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.

Review of Materials and Environment Management for Solar Thermal Collectors

2014 ◽  
Vol 521 ◽  
pp. 539-542
Author(s):  
Da Yu Zheng ◽  
Juan Zheng ◽  
Xiang Yi Guan ◽  
Jia Zheng ◽  
Yi Ming Zhang
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Heat Pipe ◽  
Research Work ◽  
Solar Thermal ◽  
Senior Managers ◽  
Solar Thermal Collectors ◽  
Evacuated Tubes ◽  
Evacuated Tube Collectors ◽  
Evacuated Tube

To cover the main contributions and developments in solar thermal collectors through focusing on materials, heat transfer characteristics and manufacturing challenges. A range of published papers and internet research including research work on various solar thermal collectors (flat plate, evacuated tubes, and heat pipe tube) were used. Evaluation of solar collectors performance is critiqued to aid solar technologies make the transition into a specific dominant solar collector. The sources are sorted into sections: finding an academic job, general advice, teaching, research and publishing, tenure and organizations. Provides information about types of solar thermal collectors, indicating what can be added by using evacuated tube collectors instead of flat plate collectors and what can be added by using heat pipe collectors instead of evacuated tubes. Focusing only on three types of solar thermal collectors (flat plate, evacuated tubes, and heat pipe tube). Useful source of information for consultancy and impartial advice for graduate students planning to do research in solar thermal technologies. This paper fulfils identified information about materials and heat transfer properties of materials and manufacturing challenges of these three solar thermal collectors. Describes some changes made to improve the environment which have had unforeseen and adverse effects on safety and the reasons why we need more case histories. Also discusses the reasons why there are no permanent solutions to safety problems and the reasons why senior managers should become more involved in safety problems.

scholarly journals The Comparison of Solar Energy Gaining Effectiveness between Flat Plate Collectors and Evacuated Tube Collectors with Heat Pipe: Case Study

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1829 ◽  
Author(s):  
Piotr Olczak ◽  
Dominika Matuszewska ◽  
Jadwiga Zabagło
Keyword(s):  
Solar Energy ◽  
Flat Plate ◽  
Heat Pipe ◽  
Hot Water ◽  
Energy Productivity ◽  
External Conditions ◽  
Evacuated Tube Collectors ◽  
Evacuated Tube ◽  
Family House

In Poland, various solar collector systems are used; among them, the most popular are flat plate collectors (FPCs) and evacuated tube collectors (ETCs). The work presents two installations located at a distance of 80 km apart, working in similar external conditions. One of them contains 120 flat plate collectors and works for the preparation of hot water in a swimming pool building; the second one consists of 32 evacuated tube collectors with a heat pipe and supports the preparation of domestic hot water for a multi-family house. During the comparison of the two quite large solar installations, it was confirmed that the use of evacuated tube solar collectors shows a much better solar energy productivity than flat plate collectors for the absorber area. Higher heat solar gains (by 7.9%) were also observed in the case of the gross collector area. The advantages of evacuated tube collectors are observed mainly during colder periods, which allows for a steadier thermal energy production.

Testing and Analysis of a Heat-Pipe Solar Collector

1983 ◽  
Vol 105 (4) ◽  
pp. 440-445 ◽  
Author(s):  
J. Ribot ◽  
R. D. McConnell
Keyword(s):  
Heat Pipe ◽  
Solar Collector ◽  
High Efficiency ◽  
Heat Pipes ◽  
Solar Collectors ◽  
Empirical Tests ◽  
Heat Transfer System ◽  
Evacuated Tube ◽  
Glass Heat ◽  
Theoretical Analyses

We developed an integral heat-pipe/evacuated-tube solar collector in which the inner receiver tubes form the evaporator sections of glass heat pipes. This paper describes both theoretical analyses and empirical tests, comparing the performance of the glass heat-pipe solar collector with one of today’s high efficiency evacuated-tube solar collectors. The comparison demonstrates that the performance of the two collectors is effectively identical. The testing and analysis indicate that the glass-wick-type glass heat pipe is an effective heat transfer system for evacuated-tube solar collectors.

