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1 – 10 of 191Fahim Ullah, Min Kang, Lubna Hassan, Ninghui Li, Jun Yang, Xingsheng Wang and Mansoor Khan Khattak
The purpose of the study was to develop a performance flat-plate solar collector that would be used as a solar drier for fruit fig (Ficus carica L). This study proposes how and…
Abstract
Purpose
The purpose of the study was to develop a performance flat-plate solar collector that would be used as a solar drier for fruit fig (Ficus carica L). This study proposes how and why solar energy is important for drying the agricultural products. This study aims to expand the domain of solar collector for different purposes and, most important, for agricultural resource normally found in the literature.
Design/methodology/approach
The paper opted for an exploratory study using the flat-plate solar collector with drying chamber for drying purposes of agricultural products. During the experiment, the data were collected with moisture content, drying rate of the product and solar irradiation falls on the collector.
Findings
This paper describes that how flat-plate collector works for agricultural products and how to reduce the moisture content in the product (fig). Efficiency of collector was evaluated under the ambient temperatures of 24°C. Efficiency also significantly increased from 53 to 55 per cent with an increase in ambient temperature from 22 to 24 °C. Figs (Ficus carica L) were dried in the drying chamber of the flat-plate solar collector. The products were dried at temperature of 55-65°C and 15 to 20 per cent humidity.
Research limitations/implications
Because of this research chosen, the research results are beneficiary for agricultural users for drying purposes. Therefore, the researchers are encouraged to dry the agricultural product with flat-plate solar collector, because it reduced the moisture content of the product very fast.
Originality/value
This paper fulfills an identified need to study that how flat-plat solar collector can be used.
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M.A. Alghoul, M.Y. Sulaiman, B.Z. Azmi and M.Abd. Wahab
To cover the main contributions and developments in solar thermal collectors through focusing on materials, heat transfer characteristics and manufacturing challenges.
Abstract
Purpose
To cover the main contributions and developments in solar thermal collectors through focusing on materials, heat transfer characteristics and manufacturing challenges.
Design/methodology/approach
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.
Findings
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.
Research limitations/implications
Focusing only on three types of solar thermal collectors (flat plate, evacuated tubes, and heat pipe tube).
Practical implications
Useful source of information for consultancy and impartial advice for graduate students planning to do research in solar thermal technologies.
Originality/value
This paper fulfils identified information about materials and heat transfer properties of materials and manufacturing challenges of these three solar thermal collectors.
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N. H. Waziri, A.M. Usman and J. S. Enaburekhan
– The purpose of this paper is to determine the optimum temperature and solar radiation periods from November 2008 to April 2009.
Abstract
Purpose
The purpose of this paper is to determine the optimum temperature and solar radiation periods from November 2008 to April 2009.
Design/methodology/approach
Four flat plate collectors were constructed and inclined at an angle ß = 0o, Φ°, (Φ + 15)o and (Φ − 15)° tilt angles where Φ is the latitude of the location (12.1o). The tests were conducted for a period of six months spanning from November 2008 to April 2009. Readings were taken for solar radiation, absorber surface temperature and ambient temperature from 10 a.m. to 3 p.m. on an hourly basis. The amount of solar energy in W/m2 for Kano metropolis, which lies on latitude 12.1°, was determined experimentally.
Findings
It was observed that the maximum temperature was 100°C, and it falls in April at the 12.1° tilt angle followed by 99.9°C and 99.8°C at –2.9° and 0°, respectively, within same month. April is the optimum period having the highest temperature. The maximum solar radiation for the six months recorded was 1070.4 W/m2 and fell on 4th and 8th of February at the 27.1° tilt angle and the highest mean monthly solar radiation was 953.7593W/m2 in November at the 27.1° tilt angle followed by 895.7321 and 888.6286W/m2 in February at the 27.1° and 12.1° tilt angle, respectively.
Research limitations/implications
The research is limited to six-month periods and Kano metropolis.
Originality/value
The research was carried out in the Department of Mechanical Engineering Bayero University Kano, Nigeria.
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Ranga Babu J.A., Kiran Kumar K. and Srinivasa Rao S.
This paper aims to present an analytical investigation of energy and exergy performance on a solar flat plate collector (SFPC) with Cu-CuO/water hybrid nanofluid, Cu/water and…
Abstract
Purpose
This paper aims to present an analytical investigation of energy and exergy performance on a solar flat plate collector (SFPC) with Cu-CuO/water hybrid nanofluid, Cu/water and CuO/water nanofluids as collector running fluids.
Design/methodology/approach
Heat transfer characteristics, pressure drop and energy and exergy efficiencies of SFPC working on these nanofluids are investigated and compared. In this study, a comparison is made by varying the mass flow rates and nanoparticle volume concentration. Thermophysical properties of hybrid nanofluids are estimated using distinctive correlations available in the open literature. Then, the influence of these properties on energy and exergy efficiencies of SFPC is discussed in detail.
