The NBS Solar Collector Reliability/Durability Test Program: Summary of Results and Recommendations for Collector Testing

1986 ◽  
Vol 108 (1) ◽  
pp. 35-40 ◽  
Author(s):  
D. Waksman ◽  
W. C. Thomas

Efforts in the development of reliability/durability tests for solar collectors and their materials have been hampered by the lack of real time and accelerated degradation data that can be correlated with in-use conditions. In 1977, the Solar Collector Reliability/Durability Test Program was initiated by the US Department of Energy at the National Bureau of Standards (NBS) to help generate the data required to develop methods for predicting the long term durability and reliability of flat-plate solar collectors and their materials. This paper summarizes the results obtained in the test program for full-size solar collectors. Recommendations are made regarding the use and limitations of thermal performance measurements and environmental exposure tests for assessing the durability of flat-plate solar collectors.

2018 ◽  
Vol 4 (3) ◽  
pp. 25 ◽  
Author(s):  
Daniel Ferrández ◽  
Carlos Moron ◽  
Jorge Pablo Díaz ◽  
Pablo Saiz

ResumenEl actual Código Técnico de la Edificación (CTE) pone de manifiesto la necesidad de cubrir parte de la demanda energética requerida para el abastecimiento de agua caliente sanitaria y climatización de piscinas cubiertas mediante sistemas de aprovechamiento de la energía solar térmica. En este artículo se presenta una comparativa entre las dos principales tipologías de captadores solares térmicos que existen en el mercado: el captador de placa plana y el captador de tubo de vacío, atendiendo a criterios de fracción solar, diseño e integración arquitectónica. Todo ello a fin de discernir en qué circunstancias es más favorable el uso de uno u otro sistema, comparando los resultados obtenidos mediante programas de simulación con la toma de medidas in situ.AbstractThe current Technical Building Code (CTE) highlights the need to cover part of the energy demand required for the supply of hot water and heating of indoor swimming pools using solar thermal systems. This article presents a comparison between the two main types of solar thermal collectors that exist in the market: the flat plate solar collector and the vacuum tube solar collector, according to criteria of solar fraction, design and architectural integration. All of this in order to discern in what circumstances the use of one or the other system is more favourable, comparing the results obtained through simulation programs with the taking of measurements in situ.


Author(s):  
Mohamed Nabeel A. Negm ◽  
Ahmed A. Abdel-Rehim ◽  
Ahmed A. A. Attia

The world is still dependent on fossil fuels as a continuous and stable energy source, but rising concerns for depletion of these fuels and the steady increase in demand for clean “green” energy have led to the rapid growth of the renewable energy field. As one of the most available energy sources with high energy conversion efficiency, solar energy is the most prominent of these energies as it also has the least effect on the environment. Flat plate collectors are the most common solar collectors, while their efficiency is limited by their absorber’s effectiveness in energy absorption and the transfer of this energy to the working fluid. The efficiency of flat plate solar collectors can be increased by using nanofluids as the working fluid. Nanofluids are a relatively recent development which can greatly enhance the thermophysical properties of working fluids. In the present study, the effect of using Al2O3/Water nanofluid as the working fluid on the efficiency of a thermosyphon flat-plate solar collector was experimentally investigated. The results of this experiment show an increase in efficiency when using nanofluids as the working fluid compared to distilled water. It was found that Al2O3/water nanofluids are a viable enhancement for the efficiency of flat-plate solar collectors.


1988 ◽  
Vol 110 (2) ◽  
pp. 102-106 ◽  
Author(s):  
Akio Suzuki

This paper presents the exergy balance equation on a solar collector which acts as the fundamental and principal expression for the solar thermal design. The equation fully explains the exergy loss processes and can be used to derive the approximate optimum operating condition for solar collectors. Furthermore, using the equation, it can be shown that two different collectors, an evacuated tubular collector and a flat-plate collector, have both nearly equal capabilities in exergy gain despite large differences in technological efforts and expenses to produce them. In addition, ways for improvement for a solar collector are also discussed here briefly.


2021 ◽  
pp. 173-173
Author(s):  
Yedilkhan Amirgaliyev ◽  
Murat Kunelbayev ◽  
Talgat Ormanov ◽  
Talgat Sundetov ◽  
Salauat Daulbayev

The given article considers results of experimental measurements, productivity comparison and master controller executive system of flat-plate solar collector with thermosiphon circulation and flat solar collector with special chemical coating. There has been developed master controllers control module, which receives data from temperature and lighting sensors, obtained in operation process. The aim of the research is getting the solar collectors? optimal parameters, representing maximal usage performance index, controllability, as well as, construction type, allowing energy saving. In the recent years flat-plate solar collectors with chemical coating are characterized with higher efficiency in real conditions usage. The developed master controllers? executive system is used for monitoring the installation?s main parameters, as well, it permits to compare characteristics of solar collector with thermosiphon circulation to those of flat-plate solar collector with chemical coating. The obtained experimental data has shown, that flat solar collectors, using chemical coating as a transfer medium in solar heat supply system, have an advantage in the context of usage effectiveness. The heat output and water heating in a flat solar collector are calculated, which vary depending on the intensity of solar radiation. The thermal efficiency of a flat solar collector with a thermosiphon tank based on the Mojo V3 platform using Dallas sensors is calculated.


