Experimental test of an innovative high concentration nanofluid solar collector

Colangelo, Gianpiero; Favale, Ernani; Miglietta, P.; Risi, Arturo de; Milanese, Marco; Laforgia, Domenico

doi:10.1016/j.apenergy.2015.05.031

Cited by 109 publications

(28 citation statements)

References 30 publications

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“…This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Al 2 O 3 -distillated water nanofluid in the collector increased the thermal efficiency up to 11.7% [10].…”

Section: Introductionmentioning

confidence: 99%

Mathematical modelling and simulation of multiphase flow in a flat plate solar energy collector

Helvaci

Khan

2015

Energy Conversion and Management

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a b s t r a c tNon-conventional collectors where organic fluid or refrigerant experience a phase change have many advantages over conventional collectors which have either air or relatively high temperature boiling liquid. Increase in heat transfer coefficient and system efficiency, corrosion prevention and freeze protection are the main benefits of the first type. In this study, a detailed numerical model of a flat plate collector is developed to investigate the fluid mean temperature, useful heat gain and heat transfer coefficient along the collector tube. The refrigerant HFC-134a was used in the simulation as the working fluid of the collector. The model can both predict the location where the fluid undergoes a phase change in the tube and the state at the exit under given inlet conditions. The effect of boiling on the heat transfer coefficient of the fluid is also investigated. Simulations were performed at three different mass flow rates (0.001, 0.005 and 0.01 kg/s) and three different operating pressures (4, 6 and 8 bar) to be able to see the effect of mass flow rate and pressure on plate temperature, heat loss coefficient, efficiency of the collector and the heat transfer coefficient of the fluid. The simulation results indicate that the heat transfer coefficient of the fluid increases from 153.54 W/m 2 K to 610.27 W/m 2 K in multiphase flow region. In the liquid single phase region, the collector efficiency rises from 60.2% to 68.8% and the heat transfer coefficient of the fluid increases from 39.24 W/m 2 K to 392.31 W/m 2 K with an increased flow rate whereas the collector efficiency decreases from 72.5% to 62.3% as the operating pressure increases from 4 bar to 8 bar. In order to validate the simulation model an experimental test rig was built and the experiments were performed with HFE 7000 as working thermo-fluid. A new simulation model utilizing HFE 7000 has been developed and the outlet temperature of the fluid was compared with the measured outlet temperature. Both measured and simulated results have shown close conformity.

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Section: Introductionmentioning

confidence: 99%

Mathematical modelling and simulation of multiphase flow in a flat plate solar energy collector

Helvaci

Khan

2015

Energy Conversion and Management

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“…[8][9][10]. For comparison, the experimentally obtained steady PSDs are also provided in those figures and show that the calculated PSD results at t = 100 and 500 ms almost overlap.…”

Section: Particle Size Distributionmentioning

confidence: 78%

“…have been intensively studied for possible application in solar collectors of various design. These nanofluids with quite low concentration have demonstrated to have increased efficiency compared to water as absorption medium [3][4][5][6][7]. On the other hand, Colangelo et al [8] found in their study of the thermal efficiency of solar flat-plate collectors with pure water or CNT/water nanofluid as work fluid, the size of solar collectors can be reduced by applying nanofluid.…”

Section: Introductionmentioning

confidence: 99%

Prediction of hydrodynamic and optical properties of TiO 2 /water suspension considering particle size distribution

Song

Hatami

Wang

et al. 2016

International Journal of Heat and Mass Transfer

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“…For instance, the solar energy that reaches the Earth's surface over one hour is greater than the worldwide energy consumption for one year [3,4]. The challenges for solar energy lie in the effective absorption, conversion, and storage of solar radiation, which are significantly affected by the working medium [5][6][7][8]. To simplify the collector and enhance its efficiency, a so-called Direct Solar Absorption Collector (DASC) has been proposed [9].…”

Section: Introductionmentioning

confidence: 99%

Investigating the collector efficiency of silver nanofluids based direct absorption solar collectors

et al. 2016

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volume fraction increase and then reaches a maximum value. An optimum collector height (~ 10 mm) and particle concentration (~ 0.03%) achieving a collector efficiency of 90% of the maximum efficiency can be obtained under the conditions used in the simulation. However, the collector efficiency decreases as the irradiation time increases owing to the increased heat loss. A high solar flux is desirable to maintain a high efficiency over a wide temperature range, which is beneficial for subsequent energy utilization. The modeling results also show silver and gold nanofluids obtain higher photothermal conversion efficiencies than the titanium dioxide nanofluid because their absorption spectra are similar to the solar radiation spectrum.

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Experimental test of an innovative high concentration nanofluid solar collector

Cited by 109 publications

References 30 publications

Mathematical modelling and simulation of multiphase flow in a flat plate solar energy collector

Mathematical modelling and simulation of multiphase flow in a flat plate solar energy collector

Prediction of hydrodynamic and optical properties of TiO 2 /water suspension considering particle size distribution

Investigating the collector efficiency of silver nanofluids based direct absorption solar collectors

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