Findings
Energy analysis reveals that by introducing the hybrid nanoparticles in water, the thermal conductivity of the working fluid is enhanced by 17.52 per cent and that of the individual constituents is enhanced by 15.72 and 15.35 per cent for Cu/water and CuO/water nanofluids, respectively. This resulted in 2.16 per cent improvement in useful heat gain for hybrid nanofluid and 1.03 and 0.91 per cent improvement in heat gain for Cu/water and CuO/water nanofluids, respectively. In line with the above, the collector efficiency increased by 2.175 per cent for the hybrid nanofluid and 0.93 and 1.05 per cent enhancement for Cu/water and CuO/water nanofluids, respectively. Exergy analysis elucidates that by using the hybrid nanofluid, exergy efficiency is increased by 2.59 per cent, whereas it is 2.32 and 2.18 per cent enhancement for Cu/water and CuO/water nanofluids, respectively. Entropy generation is reduced by 3.31, 2.35 and 2.96 per cent for Cu-CuO/water, Cu/water and CuO/water nanofluids, respectively, as compared to water.
Research limitations/implications
However, this is associated with a penalty of increment in pressure drop of 2.92, 3.09 and 2.74 per cent for Cu-CuO/water, Cu/water and CuO/water nanofluids, respectively, compared with water.
Originality/value
It is clear from the analysis that Cu-CuO/water hybrid nanofluids possess notable increment in both energy and exergy efficiencies to use them in SFPCs.
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In this study, the effects of using corrugated absorber plate (instead of flat plate) and also using aerosol/carbon-black nanofluid (instead of air) on heat transfer and turbulent…
Abstract
Purpose
In this study, the effects of using corrugated absorber plate (instead of flat plate) and also using aerosol/carbon-black nanofluid (instead of air) on heat transfer and turbulent flow characteristics in solar collectors were numerically investigated.
Design/methodology/approach
The 3D continuity, momentum and energy equation were solved by finite volume and SIMPLE algorithm. As a result, the corrugated absorber plate was inspected in the case of triangle, rectangle and sinuous with the wave length of 1 mm and wave amplitude of 3 mm in turbulent flow regime and Reynolds number between 2,500 and 4,000. Choosing the proper geometry was carried out based on the best performance evaluation criteria (PEC) and increasing the air temperature from collector inlet to outlet.
Findings
The results revealed that for all times of the year the highest PEC was obtained for corrugated Sinusoidal model; however, the highest temperature increase from inlet to outlet was obtained for rectangular corrugated model. In addition, the results indicated that in sinusoidal model, the nanoparticles volume fractions increase leads to heat performance coefficient increase and the best heat performance conditions were attained in volume fraction of 0.1 per cent and Reynolds number of 4,000 for both six months period. In model with rectangular corrugated plate, usage of nanofluid in all range of Reynolds numbers leads to reduction of outlet temperature.
Originality/value
The effect of some nanoparticles on heat transfer using thermal– hydraulic performances in heat exchangers has been assessed, but the effects of atmospheric aerosol-based nanofluid using carbon-black nanoparticles (CBNPs) on the heat transfer in corrugated heat sink solar collectors by 3D numerical modeling has not been yet investigated. In present study, usage of CBNPs with different volume fractions in range of 0 to 0.1 per cent in turbulent regime of fluid flow is analyzed. Furthermore, in this paper, besides the effects of using CBNPs, a solar absorber located in Shiraz, as one of the best solar irradiation receiver cities in Iran is evaluated.
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Mohamed Louajari, Ahmed Ouammi and Abdelaziz Mimet
The purpose of this paper is to demonstrate the possibility of the use of a solar adsorption refrigeration machine, using the pair activated carbon/ammonia within the framework of…
Abstract
Purpose
The purpose of this paper is to demonstrate the possibility of the use of a solar adsorption refrigeration machine, using the pair activated carbon/ammonia within the framework of sustainability and development of rural areas.
Design/methodology/approach
The limited availability of electrical grid in rural areas of Morocco makes necessary the adoption of new methods in order to provide the needs of energy services, which represent an important factor affecting the quality of life. The studies that were undertaken in this current paper investigated the sensitivity of the COP as well as the production of the cold at various refrigeration machine temperatures.
Findings
It can be recognized that the feasibility of the machine with significant production of cold in the form of ice is between 3.33 and 4.14 kg/m2 for a solar flat plate collector; and between 7.16 and 9.94 kg/m2 for solar flat plate.
Originality/value
The paper presents a model of decision‐making support for selecting the optimal conditions for the use of a solar adsorption refrigeration machine. The model optimises the quantity of cold produced and the coefficient of performance (COP) of the machine and investigates the sensitivity of the COP to the characteristic temperatures of the cycle of the machine.
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Akbar Alidadi Shamsabadi, Mehdi Jahangiri, Tayebeh Rezaei, Rouhollah Yadollahi Farsani, Ali Seryani and Siavash Hakim
In this study, a solar water heating system along with a seasonal thermal energy storage and a heat pump is designed for a villa with an area of 192 m2 in Tehran, the capital of…
Abstract
Purpose
In this study, a solar water heating system along with a seasonal thermal energy storage and a heat pump is designed for a villa with an area of 192 m2 in Tehran, the capital of Iran.
