scholarly journals Effect of Glass Thickness on Performance of Flat Plate Solar Collectors for Fruits Drying

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ramadhani Bakari ◽  
Rwaichi J. A. Minja ◽  
Karoli N. Njau
Keyword(s):  
Flat Plate ◽  
Solar Collector ◽  
Heat Losses ◽  
Solar Collectors ◽  
Glass Thickness ◽  
North Direction ◽  
Clear Glass ◽  
Collector Efficiency ◽  
Different Thickness

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.

Parametric Study of a Flat Plate Wick Assisted Heat Pipe Solar Collector

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Brahim Taoufik ◽  
Mhiri Foued ◽  
Jemni Abdelmajid
Keyword(s):  
Flat Plate ◽  
Heat Pipe ◽  
Solar Collector ◽  
Solar Collectors ◽  
Absorber Plate ◽  
Steady State Condition ◽  
Collector Efficiency ◽  
Evacuated Tube Collectors ◽  
Gap Spacing ◽  
Evacuated Tube

The use of heat pipes in solar collectors offers several advantages regarding flexibility in operation and application, as they are very efficient in transporting heat even under a small temperature difference. Compared with other systems powered by evacuated tube collectors or flat plate solar collectors using a wickless heat pipe, little attention has been paid to a flat plate solar collectors wick assisted heat pipe. In this paper an analytical model based on energy balance equations assuming a steady state condition was developed to evaluate the thermal efficiency of a flat plate wick assisted heat pipe solar collector. Parameters which affect the collector efficiency are identified, such as tube spacing distance, gap spacing between the absorber plate and the glazing cover, and the emissivity of the absorber plate. The results reflect the contribution and significance of each of these parameters to the collector overall heat loss coefficients. Three heat pipe working fluids are examined and results show that acetone performs better than methanol and ethanol.

Heat Exchanger Theory Applied to the Design of Water- and Air-Heating Flat-Plate Solar Collectors

1988 ◽  
Vol 110 (2) ◽  
pp. 132-138 ◽  
Author(s):  
Gregory J. Kowalski ◽  
Arthur R. Foster
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Flat Plate ◽  
Solar Collector ◽  
Operating Conditions ◽  
Solar Collectors ◽  
Heat Transfer Characteristics ◽  
Air Heating ◽  
Collector Efficiency ◽  
The Difference

A general method for the design of flat-plate solar collectors based on solar collector theory has been developed. It can be applied to both liquid- and air-heating solar collectors. The solar collector efficiency is determined by the product of the effectiveness (ε) and the insolation use factor (IUF). The effectiveness describes the heat transfer characteristics of the collector and is shown to be a function of a solar number of transfer units (SNTU) and a parameter ψ. For an air-heating collector, the ψ parameter equals the collector efficiency factor, while for a liquid-heating collector it must account for the difference between the plate and tube heat transfer areas. The effectiveness and SNTU parameters are similar to the effectiveness and NTU parameters used in heat exchanger design methods. The IUF is a measure of the operating conditions of the collector. It represents the difference between the transmittance-absorptance product and the ratio of the minimum heat loss to the insolation on the exterior cover. The relationship between the effectiveness and the SNTU parameter is general for all nonconcentrating collectors. One advantage of this method over the traditional Hottel-Whillier method is that it separates the heat transfer characteristics of the solar collector from its optical properties and the operating conditions.

scholarly journals Performance of Flat Plate Solar Collectors using Different Thickness of Glazing Material

2020 ◽  
Vol 8 (6) ◽  
pp. 5787-5793
Keyword(s):  
Flat Plate ◽  
Solar Collectors ◽  
Time Duration ◽  
Varying Thickness ◽  
Different Thickness

This paper throws light on the research of the outcome of breadth of glazing material such as glass on the flat plate solar saver presentation. There are 4 models of the solar saver comprised with varying thickness of glass which are investigated experimentally. The area of the collector fabricated is 0.72x0.15 meters. The thickness parameters considered in the study is low glass iron having the values of 2mm, 3mm, 4mm and 5mm. these materials are used as the glazing material in the present setup. The performance regarding the collector was evaluated and contrasted with the 5mm thickness glass. The result depicted that thickness material having 4mm value has the best results in the time duration considered in the study from morning 7:30 am to evening 6 pm. The effectiveness calibrated showed that 4mm glass gave 35.98% in comparison to the 5mm which incorporated 28.2%.

