Thermal and rheological characteristics of CuO–Base oil nanofluid flow inside a circular tube

Saeedinia, M.; Akhavan-Behabadi, M.A.; Razi, Pooyan

doi:10.1016/j.icheatmasstransfer.2011.08.001

Cited by 179 publications

(79 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The performance of solar radiation absorption in a short wave by a CNT is demonstrated by Shende and Sundara (2015). Saeedinia et al, (2012) present a review of solar applications with a nanofluid. They confirm that the gain is 13% greater than that of a conventional fluid in solar applications.…”

Section: Introductionmentioning

confidence: 99%

Thermal Performance of Carbon Nanotube Nanofluids in Solar Microchannel Collectors: an Experimental Study

Ahlatli¹,

Maré²,

Estellé³

et al. 2016

IJTech

View full text Add to dashboard Cite

Many studies show that nanofluids, especially with carbon nanotubes, improve heat transfer. Other studies show that a nanofluid is a good candidate for solar systems because of its good absorptivity. We are facing an increasing number of miniaturized and more powerful systems. Especially in microelectronics, small heat sinks with high heat transfer are being developed, called micro-channel heat sinks (MCHS). In this paper, the heat transfer behavior of carbon nanotube-water nanofluid in a microchannel solar collector is studied experimentally. The exchanger is composed of 16 micro-channel hydraulic diameters of 1 mm and a glass or quartz cover with a surface area of 25 cm 2 . Solar radiation is simulated by a halogen lamp. The experimental set-up includes a solar meter, pressure, and temperature sensors, and it is allowed to control the flow. The nanofluid is a solution of water containing a 0.01%, 0.05%, 0.1%, and 0.5% weight fraction, respectively, of the carbon nanotubes, which are 9.2 nm in diameter and 1.5 µm in length. Viscosity and density are measured experimentally. The evolution of efficiency and the pressure drop are presented according to the Reynolds number and are compared with the results obtained with distilled water.

show abstract

Section: Introductionmentioning

confidence: 99%

Thermal Performance of Carbon Nanotube Nanofluids in Solar Microchannel Collectors: an Experimental Study

Ahlatli¹,

Maré²,

Estellé³

et al. 2016

IJTech

View full text Add to dashboard Cite

show abstract

“…Low nanoparticle volume fraction, ranging from 0.0055% to 0.278%, showed positive effect on density, thermal conductivity and viscosity of nanofluids for temperature range of 20-40°C. Enhancement in density, thermal conductivity and viscosity of nanofluids with volume fraction in nanotubes was observed in comparison to base fluids [40][41][42].…”

Section: Low Temperature Collectormentioning

confidence: 94%

Recent Developments in Heat Transfer Fluids Used for Solar Thermal Energy Applications

Srivastva¹,

Malhotra²,

Sc³

2015

J Fundam Renewable Energy Appl

View full text Add to dashboard Cite

Solar thermal collectors are emerging as a prime mode of harnessing the solar radiations for generation of alternate energy. Heat transfer fluids (HTFs) are employed for transferring and utilizing the solar heat collected via solar thermal energy collectors. Solar thermal collectors are commonly categorized into low temperature collectors, medium temperature collectors and high temperature collectors. Low temperature solar collectors use phase changing refrigerants and water as heat transfer fluids. Degrading water quality in certain geographic locations and high freezing point is hampering its suitability and hence use of water-glycol mixtures as well as water-based nano fluids are gaining momentum in low temperature solar collector applications. Hydrocarbons like propane, pentane and butane are also used as refrigerants in many cases. HTFs used in medium temperature solar collectors include water, waterglycol mixtures -the emerging "green glycol" i.e., trimethylene glycol and also a whole range of naturally occurring hydrocarbon oils in various compositions such as aromatic oils, naphthenic oils and paraffinic oils in their increasing order of operating temperatures. In some cases, semi-synthetic heat transfer oils have also been reported to be used. HTFs for high temperature solar collectors are a high priority area and extensive investigations and developments are occurring globally. In this category, wide range of molecules starting from water in direct steam generation, air, synthetic hydrocarbon oils, nanofluid compositions, molten salts, molten metals, dense suspension of solid silicon carbide particles etc., are being explored and employed. Among these, synthetic hydrocarbon oils are used as a fluid of choice in majority of high temperature solar collector applications while other HTFs are being used with varying degree of experimental maturity and commercial viability -for maximizing their benefits and minimizing their disadvantages. Present paper reviews the recent developments taking place in the area of heat transfer fluids for harnessing solar thermal energy. Refrigerants/phase changing materials: These are low boiling point but high heat capacity substances used in the solar collectors to transfer heat in applications like solar space cooling and heating, refrigerators, air conditioning, etc [7]. These materials absorb heat from the solar collectors, produce work either by expanding in a turbo-generator of a vapor compression cycle or by dissociating the refrigerant from its absorbent in a vapor absorption cycle [8]. In some of the relatively high temperature applications, higher boiling point refrigerants are used as indirect heat transfer fluids, wherein the heat collected from the solar collectors is transferred to another fluid like water from where the refrigerants pick-up heat to do the required work in the turbo-generators [9,10]. Recent Developments in Heat Transfer

