scholarly journals Performance of two solar cooking storage pots using parabolic dish solar concentrators during solar and storage cooking periods with different heating loads

2022 ◽  
pp. 100336
Author(s):  
Ashmore Mawire ◽  
Katlego Lentswe ◽  
Prince Owusu
Keyword(s):  
Solar Concentrators ◽  
Parabolic Dish ◽  
Heating Loads ◽  
And Storage

Dynamic Behavior of a Solar Heated Receiver of a Gas Turbine Plant

1986 ◽  
Author(s):  
K. Bammert ◽  
J. Johanning
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Dynamic Behavior ◽  
Calculation Method ◽  
Sufficient Accuracy ◽  
Turbine Plant ◽  
Parabolic Dish ◽  
Gas Turbine Plant ◽  
And Storage ◽  
Storage Processes

The mainly instationary operation of a solar heated receiver can be simulated with sufficient accuracy only if data about the dynamic behavior are available. For this reason, the dynamic behavior of a solar cavity receiver with parabolic dish collector is investigated. The development of a mathematical simulation considering heat transfer and storage processes is presented and the procedure for a numerical solution is illustrated. The performance of the calculation method is finally demonstrated by simulating the passage of a cloud.

scholarly journals Matching of Local Load with On-Site PV Production in a Grid-Connected Residential Building

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2409 ◽  
Author(s):  
Arslan Bashir ◽  
Mahdi Pourakbari Kasmaei ◽  
Amir Safdarian ◽  
Matti Lehtonen
Keyword(s):  
Demand Response ◽  
Programming Model ◽  
Residential Building ◽  
Hot Water ◽  
Mixed Integer ◽  
Efficient Utilization ◽  
Space Cooling ◽  
Pv Generation ◽  
Heating Loads ◽  
And Storage

Efficient utilization of renewable generation inside microgrids remains challenging. In most existing studies, the goal is to optimize the energy cost of microgrids by working in synergy with the main grid. This work aimed at maximizing the self-consumption of on-site photovoltaic (PV) generation using an electrical storage, as well as demand response solutions, in a building that was also capable of interacting with the main grid. Ten-minute resolution data were used to capture the temporal behavior of the weather. Extensive mathematical models were employed to estimate the demand for hot-water consumption, space cooling, and heating loads. The proposed framework is cast as mixed-integer linear programming model while minimizing the interaction with the grid. To evaluate the effectiveness of the proposed framework, it was applied to a typical Finnish household. Matching indices were used to evaluate the degree of overlap between generation and demand under different PV penetrations and storage capacities. Despite negative correlation of PV generation with Finnish seasonal consumption, a significant portion of demand can be satisfied solely with on-site PV generation during the spring and summer seasons.

Sunshape and Its Influence on the Flux Distribution in Imaging Solar Concentrators

1992 ◽  
Vol 114 (4) ◽  
pp. 260-266 ◽  
Author(s):  
M. Schubnell
Keyword(s):  
Concentration Ratio ◽  
Flux Distribution ◽  
Measurement Techniques ◽  
Solar Limb ◽  
Solar Furnace ◽  
Optical Systems ◽  
Solar Concentrators ◽  
Parabolic Dish ◽  
The Mean ◽  
Mean Concentration

Imaging solar concentrators, such as a parabolic dish, image the sun to their focal plane. Thus, the flux distribution is basically an image of the angular distribution of the direct incident solar radiation. This distribution, referred to as sunshape, is determined by solar limb darkening and by small angle scattering in the atmosphere. In this paper we present measurements of the sunshape and investigate its influence on the flux distribution in the solar furnace at Paul Scherrer Institute (PSI) and in parabolic concentrators, both experimentally and by a ray tracing procedure. Analyzing the influence of the spectral dependence of the sunshape we find that the characteristic width of the focal spot increases with longer wavelengths. In contrary, the mean concentration ratio is higher at shorter wavelengths. Although these effects are rather small, they can be important in radiometric measurement techniques to determine the emissivity and the temperature distribution of an irradiated sample as well as in designing solar pumped lasers. Comparing various sunshapes with the corresponding flux distributions in the two-stage solar furnace at PSI, we show that the influence of the circumsolar radiation on the flux distribution is usually negligible as compared to the distortion due to astigmatism. However, in more accurate optical systems, such as highly concentrating parabolic dishes, the flux distribution is a fairly accurate image of the sunshape. We find, that due to sunshape, the mean concentration ratio in a parabolic dish is decreased by about ten percent. As an example we subsequently estimate the mean annual conversion efficiency of an ideal solar converter operated in the Swiss mountains.

