scholarly journals Thermal Oxidating Stabilization and Cleaning from Conductive Impurities of Dielectric Liquid - Esters

2020 ◽  
Vol 6 (9) ◽  
pp. 204-210
Author(s):  
M. Abdullayeva
Keyword(s):  
Dielectric Liquid ◽  
Dielectric Fluid ◽  
Electrophysical Properties ◽  
Adsorption Method ◽  
Oxidative Stabilization ◽  
Electrophysical Parameters

In this work are developed the basic electrophysical properties of the ester- acetoxymethyl-sec.hexyl-o-xylene; methods for its purification and stabilization. There were chosen the adsorption method of thermo-oxidative stabilization to clean dielectric fluid from conductive impurities. As a result of The electrophysical characteristics of the acetoxymethyl-sec.hexyl-o-xylene ester, as well as the method of its purification using alumina, and hydrogenation on a catalyst representing 0.2% palladium on alumina and stabilization using additives NG-2246. As a result of the research, it was possible to obtain an ester with improved electrophysical parameters.

scholarly journals IMPROVEMENT OF THE ELECTRICAL PROPERTIES OF SYNTHETIC LIQUID DIELECTRIC FOR PULSE CAPACITORS

2020 ◽  
pp. 13-18
Author(s):  
Maya Abdullayeva ◽  
Ibrahim Abulfas Habibov
Keyword(s):  
Castor Oil ◽  
Power Plants ◽  
Dielectric Fluid ◽  
Atmospheric Effects ◽  
Electrophysical Properties ◽  
Adsorption Method ◽  
Oxidative Stabilization ◽  
New Energy ◽  
Liquid Impregnation ◽  
Electrophysical Parameters

An increase in electricity generation is possible not only through the construction of power plants, but also through the creation of fundamentally new energy sources. One of the problems of modern electrical engineering is to ensure the reliability of the operation of capacitors at electric field strengths exceeding I50-200MV. In the domestic and foreign capacitor industry, for heavy pulse modes, castor oil (CO) is used as a liquid impregnation. The development of a method for producing a substitute for natural castor oil, which is a universal impregnating liquid in capacitors, is an urgent problem in the electrical industry. Thus, we have developed a method for the production of acetoxymethyl-w.hexyl-o-xylene, the electrophysical properties of which make it possible to use it as an environmentally friendly and promising substitute for natural castor oil. However, there was a problem of stabilization, since compounds of the ester type have (as impregnating liquids in capacitors) a disadvantage, which consists in their sensitivity to light hydrolysis and atmospheric effects. Ester exhibits high stability with respect to air up to 200 °С, therefore, inhibition by the addition of antioxidants is required is not new. In this work developed the basic electrophysical properties of the ester-acetoxymethyl-secondary hexyl-o-xyleole; methods for its purification and stabilization. There were chosen the adsorption method of thermo-oxidative stabilization to clean dielectric fluid from conductive impurities. As a result of the electrophysical characteristics of the acetoxymethyl-secondary hexyl-o-xyleole ester, as well as the method of its purification using alumina, and hydrogenation on a catalyst representing 0.2 % palladium on alumina and stabilization using additives NG-2246. As a result of the research, it was possible to obtain an ester with improved electrophysical parameters

Chip-Ejection Mechanism and Experimental Study of Water Dispersant Dielectric Fluid on Small-Hole EDM

2010 ◽  
Vol 97-101 ◽  
pp. 4111-4115 ◽  
Author(s):  
Ming Rang Cao ◽  
Sheng Qiang Yang ◽  
Wen Hui Li ◽  
Shi Chun Yang
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Tap Water ◽  
Dielectric Liquid ◽  
Small Hole ◽  
Dielectric Fluid ◽  
Tool Electrode ◽  
Machining Quality ◽  
Hole Machining

The small hole EDM is one main method of micro holes machining and applied very widely. But it’s machining efficiency is low and machining stability is bad, which is more obvious because of chip-ejection difficulty when the ratio of length to diameter is rather large. Secondary discharge caused by chip-ejection difficulty not only makes the material removal rate reduce, but also causes geometric tolerance and affects product performance. Based on dispersion mechanism study of the water dispersant, the influence of the water dispersant is analyzed to chip-ejection, material removal rate and machining quality of the high-speed small-hole EDM. By contrasting the machining effect on using tap water with disperser dielectric liquid during electric spark small hole machining, adding the certain proportion disperser in water-based dielectric liquid may increase the material removal rate, decrease the tool wear rate, improve the effective impulse numbers, obviously reduce the second discharge number, and the taper of tool electrode and hole becomes small, so the hole machining quality enhances.

