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.

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.

scholarly journals Analysis and Design of IoT-Enabled, Low-Cost Distributed Angle Measurement System

Proceedings ◽  
2019 ◽  
Vol 42 (1) ◽  
pp. 58
Author(s):  
Rowida Meligy ◽  
Imanol Picallo ◽  
Hicham Klaina ◽  
Peio Lopez-Iturri ◽  
José Javier Astrain ◽  
...  
Keyword(s):  
Focal Point ◽  
Tracking System ◽  
Low Cost ◽  
Angle Measurement ◽  
Sensor Technology ◽  
Small Scale ◽  
Maximum Output ◽  
The Sun ◽  
Cloud Infrastructure ◽  
Analysis And Design

A Linear Fresnel Reflector (LFR) is a recent technology with good potential in small-scale solar power applications. It is composed of many long rows of mirrors that focus the sunlight onto a fixed elevated tubular receiver. Mirror segments are aligned horizontally and track the sun such that the receiver does not need to be moved. The efficiency with which the LFR can convert solar to thermal energy depends on the accuracy of the sun tracking system. To maximize the degree of sunlight capture, precise solar tracking is needed so that incident solar rays can be adequately focused to the focal point given by the location of the tubular receiver. The tilt angles of each row are relevant for the tracking controller to achieve correct positioning. Encoders are generally employed in closed-loop tracking systems as feedback signals used to inform the controller with the actual position of collector mirrors. Recently, inclinometers have begun to replace encoders as the most viable and cost-effective sensor technology solution; they offer simpler and more precise feedback, as they measure the angle of tilt with respect to gravity and provide the ability to adjust the system to the optimal angle for maximum output. This paper presents the research results on the development of remote measurements for the precise control of an LFR tracking system, by using distributed angle measurements. The applied methodology enables precision measurement LFR inclination angles through the fusion of data from multiple accelerometers, supported by low-cost wireless transceivers in a wireless sensor network, capable of exchanging information in a cloud infrastructure.

Microcontroller Based Single Axis Intelligent Control Sun Tracker for Parabolic Trough Collectors

2012 ◽  
Vol 562-564 ◽  
pp. 1772-1775
Author(s):  
Shakeel Akram ◽  
Farhan Hameed Malik ◽  
Rui Jin Liao ◽  
Bin Liu ◽  
Tariq Nazir
Keyword(s):  
Energy Efficiency ◽  
Embedded System ◽  
Alternative Energy ◽  
Power Plants ◽  
Tracking System ◽  
Appropriate Technology ◽  
Working Fluid ◽  
The Sun ◽  
Solar Collectors ◽  
Parabolic Trough

Due to the complex design and high costs of production, solar thermal systems have fallen behind in the world of alternative energy systems. Different mechanisms are applied to increase the efficiency of the solar collectors and to reduce the cost. Solar tracking system is the most appropriate technology to increase the efficiency of solar collectors as well as solar power plants by tracking the sun timely. In order to maximize the efficiency of collectors, one needs to keep the reflecting surface of parabolic trough collectors perpendicular to the sun rays. For this purpose microcontroller based real time sun tracker is designed which is controlled by an intelligent algorithm using shadow technique. The aim of the research project is to test the solar-to-thermal energy efficiency by tracking parabolic trough collector (PTC). The energy efficiency is determined by measuring the temperature rise of working fluid as it flows through the receiver of the collector when it is properly focused. The design tracker is also simulated to check its accuracy. The main purpose to design this embedded system is to increase the efficiency and reliability of solar plants by reducing size, complexity and cost of product.

scholarly journals Optical Design of a Solar Dish Concentrator Based on Triangular Membrane Facets

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Hongcai Ma ◽  
Guang Jin ◽  
Xing Zhong ◽  
Kai Xu ◽  
Yanjie Li
Keyword(s):  
Focal Plane ◽  
Concentration Ratio ◽  
Collection Efficiency ◽  
Optical Design ◽  
Design Procedure ◽  
Diameter Ratio ◽  
Mean Square ◽  
Optical Performance ◽  
Space Antenna ◽  
Tracing Method

The design of a solar dish concentrator is proposed based on triangular membrane facets for space power applications. The facet concentrator approximates a parabolic surface supported by a deployable perimeter truss structure, which originates from a large aperture space antenna. For optimizing the number of facets rows and focal-diameter ratio of the concentrator, Monte Carlo ray-tracing method is utilized to determine optical performance of the concentrator, and the system root-mean-square (RMS) deviation is considered in this design procedure. A 600-facet concentrator with focal-diameter ratio of 1.1 will achieve 83.63% of radiative collection efficiency over a 15 cm radius disk located in the focal plane, with a mean solar concentration ratio exceeding 300. The study in this paper is helpful for the development of the membrane facet concentrator.

