• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제36회 춘계학술대회논문집
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• pp.73-76
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• 2011

축소형 가스발생기를 제작하여 연소시험을 성공적으로 수행하였으며 분사기의 형상 변화에 따른 유량계수의 영향을 파악하였다. 연소시험 결과 연료 및 산화제 분사기의 유량계수는 혼합비와 연소압에 상관없이 거의 일정하였으며, 특히 산화제 분사기의 유량계수는 이전 결과보다 크게 향상되었다.

• 조명전기설비학회논문지
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• 제19권7호
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• pp.32-38
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• 2005

본 논문에서는 대기오염물질인 Nitrogen Oxides(NO) 가스를 제거하기 위하여 3개의 전극이 장착된 하나의 방전 공간에 무성방전과 연면방전을 동시에 발생가능한 복합방전형 오존발생기를 설계 제작하였다. 전압인가 방식에 따라 3가지 형태의 오존발생기로 구성가능한 복합방전형 오존발생기에 유입하는 산소원료가스의 유량, 방전전력 및 오존발생기의 종류에 따른 방전 및 오존생성특성을 연구 검토한 결과, 8334[ppm] 및 3249[mg/h]의 오존을 얻을 수 있었다. 또한 NO(1200[ppm])/$N_2$ 가스의 입력방식에 따른 NO 가스 제거특성을 방전전력 및 오존발생기의 종류에 따라 연구 검토한 결과, 최대 100[%]의 제거율을 얻을 수 있었다.

• 한국재료학회지
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• 제21권10호
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• pp.532-541
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• 2011

The Xe plasma flat lamp, considered to be a new eco-friendly LCD backlight, requires a further improvement of its luminance and luminous efficiency. To improve the performance of this type of lamp, it is necessary to understand the effects of the discharge variables on the luminous characteristics of the lamp. In this study, the luminous characteristics of a coplanartype Xe plasma flat lamp with a teeth-type electrode pattern were analyzed while varying the gas composition, gas pressure and input voltage. The effects of the phosphor layer on the discharge and the luminous characteristics of the lamp were also studied. The luminous efficiency of the coplanar-type Xe plasma flat lamp improved as the Xe input ratio and gas pressure increased. Higher luminous efficiency was also obtained when helium (He) was used as a buffer gas and when a phosphor layer was fabricated on the electrode region. In contrast, the luminous efficiency was reduced with increasing the input voltage. It was found that the infrared emissions from the lamp were affected by the Xe excitation rate in the plasma, the Xe gas density, the collisional quenching of excited Xe species by gas molecules, and the recombination rate between the Xe ions and electrons.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.285-288
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• 1996

The electronic operation of the gas discharge tube is controlled by the electrical energy as sinusoidal waveform in arbitrary frequency range, or as a sequence of pulses at a wide range of duty cycle, the gas composition, the kind of electrode and the vessel geometry. In this paper, the pulsed mode operated gas discharge tube is composed with mixed gas of IIg-Ne ( 10 Torr ), in the tube of 15.0 mm outer diameter and has variable color from red to blue with changing frequency and pulse width in high voltage. As increasing pulse width and frequency in the gas discharge tube, the phenomenons that the electron temperature in the positive column increases and the radiation from atoms of higher upper state energy levels increases, exist. The color have the locus from red (0.4972, 0.3128) to blue (0.2736, 0.2619) in CIE chromacity diagram with increasing pulse width and frequency. The changing method of pulse width and frequency has been shown to be suitable for the luminous color control.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2001년도 학술대회논문집
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• pp.145-149
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• 2001

The most of faults in gas insulation of power facilities are caused by partial discharge. Therefore we simulated partial discharge and measured the radiated electromagnetic wave emitted from partial discharge in SF$_{6}$ gas by biconical antenna. This paper describes time delay and electric fields pulse characteristics of radiated electromagnetic waves with distance(1[m], 3[m], 5[m]) between antenna and discharge source.e.