scholarly journals Aplicaciones del Captador Solar de Placa Plana y del Captador de Tubo de Vacío en la Edificación = Applications of the Flat Plate Solar Collectors and the Vacuum Tube Solar Collectors in Building

2018 ◽  
Vol 4 (3) ◽  
pp. 25 ◽  
Author(s):  
Daniel Ferrández ◽  
Carlos Moron ◽  
Jorge Pablo Díaz ◽  
Pablo Saiz
Keyword(s):  
Flat Plate ◽  
Solar Collector ◽  
Energy Demand ◽  
Hot Water ◽  
Solar Thermal ◽  
Solar Collectors ◽  
Thermal Systems ◽  
Vacuum Tube ◽  
Solar Thermal Collectors ◽  
Flat Plate Solar Collector

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.

scholarly journals Flat plate thermal solar collector efficiency: Transient behavior under working conditions part II: Model application and design contributions

2011 ◽  
Vol 31 (14-15) ◽  
pp. 2385-2393 ◽  
Author(s):  
M.C. Rodríguez-Hidalgo ◽  
P.A. Rodríguez-Aumente ◽  
A. Lecuona ◽  
G.L. Gutiérrez-Urueta ◽  
R. Ventas
Keyword(s):  
Flat Plate ◽  
Working Conditions ◽  
Solar Collector ◽  
Transient Behavior ◽  
Model Application ◽  
Collector Efficiency

Investigating the Effect of Al2O3/Water Nanofluid on the Efficiency of a Thermosyphon Flat-Plate Solar Collector

2016 ◽  
Author(s):  
Mohamed Nabeel A. Negm ◽  
Ahmed A. Abdel-Rehim ◽  
Ahmed A. A. Attia
Keyword(s):  
Flat Plate ◽  
Solar Collector ◽  
Fossil Fuels ◽  
Energy Conversion Efficiency ◽  
High Energy ◽  
Green Energy ◽  
Working Fluid ◽  
Steady Increase ◽  
Solar Collectors ◽  
Flat Plate Solar Collector

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.

scholarly journals Heat transfer in a low latitude flat-plate solar collector

2012 ◽  
Vol 16 (2) ◽  
pp. 583-591
Author(s):  
C.O.C. Oko ◽  
S.N. Nnamchi
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Solar Collector ◽  
Design Parameters ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Port Harcourt ◽  
Collector Efficiency ◽  
One Year ◽  
Flat Plate Solar Collector

Study of rate of heat transfer in a flat-plate solar collector is the main subject of this paper. Measurements of collector and working fluid temperatures were carried out for one year covering the harmattan and rainy seasons in Port Harcourt, Nigeria, which is situated at the latitude of 4.858oN and longitude of 8.372oE. Energy balance equations for heat exchanger were employed to develop a mathematical model which relates the working fluid temperature with the vital collector geometric and physical design parameters. The exit fluid temperature was used to compute the rate of heat transfer to the working fluid and the efficiency of the transfer. The optimum fluid temperatures obtained for the harmattan, rainy and yearly (or combined) seasons were: 317.4, 314.9 and 316.2 [K], respectively. The corresponding insolation utilized were: 83.23, 76.61 and 79.92 [W/m2], respectively, with the corresponding mean collector efficiency of 0.190, 0.205 and 0.197 [-], respectively. The working fluid flowrate, the collector length and the range of time that gave rise to maximum results were: 0.0093 [kg/s], 2.0 [m] and 12PM - 13.00PM, respectively. There was good agreement between the computed and the measured working fluid temperatures. The results obtained are useful for the optimal design of the solar collector and its operations.

A Fundamental Equation for Exergy Balance on Solar Collectors

1988 ◽  
Vol 110 (2) ◽  
pp. 102-106 ◽  
Author(s):  
Akio Suzuki
Keyword(s):  
Flat Plate ◽  
Balance Equation ◽  
Solar Collector ◽  
Fundamental Equation ◽  
Thermal Design ◽  
Optimum Operating ◽  
Solar Collectors ◽  
Optimum Operating Condition ◽  
Flat Plate Collector ◽  
Exergy Balance

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.

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