Effect of Solar Brightness Profiles on the Performance of Parabolic Concentrating Collectors

2009 ◽  
Author(s):  
Daniel J. Chapman ◽  
Diego A. Arias
Keyword(s):  
Analytical Methods ◽  
Meteorological Data ◽  
Uncertainty Propagation ◽  
Gaussian Function ◽  
Analytical Models ◽  
The Sun ◽  
Solar Concentrator ◽  
Optical Performance ◽  
Optical Surface ◽  
Solar Brightness

Solar brightness profiles were used to model the optical performance of a parabolic linear solar concentrator. A sensitivity analysis of the sun size on collector performance was completed using analytical methods. Ray traces were created for solar brightness profiles having circumsolar ratios from 0–40%, slope errors of the optical surface from 2–5 mrads, and angles of incidence varying from 0–60 degrees. Using typical meteorological data for two locations, the optical performance was calculated and averaged over a year. Intercept factors of these simulations were compared to simpler analytical models that cast the sun shape as a Gaussian function. Results showed that collector performance is relatively insensitive to solar profile, and that using a representative Gaussian solar profile will tend to underestimate collector performance compared to using exact weighted solar profiles by about 1%. This difference is within the uncertainty propagation of the intercept factor calculated with analytical methods.

FUNGI IN AIR MASSES OVER MONTREAL DURING 1950 AND 1951

1956 ◽  
Vol 34 (1) ◽  
pp. 1-15 ◽  
Author(s):  
S. M. Pady ◽  
L. Kapica
Keyword(s):  
Seasonal Variation ◽  
Pollen Grains ◽  
Average Concentration ◽  
Yeast Cells ◽  
The Sun ◽  
Air Masses ◽  
Air Sampler ◽  
Agricultural Areas ◽  
Very High ◽  
Made In

Numbers and kinds of fungi were determined from nutrient plate and silicone slide studies from the roof of the Sun Life Building, Montreal, between September 1950 and December 1951. Exposures of plates were made in the General Electric Bacterial Air Sampler, and plates and silicone slides in the Bourdillon Slit Sampler. A total of 978 exposures was made on 113 sampling days during 16 months; 507 plates in the G. E. Sampler, 344 plates and 127 slides in the Slit Sampler. Of 40,359 colonies examined, Cladosporium, Penicillium, yeasts, Aspergillus, Alternaria, and Actinomycetes were commonest, constituting 47.7, 15.8, 10.4, 4.6, 4.2, and 2.2% of the total. The next commonest fungi were Pullularia, Oöspora, Fusarium, Stemphylium, Verticillium, Rhizopus, Spicaria, Scopulariopsis, Phoma, Mucor, Botrytis, Cephalosporium, Trichoderma, Helmin-thosporium, Neurospora, Papularia, Cephalothecium, Pyrenochaeta, Zythia, and Nigrospora. In addition 12 genera were infrequently found. Unidentified colonies numbered 174 and nonsporulating 3371 (8.3%). On a cubic foot basis numbers in the plates varied from 17.7 per cu. ft. in August to 0.4 per cu. ft in February.Fungus spores showed a seasonal variation with summer highs averaging 244 per cu. ft. in July to a low of 0.8 per cu. ft. in December. The most abundant spores were Cladosporium, yeasts, smuts, Fusarium, Alternaria, Venturia-like, Stemphylium, rusts, Septoria, and Helminthosporium. Hyphal fragments and pollen grains were present also. On eight occasions during the summer, readings of over 200 spores per cu. ft. were recorded, the maximum being 445 per cu. ft. on September 6, 1951. Cladosporium in August reached a peak of 74.1 per cu. ft. and yeast cells in July had an average concentration of 100 per cu. ft.An analysis of the air masses indicated that pure polar air carried low numbers of fungi, whereas tropical air had very high numbers. Most of the air masses were modified polar air and their fungus content varied considerably. The fungi in the air over Montreal are believed to have had their origin in agricultural areas.

Design, Development and Performance Test of Two-Axis Solar Tracker System

2014 ◽  
Vol 704 ◽  
pp. 350-354
Author(s):  
Muhammad Ikram Mohd Rashid ◽  
Nik Fadhil bin Nik Mohammed ◽  
Suliana binti Ab Ghani ◽  
Noor Asiah Mohamad
Keyword(s):  
Tilt Angle ◽  
Solar Collector ◽  
Performance Test ◽  
Tracking System ◽  
Electrical Power ◽  
Solar Thermal ◽  
The Sun ◽  
Solar Pv ◽  
Design Development ◽  
Solar Tracking

