  
Solar Concentrator ◽  
Optical Analysis ◽  
Optical Efficiency ◽  
Solar Concentrators ◽  
Displacement Error ◽  
Slope Error

As the optical efficiency of solar concentrators has a high impact on its thermal performance. However a qualification method determining the geometrical accuracy of a solar concentrator system is necessary. The purpose of this chapter is to gives an optical analysis of solar concentrator with an imaging process in order to improve the thermal efficiency of the solar concentrator. In this order measurement techniques used to determine geometric errors of the solar concentrating system have been described. Intercept factor, slope error and displacement error have been identified and analyzed. Examples of the intercept factor for concentrator reflector along with optical efficiency has been developed and determined related to the experimental results given by photogrammetry measurement technique.

Optical Performance Comparison of Six ACPCs for Concentrating Radiation on All-Glass Evacuated Solar Tubes

2015 ◽  
Vol 1092-1093 ◽  
pp. 52-58 ◽  
Author(s):  
Rui Hua Xu ◽  
Qi Chao Zhang ◽  
Run Sheng Tang
Keyword(s):  
Ray Tracing ◽  
Concentration Factor ◽  
Performance Comparison ◽  
Optical Performance ◽  
Acceptance Angle ◽  
Direct Sunlight ◽  
Optical Efficiency ◽  
The One ◽  
East West ◽  
Tracing Method

In this work, six asymmetric compound parabolic concentrators (ACPC) were designed for concentrating radiation on all-glass evacuated solar tubes (EST). The ACPCs are required to be horizontally oriented in the east-west direction and to collect direct sunlight for at least 6 hrs in any day of a year. The angular dependence of optical efficiency of six ACPCs, identical in the height of both reflectors after the higher reflector being truncated, was investigated by ray-tracing method, and the annual radiation on EST concentrated by ACPCs was estimated based on solar geometry and monthly horizontally radiation. Results shows that the ACPC designed based on “hat shaped” virtual absorber with a V-groove at the bottom of reflectors is the best in terms of the optical efficiency averaged over the acceptance angle, followed by the one designed based on “hat-shaped” absorber without a V-groove at the bottom, and the one designed based on the cover tube of EST is the worst. However, from the point of annual radiation on EST, the ACPC designed based on the cover tube is the best solution, followed by the one designed based on “ice-cream shaped” absorber and the one designed based on “hat shaped” absorber is the worst due to the smallest geometric concentration factor.

Optical Analysis of a Novel Linked Heliostat Tracking System for Distributed-Scale Concentrated Solar Power

2012 ◽  
Author(s):  
Marc Dunham ◽  
Rajan Kasetty ◽  
Anoop Mathur ◽  
Wojciech Lipiński
Keyword(s):  
Concentration Ratio ◽  
Solar Power ◽  
Tracking System ◽  
Thermal Power ◽  
Solar Irradiation ◽  
Optical Efficiency ◽  
Daily Average ◽  
Flux Concentration ◽  
Solar Noon ◽  
Simulation Parameters

In this work, a novel concentrating solar power system consisting of a small heliostat field utilizing simplified two-axis tracking is proposed for distributed-scale solar thermal power generation. Monte Carlo ray tracing is used to characterize the optical performance of the system and to parametrically evaluate its design. Radiative flux distributions are obtained in the receiver plane for solar irradiation at an example location of Albuquerque, NM, and date of June 21. The system delivers an 8-hour daily average optical efficiency of 64.4%, flux concentration ratio of 122.8 suns, and daily average thermal power of 47.3 kWt for a receiver of 0.35 m radius. The peak optical efficiency at solar noon was found to be 97.9% with a concentration ratio of 201.3 and thermal power of 77.5 kWt for the base simulation parameters.

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 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.

Distributed Industrial Scale Hybrid Solar Concentrator Photovoltaics and Thermal Energy

2010 ◽  
Author(s):  
David N. Borton
Keyword(s):  
Solar Energy ◽  
Flat Plate ◽  
Tracking System ◽  
Polar Axis ◽  
Energy System ◽  
Solar Concentrator ◽  
Large Area ◽  
Photovoltaic Panel ◽  
Physical Scale ◽  
The Individual

While solar photovoltaic (PV) panels have been used successfully to produce electricity for quite some time, it has been technically difficult to capture their heat because of the large area of a flat-plate photovoltaic panel. Likewise it has been difficult to manufacture solar concentrator systems that are of the same physical scale, about one square meter, as successful commercial flat-plate photovoltaic panels and incorporate them into a commercializable and easily manufactured solar energy system. This paper addresses the two problems by considering the feasibility of a single design of a one square meter plastic nonimaging solar concentrator that focuses sunlight on a heat-capturing, dense array of high-intensity photovoltaic chips. The individual one square meter modules are designed to be mounted on a 2-axis tracking system which could have a double polar-axis support for energy and cost efficiency. When coupled with an existing electronic control, these three components create a commercial-scale solar electricity device that also provides heat in quantities suitable for heating or cooling. Preliminary contacts with electric utilities and commercial/industrial businesses have found interest in procurement of the proposed technology for widespread harvesting and use of solar energy in the US and abroad.

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