Practical Field Alignment of Parabolic Trough Solar Concentrators

2006 ◽  
Vol 129 (2) ◽  
pp. 153-159 ◽  
Author(s):  
Richard B. Diver ◽  
Timothy A. Moss
Keyword(s):  
Test Facility ◽  
Parabolic Trough ◽  
Rotating Platform ◽  
Solar Concentrators ◽  
Photographic Images ◽  
Parabolic Dish ◽  
A New Technique ◽  
Solar Field ◽  
Practical Field ◽  
Alignment Uncertainty

In this paper a new technique for parabolic trough mirror alignment based on the use of an innovative theoretical overlay photographic (TOP) approach is described. The technique is a variation on methods used to align mirrors on parabolic dish systems. It involves overlaying theoretical images of the heat collection element (HCE) in the mirrors onto carefully surveyed photographic images and adjustment of mirror alignment until they match. From basic geometric principles, for any given viewer location the theoretical shape and location of the reflected HCE image in the aligned mirrors can be predicted. The TOP approach promises to be practical and straightforward, and inherently aligns the mirrors to the HCE. Alignment of an LS-2 mirror module on the rotating platform at the National Solar Thermal Test Facility (NSTTF) with the TOP technique along with how it might be implemented in a large solar field is described. Comparison of the TOP alignment to the distant observer approach on the NSTTF LS-2 is presented and the governing equations used to draw the theoretical overlays are developed. Alignment uncertainty associated with this technique is predicted to be less than the mirror slope error.

Dynamic Behavior of a Solar-Heated Receiver of a Gas Turbine Plant

1987 ◽  
Vol 109 (1) ◽  
pp. 71-78
Author(s):  
K. Bammert ◽  
J. Johanning
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Dynamic Behavior ◽  
Calculation Method ◽  
Sufficient Accuracy ◽  
Turbine Plant ◽  
Parabolic Dish ◽  
Gas Turbine Plant ◽  
And Storage ◽  
Storage Processes

The mainly nonstationary operation of a solar-heated receiver can be simulated with sufficient accuracy only if data about the dynamic behavior are available. For this reason, the dynamic behavior of a solar cavity receiver with parabolic dish collector is investigated. The development of a mathematical simulation considering heat transfer and storage processes is presented and the procedure for a numerical solution is illustrated. The performance of the calculation method is finally demonstrated by simulating the passage of a cloud.

Practical Field Alignment of Parabolic Trough Solar Concentrators

Solar Energy ◽  
2006 ◽  
Author(s):  
Richard B. Diver ◽  
Timothy A. Moss
Keyword(s):  
Test Facility ◽  
Parabolic Trough ◽  
Rotating Platform ◽  
Solar Concentrators ◽  
Photographic Images ◽  
Parabolic Dish ◽  
A New Technique ◽  
Solar Field ◽  
Practical Field ◽  
Alignment Uncertainty

In this paper a new technique for parabolic trough mirror alignment based on the use of an innovative Theoretical Overlay Photographic (TOP) approach is described. The technique is a variation on methods used to align mirrors on parabolic dish systems. It involves overlay of theoretical images of the Heat Collection Element (HCE) in the mirrors onto carefully surveyed photographic images and adjustment of mirror alignment until they match. From basic geometric principles, for any given viewer location the theoretical shape and location of the reflected HCE image in the aligned mirrors can be predicted. The TOP approach promises to be practical and straightforward and inherently aligns the mirrors to the HCE. Alignment of an LS-2 mirror module on the rotating platform at the National Solar Thermal Test Facility (NSTTF) with the TOP technique along with how it might be implemented in a large solar field is described. Comparison of the TOP alignment to the distant observer approach on the NSTTF LS-2 is presented and the governing equations used to draw the theoretical overlays are developed. Alignment uncertainty associated with this technique is predicted to be less than the mirror slope error.

Analysis and Design of Two Stretched-Membrane Parabolic Dish Concentrators

1991 ◽  
Vol 113 (3) ◽  
pp. 180-187 ◽  
Author(s):  
Thomas R. Mancini
Keyword(s):  
State Of The Art ◽  
Focal Length ◽  
Production Costs ◽  
Single Element ◽  
Solar Concentrator ◽  
Optical Efficiency ◽  
Solar Concentrators ◽  
Analysis And Design ◽  
Parabolic Dish ◽  
Glass Metal

The state-of-the-art of parabolic dish solar concentrators is the faceted, glass-metal dish. The mass production costs of glass-metal dishes may be high because they do not incorporate the innovations of design and materials developed over the last eight years. Therefore, Sandia National Laboratories has undertaken to develop two stretched-membrane parabolic dish concentrators for the Department of Energy’s Solar Thermal Program. These solar concentrators are being designed for integration with an advanced solar receiver and a Stirling engine/generator in a 25-kWe power production unit. The first dish, which builds on the successful design of the stretched-membrane heliostats, is to be a low risk, near-term commercial solar concentrator. This solar concentrator comprises 12 large, 3.6-m diameter, stretched-membrane facets that are formed into parabolic shapes either with a large vacuum or by performing the thin membranes plastically. The focal length-to-diameter ratios (f/Ds) for the facets are about 3.0, relatively large for a dish but much lower than heliostats where they typically range from 50 to 100. Two contractors are currently fabricating facets for this dish, and a third contractor is designing the facet support structure and pedestal for the dish. The second stretched-membrane concentrator is a single-element monolithic dish with an f/D of 0.6. The dish is shaped into a parabola by plastically yielding the membrane using a combination of uniform and nonuniform loading. Initial measurements of the dish indicate that it has a slope error of 2.6 milliradians (one standard deviation) relative to a perfect parabola. In this paper, the designs of the two stretched-membrane dishes are analyzed using the computer code CIRCE to model the optical performance of the concentrators and a thermal model, which includes conduction, convection, and radiation heat transfer, to calculate the thermal losses from the cavity solar receivers. The solar collector efficiency, defined as the product of the optical efficiency of the collector and the thermal efficiency of the receiver, is optimized for comparing the performance of several solar concentrator configurations. Ten facet arrangements for the faceted stretched-membrane dish and the single-element stretched-membrane dish are modeled and their performances compared with that of a state-of-the-art glass-metal dish. Last, the initial designs of these two stretched-membrane dishes are described along with the results of preliminary performance measurements on their respective optical elements.