The energy extracted from photovoltaic (PV) or solar thermal depends on solar insolation. For the extraction of maximum energy from the sun, the plane of the solar collector should always be normal to the incident radiation. Sun trackers move the solar collector to follow the sun trajectories and keep the orientation of the solar collector at an optimal tilt angle. Energy efficiency of solar PV or solar thermal can be substantially improved using solar tracking system. In this paper, an automatic solar tracking system has been designed and developed using DC motor on a mechanical structure with gear arrangement. The movements of two-axis solar trackers for the elevation and azimuth angles are programmed according to the mathematical calculation by using the Borland C++ Builder. Performance of the proposed system over the important parameter like solar radiation received on the collector, maximum hourly electrical power has been evaluated and compared with those for fixed tilt angle solar collector.

scholarly journals Intelligence Solar Power System with Mobile Power Analysis

2021 ◽  
pp. 95-101
Author(s):  
Balaji K ◽  
Dharshan T R ◽  
Mahendran P ◽  
Priyadharsini R
Keyword(s):  
Solar Cells ◽  
Power Output ◽  
Power Analysis ◽  
Tracking System ◽  
Maximum Amount ◽  
Solar Panel ◽  
The Sun ◽  
Energy Demands ◽  
Solar Tracking ◽  
Reducing Costs

The renewable energies, solar energy is the only energy gained its popularity and importance quickly. Through the solar tracking system, we can produce an abundant amount of energy which makes the solar panel’s workability much more efficient. Perpendicular proportionality of the solar panel with the sun rays is the reason lying behind its efficiency. Pecuniary, its installation charge is high provided cheaper options are also available. The main control circuit is based upon NodeMcu microcontroller. Programming of this device is done in the manner that the LDR sensor, in accordance with the detection of the sun rays, will provide direction to the DC Motor that in which way the solar panel is going to revolve. Through this, the solar panel is positioned in such a manner that the maximum amount of sun rays could be received. Though a hike in the efficiency of the solar panel had a handsome increase still perfection was a far-fetched goal for it. Below 40%, most of the panels still hover to operate. Consequently, peoples are compelled to purchase a number of panels in order to meet their energy demands or purchase single systems with large outputs. Availability of the solar cells types with higher efficiencies is on provided they are too costly to purchase. Ways to be accessed for increasing solar panel efficiencies are a plethora in number still one of the ways to be availed for accomplishing the said purpose while reducing costs, is tracking. Tracking helps in the wider projection of the panel to the Sun with increased power output. It could be dual or single axis tracker

scholarly journals Minimizing the Cosine Loss in a Solar Tower Power Plant by a Change in the Heliostat Position and Number

2020 ◽  
Vol 9 (3) ◽  
pp. 2302-2304
Keyword(s):  
Solar Radiation ◽  
Tracking System ◽  
Working Fluid ◽  
The Sun ◽  
Incident Solar Radiation ◽  
Concentrated Solar Energy ◽  
Central Receiver ◽  
Receiver System ◽  
Concentrated Solar Radiation ◽  
Solar Rays

Concentrating Solar Power (CSP) focuses sunlight in order to use the heat energy of the sun. In a central receiver system configuration, many mirrors (heliostats) individually track the sun and reflect the concentrated solar energy onto a receiver on top of a tower. The receiver contains the working fluid which is heated by the concentrated solar radiation. The useful energy that absorbed by the water flows through the receiver in solar tower plant depending on the angle between the solar rays and the position of heliostat in the region of work. Heliostat will reflect the incident solar radiation in the direction of the receiver founded in the top of the tower, in order to get a maximum incident solar radiation on the heliostat reflection area. Because of the cosine factor loss effect due to the sun position is variable along the day from sunrise to sunset, which must be in a minimum value, therefore an automated tracking system with dual axes as a control system with sensors had been built and used to stay the sunrays incident on the receiver, and enable the heliostat to flow the sun where it was

Derivation of Universal Error Parameters for Comprehensive Optical Analysis of Parabolic Troughs

1986 ◽  
Vol 108 (4) ◽  
pp. 275-281 ◽  
Author(s):  
H. M. Gu¨ven ◽  
R. B. Bannerot
Keyword(s):  
Random Error ◽  
Concentration Ratio ◽  
Numerical Technique ◽  
Geometric Parameters ◽  
Optical Analysis ◽  
Ray Trace ◽  
Mathematical Derivation ◽  
Error Parameter ◽  
Absorber Surface

A study is presented where potential optical errors in parabolic troughs are divided into two groups: random and nonrandom. It is shown that the intercept factor is a function of both random and nonrandom errors as well as geometric parameters such as concentration ratio and rim angle. Three error parameters, universal to all collector geometries, that is, “universal” error parameters which combine random and nonrandom errors with collector geometric parameters, are derived analytically. The mathematical derivation of these universal error parameters is presented. A numerical technique, a detailed ray-trace computer routine which maps rays from elemental reflector surfaces to the absorber surface, is used to validate the existence of the universal error parameters. The universal error parameters are made up of one universal random error parameter, σ* ( =σC), and two universal nonrandom error parameters, β* ( = βC) and d* (=(dr)y/D). The use of universal error parameters for comprehensive optical analysis of troughs is also presented.

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