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Article
Publication date: 3 October 2016

Fahim 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…

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.

Details

World Journal of Engineering, vol. 13 no. 5
Type: Research Article
ISSN: 1708-5284

Keywords

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Article
Publication date: 6 August 2019

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…

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.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 1
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 4 September 2018

Evangelos Bellos, Ilias Daniil and Christos Tzivanidis

The purpose of this paper is to investigate a cylindrical flow insert for a parabolic trough solar collector. Centrally placed and eccentric placed inserts are…

Abstract

Purpose

The purpose of this paper is to investigate a cylindrical flow insert for a parabolic trough solar collector. Centrally placed and eccentric placed inserts are investigated in a systematic way to determine which configuration leads to the maximum thermal enhancement.

Design/methodology/approach

The analysis is performed in SolidWorks Flow Simulation with a validated computational fluid dynamics model. Moreover, the useful heat production and the pumping work demand increase are evaluated using the exergy and the overall efficiency criteria. The different scenarios are compared for inlet temperature of 600 K, flow rate of 100 L/min and Syltherm 800 as the working fluid. Moreover, the inlet temperature is examined from 450 to 650 K, and the diameter of the insert is investigated up to 50 mm.

Findings

According to the final results, the use of a cylindrical insert of 30 mm diameter is the most sustainable choice which leads to 0.56 per cent thermal efficiency enhancement. This insert was examined in various eccentric positions, and it is found that the optimum location is 10 mm over the initial position in the vertical direction. The thermal enhancement, in this case, is about 0.69 per cent. The pumping work demand was increased about three times with the insert of 30 mm, but the absolute values of this parameter are too low compared to the useful heat production. So, it is proved that the increase in the pumping work is not able to eliminate the useful heat production increase. Moreover, the thermal enhancement is found to be greater at higher temperature levels and can reach up to 1 per cent for an inlet temperature of r650 K.

Originality/value

The present work is a systematic investigation of the cylindrical flow insert in a parabolic trough collector. Different diameters of this insert, as well as different positions in two dimensions, are examined using a parametrization of angle-radius. To the authors’ knowledge, there is no other study in the literature that investigates the presented many cases systematically with the followed methodology on parabolic trough collectors. Moreover, the results of this work are evaluated with various criteria (thermal, exergy and overall efficiency), something which is not found in the literature.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 5
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 4 January 2016

Chunyu Zhao, Shijun You, Hao Gao and Wei Yu

The purpose of this paper is to use numerical simulations to investigate the energy conversion performance and the flow and temperature structures inside horizontal tubes…

Abstract

Purpose

The purpose of this paper is to use numerical simulations to investigate the energy conversion performance and the flow and temperature structures inside horizontal tubes connected to a vertical manifold channel.

Design/methodology/approach

The simulations are performed for different flow rates and inlet temperatures using CFD.

Findings

In both the “flowing wind mode” and “upwind mode,” the inlet velocity is not infinitely small under the influence of natural convection; however, such small inlet velocities cannot be achieved in practice and are of no practical significance. In the “flowing wind mode,” the appropriate velocity for achieving high efficiency is 0.01-0.02 m/s. In the “upwind mode,” the appropriate velocity for obtaining high efficiency is 0.1-0.2 m/s. A high inlet temperature can lead to high efficiency; therefore, a large temperature difference and a small flow can be used in actual designs.

Originality/value

The energy conversion performance and flow structures inside evacuated tubular collectors were investigated using CFD for different operating conditions, notably in the “following wind mode” and the “upwind mode.”

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 26 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 11 October 2018

Soroush Sadripour

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…

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.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 4
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 14 January 2020

Nedjma Abdelhafidi, Nour El Islam Bachari, Zohra Abdelhafidi, Ali Cheknane, Abdelmotaleb Mokhnache and Loranzo Castro

Integrated solar combined cycle (ISCC) using parabolic trough collector (PTC) technology is a new power plant that has been installed in few countries to benefit from the…

Abstract

Purpose

Integrated solar combined cycle (ISCC) using parabolic trough collector (PTC) technology is a new power plant that has been installed in few countries to benefit from the use of hybrid solar-gas systems. The purpose of this paper is to investigate the challenges in modeling the thermal output of the hybrid solar-gas power plant and to analyze the factors that influence them.

Design/methodology/approach

To validate the proposal, a study was conducted on a test stand in situ and based on the statistical analysis of meteorological data of the year 2017. Such data have been brought from Abener hybrid solar-gas central of Hassi R’mel and used as an input of our model.

Findings

The proposal made by the authors has been simulated using MATLAB environment. The simulation results show that the net solar electricity reaches 18 per cent in June, 15 per cent in March and September, while it cannot exceed 8 per cent in December. Moreover, it shows that the power plant responses sensibly to solar energy, where the electricity output increases accordingly to the solar radiation increase. This increase in efficiency results in better economic utilization of the solar PTC equipment in such kind of hybrid solar-gas power plant.

Practical implications

The obtained results would be expected to provide the possibility for designing other power plants in Algeria when such conditions are met (high DNI, low wind speed, water and natural-gas availability).

