Thermal Assessment of Nano-Particulate Graphene-Water/Ethylene Glycol (WEG 60:40) Nano-Suspension in a Compact Heat Exchanger

Sarafraz, M.M.; Safaei, Mohammad Reza; Tian, Zhe; Goodarzi, Marjan; Filho, Ênio Pedone Bandarra; Arjomandi, Maziar

doi:10.3390/en12101929

Cited by 111 publications

(34 citation statements)

References 48 publications

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“…From the thermal standpoint, the addition of nanoparticles (mainly metal oxides) to a dielectric base oil seems to enhance its thermal conductivity (k) or cooling capacity. This was first noticed with other cooling base fluids, including water and etilenglicol [10][11][12][13]. Regarding their expected behavior as insulators, the presence of nanoparticles in a suspension improves the dielectric strength of the base fluid, as the breakdown voltages (BDV) of the tested nanofluids are usually higher.…”

Section: Introductionmentioning

confidence: 87%

“…As in other scientific fields, a possible improvement of the dielectric oils could arise from nanotechnology. The use of nanoparticles is growing in importance in medicine, in detection and treatments against cancer and in the administration of medicines [1,2]; in material science, for obtaining polymers and materials with enhanced properties for several applications [3][4][5]; in the treatment of industrial wastes, as they are able to capture polluting substances [6]; and in energy and thermal engineering, for energy and heat storage and cooling [7][8][9][10]. The research on dielectric nanofluids is being carried out under this context, aiming at the improvement of the cooling and the electrical isolation of the transformer wires.…”

Section: Introductionmentioning

confidence: 99%

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Titania Nanofluids Based on Natural Ester: Cooling and Insulation Properties Assessment

et al. 2020

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The assessment of a TiO2 vegetal-based dielectric nanofluid has been carried out, and its characteristics and behavior have been tested and compared with a previously tested maghemite nanofluid. The results obtained reflect a similar affectation of the main properties, with a maximal improvement of the breakdown voltage of 33% at 0.5 kg/m3, keeping the thermal conductivity and the viscosity almost constant, especially the first one. This thermal characterization agrees with the results obtained when applying the TiO2 optimal nanofluid in the cooling of an experimental setup, with a slightly worse performance than the base fluid. Nevertheless, this performance is the opposite to that noticed with the ferrofluid, which was capable of improving the cooling of the transformer and decreasing its temperature. The similarities between the characterizations of both nanofluids, the differences in their cooling performances and their different magnetic natures seem to point out the presence of additional thermomagnetic buoyancy forces to support the improvement of the cooling.

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Section: Introductionmentioning

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Titania Nanofluids Based on Natural Ester: Cooling and Insulation Properties Assessment

et al. 2020

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“…A substantial increase in the experimental thermal efficiency has then resulted from the combination of the above two conditions. [48][49][50] Table 3 and Figure 10(a) and (b) below illustrate the F R (ta) and F R U L for PEG-TGr-DW nanofluids. When the nanofluid flows at a constant flow rate (0.00833 kg s À1 ) and varied Gr weight concentrations (0.025 wt%, 0.05 wt%, 0.075 wt%, and 0.1 wt%), F R (ta) values progressively increased by 6.28%, 8.49%, 9.68%, and 10.53%, respectively, relative to the data of base fluid.…”

Section: Analysis Of Thermal Efficiency Using H 2 Omentioning

confidence: 99%

Energy efficiency of a flat-plate solar collector using thermally treated graphene-based nanofluids: Experimental study

Alawi

Kamar

Mohammed

et al. 2020

Nanomaterials and Nanotechnology

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A covalent functionalization approach was utilized for the preparation of highly dispersed pentaethylene glycol-thermally treated graphene-water as the absorbing material inside a flat-plate solar collector. Four mass fractions of nanofluids were prepared (0.025, 0.05, 0.075, and 0.1 wt% pentaethylene glycol-thermally treated graphene-water). Graphene nanoparticles were characterized by energy dispersive X-ray analysis with a scanning electron microscope. Measurements of the thermophysical properties were subsequently carried out for the nanosuspensions. The raw investigation data were collected from an indoor flat-plate solar collector test setup. The experimental procedure included different sets of variables such as input temperatures of 303, 313, and 323 K; fluid mass flow rate of 0.00833, 0.01667, and 0.025 kg s−1; and heat flow density of 500, 750, and 1000 W m−2. The thermophysical tests of pentaethylene glycol-thermally treated graphene-water nanofluids showed a proportional increase against weight concentrations, while the specific heat power was reduced. The tests showed an increment in energy efficiency by increasing the fluid mass flow rate and heat input. By comparison, the thermal efficiency decreased with the increasing temperature of the fluid supply. Relative to the base fluid, the energy efficiency of pentaethylene glycol-thermally treated graphene/water-based flat-plate solar collector increased to 10.6%, 11%, and 13.1% at the three fluid mass flow rates. In conclusion, an exponential form was used to derive the thermal effectiveness of flat-plate solar collector based on the experimental data.

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“…They found that when compared to zero-field condition, the particles rotate faster and the viscosity of ferrofluid is reduced, leading to enhanced heat transfer rate under an oscillating magnetic field [8]. Many other studies have been carried out investigating the role of nanofluids in the heat transfer rate [9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Self-cooling by ferrofluid in magnetic field

Phor

Kumar

2019

SN Appl. Sci.

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This paper reports the synthesis of Fe 3 O 4 ferrite nanoparticles and ferrofluid via a coprecipitation method. Structural studies were investigated using X-ray diffraction technique that confirmed the formation of single-phase cubic spinel structure. Morphology and particle size were elucidated using high-resolution transmission electron microscopy. Magnetic characteristics were investigated using a vibrating sample magnetometer, and saturation magnetization of nanoparticles was found to be 23.72 emu/gm with negligible coercivity and retentivity showing superparamagnetic behaviour. A functional self-cooling design employing ferrofluid (as a coolant) was demonstrated in which the system uses heat from the heat source and a permanent magnet to maintain the fluid flow that transfers heat to heat sink. The system is self-regulating and requires no power or pump for flowing of the fluid in the loop. The performance of the device on various parameters like volume fraction of nanoparticles, the temperature of heat source and strength of the magnetic field has also been studied. It was found that cooling by ~ 20 °C was achieved when temperature of heat source was maintained at 85 °C. Cooling performance was enhanced by ~ 7% when the concentration of nanoparticles in ferrofluid was increased from 2 to 6% and by ~ 4% upon the application of magnetic field.

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Thermal Assessment of Nano-Particulate Graphene-Water/Ethylene Glycol (WEG 60:40) Nano-Suspension in a Compact Heat Exchanger

Cited by 111 publications

References 48 publications

Titania Nanofluids Based on Natural Ester: Cooling and Insulation Properties Assessment

Titania Nanofluids Based on Natural Ester: Cooling and Insulation Properties Assessment

Energy efficiency of a flat-plate solar collector using thermally treated graphene-based nanofluids: Experimental study

Self-cooling by ferrofluid in magnetic field

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