Recent progress in nanofluids based on transformer oil: preparation and electrical insulation properties

Lv, Yuzhen; Zhou, Yiyang; Li, C. R.; Wang, Q.; Qi, Bo

doi:10.1109/mei.2014.6882597

Cited by 136 publications

(64 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It was observed that improvements with the same nanoparticles, such as Madawan et al [23], are two times higher than the ones reported by these authors. Also, our findings confirm those reported by a number of authors [13,[19][20][21][22][23] and contradict others [26] regarding concerns of the influence of Al2O3 and Fe3O4 nanoparticles on the breakdown voltage of mineral oil.…”

Section: Discussionsupporting

confidence: 89%

AC Dielectric Strength of Mineral Oil-Based Fe3O4 and Al2O3 Nanofluids

Khaled

Béroual

2018

Energies

View full text Add to dashboard Cite

This paper deals with an experimental study of the influence of conductive (Fe 3 O 4 ) and insulating (Al 2 O 3 ) nanoparticles at various concentrations on the dielectric strength of transformer mineral oil. The method of preparation and characterization of these nanofluids (NFs) through the measurements of zeta potential, the real and imaginary parts of dielectric permittivity as well as the concentration and size of nanoparticles using scanning electron microscope images of nanoparticles powders and energy dispersive x-ray spectroscopy analysis are presented. Experimental findings reveal that these two types of nanoparticles materials significantly improve AC breakdown voltage and the magnitude of this enhancement depends on the nanoparticle concentration, and the size and nature (material) of nanoparticles. For a given type of nanoparticle, the effect is more marked with the smallest nanoparticles. The conductive nanoparticles offer higher enhancement of dielectric strength compared with insulating nanoparticle based nanofluids. With Fe 3 O 4 , the breakdown voltage (BDV) can exceed twice that of mineral oil and it increases by more than 76% with Al 2 O 3 . The physicochemical mechanisms implicated in this improvement are discussed. Energies 2018, 11, 3505 2 of 13This cooling property (heat transfer) was at the origin of NFs' development. Nowadays, NFs are used in several fields, like electronics (chips, electronic circuitry components); transportation (the cooling systems of heavy power machines and heat generation parts of vehicles); heating buildings and reducing pollution; nuclear cooling systems; space and defense (space stations and aircrafts); and solar absorption for heat-transfer performance. Indeed, they have preferable better thermal characteristics (thermal diffusivity, thermal conductivity, convective coefficient of heat transfer) than the base fluids. These strongly depend on properties and the volume fraction of the added nanomaterial [7,8]. Furthermore, for a given particles volume, the contact area of the solid-liquid surface between nano-size particles and the suspension fluid is greater than that for micro-size particles. Therefore, the shape and size of particles has a clear impact on heat transfer and thermal conductivity characteristics [9][10][11].The volume fraction of particles (concentration), their shape and size, and the surface contact area between particles and liquid are major parameters that influence not only the thermal properties as indicated above, but also have a very great influence on the dielectric properties of composite materials.

show abstract

Section: Discussionsupporting

confidence: 89%

AC Dielectric Strength of Mineral Oil-Based Fe3O4 and Al2O3 Nanofluids

Khaled

Béroual

2018

Energies

View full text Add to dashboard Cite

show abstract

“…NE-based nanofluids have higher dielectric strength, cooling efficiency, and ability to withstand electrical discharges [9,10]. For instance, the discovered role of nanoparticles when being dispersed into base oil is to energise the potential well.…”

Section: Introductionmentioning

confidence: 99%

Influence of Conductive and Semi-Conductive Nanoparticles on the Dielectric Response of Natural Ester-Based Nanofluid Insulation

et al. 2018

View full text Add to dashboard Cite

Nowadays, studies of alternative liquid insulation in high voltage apparatus have become increasingly important due to higher concerns regarding safety, sustainable resources and environmentally friendly issues. To fulfil this demand, natural ester has been extensively studied and it can become a potential product to replace mineral oil in power transformers. In addition, the incorporation of nanoparticles has been remarkable in producing improved characteristics of insulating oil. Although much extensive research has been carried out, there is no general agreement on the influence on the dielectric response of base oil due to the addition of different amounts and conductivity types of nanoparticle concentrations. Therefore, in this work, a natural ester-based nanofluid was prepared by a two-step method using iron oxide (Fe 2 O 3 ) and titanium dioxide (TiO 2 ) as the conductive and semi-conductive nanoparticles, respectively. The concentration amount of each nanoparticle types was varied at 0.01, 0.1 and 1.0 g/L. The nanofluid samples were characterised by visual inspection, morphology and the dynamic light scattering (DLS) method before the dielectric response measurement was carried out for frequency-dependent spectroscopy (FDS), current-voltage (I-V), and dielectric breakdown (BD) strength. The results show that the dielectric spectra and I-V curves of nanofluid-based iron oxide increases with the increase of iron oxide nanoparticle loading, while for titanium dioxide, it exhibits a decreasing response. The dielectric BD strength is enhanced for both types of nanoparticles at 0.01 g/L concentration. However, the increasing amount of nanoparticles at 0.1 and 1.0 g/L led to a contrary dielectric BD response. Thus, the results indicate that the augmentation of conductive nanoparticles in the suspension can lead to overlapping mechanisms. Consequently, this reduces the BD strength compared to pristine materials during electron injection in high electric fields.

show abstract

“…The nanoparticles can be directly prepared via physical vapor deposition technique or liquid chemical method. Therefore, the process of drying, storage, dispersion, and transportation is avoided, so that agglomeration is minimized and, hence, nanoparticle dispersion in the host fluid is improved [15]. The main demerit of this process is that the residue of reactants is left behind in the nanofluid due to incomplete reaction or stabilization which diminishes the purity of the nanofluid [92].…”

Section: Preparation Of Nanofluidsmentioning

confidence: 99%

Critical Review on Nanofluids: Preparation, Characterization, and Applications

Jama

Singh

Gamaleldin

et al. 2016

Journal of Nanomaterials

121

View full text Add to dashboard Cite

Heat transfer fluids are a crucial parameter that affects the size and costs of heat exchangers. However, the available coolants like water and oils have low thermal conductivities, which put many limitations to the development of heat transfer to achieve high performance cooling. The need for development of new classes of fluids which enhance the heat transfer capabilities attracted the attention of many researchers. In the last few decades, modern nanotechnology developed nanoparticles, which have unique thermal and electrical properties that could help improve heat transfer using nanofluids. A “nanofluid” is a fluid with suspended fine nanoparticles which increases the heat transfer properties compared with the original fluid. Nanofluids are considered a new generation of heat transfer fluids and are considered two-phase fluids of liquid solid mixtures. The efficiency of the fluid could be improved by enhancing its thermal properties, especially the thermal conductivity, and it is expected that the nanofluids will have a greater thermal conductivity than the base fluids. This paper reviews the preparation of metallic and nonmetallic nanofluids along with the stability of the produced nanofluids. Physical and thermal properties as well as a range of applications are also discussed in detail.

show abstract

Recent progress in nanofluids based on transformer oil: preparation and electrical insulation properties

Cited by 136 publications

References 40 publications

AC Dielectric Strength of Mineral Oil-Based Fe3O4 and Al2O3 Nanofluids

AC Dielectric Strength of Mineral Oil-Based Fe3O4 and Al2O3 Nanofluids

Influence of Conductive and Semi-Conductive Nanoparticles on the Dielectric Response of Natural Ester-Based Nanofluid Insulation

Critical Review on Nanofluids: Preparation, Characterization, and Applications

Contact Info

Product

Resources

About