An Overview of Concentrating Photovoltaic Thermal (CPVT) Collectors

Azarian, Reza Danesh; Cüce, Erdem; Cuce, Pınar Mert

doi:10.3844/erjsp.2017.11.21

Cited by 13 publications

(5 citation statements)

References 54 publications

(64 reference statements)

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“…A working Glass-glass absorber tube fluid goes through the absorber tube where it absorbs the reflected solar radiation from the reflector. Even this parabolic system could be coupled by a PV system for harvesting the energy to be converted into electricity and enhanced the performance of the system (Daneshazarian et al, 2018;Daneshazarian et al, 2017). Another way of improving the efficiency of the typical PTC systems is adding a coating to the absorber tube which enhances the performance of the system by increasing the absorbance of the receiver (Kasaeian et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of MWCNT/ethylene glycol nanofluid flow in a parabolic trough collector with glass-glass absorber tube

Kasaeian

Daneshazarian

Pourfayaz

et al. 2019

HFF

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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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Section: Introductionmentioning

confidence: 99%

Evaluation of MWCNT/ethylene glycol nanofluid flow in a parabolic trough collector with glass-glass absorber tube

Kasaeian

Daneshazarian

Pourfayaz

et al. 2019

HFF

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“…Solar energy is believed in having the greatest potential among the other renewable energy technologies in order to compete with fossil fuel based energy sources (Cuce et al, 2018). It is easy to underline that solar energy has numerous applications covering solar electricity, solar thermal and conventional or concentrating cogeneration technologies (Daneshazarian et al, 2017). Solar electricity, which is dominated by Photovoltaic (PV) modules, is in the centre of interest worldwide as a consequence of notable advancements in semiconductor material technologies and enhancements in energy and exergy efficiencies of PV modules .…”

Section: Introductionmentioning

confidence: 99%

Performance Assessment of Solar Chimneys: Part 2 – Impacts of Slenderness Value and Collector Slope on Power Output

Cüce¹,

Cuce²

2019

Energy Research Journal

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In the previous part, impacts of chimney height thus pressure difference on the power output of solar chimneys have been numerically evaluated. Within the scope of this research, slenderness and slope of collector are analysed in terms of their potential influence on average velocity of air at the chimney inlet. The analyses are based on a commercial and reliable CFD software ANSYS FLUENT. Chimney height is considered to be 100 m in the research and the chimney diameter is varied through a dimensionless parameter (β). Basically, β is defined as inverse slenderness and its value of 0.1 corresponds to a chimney diameter of 10 m as expected. Average velocity of air at the chimney inlet is numerically assessed for the β values in the range of 0.1-0.5. Collector slope is also investigated in the analyses through a dimensionless parameter (δ). The term δ is defined as the ratio of inlet height of collector to the collector height at the centre. Similarly, average velocity of air at the chimney inlet is determined for the δ values in the range of 0.2-1.0. The analyses are conducted for a constant solar intensity of 200 W/m 2 . The chimney height at the centre is taken to be 4 m in the slenderness analyses and 10 m in the collector slope assessments. The height of collector inlet is constant and 1 m in the slenderness research. On the other hand, it is varied from 2 to 10 m in the collector slope analyses. The results reveal that the velocity figures exponentially decrease from 15.93 to 11.85 m/s when the β value rises from 0.1 to 0.5. On the contrary, velocity figures increase with increasing δ value, the enhancement is determined to be about 23%.

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“…Solar energy is ascribed to have the greatest potential among the other renewable energy technologies to be able to mitigate the dominant impact of fossil fuel based energy economy at global scale (Cuce et al, 2018). There is a wide range of solar energy applications from solar thermal to solar electricity as well as concentrating cogeneration and trigeneration technologies (Daneshazarian et al, 2017). Solar electricity is currently dominated by Photovoltaics (PVs) worldwide owing to the remarkable advancements in semiconductor materials and notable enhancements in PV module efficiencies (Cuce et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Performance Assessment of Solar Chimneys: Part I – Impact of Chimney Height on Power Output

Cüce¹,

Cuceb²

2019

Energy Research Journal

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Solar chimney is a truly sustainable and green energy technology, which is a potential alternative to carbon-based energy economy. The working principle of solar chimneys is based on the buoyant nature of air to turn a turbine that produces electrical power. Solar chimneys are highly in the centre of interest among all solar energy applications since they enable both day and night time operation owing to greenhouse and chimney effects. A typical solar chimney consists of three main parts as chimney, collector and turbine. When the in-situ applications of solar chimneys are gone through, it can be easily asserted that the driving force in electricity generation comes from the chimney effect as a consequence of the notable pressure differences between the inlet and outlet of the chimneys. In most cases, the greenhouse effects on power output are considered auxiliary only due to non-optimised geometric properties for the air medium beneath the collector. Within the scope of this CFD research, the impacts of chimney height on power output of a typical solar chimney are evaluated. A commercial and reliable CFD software ANSYS FLUENT is considered for the numerical analyses. For different chimney heights, the average velocity at the inlet of chimney in which the turbine is placed is determined by applying k-ε turbulence model, continuity, momentum and energy equations for a 2D model. The results reveal that there is an exponential relationship between the pressure difference and the average air velocity and the solar chimney is found to be practical after a certain value of chimney height. For a chimney and collector diameter of 10 and 1000 m, respectively, the average velocity at the inlet of chimney is calculated to be 25.17 m/s for a chimney height of 100 m, whereas it is 18.06 m/s for the height of 50 m. The findings are of vital importance in terms of feasibility studies on solar chimneys since they give a clear understanding about the influence of chimney height on the electrical power output of any solar chimney power plant.

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An Overview of Concentrating Photovoltaic Thermal (CPVT) Collectors

Cited by 13 publications

References 54 publications

Evaluation of MWCNT/ethylene glycol nanofluid flow in a parabolic trough collector with glass-glass absorber tube

Evaluation of MWCNT/ethylene glycol nanofluid flow in a parabolic trough collector with glass-glass absorber tube

Performance Assessment of Solar Chimneys: Part 2 – Impacts of Slenderness Value and Collector Slope on Power Output

Performance Assessment of Solar Chimneys: Part I – Impact of Chimney Height on Power Output

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