Effects of working pressure on temperature characteristics in multiphase AC arc

Okuma, Takafumi; Imatsuji, Tomoyuki; Hashizume, Takumi; Tanaka, Manabu; Watanabe, Takayuki; Nagai, Hiroki; Koiwasaki, Takeshi; Nasu, Hiroshi

doi:10.1299/jfst.2018jfst0024

Cited by 7 publications

(7 citation statements)

References 16 publications

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“…The energy deposition in the arc channel increases with the filling pressure due to high arc voltage. As the filling pressure is increased, the arc radius decreases [24]. Without forced gas flow, the thermal energy stored in the arc core fails to dissipate quickly.…”

Section: Discussionmentioning

confidence: 99%

Effect of filling pressure on post-arc gap recovery of N₂

Abid

Niayesh

Viken

et al. 2020

IEEE Trans. Dielect. Electr. Insul.

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Experimental investigation of the effect of filling pressure on the post-arc dielectric recovery characteristics of nitrogen is reported in this paper. A half-cycle arc current duration of 540 µs followed by a 10 kV pulse with a rise rate of 150 V/µs is applied across the contact gap. The pulse is applied from 10 µs to 10 ms after the current zero. First, a free-burning arc is studied without any forced gas flow. The effect of the gap distance on the recovery process is studied by using two different inter-electrode gaps: 20 mm and 50 mm. The effect of arc current on the recovery process is investigated by using current amplitudes of 275 A and 425 A. Moreover, the effect of forced nitrogen flow near current zero is explored using two different arrangements: self-blast and puffer type. Four different nitrogen filling pressures are studied: 1, 20, 40, and 80 bar, the latter two being in the supercritical region. The experimental results show that, in the free-burning arc configuration, the breakdown voltage of the contact gap increases faster with the increase of the filling pressure. A gap of 50 mm recovers quicker than a 20 mm gap, whereas no strong current dependency is observed on the recovery characteristics in the investigated range. In the free-burning arc configuration, just after the current zero up to approximately 300 µs, the breakdown voltage at high filling pressure is found to be lower than at 1 bar. Forced gas flow, however, significantly enhances the dielectric recovery at a high filling pressure, also in the thermal phase.

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Section: Discussionmentioning

confidence: 99%

Effect of filling pressure on post-arc gap recovery of N₂

Abid

Niayesh

Viken

et al. 2020

IEEE Trans. Dielect. Electr. Insul.

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“…The free-burning arc voltage is reported to increase with filling pressure of N 2 without any abrupt change during the transition from gas to SC state [12]. The arc radius decreases as the filling pressure increases [13,14].…”

Section: Introductionmentioning

confidence: 94%

Current interruption performance of ultrahigh-pressure nitrogen arc

Abid

Niayesh

Espedal

et al. 2020

J. Phys. D: Appl. Phys.

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In this paper, the influence of gas filling pressure on the current interruption performance of different switch configurations with electric arcs burning in nitrogen has been experimentally investigated. A synthetic circuit generating a current of 130 A at 190 Hz is used and the initial rate of rise of recovery voltage just after current zero is varied from 9.8 V/µs to 84.9 V/µs. To evaluate the effect of forced gas flow on current interruption performance, three different test arrangements are investigated: a simple contact configuration with a free-burning arc, a contact and a cylindrical nozzle setup (tube-constricted arc), and finally a self-blast arrangement where the arc is cooled by a gas flow near current zero. In each arrangement, three different filling pressures are mainly studied: 1, 20, and 40 bar, the latter being in the supercritical region. In all cases, the interelectrode gap is fixed at 50 mm. It is observed that the interruption performance deteriorates with increased filling pressure in the absence of forced gas flow. A higher post-arc current is observed for the arcs burning at high filling pressures (i.e. 20 and 40 bar) compared to at atmospheric pressure in cases with no or little forced cooling. On the other hand, a forced gas flow near the current zero reduces the post-arc current and improves the interruption performance also at high filling pressures. Little effect of the supercritical state on the interruption performance of nitrogen is observed. Under the above-mentioned test conditions, the majority of the failures at high filling pressure are observed to be of thermal re-ignition type.

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“…Furthermore, it is expected to be utilized in nanomaterial fabrication processes owing to its high processing rate. Fundamental studies for practical use of MPA in industry have been intensively reported in terms of the arc stability (Tanaka et al, 2011), the temporal and spatial characteristics of the arc discharge (Liu et al, 2013), arc temperature fluctuation (Okuma et al, 2018(Okuma et al, , 2019, and the electrode phenomena (Tanaka et al, 2013, 2016, Hashizume et al, 2015.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Temperature Fluctuation of Diode-Rectified Multiphase AC Arc by High-Speed Visualization

et al. 2021

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An innovative multiphase AC arc was drastically improved by diode-rectification technique with bipolar electrode. Temperature fields and arc behaviour of the diode-rectified multiphase AC was successfully visualized on the basis of the high-speed camera technique with appropriate band-pass filter optics. Arc temperature was measured by Boltzmann plot method with two line emissions from atomic argon at 675.2834 nm and 794.8176 nm. Arc temperature fluctuates in the range from 7,000 to 13,000 K. The arc temperature near the cathode was higher than 13,000 K, while that near the anode was about 10,000 K. Arc temperature in the centre region in the furnace was about 7,000–9,000 K, which is sufficiently high to melt and evaporate the refractory metals or ceramics. Obtained results suggested the diode-rectified multiphase AC arc is a promising thermal plasma source for material processing at high productivity.

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Effects of working pressure on temperature characteristics in multiphase AC arc

Cited by 7 publications

References 16 publications

Effect of filling pressure on post-arc gap recovery of N₂

Effect of filling pressure on post-arc gap recovery of N₂

Current interruption performance of ultrahigh-pressure nitrogen arc

Investigation of Temperature Fluctuation of Diode-Rectified Multiphase AC Arc by High-Speed Visualization

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Effects of working pressure on temperature characteristics in multiphase AC arc

Cited by 7 publications

References 16 publications

Effect of filling pressure on post-arc gap recovery of N2

Effect of filling pressure on post-arc gap recovery of N2

Current interruption performance of ultrahigh-pressure nitrogen arc

Investigation of Temperature Fluctuation of Diode-Rectified Multiphase AC Arc by High-Speed Visualization

Contact Info

Product

Resources

About

Effect of filling pressure on post-arc gap recovery of N₂

Effect of filling pressure on post-arc gap recovery of N₂