BROKEN-CLOUD CONTRIBUTION TO SOLAR RADIATION ABSORPTION

Ice accretion is detrimental to numerous industries, including infrastructure, power generation, and aviation applications. Currently, some of the leading de-icing technologies utilize a heating source coupled with a superhydrophobic surface. This superhydrophobic surface reduces the power consumption by the heating element. Further power consumption reduction in these systems can be achieved through an increase in passive heat generation through absorption of solar radiation. In this work, a superhydrophobic surface with increased solar radiation absorption is proposed and characterized. An existing icephobic surface based on a polytetrafluoroethylene (PTFE) microstructure was modified through the addition of graphite microparticles. The proposed surface maintains hydrophobic performance nearly identical to the original superhydrophobic coating as demonstrated by contact and roll-off angles within 2.5% of the original. The proposed graphite coating also has an absorptivity coefficient under exposure to solar radiation 35% greater than typical PTFE-based coatings. The proposed coating was subsequently tested in an icing wind tunnel, and showed an 8.5% and 50% decrease in melting time for rime and glaze ice conditions, respectively.

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Solar Radiation Effect on a Magneto Nanofluid Flow in a Porous Medium with Chemically Reactive Species

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2017-0212 ◽

2018 ◽

Vol 16 (9) ◽

Cited By ~ 11

Author(s):

Mohamed R. Eid ◽

O.D. Makinde

Keyword(s):

Porous Medium ◽

Solar Radiation ◽

Saturated Porous Medium ◽

Surface Concentration ◽

Radiation Absorption ◽

Physical Parameters ◽

Radiation Chemical ◽

Electrically Conducting ◽

Special Cases ◽

Chemically Reactive Species

Abstract The combined impact of solar radiation, chemical reaction, Joule heating, viscous dissipation and magnetic field on flow of an electrically conducting nanofluid over a convectively heated stretching sheet embedded in a saturated porous medium is simulated. By using appropriate similarity transformation, the governing nonlinear equations are converted into ODEs and numerical shooting technique with (RK45) method is employed to tackle the problem. The effects of various thermo-physical parameters on the entire flow structure with heat and mass transfer are presented graphically and discussed quantitatively. Special cases of our results are benchmarked with some of those obtained earlier in the literature and are found to be in excellent agreement. It is found that both the temperature and surface concentration gradients are increasing functions of the non-Darcy porous medium parameter. One describing result is the incident solar radiation absorption and its transmission into the working nanofluid by convection.

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Local Tilt Optimization of Photovoltaic Solar Panels for Maximum Radiation Absorption

International Journal of Photoenergy ◽

10.1155/2019/3254780 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10

Author(s):

Mauro Masili ◽

Liliane Ventura

Keyword(s):

Solar Radiation ◽

Tilt Angle ◽

Spectral Response ◽

Solar Spectrum ◽

Weather Conditions ◽

Solar Irradiation ◽

Radiation Absorption ◽

Radiative Transfer Model ◽

Transfer Model ◽

Solar Panels

Incident solar radiation on photovoltaic (PV) solar panels is not constant throughout the year. Besides dependence on the season, solar radiation is reliant on the location and weather conditions. For a given location on Earth, the best-fixed orientation of a PV panel can be determined by achieving the maximum incident solar irradiance throughout the year or for a predetermined period. In this paper, we use a sophisticated atmospheric radiative transfer model to calculate the direct and diffuse solar irradiation (radiant exposure) for the solar spectrum incident on PV solar panels to determine the best tilt angle of the panel in order to maximize absorption of solar radiation for selected periods. We used the Regula-Falsi numerical method to obtain the tilt angle at which the derivative of solar irradiation (concerning the tilt angle) approaches zero. Moreover, the spectral response of typical silicon cells is taken into account. These calculations were carried out in São Carlos (SP), a town in the southeast of Brazil. The best tilt angle was obtained for three selected periods. Additionally, we provide results for Southern latitudes ranging from 0° to −55° in steps of −5° for the meteorological seasons. We have shown that for each period, there is an increase in solar radiation absorption compared to the traditional installation angle based exclusively on the local latitude. These calculations can be extended to any location.

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Investigation of Electrical Conductivity, Optical Property, and Stability of 2D MXene Nanofluid Containing Ionic Liquids

Applied Sciences ◽

10.3390/app10248943 ◽

2020 ◽

Vol 10 (24) ◽

pp. 8943

Author(s):

Balaji Bakthavatchalam ◽

Khairul Habib ◽

R. Saidur ◽

Navid Aslfattahi ◽

A. Rashedi

Keyword(s):

Electrical Conductivity ◽

Ionic Liquid ◽

Ionic Liquids ◽

Solar Radiation ◽

Optical Potential ◽

Radiation Absorption ◽

Substantial Impact ◽

Vis Spectroscopy ◽

Absorption Potential ◽

Solar Thermal Collectors

The addition of ionic liquids with MXene nanofluid has a substantial impact on the solar thermal collectors’ working fluid’s optical properties that effectively absorb and distribute solar radiation. Increased solar radiation absorption potential ensures that heats are transported more rapidly and effectively. This research endeavors to investigate the concept of accumulating solar energy via the usage of ionic liquid-based 2D MXene nanofluid (Ionanofluids) for solar applications. In this study, the optical potential of Diethylene Glycol/MXene nanofluid incorporated with 1-ethyl-3-methyl imidazolium octyl sulfate ([Emim][OSO4]) ionic liquid was extensively investigated with respect to MXene concentration (0.1 to 0.4 wt%) and time (first day and seventh day) through UV-Vis Spectroscopy. A two-step approach was employed to synthesize the proposed ionanofluids with nanoparticle concentrations from 0.1 to 0.4 wt%. In wavelengths between 240 to 790 nm, the effect of ionic liquids, MXene concentration, and dispersion stability played a significant part in enhancing the absorbance capacity of the formulated MXene based Ionanofluid. Furthermore, the increase in the concentration of MXene nanoparticles resulted in more absorbance peaks facilitating high light absorption. Finally, the electrical conductivity of the ionanofluids is also analyzed as MXene renders them promising for solar cell applications. The utmost electrical conductivity of the formulated fluids of 571 μS/cm (micro siemens per centimeter) was achieved at 0.4 wt% concentration.

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