Comparative study on extinction process of gas-blasted air and CO<sub>2</sub>arc discharge using two-dimensional electron density imaging sensor

Inada, Yuki; Kumada, Akiko; Ikeda, Hisatoshi; Hidaka, Kunihiko; Nakano, T.; Murai, Kosuke; Tanaka, Yasunori; Shinkai, Takeshi

doi:10.1088/1361-6463/aa652b

Cited by 11 publications

(25 citation statements)

References 29 publications

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“…(15)] is almost constant up to a temperature of roughly 10 000 K. In other gases, such as CO 2 , this ratio depends weakly on the temperature and can lead to a small systematic error. However, if the difference in wavelengths is large enough, this small effect can be neglected, for example, in CO 2 and air [39]. The approach presented here can, thus, readily be extended to other gases relevant for circuit breakers.…”

Section: Discussionmentioning

confidence: 96%

Measuring Density Profiles of Electrons and Heavy Particles in a Stable Axially Blown Arc

et al. 2017

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Two-color spatial carrier wave interferometry employing pulsed 532-and 671-nm lasers is used to measure the electron-density and heavy-particle-density profiles in the stagnation point of a stable, axially blown arc in argon for currents of 50 to 200 A and stagnation point pressures of 0.2 to 16 bar. This technique takes advantage of the fact that the free-electron contribution to the refractive index depends strongly on the wavelength, while that of the heavy particles does not. The high spatial resolution achieved allows the hot core of the arc to be readily distinguished from the surrounding boundary layer. A custom-built test device is used to ensure flow conditions that lead to a stable, axisymmetric arc; this permits the reconstruction of the density and temperature profiles using a single projection (interferometric image) of the refractive-index distribution through the arc (at two wavelengths). The arc radius determined from the heavy-particle density decreases with increasing stagnation pressure and increases with the current. These measurements are in good agreement with a simple axially blown arc model taking into account Ohmic heating, radiation losses, and enthalpy flow for core temperatures of approximately 16 500 K. The measured electron density at the center of the arc agrees well with a prediction based on local thermodynamic equilibrium.

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Section: Discussionmentioning

confidence: 96%

Measuring Density Profiles of Electrons and Heavy Particles in a Stable Axially Blown Arc

et al. 2017

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“…Recently, two-dimensional distribution of electron density in a plasma is measured by Shack-Hartmann type laser wavefront sensor [9]. Figure 9 shows the basic concept of a Shack-Hartmann sensor for measuring electron density distribution in an arc plasma.…”

Section: Shack-hartman Methodsmentioning

confidence: 99%

“…Figure 9. A schematic of a Shack-Hartmann type laser wavefront sensor for measuring electron densities in a plasma [9].…”

Section: −3mentioning

confidence: 99%

“…In addition, some recent experiments will be introduced for decaying arcs with a detailed control of applied voltage and injected current using some power semiconductors [7]. In the experiments, two measurement methods were adopted to determine the electron density without LTE assumption: the laser Thomson scattering method [8] and the Shack-Hartmann method [9]. Finally, we compare results between the LTE simulation, the chemically non-equilibrium simulation, and the above experimental measurements [6].…”

Section: Introductionmentioning

confidence: 99%

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Non-equilibrium Studies in Switching Arc Plasmas in Japan

Tanaka

Tomita²,

Inada

et al. 2017

PPT

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Abstract. This paper briefly introduce research work examples of non-equilibrium studies in switching arcs. In understanding arc behavior, one often assumes local thermodynamic equilibrium (LTE) condition in the arc plasma. However, actual arc plasmas are not completely and not always in LTE state because of strong temperature change temporally and spatially, and high electric field application etc. Recently, we have a collaboration work in numerical simulations and experimental approaches for decaying arcs without LTE assumption. First, our numerical model is presented for decaying arcs without chemical equilibrium assumption. Secondly, two experimental methods are introduced for measuring electron density in decaying arcs without LTE assumption: Laser Thomson Scattering method and the Schack-Hartmann method. Finally, comparison results is shown between the LTE simulation, the chemically non-equilibrium simulation, and the above experimental measurements.

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“…For this reason, it is important to study the arc extinction phenomena in detail with both experimental and numerical simulation approaches . In our previous experimental approach, we established a new system of decaying arc plasmas using a direct‐current power source and an insulated gate bipolar transistor . This experimental system can accurately control the timings of supplied current and applied voltage to arc plasmas in a gas flow.…”

Section: Introductionmentioning

confidence: 99%

Numerical thermofluid simulation of a decaying arc behavior in CO₂/O₂/C₅F₁₀O (C5‐PFK) considering more than nona‐atomic molecules

Demura

Tanaka

Uesugi

et al. 2019

IEEJ Transactions Elec Engng

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The present article describes numerical thermofluid simulation results on decaying arc behavior in 80%CO 2 + 10%O 2 + 10%C 5 F 10 O (C5-PFK) gas considering molecules constituted with more than 9 atoms in a nozzle space on the assumption of local thermodynamic equilibrium (LTE) condition. The gas mixture 80%CO 2 + 10%O 2 + 10%C 5 F 10 O (C5-PFK) is one of the candidate alternatives for SF 6 in a gas circuit breaker. First, we calculated 80%CO 2 + 10%O 2 + 10%C 5 F 10 O (C5-PFK) arc characteristics only by considering less than 8-atom molecules. However, it seems possible to produce more than nona-atomic molecules in the low-temperature region in 80%CO 2 + 10%O 2 + 10%C 5 F 10 O (C5-PFK) arcs. The present work further calculated the equilibrium composition of this gas mixture at 0.1 MPa with taking account more than nona-atomic molecules. Furthermore, their thermodynamic and transport properties were also computed with collision integrals between species considered. Using these properties, the arc temperature and gas flow fields were calculated using two-dimensional LTE model for a free recovery condition from dc 50 to 0 A. Results showed that a similar temperature decay was obtained for arcs in the 80%CO 2 + 10%O 2 + 10%C 5 F 10 O (C5-PFK) gas mixture to that for arcs in 100%CO 2 gas.

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Comparative study on extinction process of gas-blasted air and CO₂arc discharge using two-dimensional electron density imaging sensor

Cited by 11 publications

References 29 publications

Measuring Density Profiles of Electrons and Heavy Particles in a Stable Axially Blown Arc

Measuring Density Profiles of Electrons and Heavy Particles in a Stable Axially Blown Arc

Non-equilibrium Studies in Switching Arc Plasmas in Japan

Numerical thermofluid simulation of a decaying arc behavior in CO₂/O₂/C₅F₁₀O (C5‐PFK) considering more than nona‐atomic molecules

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Comparative study on extinction process of gas-blasted air and CO2arc discharge using two-dimensional electron density imaging sensor

Cited by 11 publications

References 29 publications

Measuring Density Profiles of Electrons and Heavy Particles in a Stable Axially Blown Arc

Measuring Density Profiles of Electrons and Heavy Particles in a Stable Axially Blown Arc

Non-equilibrium Studies in Switching Arc Plasmas in Japan

Numerical thermofluid simulation of a decaying arc behavior in CO2/O2/C5F10O (C5‐PFK) considering more than nona‐atomic molecules

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Comparative study on extinction process of gas-blasted air and CO₂arc discharge using two-dimensional electron density imaging sensor

Numerical thermofluid simulation of a decaying arc behavior in CO₂/O₂/C₅F₁₀O (C5‐PFK) considering more than nona‐atomic molecules