Electrophysical properties of composites based on low density polyethylene and zeolite mineral

2020 ◽  
pp. 65-72
Author(s):  
A. M. Maharramov ◽  
◽  
V. J. Dzhafarov ◽  
M. N. Bayramov ◽  
N. Sh. Aliyev ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Natural Zeolite ◽  
Filler Content ◽  
Charge Carriers ◽  
Electrophysical Properties ◽  
Dielectric Parameters ◽  
Ice Water ◽  
Frequency Dependences ◽  
Electrophysical Parameters ◽  
Properties Of Composites

Dielectric parameters (ε′, tgδ) and electrical conductivity (σ) of samples composites of 60 vol. % LDPE/40 vol. % zeolite, 40 vol. % LDPE/60 vol. % zeolite was measured at frequencies 25 – 106 Hz and a temperature range 293 – 403 K. Composites based on a homogeneous mixture of LDPE with powdered natural zeolite (clinoptiolite and heilandite — Agdag deposit, Azerbaijan) were obtained in the form of film samples 140 – 200 microns and 20 mm in diameter, by hot pressing at a temperature of 403 – 413 K and a pressure of 15 MPa, followed by quenching in a mixture of ice-water. The temperature dependence of the electrophysical parameters of the samples of the composites revealed that the dielectric loss tgδ and electrical conductivity σ increase with increasing filler content, and this is due to an increase in the concentration of charge carriers and their mobility. The study of the frequency dependences ε′ = ƒ(logν), tgδ = ƒ(logν) and logσ = ƒ(logν) showed the presence of two linear regions of the frequency dependences of the electrical conductivity, which vary according to the law σас (ν) ∼ ν0,73, and this is more consistent with the hopping mechanism of the electrical conductivity of LDPE/zeolite composites.

Cooling of a lithium ion battery using phase change material with air/dielectric fluid media: A numerical study

2019 ◽  
Vol 234 (5) ◽  
pp. 722-738 ◽  
Author(s):  
T Amalesh ◽  
N Lakshmi Narasimhan
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Heat Generation ◽  
Lithium Ion ◽  
Dielectric Liquid ◽  
Dielectric Fluid ◽  
Li Ion Batteries ◽  
Fluid Media ◽  
Li Ion ◽  
Change Material

This paper proposes a method of cooling lithium ion (Li-ion) batteries using a phase change material RT35 in combination with air or a dielectric fluid media (STO 50). Three-dimensional numerical investigations have been carried out using Ansys Fluent to assess the cooling performance under different rates of discharging (1C, 2C, and 3C) of a 38120P Li-ion battery. Five different cases have been investigated and the relative benefits of the combined phase change material–air/dielectric liquid cooling compared over an air or dielectric cooling alone for the battery. Actual heat generation data available for the battery was made use of and supplied to the source term of the energy equation in the solver. A separate user-defined macro on the heat generation of the battery was developed by the authors for the purpose. The numerical simulation was validated comparing the present results with published experimental data for a bare adiabatic 38120P Li-ion cell. The results showed that the cooling was better with phase change material–air or phase change material–dielectric liquid combination compared to air or dielectric fluid alone, capable of reducing the cell temperature further by 6 ℃. From the study, employing phase change material in combination with a dielectric liquid has been suggested as a promising option for thermal management of Li-ion batteries at higher discharging rates to maintain the cell temperatures below 37 ℃.

Experimental Analysis of Canola Oil as Dielectric Fluid in Electric Discharge Machining of AISI D2 Steel

2020 ◽  
Vol 978 ◽  
pp. 49-54
Author(s):  
Kusumba Mangapathi Rao ◽  
D. Vinay Kumar ◽  
K.Chandra Shekar ◽  
Balasubramaniyan Singaravel
Keyword(s):  
Electric Discharge ◽  
Canola Oil ◽  
Removal Rate ◽  
Dielectric Liquid ◽  
Dielectric Fluid ◽  
Work Piece ◽  
Electrode Wear ◽  
Electric Discharge Machining ◽  
Plasma Generation ◽  
Aisi D2

Electric Discharge Machining (EDM) is a thermo-electrical disintegration process, utilized to cut hard materials into complex shapes. In EDM, the three vital components are work-piece material, electrode material and dielectric liquid. The significant function of the dielectric fluid is to produce a breakdown voltage for creating a spark between work-piece and electrode. This spark creates ionization by plasma generation and it expels the material from work-piece. In most cases, hydrocarbon-based dielectric liquid is preferred in the EDM process. This kind of dielectric liquid generates hazardous gases which are harmful to people, environment and ecological balances. In this experiment, Canola oil is utilized and the outcomes are compared. The input parameters are Pulse on/off time, current and gap voltage. Copper, Brass and Tungsten-Copper (Alloy) are used as electrodes. The output values from the experiments are Surface Roughness (SR), Electrode Wear Rate (EWR) and Material Removal Rate (MRR). The outcomes demonstrated that Canola oil-based dielectric fluid has comparable properties of conventional based dielectric fluid. This Canola based dielectric gives more prominent MRR value than EDM oil-based dielectric liquid and furthermore higher EWR and SR values are recorded. The proposed Canola oil-based dielectric fluid is biodegradable and has improved suitability in machining.

