• Title/Summary/Keyword: Arc behavior

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Influence of $SF_6$ Gas On An Arc Plasma In UHV Circuit Breaker ($SF_6$ gas가 초고압 차단기 내에서 Arc Plasma에 미치는 영향)

  • Choi, Kyung-Chuel;Whang, Ki-Woong
    • Proceedings of the KIEE Conference
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    • 1987.11a
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    • pp.278-282
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    • 1987
  • Computational and theoritical investigations of an arc plasma have been made for the design of a circuit breaker. Modeling of an arc plasma used to be very involved and difficult because of the many variables and factors, In this paper, the dynamic behavior of an arc plasma is investigated by solving the MHD equations. Comparing an $SF_6$-blast arc with a non-blast arc, it has been found that the effect of gas-blast has a great influence on density rather than temperature.

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An Experimental Study on Underwater Wet Arc Welding and Weldability (TMCP강의 수중 ARC용접 실험과 용접성)

  • 오세규;김민남
    • Journal of Ocean Engineering and Technology
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    • v.1 no.2
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    • pp.67-73
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    • 1987
  • The feasibility for a practical use of underwater wet arc welding process is experimentally investigated by using low hydrogen and high oxide type electrodes and TMCP steel plates. Main results are summarized as follows: 1)The absorption speed of the coated low hydrogen and high titanium oxide type eletrodes becomes constant after about 30 minutes in water, and more steeping time in water does not influnce welding arc behavior. 2) By bead appearance and X-ray inspection, the high titanium oxide type electrode is better than the low hydrogen type in underwater arc welding process. 3) The mechanical properties of underwater wet arc welds depend upon welding conditions more than those of in-air welds, and the optimum welding condition can be obtained. 4) Because of quenching effect by rapid cooling rate in underwater wet welding, the maximum hardness of HAZ is increased relatively higher in underwater wet welding, process.

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Snap-Through Behavior Analysis of Space Truss using Arc-Length Method (호장법을 이용한 공간트러스의 스냅스루거동 해석)

  • 권택진;서일교;이상환
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.10a
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    • pp.47-54
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    • 1993
  • This paper is concerned with the geometrically nonlinear behavior of elastic systems under conservative loading conditions. In particular, the topic are snap through problems and the arc-length method to pass limit points of space trusses is used. And numerical examples are presented to trace nonlinear equilibrium paths.

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A Study on Dynamic Characteristics of Welding Current and Arc Length At GMAW (GMA용접에서 용접전류와 아크 길이의 동특성에 관한 연구)

  • Lee, Tae-Young
    • Journal of the Korean Society of Industry Convergence
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    • v.14 no.1
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    • pp.15-21
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    • 2011
  • Welding variables and conditions in gas metal arc welding (GMAW) effect on the quality and productivity of the weld, extensive research efforts have been made to analyze the effect of the welding variables and conditions. In this study dynamic behavior of GMAW system is investigated using the characteristics of the power supply, wire and welding arc. Characteristic equation of wire is modified to include the effect of droplets attached at the electrode tip. The dynamic characteristics of arc length, current, voltage with respect to the step, ramp inputs of CTWD was simulated. From results of simulation, some predictions about dynamic characteristics of GMAW and welding process are available. The proposed simulator and results appear to be utilized to determine the proper welding conditions, to be improved by considering power supply dynamic characteristics.

A study on the physical behavior of arc plasmas in transferred-type Torch (이행형 토치에서의 아크 플라즈마의 물리적 거동에 관한 연구)

  • 김외동;고광철;강형부
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.3
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    • pp.415-425
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    • 1996
  • This study presents an analytical method of solving the behaviors of arc plasma in a nozzle constricting transferred-type torch and purposes to obtain the basic data for the design of a plasma torch, which can be obtained from the temperature, pressure, velocities and voltage distributions. We have to solve some conservation equations simultaneously and need to know the exact thermal gas properties in order to obtain the correct behaviors of arc plasma. It is also necessary to give the relevant physical or geometric boundary conditions. For the simplicity of analysis, we assumed that (a) the plasma flow is laminar, (b)the local thermodynamic equilibrium, i.e. LTE, prevails over the entire arc column region. The electrode sheath effects were neglected and the nozzle area was excluded from the analysis by assuming that the current flow into the nozzle is zero. We solved the momentum transfer equation including the self-magnetic pinch effect, and obtained the temperature distribution from the energy conservation equation. From this temperature, we could get arc voltage distribution. (author). refs., figs., tabs.