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.

scholarly journals Comparative Analysis of Exergy and Efficiency for Stratified Thermal Storage Tank with Solar Flat Plate and Evacuated Tube Collectors

2016 ◽  
Vol 855 ◽  
pp. 114-118 ◽  
Author(s):  
Sukruedee Sukchai ◽  
Yodthong Mensin ◽  
Wikarn Wansungnern
Keyword(s):  
Flat Plate ◽  
Solar Collector ◽  
Storage Tank ◽  
Water Heating ◽  
Water Heater ◽  
Solar Water ◽  
Water Heaters ◽  
Evacuated Tube Solar Collector ◽  
Evacuated Tube Collectors ◽  
Evacuated Tube

In recent years, solar water heating technology has got the major importance in water heating applications. For the efficient and effective working of solar water heaters, storage of the hot water is the main issue in this water heating technologies. This paper mainly presents the exergy and efficiency comparison between the solar flat plate water heater and evacuated tube water heater. A five level stratified thermal storage tank is designed and developed for this analysis. At each level of the tank, temperature of the water is collected for each one hour interval from 9:00 to 16:00 hours in both cases and the overall exergy and efficiency of the two water heaters were calculated. The average efficiency of all the levels for flat plate and evacuated tube collectors are 7.91% and 8.20% respectively. The overall system efficiency is obtained as 39.54% for flat plate and 41.00% for evacuated tube solar collector. At each level exergy is calculate for both systems and the average exergy of all the levels for flat plate collector is 4.243 kW and for evacuated tube solar collector is 4.371 kW.

scholarly journals Exergy Analysis of Two Kinds of Solar-Driven Cogeneration Systems in Lhasa, Tibet, China

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Haofei Zhang ◽  
Bo Lei ◽  
Tao Yu ◽  
Zhida Zhao
Keyword(s):  
Solar Collector ◽  
Exergy Analysis ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Solar Collectors ◽  
Heating Water ◽  
Different Temperatures ◽  
Parallel Mode ◽  
Evacuated Tube Collectors ◽  
Evacuated Tube

In this study, an exergy analysis of two kinds of solar-driven cogeneration systems consisting of solar collectors and an organic Rankine cycle (ORC) is presented for series mode and parallel mode. Three kinds of solar collectors are considered: flat-plate collectors (FPC), evacuated tube collectors (ETC), and parabolic trough collectors (PTC). This study mainly compares the exergy output of the two kinds of solar cogeneration systems under different temperatures of the return heating water and different inlet temperatures of the solar collectors. This study shows that, from the perspective of Wnet or E̲n, the parallel mode is superior to the series mode. From the perspective of Ez, the parallel mode is superior to the series mode when the solar collector is FPC; however, the series mode is superior to the parallel mode when the solar collector is PTC. When the solar collector is ETC, the result depends on the temperature of the return heating water. When the temperature of the return heating water is low (below 46°C), the series mode is better, and when the temperature of the return heating water is high (above 46°C), the parallel mode is better.

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 Energy and exergy efficiency of heat pipe evacuated tube solar collectors

2016 ◽  
Vol 20 (1) ◽  
pp. 327-335 ◽  
Author(s):  
Farzad Jafarkazemi ◽  
Emad Ahmadifard ◽  
Hossein Abdi
Keyword(s):  
Heat Pipe ◽  
Solar Collector ◽  
Theoretical Method ◽  
Exergy Efficiency ◽  
Inlet Temperature ◽  
Solar Collectors ◽  
Evacuated Tube Solar Collector ◽  
Energy And Exergy ◽  
Water Mass Flow Rate ◽  
Evacuated Tube

In this paper, a heat pipe evacuated tube solar collector has been investigated both theoretically and experimentally. A detailed theoretical method for energy and exergy analysis of the collector is provided. The method is also evaluated by experiments. The results showed a good agreement between the experiment and theory. Using the theoretical model, the effect of different parameters on the collector?s energy and exergy efficiency has been investigated. It is concluded that inlet water temperature, inlet water mass flow rate, the transmittance of tubes and absorptance of the absorber surface have a direct effect on the energy and exergy efficiency of the heat pipe evacuated tube solar collector. Increasing water inlet temperature in heat pipe evacuated solar collectors leads to a decrease in heat transfer rate between the heat pipe?s condenser and water.

Sign in / Sign up

Export Citation Format

Share Document