Design/methodology/approach
According to the material and the area of the residential space, the required heating of the building was calculated manually and then the thermodynamic analysis of the system and simulation was done in MATLAB software. Finally, regarding the waste of system, an efficient solar heating system, providing all the required energy to heat the building, was obtained.
Findings
The surface area of the solar collector is equal to 46 m2, the capacity of the tank is about 2,850 m3, insulation thickness stands at 55 cm and the coefficient of performance in required heat pump is accounted to about 9.02. Also, according to the assessments, the maximum level of received energy by the collector in this system occurs at a maximum temperature of 68ºC.
Originality/value
To the best of the authors’ knowledge, in the present work, for the first time, using mathematical modeling and analyzing of the first and second laws of thermodynamics, as well as using of computational code in MATLAB software environment, the solar-assisted ground source heat pump system is simulated in a residential unit located in Tehran.
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Uroš Stritih, Halime Paksoy, Bekir Turgut, Eneja Osterman, Hunay Evliya and Vincenc Butala
Bilateral project with Slovenia and Turkey with the title thermal energy storage for efficient utilization of solar energy was the basis for this paper. The paper aims to discuss…
Abstract
Purpose
Bilateral project with Slovenia and Turkey with the title thermal energy storage for efficient utilization of solar energy was the basis for this paper. The paper aims to discuss this issue.
Design/methodology/approach
The paper is the review of solar thermal storage technologies with examples of use in Slovenia and Turkey.
Findings
The authors have found out that compact and cost effective thermal energy storage are essential.
Research limitations/implications
Research on the field of thermal energy storage in Slovenia and Turkey is presented.
Practical implications
The paper presents solar systems in Slovenia and Turkey.
Originality/value
The paper gives information about the sustainable energy future on the basis of solar energy.
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Ab Kasaeian, Reza Daneshazarian, Fathollah Pourfayaz, Sahar Babaei, Mojgan Sheikhpour and Shima Nakhjavani
Because of its increased absorptance in fluid and reduced heat loss, direct absorption nanofluid (DANF) is receiving intense interest as an efficient way to harvest solar energy…
Abstract
Purpose
Because of its increased absorptance in fluid and reduced heat loss, direct absorption nanofluid (DANF) is receiving intense interest as an efficient way to harvest solar energy. This work aims to investigate, for the first time, the application of DANF in parabolic trough collectors (PTC), a promising collector for solar thermal systems.
Design/methodology/approach
A representative flow and heat transfer study of different fluids in a straight tube is conducted, and the basic energy equation and radiative transfer equations are numerically solved to obtain the fluid temperature distribution and energy conversion efficiency. Ethylene glycol (EG) and different concentrations of (i.e., 0.1-0.6 per cent) multi-wall carbon nanotubes (MWCNT) in EG are used as sample fluids. Four cases are studied for a traditional PTC (i.e., using metal tube) and a direct absorption PTC (i.e., using transparent tube) including a bare tube, a tube with an air-filled glass envelope and a tube with vacuumed glass envelop. The numerical results are verified by an experimental study using a copper-glass absorber tube, which reveals the good potential of DANFs.
Findings
Compared with a conventional PTC, using DANF shows an increase of 8.6 per cent and 6.5 K, respectively, in thermal efficiency and outlet temperature difference at a volume fraction (0.5 per cent) of nanoparticles. The results also show that the improvement in solar efficiency increases with increasing particle concentrations, and the vacuum insulated case has the highest efficiency.
Originality/value
In all previous studies, an important section was missing as the effect of photons on the direct solar absorption trough collector, which is considered in this study. This paper proposes a new concept of using direct solar absorption nanofluids for concentrated solar collectors and analyzes the performance of both absorptance and transmittance efficiency considerations. To reveal the potential of the new concept, an analytical model based on energy balance is developed, and two case studies are performed.
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Sonali A. Deshmukh, Praveen Barmavatu, Mihir Kumar Das, Bukke Kiran Naik, Vineet Singh Sikarwar, Alety Shivakrishna, Radhamanohar Aepuru and Rathod Subash
This study has covered many types of solar-powered air-conditioning systems that may be used as an alternative to traditional electrically powered air-conditioning systems in…
Abstract
This study has covered many types of solar-powered air-conditioning systems that may be used as an alternative to traditional electrically powered air-conditioning systems in order to reduce energy usage. Solar adsorption air cooling is a great alternative to traditional vapor compression air-conditioning. Solar adsorption has several advantages over traditional vapor-compression systems, including being a green cooling technology which uses solar energy to drive the cycle, using pure water as an eco-friendly HFC-free refrigerant, and being mechanically simple with only the magnetic valves as moving parts. Several advancements and breakthroughs have been developed in the area of solar adsorption air-conditioners during the previous decade. However, further study is required before this technology can be put into practise. As a result, this book chapter highlights current research that adds to the understanding of solar adsorption air-conditioning technologies, with a focus on practical research. These systems have the potential to become the next iteration of air-conditioning systems, with the benefit of lowering energy usage while using plentiful solar energy supplies to supply the cooling demand.
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