Preparation and Characterization of Transformer Oil Based Nano Fluids

2019 ◽  
Vol 895 ◽  
pp. 218-223
Author(s):  
N. Kishore ◽  
H.N. Vidyasagar ◽  
D.K. Ramesha
Keyword(s):  
Thermal Conductivity ◽  
Heat Exchangers ◽  
Volume Concentration ◽  
Experimental Studies ◽  
Cuo Nanoparticles ◽  
Transformer Oil ◽  
Preparation Methods ◽  
One Step ◽  
Nano Fluids

This paper is concerned with the preparation and characterization of transformer oil based nanofluids with the suspensions of Al2O3 and CuO nanoparticles . As a part of experimental study the transformer oil based nanofluids for heat exchangers in transformer cooling application, preparation and characterization has been performed. The preparation of nanofluids is the first key step in experimental studies with nanofluids. One step technique and two step technique are generally used for preparing the nanofluids. This work deals with the preparation methods of (Al2O3-Transformer oil ,CuO-Transformer oil) and characterizing the transformer oil based nanofluids of different volume concentrations (0.05%, 0.1%, 0. 5%, 1.0% and 1.5%).From the results it is revealed that increasing the volume concentration resulted in increase in thermal conductivity, viscosity of the nanofluid and decrease in density and specific heat of nanofluid.

Facile synthetic strategy of oleophilic zirconia nanoparticles allows preparation of highly stable thermo-conductive coolant

RSC Advances ◽  
2014 ◽  
Vol 4 (53) ◽  
pp. 28020-28028 ◽  
Author(s):  
Thadathil S. Sreeremya ◽  
Asha Krishnan ◽  
Lakshmi Narayan Satapathy ◽  
Swapankumar Ghosh
Keyword(s):  
Thermal Conductivity ◽  
Transformer Oil ◽  
Synthetic Strategy ◽  
One Step ◽  
Enhanced Thermal Conductivity ◽  
Zirconia Nanoparticles

A simple one-step synthetic strategy was adopted for fabricating oil dispersable zirconia nanoparticles which produced a remarkably stable nanofluid in transformer oil with enhanced thermal conductivity for cooling applications.

scholarly journals CHARACTERIZATION OF HEAT CONDUCTIVITY OF ECCENTRICALLY ROTATING HEAT PIPES USED FOR COOLING OF MOTOR SPINDLES

2021 ◽  
Vol 2021 (3) ◽  
pp. 4698-4705
Author(s):  
B. Denkena ◽  
◽  
B. Bergmann ◽  
K. Kono ◽  
R. Ishiguro ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Pipe ◽  
Heat Exchangers ◽  
Thermal Characteristics ◽  
Heat Pipes ◽  
Simulation Based ◽  
Wick Structure ◽  
Parameter Values

Heat losses within motor spindles lead to undesired effects such as machining inaccuracies and de-creasing lifetime of the motor and bearings. To reduce thermal loads, complex shaft cooling concepts with costly sealing techniques exist. For this reason, a novel, less costly cooling concept has been de-veloped based on heat pipes with high thermal conductivity and fin-shaped heat exchangers. The de-sign and integration of these heat exchanger elements into a motor spindle is carried out using the fi-nite element method. The aim is to optimize the efficiency of the heat pipes and heat exchangers for optimal shaft cooling performance. For a simulation-based development of a prototype spindle, un-known thermal characteristics of the heat transfer elements must be determined. In this paper, the de-termination of the thermal conductivity of the heat pipes is described. The determination of conductivi-ty is done experimentally. First, the developed test rig and the applied procedure for the determination of the conductivity are shown. Subsequently, the experimental results are presented and discussed. Two types of heat pipes were analyzed: Copper heat pipes with sintered wick structure and nickel-plated copper heat pipes with axial grooves. The influences of rotational speed, heat flow rates and the angle between the heat pipe and main axis of rotation were investigated. The results indicate a distinct dependency of the conductivity on the varied parameters. However, changes of parameter values have very different quantitative and qualitative effects on the determined conductivities de-pending on the type of heat pipe.

scholarly journals Improving the thermal performance of electrical transformers using hybrid mixture of (transformer oil, nanoparticles, and PCM)

2020 ◽  
Vol 13 (3) ◽  
pp. 175-182
Author(s):  
Mushtaq I. Hasan ◽  
Adnan A. Ugla ◽  
Hassan S. Kadhim
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Volume Concentration ◽  
Transformer Oil ◽  
Paraffin Wax ◽  
Smelting Process ◽  
Distribution Transformer ◽  
Cooling Performance ◽  
Electrical Transformers ◽  
A New Technique

In this paper, an experimental electrical distribution transformer was studied and a new technique was proposed to improve the performance of a new mixed cooling consisting of pure transformer oil, paraffin wax and nanoparticles. The experiment was carried out on a small transformer that was done by taking a model with dimensions (15 * 10 * 10) cm to facilitate calculations. Paraffin wax absorbs the heat generated in the transformer due to the smelting process that can be used to cool electrical appliances. Nanoparticles have good thermal properties and lead to increased oil insulation to thermal improvements in transformer oil with dispersal of solid nanoparticles and their effects on transformer cooling. Three types of solid nanoparticles were used in this experiment (Al2O3, TiO2, and Sic) with a different volume concentration (1%, 3%, and 5%) and 4% paraffin wax as a certified added percentage for each process. The obtained results showed that when mixing paraffin wax and solid nanoparticles with transformer oil, the transformer cooling performance is improved by reducing the temperature. The best selected nanoparticles were found to be Sic and the reason for this is that Sic has a higher thermal conductivity compared to (Al2O3 and TiO2). The proposed hybrid oil reduces the temperature by 10 ° C (in the case of PCM and Sic) and it is possible to improve the cooling performance of electrical transformers.

