In Search of a “Stable Green Nanofluid” for Applications in High Voltage Equipment

Nanofluids are considered as the next generation of dielectric fluids due to their higher thermal conductivity and dielectric properties. In this investigation, locally produced ester oils, such as rice bran oil (RBO) and jatropha oil (JO), were compared with mineral oil (MO). Initially, hydrophilic SiO2 nano particles were used to prepare nanofluids using RBO and MO. However, results showed that with loading of nanoparticles (NPs) up to 0.075 g/L, the dielectric strength (DS) of MO based NFs increased but decreased drastically with further increase in loading as these suffered agglomeration and sedimentation in less than 72 h. To overcome this drawback, NPs were functionalized under plasma discharge. These efforts also did not yield many favorable results. Instead, hydrophobic fumed silica NPs grafted with hexamethyldi-siloxane (HMDS) were utilized for further study. Plasma treated NFs exhibited improved DS, as well as excellent dispersibility and stability.

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Viscosity behaviour and thermal conductivity prediction of CuO-blend oil based nano-blended lubricant

Proceedings of the Institution of Mechanical Engineers Part J Journal of Engineering Tribology ◽

10.1177/1350650118819634 ◽

2018 ◽

Vol 233 (8) ◽

pp. 1154-1168 ◽

Cited By ~ 1

Author(s):

Dhananjay C Katpatal ◽

Atul B Andhare ◽

Pramod M Padole

Keyword(s):

Thermal Conductivity ◽

Mineral Oil ◽

Cuo Nanoparticles ◽

Jatropha Oil ◽

Step Method ◽

Viscosity Models ◽

Thermal Conductivity Model ◽

Experimental Values ◽

Surface Modified ◽

Edible Vegetable Oil

Lubricants play a major role in mechanical machines and studies on various nanolubricants are reported in the literature. This work deals with nanolubricants using blend of oils as base for nanolubricants. Nano-blended lubricants were prepared with a blend of ISO VG46 oil (mineral oil) and Jatropha oil (non-edible vegetable oil) and using them in proportions of 90:10 and 80:20 by dispersing 0.5–3 wt.% of surface-modified CuO nanoparticles by a two-step method. Various properties of these oils such as dispersion stability, viscosity and thermal conductivity were determined. Experimental values of viscosity were compared with the values predicted by using different viscosity models. Nano-blended lubricant 9010 was found more sensitive at lower concentration of nanoparticles compared to nano-blended lubricant 8020. It is observed that nano-blended lubricant 9010 with 1.5 wt.% CuO is more suitable for use in place of ISO VG46 oil compared to nano-blended lubricant 8020. Thermal conductivity values of all types of nano-blended lubricants have been found by thermal conductivity model to be approximately matching with the measured values.

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ENHANCING HEAT TRANSFER COEFFICIENT AND BREAKDOWN STRENGTH OF MINERAL OIL BY (AL2O3 AND TIO2) NANOPARTICLES

Journal of Engineering and Sustainable Development ◽

10.31272/jeasd.conf.2.2.5 ◽

2021 ◽

Vol 25 (Special) ◽

pp. 2-33-2-38

Author(s):

Mohammad M. Ali ◽

◽

Amer H. Majeed ◽

Keyword(s):

Heat Transfer ◽

Heat Transfer Coefficient ◽

Thermal Properties ◽

Transfer Coefficient ◽

Breakdown Strength ◽

Dielectric Strength ◽

Mineral Oil ◽

Nano Particles ◽

Paper Study ◽

Enhancing Heat Transfer

The aims of this paper study the effects of two types of nanoparticle on dielectric strength and heat transfer coefficient within mineral oil used in an electrical transformer. These nanoparticles (NPs) including (semi conductive TiO2 and insulating Al2O3), have been prepared with the same size and surface modification, it is shown that nano-particles enhance insulating and thermal properties of mineral oil as well as the degree of enhancement is dependent on the NPs concentration.

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A Study of Some Mechanical and Physical Properties for Palm Fiber/Polyester Composite

Engineering and Technology Journal ◽

10.30684/etj.v38i3b.598 ◽

2020 ◽

Vol 38 (3B) ◽

pp. 104-114

Author(s):

Samah M. Hussein

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Dielectric Constant ◽

Date Palm ◽

Volume Fraction ◽

Unsaturated Polyester ◽

Dielectric Strength ◽

Palm Fiber ◽

Mechanical And Physical Properties ◽

Polyester Composite

This research has been done by reinforcing the matrix (unsaturated polyester) resin with natural material (date palm fiber (DPF)). The fibers were exposure to alkali treatment before reinforcement. The samples have been prepared by using hand lay-up technique with fiber volume fraction of (10%, 20% and 30%). After preparation of the mechanical and physical properties have been studied such as, compression, flexural, impact strength, thermal conductivity, Dielectric constant and dielectric strength. The polyester composite reinforced with date palm fiber at volume fraction (10% and 20%) has good mechanical properties rather than pure unsaturated polyester material, while the composite reinforced with 30% Vf present poor mechanical properties. Thermal conductivity results indicated insulator composite behavior. The effect of present fiber polar group induces of decreasing in dielectric strength, and increasing dielectric constant. The reinforcement composite 20% Vf showed the best results in mechanical, thermal and electrical properties.

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Effects of Plasma Treated Alumina Nanoparticles on Breakdown Strength, Partial Discharge Resistance, and Thermophysical Properties of Mineral Oil-Based Nanofluids

Materials ◽

10.3390/ma14133610 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3610

Author(s):

Norhafezaidi Mat Saman ◽

Izzah Hazirah Zakaria ◽

Mohd Hafizi Ahmad ◽

Zulkurnain Abdul-Malek

Keyword(s):

Thermal Conductivity ◽

Plasma Treatment ◽

Base Fluid ◽

Breakdown Strength ◽

Partial Discharge ◽

Mineral Oil ◽

Transformer Oil ◽

Alumina Nanoparticles ◽

Discharge Characteristics ◽

Nano Alumina

Mineral oil has been chosen as an insulating liquid in power transformers due to its superior characteristics, such as being an effective insulation medium and a great cooling agent. Meanwhile, the performance of mineral oil as an insulation liquid can be further enhanced by dispersing nanoparticles into the mineral oil, and this composition is called nanofluids. However, the incorporation of nanoparticles into the mineral oil conventionally causes the nanoparticles to agglomerate and settle as sediment in the base fluid, thereby limiting the improvement of the insulation properties. In addition, limited studies have been reported for the transformer oil as a base fluid using Aluminum Oxide (Al2O3) as nanoparticles. Hence, this paper reported an experimental study to investigate the significant role of cold plasma treatment in modifying and treating the surface of nano-alumina to obtain a better interaction between the nano-alumina and the base fluid, consequently improving the insulation characteristics such as breakdown voltage, partial discharge characteristics, thermal conductivity, and viscosity of the nanofluids. The plasma treatment process was conducted on the surface of nano-alumina under atmospheric pressure plasma by using the dielectric barrier discharge concept. The breakdown strength and partial discharge characteristics of the nanofluids were measured according to IEC 60156 and IEC 60270 standards, respectively. In contrast, the viscosity and thermal conductivity of the nanofluids were determined using Brookfield DV-II + Pro Automated viscometer and Decagon KD2-Pro conductivity meter, respectively. The results indicate that the 0.1 wt% of plasma-treated alumina nanofluids has shown the most comprehensive improvements in electrical properties, dispersion stability, and thermal properties. Therefore, the plasma treatment has improved the nanoparticles dispersion and stability in nanofluids by providing stronger interactions between the mineral oil and the nanoparticles.

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