scholarly journals Solar concentrators manufacture and automation

Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 93-103
Author(s):  
Ernst Kussul ◽  
Tetyana Baydyk ◽  
Alberto Escalante Estrada ◽  
Maria Teresa Rodríguez González ◽  
Donald Wunsch II
Keyword(s):  
Solar Energy ◽  
Production Systems ◽  
Low Cost ◽  
Solar Concentrators ◽  
Energy Devices ◽  
Automated Technology ◽  
Parabolic Dish ◽  
Cost Of Materials ◽  
The Cost ◽  
Energy Plants

Abstract Solar energy is one of the most promising types of renewable energy. Flat facet solar concentrators were proposed to decrease the cost of materials needed for production. They used small flat mirrors for approximation of parabolic dish surface. The first prototype of flat facet solar concentrators was made in Australia in 1982. Later various prototypes of flat facet solar concentrators were proposed. It was shown that the cost of materials for these prototypes is much lower than the material cost of conventional parabolic dish solar concentrators. To obtain the overall low cost of flat facet concentrators it is necessary to develop fully automated technology of manufacturing and assembling processes. Unfortunately, the design of known flat facet concentrators is too complex for automation process. At present we develop the automatic manufacturing and assembling system for flat facet solar concentrators. For this purpose, we propose the design of flat facet solar concentrator that is convenient for automatization. We describe this design in the paper. At present, almost all solar-energy plants in the world occupy specific areas that are not used for agricultural production. This leads to a competition between the solar-energy plants and agriculture production systems. To avoid this competition, it is possible to co-locate solar-energy devices in agricultural fields. The energy obtained via such co-location can be used for agricultural needs (e.g., water extraction for irrigation) and other purposes (e.g., sent to an electrical grid). In this study, we also describe the results of an investigation on co-location methods for the minimal loss of agricultural harvest too.

scholarly journals Concentrated Solar Power (CSP) for Sustainable Architecture to Supply Domestic Hot Water and Heating Loads of Buildings

2021 ◽  
Vol 2042 (1) ◽  
pp. 012110
Author(s):  
Hamidreza Zarrinkafsh ◽  
Nasim Eslamirad ◽  
Francesco De Luca
Keyword(s):  
Energy Production ◽  
Tracking System ◽  
Hot Water ◽  
Production Operation ◽  
Concentrated Solar Power ◽  
Parabolic Trough ◽  
Solar Concentrators ◽  
Sustainable Architecture ◽  
Urban Contexts ◽  
Heating Loads

Abstract Parabolic Trough Concentrators (PTC) are the most common solar concentrators. However, the high cost of production, operation, sun- tracking system, and the environmental sensitivity made them unprofitable for urban contexts. Lenses are more efficient and effective, but the complexity of manufacturing made them less used in sustainable architecture. This research proposes a liquid lens to be integrated into buildings’ envelope and compared with a PTC based on the energy production and reduced CO2 emissions over a year. The output energy, temperature, and efficiency of concentrator are obtained by the physics of light equations, and Ray-tracing software simulation. The results show that water lenses are at least 6% more efficient, their output temperature is higher, their underneath greenhouse effect made them less sensitive to the environment, and are still productive in high latitudes where PTCs are not operative. The paper presents the full result of the research that was registered as a patent.

An Overview of Digital Image Processing and Recognition (Invited Paper)

1982 ◽  
Vol 40 ◽  
pp. 700-702
Author(s):  
R. C. Gonzalez
Keyword(s):  
Image Processing ◽  
New York ◽  
Digital Image Processing ◽  
Digital Image ◽  
Practical Implementation ◽  
Submarine Cable ◽  
Vigorous Growth ◽  
Digitized Pictures ◽  
Processing Techniques ◽  
And Storage

Interest in digital image processing techniques dates back to the early 1920's, when digitized pictures of world news events were first transmitted by submarine cable between New York and London. Applications of digital image processing concepts, however, did not become widespread until the middle 1960's, when third-generation digital computers began to offer the speed and storage capabilities required for practical implementation of image processing algorithms. Since then, this area has experienced vigorous growth, having been a subject of interdisciplinary research in fields ranging from engineering and computer science to biology, chemistry, and medicine.

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