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Measurement of Radiation Intensity of the High-Pressure and Large-Current Arc (고압 대전류 아크의 복사강도 측정)

  • Song, Ki-Dong;Oh, Yeon-Ho;Chong, Jin-Kyo;Cho, Yong-Sung
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.55 no.11
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    • pp.555-563
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    • 2006
  • This paper presents the measured radiation intensity of high-pressure and large-current arc with the current. In order to measure the radiation intensity of large-current arc, a model circuit breaker was specially designed and manufactured and the method using an astronomical telescope was utilized after various measuring methods were investigated. A trigger system was designed and fabricated to coincide the time of desired current with the exposure time of 1ms of the spectroscope. A high-speed camera was used to investigate the shape and behavior of the arc and the captured results have been used to calculate the radiation energy. The calculated arc temperature with Boltzmann plot method using the measured radiation intensity have $18,000{\sim}27,000K$ to the current $4kA{\sim}15kA$. And also, using the calculated arc temperature and the captured arc shape the radiation energy of the current $5kA{\sim}15kA$ were calculated with $8{\times}10^5{\sim}4.0{\times}10^6W/m$ respectively.

Analytical model of expansion for electric arc furnace oxidizing slag-containing concrete

  • Shu, Chun-Ya;Kuo, Wen-Ten;Juang, Chuen-Ul
    • Computers and Concrete
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    • v.18 no.5
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    • pp.937-950
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    • 2016
  • This study applied autoclave expansion and heat curing to accelerate the hydration of concrete and investigated how these methods affect the expansion rate, crack pattern, aggregate size effect, and expansion of electric arc furnace oxidizing slag (EOS)-containing concrete. An expansion prediction model was simulated to estimate the expansion behavior over a long period and to establish usage guidelines for EOS aggregates. The results showed that the EOS content in concrete should range between 20% and 30% depending on the construction conditions, and that coarse aggregates with a diameter of ${\geq}4.75-mm$ are not applicable to construction engineering. By comparison, aggregates with a size of 1.18-0.03 mm resulted in higher expansion rates; these aggregates can be used depending on the construction conditions. On Day 21, the prediction model attained a coefficient of determination ($R^2$) of at least 0.9.

Spatial and Temporal Behavior of Arc with Magnetic Field (자계가 인가된 아크의 공간적, 시간적 거동)

  • Choi, Won-Joon;Kang, Jin;Choi, Seung-Kil;Ko, Hwang-Cheol
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1809-1811
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    • 1998
  • Axial magnetic field restrains arc diffusion that appear at cutting off fault current in vacuum interrupter(VI). In this study, spatial and temporal behavior simulation of arc is carried out for various axial magnetic field. Also the results of this simulation show that axial magnetic field controls and helps to extinguish arcs. This study can be applied to design and analysis of VI. Dymo theory that is not considered in this study will be considered latter.

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Cavitation Damage Behavior of Inconel 625 Coating Layer by Arc Thermal Spraying Method in Sea Water (아크 용사법을 이용한 Inconel 625 코팅 층의 해수 내 캐비테이션 손상 거동)

  • Park, Il-Cho;Kim, Seong-Jong
    • Journal of the Korean institute of surface engineering
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    • v.48 no.6
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    • pp.349-353
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    • 2015
  • In this paper, arc thermal spray coating was conducted onto the SS400 steel using Inconel 625 wires in order to improve the durability of marine steel structures, and then investigated cavitation damage behavior of Inconel 625 coating layer in sea water. For the Inconel 625 coating layer, surface hardness appeared similar to that of existing high velocity oxy-fuel coating technology with 380~480 HV, but the porosity of about 6 % was larger relatively. During the cavitation experiment, pit damages were originated and grown at the rough surface and pore defect area of Inconel 625 coating layer. And, after the 72 hours of experimental time, weight loss of Inconel 625 coating layer exhibited gradually increasing tendency due to surface damage effect of the undercut.