scholarly journals Processing and Generalization of Experimental Data on Thermal Diffusivity and Thermal Conductivity of Magnetic Fluids Depending on the Impact of the Magnetic Field

2021 ◽  
Vol 27 (2) ◽  
pp. 231-237
Author(s):  
D. S. Dzhuraev
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Thermal Conductivity ◽  
Thermal Diffusivity ◽  
Iron Powder ◽  
Experimental Studies ◽  
Magnetic Fluids ◽  
Transformer Oil ◽  
The Impact ◽  
The Magnetic Field

The paper presents the results of experimental studies of the thermal diffusivity and thermal conductivity of magnetic fluids based on transformer oil, depending on the effect of a magnetic field in the range of B = 1.59...3.866 mT, and the addition of iron powder 0.1...0.3 g with an interval of 0.05 g. Equations were obtained for calculation with a certain fraction of error in thermal diffusivity and thermal conductivity of unexplored magnetic fluids.

scholarly journals Preparation and characterization of CuO/Muscovite flakes pearlescent pigment with UV absorption and high NIR reflectance

2019 ◽  
Vol 2 (2) ◽  
pp. 265-270
Author(s):  
Yuksel AKINAY ◽  
Ihsan Nuri AKKUŞ
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Near Infrared ◽  
Sol Gel ◽  
Cuo Nanoparticles ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Ultraviolet Shielding ◽  
Pearlescent Pigment

The CuO nanoparticles were deposited onto muscovite flakes using sol-gel methods. The thermal, conductivity, optic and structural properties of obtained pigments (CuO/Muscovite) were studied. Hence, the prepared pigments were characterized via using scanning electronic microscopy (SEM) and ultraviolet–visible spectrophotometer (UV-Vis). The results show that CuO was coated on the surface of muscovite flakes uniformly. The obtained pigments show the more stable thermal properties than those obtained from undeposited flakes. The CuO/Muscovite pigments showed high ultraviolet shielding performance. In addition that CuO/Muscovite pigments exhibited higher near-infrared (NIR) reflectance than those of pure-CuO.

Characterization of Interconnect Defects Using Scanning Thermal Conductivity Microscopy

2004 ◽  
Author(s):  
H.W. Ho ◽  
J.C.H. Phang ◽  
A. Altes ◽  
L.J. Balk
Keyword(s):  
Thermal Conductivity ◽  
Integrated Circuits ◽  
Large Scale

Abstract In this paper, scanning thermal conductivity microscopy is used to characterize interconnect defects due to electromigration. Similar features are observed both in the temperature and thermal conductivity micrographs. The key advantage of the thermal conductivity mode is that specimen bias is not required. This is an important advantage for the characterization of defects in large scale integrated circuits. The thermal conductivity micrographs of extrusion, exposed and subsurface voids are presented and compared with the corresponding topography and temperature micrographs.

Synthesis and characterization of L-threonine ammonium bromide: grown on single crystal with experimental studies on NLO

2021 ◽  
Vol 44 (3) ◽  
Author(s):  
T KALAIARASI ◽  
M SENTHILKUMAR ◽  
S SHANMUGAN ◽  
T JARIN ◽  
V CHITHAMBARAM ◽  
...  
Keyword(s):  
Single Crystal ◽  
Experimental Studies ◽  
Synthesis And Characterization ◽  
Ammonium Bromide

scholarly journals Experimental Investigation and Comparison of the Thermal Performance of Additively and Conventionally Manufactured Heat Exchangers

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 574
Author(s):  
Ana Vafadar ◽  
Ferdinando Guzzomi ◽  
Kevin Hayward
Keyword(s):  
Surface Roughness ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
High Efficiency ◽  
Cooling System ◽  
Fluid Dynamic ◽  
Dynamic Performance ◽  
Experimental Studies ◽  
Manufacturing Method ◽  
Industrial Sectors

Air heat exchangers (HXs) are applicable in many industrial sectors because they offer a simple, reliable, and cost-effective cooling system. Additive manufacturing (AM) systems have significant potential in the construction of high-efficiency, lightweight HXs; however, HXs still mainly rely on conventional manufacturing (CM) systems such as milling, and brazing. This is due to the fact that little is known regarding the effects of AM on the performance of AM fabricated HXs. In this research, three air HXs comprising of a single fin fabricated from stainless steel 316 L using AM and CM methods—i.e., the HXs were fabricated by both direct metal printing and milling. To evaluate the fabricated HXs, microstructure images of the HXs were investigated, and the surface roughness of the samples was measured. Furthermore, an experimental test rig was designed and manufactured to conduct the experimental studies, and the thermal performance was investigated using four characteristics: heat transfer coefficient, Nusselt number, thermal fluid dynamic performance, and friction factor. The results showed that the manufacturing method has a considerable effect on the HX thermal performance. Furthermore, the surface roughness and distribution, and quantity of internal voids, which might be created during and after the printing process, affect the performance of HXs.

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

Materials ◽  
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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