1981 ◽  
Vol 103 (2) ◽  
pp. 126-134 ◽  
Author(s):  
E. R. Streed ◽  
D. Waksman

Thermal performance measurements of eight types of liquid-heating flat-plate solar collectors were conducted with two to four collectors of each type at four outdoor test sites. Tests were performed in accordance with the procedure prescribed by ASHRAE Standard 93-77. Statistical analysis of data sets for each collector type within test sites and between test sites was done using ASTM recommended methods to evaluate test method measurement uncertainty.


2015 ◽  
Author(s):  
Singiresu S. Rao

The optimum design of stationary flat-plate solar collectors is considered using the game theory approach for multiple objectives. The clear day solar beam radiation and diffuse radiation at the location of the solar collector are estimated. Three objectives are considered in the optimization problem formulation: maximization of the annual average incident solar energy, maximization of the lowest month incident solar energy and minimization of the cost. The game theory solution represents the best compromise in terms of the supercriterion selected. Because some design parameters such as solar constant, altitude, typical day of each month and most of the design variables are not precisely known, a probabilistic approach is also proposed in this work. The results obtained by the determinist and probabilistic approaches are compared. It is found that the absolute value of each objective function decreases with an increase in either the probability of constraint satisfaction or the coefficient of variation of the random variables. This work represents the first work aimed at the application of multi-objective optimization strategy, particularly the game theory approach, for the solution of the solar collector design problem.


2016 ◽  
Vol 831 ◽  
pp. 181-187 ◽  
Author(s):  
Janusz T. Cieśliński ◽  
Bartosz Dawidowicz ◽  
Aleksandra Popakul

Solar collectors is one of the technologies absorbing energy from solar beam and utilizing it for heating purposes, displacing the need to burn fossil fuels. There are many ways to improve effectiveness of the solar collectors [1,2]. Recent method to absorb more heat from the solar beam is to modify thermal characteristics of the working fluid. For this purpose one can use nanofluids, i.e. suspensions of metallic or nonmetallic nanoparticles in a base fluid [3].


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ramadhani Bakari ◽  
Rwaichi J. A. Minja ◽  
Karoli N. Njau

This study aimed at investigating the effect of thickness of glazing material on the performance of flat plate solar collectors. Performance of solar collector is affected by glaze transmittance, absorptance, and reflectance which results into major heat losses in the system. Four solar collector models with different glass thicknesses were designed, constructed, and experimentally tested for their performances. Collectors were both oriented to northsouth direction and tilted to an angle of 10° with the ground toward north direction. The area of each collector model was 0.72 m2with a depth of 0.15 m. Low iron (extra clear) glass of thicknesses 3 mm, 4 mm, 5 mm, and 6 mm was used as glazing materials. As a control, all collector performances were analysed and compared using a glass of 5 mm thickness and then with glass of different thickness. The results showed that change in glass thickness results into variation in collector efficiency. Collector with 4 mm glass thick gave the best efficiency of 35.4% compared to 27.8% for 6 mm glass thick. However, the use of glass of 4 mm thick needs precautions in handling and during placement to the collector to avoid extra costs due to breakage.


2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Saif Ali Kadhim ◽  
Osama Abd AL-Munaf Ibrahim

Solar energy is one of the most important types of renewable energy and is characterized by its availability, especially in Iraq. It can be used in many applications, including supply thermal energy by solar collectors. Improving the thermal efficiency of solar collector leads to an increase in the thermal energy supplied. Using a nano-fluid instead of base fluid (water is often used) as a working fluid is a method many used to increase the thermal efficiency of solar collectors. In this article, the latest research that used nano-fluid as a working fluid in evaluating the thermal efficiency of solar collector, type flat plate was reviewed. The thermal efficiency improvement of flat plate solar collector was reviewed based on the type of nanoparticles (metal oxides, semiconductors oxides, carbon compounds) used in the base fluid and comparison was made between these nanoparticles under the same conditions. Moreover, the effect of varying the concentration of nanoparticles in the base fluid and changing the working fluid flow rate on the thermal efficiency of flat plate solar collector was also reviewed. The results of the review showed that nano-fluids containing carbon compounds are better than other nano-fluids and that copper oxide is better than the rest of the metal oxides used in improving the thermal efficiency of flat plate solar collectors.


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