scholarly journals Finite Element Solution of the Corona Discharge of Wire-Duct Electrostatic Precipitators at High Temperatures—Numerical Computation and Experimental Verification

Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1406
Author(s):  
Hamdy A. Ziedan ◽  
Hegazy Rezk ◽  
Mujahed Al-Dhaifallah ◽  
Emad H. El-Zohri
Keyword(s):  
Finite Element ◽  
High Temperature ◽  
High Temperatures ◽  
Current Density ◽  
Electrostatic Field ◽  
Field Potential ◽  
Simulation Method ◽  
Onset Voltage ◽  
Electrostatic Precipitators ◽  
High Voltage Engineering

Global warming is the greatest challenge faced by humankind, and the only way to reduce or totally eliminate its effects is by minimizing CO2 emissions. Electrostatic precipitators are very useful as a means to reduce emissions from heavy industry factories. This paper aims to examine the performance of wire-duct electrostatic precipitators (WDESP) as affected by high-temperature incoming gases with a varying number of discharge wires while increasing their radius. The precipitator performance is expressed in terms of the corona onset voltage on the stressed wires and the corona current–voltage (I–V) characteristic of the precipitators working with incoming gases at high temperatures. The start of the corona onset voltage on the surface of the discharge wires is calculated for the precipitators under high temperatures based on the standard of the self-repeat of avalanches’ electrons developing on the surface of the stressed wires at high temperatures. For this, calculating the electrostatic field in the precipitators with single- and multi-discharge wires due to the stressed wire with the use of the well-known charge simulation method (CSM) with high-temperature incoming gases is important. The modeling of corona I–V characteristics is adopted using the finite element method (FEM) for single- and multi- (3-, 5-, and 7-) discharge wires of WDESP with high-temperature incoming gases. Additionally, the electrostatic field, potential, and space charge of WDESP are calculated by a simultaneous solution of equations of Poisson, current density, and the continuity current density. A WDESP was set up in the Laboratory of High Voltage Engineering of Czech Technical University (CTU) in Prague, the Czech Republic, to measure the corona onset voltage values and corona I–V characteristics for different WDESP configurations at high temperatures with a varying number of discharge wires while increasing their radius. The calculated values of the corona onset voltage based on CSM and the calculated corona I–V characteristics based on FEM agree reasonably with those measured experimentally with high-temperature WDESP.

An Equivalent Electrode System for Efficient Charging of Filtration Media

2016 ◽  
Vol 3 (3) ◽  
pp. 646
Author(s):  
Mohamed Anwar Abouelatta ◽  
Abdelhadi R Salama
Keyword(s):  
Genetic Algorithms ◽  
Electrostatic Field ◽  
Simulation Method ◽  
Electrode System ◽  
Laboratory Measurements ◽  
Charge Simulation Method ◽  
Accurate Calculation ◽  
Filtration Process ◽  
Onset Voltage ◽  
Ground Plate

<p>This paper concerns the influence of moving an auxiliary limiting cylinder in X-Y directions on the electrostatic field and corona onset voltage of the dual electrode system employed in the electrostatic filtration process resulting in a “Tri-electrode” system. The Tri-electrode system is applied in order to control the field around the ionized wire and on the ground plate. Accurate calculation of the electrostatic field is obtained using the charge simulation method coupled with genetic algorithms. The calculated field values are utilized in computing the corona onset voltage of the ionized electrode. Laboratory measurements of the onset voltage of the ionized electrode are applied. It is found that the limiting cylinder controls the onset voltage of the ionized wire such that the ionized wire may be in ionized or non-ionized state without changing the position of the ionized wire itself. The numerical onset voltage values agreed satisfactorily with those measured experimentally. </p>

Fire performance of concrete sandwich panel under axial load

2020 ◽  
Vol 15 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Behnam Sajadian ◽  
Hamidreza Ashrafi
Keyword(s):  
Finite Element ◽  
High Temperature ◽  
Finite Element Model ◽  
High Temperatures ◽  
Axial Load ◽  
Sandwich Panel ◽  
Element Model ◽  
Fire Performance ◽  
Maximum Displacement ◽  
Sandwich Wall

Abstract In the present study, the performance of concrete sandwich panel against fire and axial load has been considered. A finite element model of a sandwich wall is presented and evaluated the performance under different temperature (200, 400, 600 °C. The ratio of width, thickness and length of wall are constant and the axial load enters on the top of wall. The maximum displacement and stress in different models shows the capacity of wall is increased at high temperature. The displacement has dramatically increased at temperature loading of 800 °C and it has gained which shows poor efficiency of wall at high temperatures.