Originality/value

This paper presents a new model able to predict the thermal solar energy and the net solar-electricity efficiency of such kind solar hybrid power plant.

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Article
Publication date: 1 December 2016

Esteban Zalamea León, Rodrigo García Alvarado, Reinaldo Sánchez Arriagada and Sergio Baeriswy

The roofs of houses located at middle latitudes receive significant solar radiation useful to supply their own energy demands and to feed back into the urban electricity…

Abstract

The roofs of houses located at middle latitudes receive significant solar radiation useful to supply their own energy demands and to feed back into the urban electricity network. However, solar panels should be properly integrated into roofs. This study analyzed roof geometry and integrated solar performance of Photovoltaic, thermal-photovoltaic, and hybrid solar collection technologies on dwelling cases selected from a sample of recent housing developments in Concepción, Chile. Hour-by-hour energy generation estimates and comparisons with demand levels were calculated for representative days during seasons of maximum, minimum as well as mid-season. These estimates took into account the roof tilt and orientation effects also. Trnsys@ software was used to determine electricity supply and F-Chart tool for thermal energy supply. The results show five times more panels can be placed on the largest and most regular shaped roof sections than on those with the smallest and most irregular shapes. The house model with the largest roof section can provide up to six times more energy than the model with the smallest second roof section in different seasons and systems. This paper thus provides new findings on the performance of solar technologies when related to home energy demands and roof geometry.

Details

Open House International, vol. 41 no. 4
Type: Research Article
ISSN: 0168-2601

Keywords

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Article
Publication date: 1 February 1998

Jyoti Lata Pandey and M.K. Banerjee

Solar selective coatings are designed and formulated for effective collection and retention of solar energy. Several types of coatings can be utilized for economical…

Abstract

Solar selective coatings are designed and formulated for effective collection and retention of solar energy. Several types of coatings can be utilized for economical collection of solar energy, the most common and simplest will be ordinary non‐glass, heat resistant black paint. The coatings may be moderately selective or non‐selective absorbers, consisting of organic or inorganic matt black paints. These are easiest to apply and the least expensive of all collector coatings. In this category other types are ceramic and organic enamels and chemical or electrochemical metal conversion coatings. An impending energy crisis has already aroused interest and scientific pursuit in the field. An analysis of the state‐of‐the‐art in solar selective coatings was felt necessary at this time.

Details

Anti-Corrosion Methods and Materials, vol. 45 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 4 July 2016

Seyed Masoud Sajjadian

The purpose of this paper is to present the advantages of a solar store system with transpired solar air collector (TSC) in North Wales, UK. The collectors are designed as…

Abstract

Purpose

The purpose of this paper is to present the advantages of a solar store system with transpired solar air collector (TSC) in North Wales, UK. The collectors are designed as a proposal to meet the target of the solar air storage and heating project to improve the efficiency of solar collectors in the UK.

Design/methodology/approach

IES software simulation is used to examine the potential of a solar store system in Deeside Leisure Centre compared to the traditional constant air volume (CAV) system and CAV system with heat pump. The design parameters and configurations are determined on the basis of the monitoring results gained from recent experiments.

Findings

The result demonstrates good agreement between simulations and monitoring results and the solar store system demonstrates considerably lower energy consumption compared to the traditional CAV system with and without heat pump.

Originality/value

The usage of TSC is proven to be useful in improving COP of the heat pumps and reducing overall energy consumption in a leisure center. The framework proposed in this study could also be applied to different building types in order to highlight their advantages.

Details

Smart and Sustainable Built Environment, vol. 5 no. 2
Type: Research Article
ISSN: 2046-6099

Keywords

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Article
Publication date: 1 May 2019

Shoaib Khanmohammadi, Mohammad Zanjani and Farzad Veysi

Present research focus on using solar energy as a renewable option for office buildings in different climatic conditions in Iran. To seeking a way to use clean solar…

Abstract

Purpose

Present research focus on using solar energy as a renewable option for office buildings in different climatic conditions in Iran. To seeking a way to use clean solar energy and reduce current expense in buildings an investigation carried out. Nine office buildings in various climatic regions selected as case studies. Through a precise examination, buildings specifications, energy demand and climate information carried out. In the first step based on the buildings type and hot water demand, solar water heater systems designed for each case. In the second step, a cost-benefit analysis is done to detriment the economic aspects of implement aforementioned type of solar system. A cost-benefit analysis is done from saving energy and return time of investment point of view. Results indicate that solar water heater with low investment about US$500 and payback time between 2 and 5 years can be noticed as a desirable renewable option in case studies. Furthermore, analysis reveals that thermal load of building is more effective on fuel saving in building, while solar radiation intensity has more effective on the payback in solar water heater utilization.

Design/methodology/approach

In this study based on thermal load of nine building office and radiation of different part of Kermnashah province, the possibility of solar water system is investigated.

Findings

Analyses reveal that the thermal load of building is more effective on fuel saving, while solar radiation intensity has more effective on the payback in solar water heater utilization. The main originality goes back to consideration of different meteorological conditions in solar water heater selection.

Details

World Journal of Engineering, vol. 16 no. 2
Type: Research Article
ISSN: 1708-5284

Keywords

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