Study of a Heat Transfer Mechanism and Critical Heat Flux at Nanofluids Boiling

Бондаренко, Б. І.; Moraru, V. N.; Ilienko, B.K.; Khovavko, A.; Komysh, D. V.; Panov, E. M.; Sydorenko, Sergey; Snigur, O.V.

doi:10.1615/interjenercleanenv.2014006801

Cited by 11 publications

(22 citation statements)

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“…Over the last decade, a considerable number of studies have shown that for NFs the increased values (up to 10-35%) of heat conductivity are characteristic in comparison with those for the base fluid (water, ethylene glycol) [3,[13][14][15][16], and that the use of NFs as heat transfer mediums allows to achieve high values of CHF and heat transfer coefficient at boiling [7][8][9][17][18][19][20]. In spite of this, the mentioned increase of heat conductivity can't explain the anomalously high intensity of heat transfer (>200%) at NFs boiling compared with water.…”

Section: Introductionmentioning

confidence: 99%

Nanostructured Architectures on the Heater Surface at Nanofluids Boiling and Their Role in the Intensification of Heat Transfer

Бондаренко¹,

Moraru²,

Sydorenko³

et al. 2016

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A major problem of modern science and industry is intensification of a heat transfer. One of the most promising ways for its solution is use of nanofluids as heat carrier and coolant that is capable to operate at high specific heat fluxes. In the course of nanofluids boiling porous sediments of nanoparticles are formed on the heating surfaces and provide a stable nucleate boiling mode. Whereas the specific heat fluxes grow up to 300-400% compared with water there is observed a significant increase of heat transfer coefficients, which is probably associated with the increase of porosity, roughness and wettability of heating surface. In order to clarify this question we studied the process of nanostructures formation in the course of different nanofluids boiling on the surface of Ni/Cr-heater. The morphology and topography of artificial coatings were studied and the results were compared with the values of the basic boiling parameters: specific heat flux and heat transfer coefficient. The conclusions based on experimental results are: maximum values of the specific heat flux and the heat transfer coefficient refer for nanofluids consisting of a mixture of nanoparticles with anisometric shape. While boiling process in on they are able to create nanostructures with the most developed surface roughness and porosity. Most likely, this is due to the highest density of nucleation sites and the area of heat transfer surface formed in these nanostructures.

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Section: Introductionmentioning

confidence: 99%

Nanostructured Architectures on the Heater Surface at Nanofluids Boiling and Their Role in the Intensification of Heat Transfer

Бондаренко¹,

Moraru²,

Sydorenko³

et al. 2016

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“…Nanofluids using in systems with a coolant boiling can rise a CHF in 2-3,5 times ( Figure 5) ( Figure 6). 6 It was found that NFs based on attapulgite and montmorillonite more stable to prolonged and repeated boiling-cooling and coagulation action of direct current compared with NFs -based on carbon materials, due to their different chemical nature and hydrophilic surface. A convincing proof is obtained that the CHF growth at NFs boiling in comparison with water is due to the change in the nature and microrelief of the heating surface.…”

Section: A) C) B)mentioning

confidence: 99%

Carbonaceous nanomaterials: production and application. R&D of gas institute of NAS of Ukraine

Ai¹,

Ev²,

Ap³

et al. 2018

IJBSBE

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Experimental results and their analysis Gas Institute of NAS of Ukraine made a series of important new researches to create technology and equipment for nanomaterials and nanofluids that can effectively be used in the newest and traditional energetics. Scientists of the Institute carried out thermodynamic study and created a pilot unit of electro thermal fluidized bed (ETFB). ETFB-a bed of electrically conductive particles in a fluidized state heated by electric current passing through its volume. It is possible to realize various processes at extremely high level of temperature (up to 2000 °C). For the benefit of micro plasma charges in the created aggregate (one of the biggest in the Western Europe) it was implemented a continuous coating of pure quartz particles by lustrous nanopyrocarbon. 1 The layer of pyrographite that capsulated quarts can be obtained in different thickness range by pyrolysis of hydrocarbons. Carbothermic reduction of silicon from quartz sand coated by pyrolytic carbon was accomplished in plasma arc discharge in the environment of vacuum with atomic hydrogen. So, we suggested to obtain pure silicon suitable for use in photovoltaic bypassing the expensive and dangerous "Siemens" chloride method (Figure 1).

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“…et al, ,b, 2014Kim, S.J. et al, 2007a;Wen, 2008a;You et al, 2003;Bondarenko et al, 2012Bondarenko et al, , 2013 showed that even very small concentrations of NPs in the basic fluids (0.001-0.1 vol.%) led to significant increases in CHF. Also, the thermophysical properties of water with NPs (surface tension, viscosity, heat of vapourization, boiling point), appear to not differ noticeably from the thermophysical properties of distilled water (Kim et al, 2007a,b).…”

mentioning

confidence: 99%

New nanofluids, based on clay minerals, as promising heat carriers for energetics

Moraru

2018

Clay miner.

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In an automated installation powered by direct current (DC), the boiling curves and heat-transfer-coefficient (HTC) dependencies on the superheat values (ΔT) under free convection conditions for the water nanodispersions of clay minerals – illite, montmorillonite, palygorskite and genetic mixtures of the latter two – were obtained. The effects of some factors on pool boiling heat transfer were also studied.A significant influence of the shape and anisotropy of nanoparticles (NPs) on the heat-transfer parameters of nanofluids (NFs) was detected. A significant critical heat flux (CHF) enhancement (up to 200–300%) at boiling of the nanofluids studied was established, which is due to nanoparticle deposition on the heater surface during nanofluid boiling. The structure of the nanomaterials deposited is important in the enhancement of heat transfer at boiling of nanofluids and in avoiding boiling crises.The present study showed the effectiveness of clay-mineral nanofluids for extra emergency cooling of overheated surfaces of powerful equipment in the event of the sudden onset of a boiling crisis.

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Study of a Heat Transfer Mechanism and Critical Heat Flux at Nanofluids Boiling

Cited by 11 publications

References 0 publications

Nanostructured Architectures on the Heater Surface at Nanofluids Boiling and Their Role in the Intensification of Heat Transfer

Nanostructured Architectures on the Heater Surface at Nanofluids Boiling and Their Role in the Intensification of Heat Transfer

Carbonaceous nanomaterials: production and application. R&D of gas institute of NAS of Ukraine

New nanofluids, based on clay minerals, as promising heat carriers for energetics

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