show abstract

“…No que tange ao momento atual do desenvolvimento da tecnologia dos processos de transferência de calor, uma importante área de pesquisa e desenvolvimento refere-se à aplicação de nanofluidos como fluidos de troca térmica dentro de trocadores de calor do tipo casco-tubo como apresentado por Choi et al, (2011), Saeedinia et al, (2012), Azad e Azad (2016), Han et al, (2017), Akyürek et al, (2018).…”

Section: Motivaçãounclassified

Síntese e caracterização de nanofluidos para aplicação em sistemas térmicos

Oliveira¹

View full text Add to dashboard Cite

iii À minha mãe Regina, exemplo de vida, força, fé e amor.Ao meu esposo Elias, companheiro, amigo e motivador de todas as minhas conquistas.E, ao progresso da ciência! iv "Nothing in life is to be feared, it is only to be understood. Now is the time to understand more, so that we may fear less." Marie Curie v AGRADECIMENTOSAgradeço à Deus por sempre guiar o meu caminho.À minha família pela educação e por toda a sua contribuição para o meu crescimento.Ao Prof. Dr. Enio Pedone Bandarra Filho pela confiança em mim depositada, acolhimento, oportunidade e orientação desta Tese. AbstractThe goals of this work were to study the synthesis and characterization of the thermophysical properties of various types of nanofluids in order to evaluate their application in thermal exchange systems. For this, nanofluids of aqueous base, base oil and ethylene glycol base were prepared and studied, containing six types of nanoparticles: TiO2, Ag, Cu, MWCNT, diamond and graphene. Hybrid nanoparticles (Diamond-Nickel, MWCNT-Ag, graphene-Ag) and functionalized surface MWCNT-COOH, Di-COOH and TiO2-PVA were also produced. For the structural characterization of the nanoparticles, X-ray diffraction (XRD), Raman spectroscopy and infrared (FTIR) techniques were used, as well as transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images. The synthesis of the nanofluids consisted of the application of the "two-step" method, using sonication processes and high pressure homogenization to disperse the nanoparticles, using volumetric concentrations ranging from 0.00125% to 0.1%, and mass concentrations of 0.05 to 1.0 wt%, in base fluids. The thermophysical properties (thermal conductivity and viscosity) were measured experimentally in a temperature range of 10° to 60° C and an increase in both the thermal conductivity and the viscosity were observed with the increase in the volumetric fraction of nanoparticles and with the temperature. The stability of the nanofluids was evaluated by the sedimentation observation method. In general, nanofluids without stabilizers remained stable for a few weeks. The experimental results, obtained for thermal conductivity, revealed a maximum increase of 10.67% for diamond nanofluids in mineral oil with oleic acid as stabilizing agent. The maximum increase in viscosity was obtained for nanofluidos of MWCNT, being 1.6 times greater than the viscosity of the water. The results, of thermal conductivity, viscosity and specific mass, were still compared with the classic models of the literature. Thus, the studies of the synthesis and characterization of nanofluids revealed an increase of the thermal conductivity with the dispersion of nanoparticles being a promising alternative as fluids applied in processes of thermal changes.

show abstract

Thermal and rheological characteristics of CuO–Base oil nanofluid flow inside a circular tube

Cited by 179 publications

References 16 publications

Thermal Performance of Carbon Nanotube Nanofluids in Solar Microchannel Collectors: an Experimental Study

Thermal Performance of Carbon Nanotube Nanofluids in Solar Microchannel Collectors: an Experimental Study

Recent Developments in Heat Transfer Fluids Used for Solar Thermal Energy Applications

Síntese e caracterização de nanofluidos para aplicação em sistemas térmicos

Contact Info

Product

Resources

About