scholarly journals Electrophysical Properties of the PMN–PT–PS Solid Solution

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1292
Author(s):  
Dariusz Bochenek ◽  
Ryszard Skulski ◽  
Przemysław Niemiec
Keyword(s):  
Solid Solution ◽  
Energy Dispersive Spectrometry ◽  
Sol Gel ◽  
Rhombohedral Phase ◽  
Electrophysical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ceramic Samples ◽  
Microstructure Measurements ◽  
Electrophysical Parameters

The (1 − y) ((1 − x)Pb(Mg1/3Nb2/3)O3–xPbTiO3)–yPbSnO3 solid solution (PMN–PT–PS) was obtained and investigated in the present paper. For the analysis of the influence of the PbSnO3 component on the electrophysical parameters, the compositions from the rhombohedral phase, tetragonal phase, and a mixture of these phases were selected. The six compositions of the PMN–PT have been obtained using sol–gel methods (for values of x equal to 0.25, 0.28, 0.31, 0.34, 0.37, and 0.40). The ceramic samples of the 0.9(PMN–PT)–0.1(PS) solid solution have been obtained using the conventional ceramic route. X-ray diffraction (XRD), energy dispersive spectrometry (EDS), and microstructure measurements were performed, as well as tests regarding the dielectric, ferroelectric, piezoelectric properties and electric conductivity of the PMN–PT–PS ceramic samples versus temperature. Results of the measurements show that the obtained PMN–PT–PS materials have good electrophysical properties and are well suited for use in micromechatronic and microelectronic applications.

scholarly journals Generation and Transport of Dielectric Droplets along Microchannels by Corona Discharge

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 181
Author(s):  
Qiang Tang ◽  
Shangru Zhou ◽  
Ruiheng Hu ◽  
Huai Zheng ◽  
Junheng Pan ◽  
...  
Keyword(s):  
Corona Discharge ◽  
Simple Approach ◽  
Dielectric Liquid ◽  
Dielectric Fluid ◽  
Spreading Speeds

In this paper, a phenomenon of generation and transport of droplets is proposed, which is based on the dielectric liquid electroconvection induced by corona discharge. We placed the dielectric fluid on a conductive/nonconductive substrate, and then it broke apart to become many small droplets that move along the conductive microchannel. The behaviors of dielectric droplets were experimentally observed on different conductive microchannels in details. Spreading speeds and sizes of dielectric droplets were analyzed at different driving voltages and conductive microchannels. This work highlights a simple approach to produce and manipulate dielectric droplets along microchannels.

Optical and Infrared Study of the Effect of a High Electric Field on the Pool Boiling Behavior of a Sub-Cooled Dielectric Liquid

2017 ◽  
Author(s):  
Sathiyanathan Sargunanathan ◽  
Abhishek Basavanna ◽  
Navdeep S. Dhillon ◽  
Seyed Reza Mahmoudi
Keyword(s):  
Heat Transfer ◽  
Electric Field ◽  
Applied Electric Field ◽  
Boiling Heat Transfer ◽  
Imaging Techniques ◽  
Pool Boiling ◽  
Bubble Nucleation ◽  
Dielectric Liquid ◽  
Dielectric Fluid ◽  
Nucleation Behavior

The formation and departure of bubbles on hot surfaces is of fundamental significance in many engineering applications including in boiling heat transfer. Both the bubble growth behavior and the boiling heat transfer performance parameters are affected by different variables and conditions, an interesting one of which is the electric field. Understanding its effect is of considerable significance, as it has been observed experimentally that the application of an electric field can lead to a significant enhancement in the boiling critical heat flux of a dielectric fluid. Although the exact physical mechanism behind this effect is not well understood, we hypothesize that it could be correlated to the effect of the electric field on individual evaporating bubbles and their altered interactions with the boiling surface. In this study, we employ optical and infrared imaging techniques to experimentally illustrate the effect of an applied electric field on the behavior of bubbles in sub-cooled pool boiling of a dielectric liquid (HFE-7100). Results indicate that bubble nucleation behavior, bubble geometry, and the bubble three-phase contact line dynamics are all simultaneously affected by the electric field. To help explain the experimental results, we further implement a CFD numerical model of an individual vapor bubble in the presence of an applied electric field.

Modeling of a sensitive element on a planar mushroom-shaped metamaterial for non-destructive testing and searching for inhomogeneities in technological media

2020 ◽  
pp. 54-59
Author(s):  
A. A. Yelizarov ◽  
A. A. Skuridin ◽  
E. A. Zakirova
Keyword(s):  
Sensitive Element ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Resonant Frequency Shift ◽  
Maltese Cross ◽  
Informative Parameters ◽  
Non Destructive ◽  
Cross Type ◽  
Electrodynamic Structure ◽  
Electrophysical Parameters

A computer model and the results of a numerical experiment for a sensitive element on a planar mushroom-shaped metamaterial with cells of the “Maltese cross” type are presented. The proposed electrodynamic structure is shown to be applicable for nondestructive testing of geometric and electrophysical parameters of technological media, as well as searching for inhomogeneities in them. Resonant frequency shift and change of the attenuation coefficient value of the structure serve as informative parameters.

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