High Temperature Characterisation of 4H-SiC VJFET

2007 ◽  
Vol 556-557 ◽  
pp. 799-802 ◽  
Author(s):  
Praneet Bhatnagar ◽  
Nicolas G. Wright ◽  
Alton B. Horsfall ◽  
Konstantin Vassilevski ◽  
C. Mark Johnson ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Coefficient ◽  
High Temperatures ◽  
Current Density ◽  
Threshold Voltage ◽  
Room Temperature ◽  
Drain Current ◽  
Drain Voltage ◽  
Average Temperature

4H-SiC depletion mode (normally-on) VJFETs were fabricated and characterised at temperatures up to 377 °C. The device current density at drain voltage of 50 V drops down from 54 A/cm2 at room temperature to around 42 A/cm2 at 377 °C which is a 20 % reduction in drain current density. This drop in drain currents is much lower than previously reported values of a 30 % drop in JFETs at high temperatures. The average temperature coefficient of the threshold voltage was found to be -1.36 mV/°C which is smaller than for most Si FETs. We have found that these devices have shown good I-V characteristics upto 377 °C along with being able to retain its characteristics on being retested at room temperature.

High Temperature n- and p-type Doped Microcrystalline Silicon Layers Grown by VHF PECVD Layer-by-Layer Deposition

2003 ◽  
Vol 762 ◽  
Author(s):  
A. Gordijn ◽  
J.K. Rath ◽  
R.E.I. Schropp
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
High Temperatures ◽  
Continuous Wave ◽  
Hydrogen Plasma ◽  
Silicon Layer ◽  
Dark Conductivity ◽  
High Deposition Rate ◽  
Layer By Layer ◽  
Microcrystalline Silicon

AbstractDue to the high temperatures used for high deposition rate microcrystalline (μc-Si:H) and polycrystalline silicon, there is a need for compact and temperature-stable doped layers. In this study we report on films grown by the layer-by-layer method (LbL) using VHF PECVD. Growth of an amorphous silicon layer is alternated by a hydrogen plasma treatment. In LbL, the surface reactions are separated time-wise from the nucleation in the bulk. We observed that it is possible to incorporate dopant atoms in the layer, without disturbing the nucleation. Even at high substrate temperatures (up to 400°C) doped layers can be made microcrystalline. At these temperatures, in the continuous wave case, crystallinity is hindered, which is generally attributed to the out-diffusion of hydrogen from the surface and the presence of impurities (dopants).We observe that the parameter window for the treatment time for p-layers is smaller compared to n-layers. Moreover we observe that for high temperatures, the nucleation of p-layers is more adversely affected than for n-layers. Thin, doped layers have been structurally, optically and electrically characterized. The best n-layer made at 400°C, with a thickness of only 31 nm, had an activation energy of 0.056 eV and a dark conductivity of 2.7 S/cm, while the best p-layer made at 350°C, with a thickness of 29 nm, had an activation energy of 0.11 V and a dark conductivity of 0.1 S/cm. The suitability of these high temperature n-layers has been demonstrated in an n-i-p microcrystalline silicon solar cell with an unoptimized μc-Si:H i-layer deposited at 250°C and without buffer. The Voc of the cell is 0.48 V and the fill factor is 70 %.

NICROFER 5520 Co

Alloy Digest ◽  
1995 ◽  
Vol 44 (3) ◽  
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Temperatures ◽  
Heat Treating ◽  
High Temperature Corrosion ◽  
Creep Properties ◽  
Nickel Chromium ◽  
Temperature Performance

Abstract NICROFER 5520 Co is a nickel-chromium-cobalt-molybdenum alloy with excellent strength and creep properties up to high temperatures. Due to its balanced chemical composition the alloy shows outstanding resistance to high temperature corrosion in the form of oxidation and carburization. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ni-480. Producer or source: VDM Technologies Corporation.

CARLSON ALLOY C601

Alloy Digest ◽  
1994 ◽  
Vol 43 (7) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
High Temperatures ◽  
Stress Corrosion Cracking ◽  
Heat Treating ◽  
Resistance To Stress ◽  
Extended Exposure ◽  
Sulfur Containing

Abstract Carlson Alloy C601 is characterized by high tensile, yield and creep-rupture strengths for high temperature service. The alloy is not embrittled by extended exposure to high temperatures and has excellent resistance to stress-corrosion cracking, to carburizing, nitriding and sulfur containing environments. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on forming, heat treating, machining, and joining. Filing Code: Ni-458. Producer or source: G.O. Carlson Inc.

INCOTHERM TD

Alloy Digest ◽  
2005 ◽  
Vol 54 (11) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Oxidation Resistance ◽  
High Temperatures ◽  
Rare Earths ◽  
Temperature Performance

Abstract Incotherm TD is a thermocouple-sheathing alloy with elements of silicon and rare earths to enhance oxidation resistance at high temperatures. This datasheet provides information on composition, physical properties, and tensile properties as well as deformation. It also includes information on high temperature performance and corrosion resistance as well as forming. Filing Code: Ni-628. Producer or source: Special Metals Corporation.

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