Enhanced nucleate boiling using a reduced graphene oxide-coated micropillar

Choi, Geehong; Shim, Dong Il; Lee, Donghwi; Kim, Beom-Seok; Cho, Hyung Hee

doi:10.1016/j.icheatmasstransfer.2019.104331

Cited by 32 publications

(10 citation statements)

References 41 publications

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“…The higher thermal conductivity of nanofluids such as MWCNTs/water nanofluids has a significant effect on the boiling HTC enhancement. The presence of nanoparticles causes collisions between the heating surface and the particles, thereby increasing the turbulence of the solution and, as a result, higher HTCs 31 …”

Section: Resultsmentioning

confidence: 99%

“…Due to the conduction and/or convective mechanisms, thermal energy is absorbed by the nanoparticles in the hot region, which is then delivered to the cold region via the same mechanisms. Thus, these two contributors can facilitate heat transfer and augment the HTC value 31,32 . A schematic illustration of the mechanisms improving the thermal performance of the system is shown in Figure 11 33,34 …”

Section: Resultsmentioning

confidence: 99%

“…The presence of nanoparticles causes collisions between the heating surface and the particles, thereby increasing the turbulence of the solution and, as a result, higher HTCs. 31 To evaluate the nanofluid boiling HTC enhancement compared to water with increasing nanoparticles concentration and heat flux, the HTC ratio of MWCNTs/water nanofluid to water is shown in Figure 10. As it can be seen, this ratio is increasing with nanoparticle concentration, which itself is increasing.…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Experimental investigation of multiwall carbon nanotubes/water nanofluid pool boiling on smooth and groove surfaces

Moghadam

Goshayeshi

Chaer

et al. 2022

Intl J of Energy Research

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Boiling is an essential process for many industrial applications, such as refrigeration, distillation, and chemical processes. The effectiveness of the heat transfer processes determines the efficiencies of these applications. This study presents the experimental data analysis for pool boiling performance of 0.10, 0.15, and 0.20 wt.% of multiwall carbon nanotubes/water nanofluid on smooth and straight, square, and circular grooved surfaces. According to the experimental results, the configuration S4 with a 30 mm deep circular groove inclined at a 45 angle and 33% higher than the base fluid on the smooth surface had the greatest enhancement in boiling heat transfer coefficient. The result indicated that the inclination of the circular groove had the potential to enhance significantly the pool boiling heat transfer process. Furthermore, this study demonstrated that analyzing the effectiveness of nanofluids in a variety of concentrations and geometrical configurations of heat transfer surfaces is still essential and desirable.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Experimental investigation of multiwall carbon nanotubes/water nanofluid pool boiling on smooth and groove surfaces

Moghadam

Goshayeshi

Chaer

et al. 2022

Intl J of Energy Research

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show abstract

“…Evaporation at the solid-liquid phase interface is called pool boiling. The increase in pool-boiling heat transfer coefficient has been a heated topic among researchers for many years [1][2][3][4][5][6][7][8][9][10]. This is one of the most widely used processes in areas such as oil, petrochemicals, internal combustion engines, and refrigerators due to its high heat transfer coefficient.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation and Modeling of Bubble Departure Frequency for Pool‐Boiling Heat Transfer

et al. 2022

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The artificial neural network (ANN) method and response surface methodology (RSM) were used to predict the bubble departure frequency for the pool-boiling heat transfer of pure liquids, by using experimental data. The effects of vaporliquid density difference, vapor-liquid viscosity difference, surface tension, thermal conductivity, and heat flux on the departure frequency of vapor bubbles were investigated by RSM and ANN. The results showed that the outputs of the ANN and RSM had a suitable overlap with the experimental data, but the RSM model was more accurate than the ANN model.

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“…Previous studies have shown that engineered surfaces can significantly enhance the boiling performance. Surfaces with microcavities or heterogeneous wettability patterns, for example, have improved HTC values by promoting vapor bubble nucleation (Figure a). − Surfaces with permeable structures such as micropillars, in contrast, have shown significant enhancement of CHF values by harnessing contact line augmentation and capillary-fed rewetting, that is, surface wickability (Figure b). − In particular, a strong relationship between CHF values and the surface wickability has been widely reported. ,, A few studies have combined micropermeable structures (micropillars or microchannels) with functional coatings, for example, self-assembled monolayers, reduced graphene oxide membranes, and porous copper layers, which exploit micropermeable structures and the coatings to enhance CHF and HTC values, respectively. − The addition of nanostructures to microstructures or to heterogeneous wettability patterns has shown further increases in CHF and HTC values; ,,,, however, these approaches are less durable than microstructures and have limited control over the boiling performance due to the random nature of nanostructures and limited variability of heterogeneous wettability materials. , …”

Section: Introductionmentioning

confidence: 99%

Microtube Surfaces for the Simultaneous Enhancement of Efficiency and Critical Heat Flux during Pool Boiling

Song

Gong

Vaartstra

et al. 2021

ACS Appl. Mater. Interfaces

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Boiling is an essential process in numerous applications including power plants, thermal management, water purification, and steam generation. Previous studies have shown that surfaces with microcavities or biphilic wettability can enhance the efficiency of boiling heat transfer, that is, the heat transfer coefficient (HTC). Surfaces with permeable structures such as micropillar arrays, in contrast, have shown significant enhancement of the critical heat flux (CHF). In this work, we investigated microtube structures, where a cavity is defined at the center of a pillar, as structural building blocks to enhance HTC and CHF simultaneously in a controllable manner. We demonstrated simultaneous CHF and HTC enhancements of up to 62 and 244%, respectively, compared to those of a smooth surface. The experimental data along with high-speed images elucidate the mechanism for simultaneous enhancement where bubble nucleation occurs in the microtube cavities for increased HTC and microlayer evaporation occurs around microtube sidewalls for increased CHF. Furthermore, we combined micropillars and microtubes to create surfaces that further increased CHF by achieving a path to separate nucleating bubbles and rewetting liquids. This work provides guidelines for the systematic surface design for boiling heat transfer enhancement and has important implications for understanding boiling heat transfer mechanisms.

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Enhanced nucleate boiling using a reduced graphene oxide-coated micropillar

Cited by 32 publications

References 41 publications

Experimental investigation of multiwall carbon nanotubes/water nanofluid pool boiling on smooth and groove surfaces

Experimental investigation of multiwall carbon nanotubes/water nanofluid pool boiling on smooth and groove surfaces

Experimental Investigation and Modeling of Bubble Departure Frequency for Pool‐Boiling Heat Transfer

Microtube Surfaces for the Simultaneous Enhancement of Efficiency and Critical Heat Flux during Pool Boiling

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