• Journal of Electrical Engineering and Technology
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• 제10권2호
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• pp.603-609
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• 2015

Dry air is an excellent alternative to $SF_6$ gas and is used as an insulation gas in Eco-friendly Gas Insulated Switchgears (EGISs), which has gained popularity in industry. Solid insulators in EGIS play an important role in electrical insulation. On the other hand, surface discharge can occur easily when solid insulators are used. This paper explored the surface discharge characteristics on the structure of three-layered laminated solid insulators to elevate the flashover voltage. A laminated solid insulator was inserted after the quasi-uniform electric field was formed in the test chamber. Dry air was then injected to set the internal pressure to 1 ~ 6 atm, and the AC voltage was applied. When identical solid insulators were stacked, the surface discharge characteristics were similar to those of a single solid insulator. On the other hand, the flashover voltage rose when the middle part was thicker and had lower permittivity than the top and bottom parts in the laminated solid insulator. Based on experimental results, when stacking a solid insulator in three layers, the middle part of the solid insulator should be at least four times as thick as the top and bottom parts and have lower permittivity than the others. In addition, the flashover voltage increased with increasing gas pressure on the surface of the laminated solid insulator due to the gas effect. This study may allow insulation design engineers to have useful information when using dry air for the insulation gas where the surface discharge can occur.

• 한국전기전자재료학회논문지
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• 제32권4호
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• pp.320-326
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• 2019

Recently, the application of atmospheric plasma technology in air filtration is increasing. Sterilization by an atmospheric plasma device is very effective. However, ozone gas, which is generated during atmospheric plasma formation, poses a hazard to human health. To reduce the ozone gas during plasma discharge, we fabricated a one-plate hybrid plasma discharge device with a heating element, which can decompose ozone gas effectively by a simple heating action. In this study, we evaluated the plasma discharge characteristics and ozone concentrations with various Ar flow rates and temperatures. With increasing Ar gas flow rate, the ozone concentration and spectrum intensity increased till an Ar gas flow rate of 60 sccm, and decreased thereafter. When discharged in high temperature, the ozone concentration and spectrum intensity decreased. Further, to evaluate the state of the treated surface under various plasma discharge and heating conditions, we measured the variation in the contact angles on the surface. Regardless of the temperature, the contact angle increased with increasing discharge voltage. However, the contact angle increased when discharged at high temperature.

• 한국대기환경학회지
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• 제18권3호
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• pp.173-182
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• 2002

We investigated the effects of operating variables, such as electrical. reactor and gas parameters on toluene removal and discharge property in the dielectric barrier discharge (DBD) process. The toluene removal was initiated with the energy transfer to the reactor by loading of voltages higher than the discharge onset value. The energy transfer and toluene removal increased with the applied voltage. Higher removal rate was observed with smooth surface electrode despite of lower energy transfer compared with the coarse electrode, because more uniform discharge can be obtained on smooth surface state. The decrease of dielectric material thickness enhanced the removal efficiency by increasing the discharge potential. The toluene removal efficiency decreased with the increase of the inlet concentration. The increase of gas retention time enhanced the removal efficiency by the increase of energy density. The oxygen and humidity contents seem to exert significant influences on the toluene removal by dominating the generation of electrons, ions, and radicals which are key factors in the removal mechanism.

• 한국안전학회지
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• 제28권1호
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• pp.29-34
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• 2013

When flammable gases are mixed with air or oxygen in the explosion concentration range and are ignited by sufficiently large electrostatic discharge energy, they may explode causing severe disaster in workplace. The minimum ignition energy(MIE) of single gas-air mixtures has been already investigated by many research, but the MIE of mixtures of more than ternary gas mixture is not examined yet. The purpose of this study is to investigate the MIE of a ternary gas(methane, ethylene, hydrogen, propane) mixtures experimentally. The results of our experiment show that the ignition of a methane-ethylene-air, methane-hydrogen-air, methane-propane-air, ethylene-hydrogen-air, ethylene-propane-air and hydrogen-propane-air mixture due to electrostatic discharge energy primarily depends on that the mixture: the MIE decreases gradually with the increase of having the lower MIE than other mixture ratio in the normal atmospheric pressure.

• Transactions on Electrical and Electronic Materials
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• 제16권6호
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• pp.323-327
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• 2015

In this paper, parameters related with partial discharge (PD) were analyzed in SF₆ gas under AC and DC voltages. Three electrode systems (protrusion on conductor, protrusion on enclosure, and free particle) were fabricated to simulate PD defects in a gas-insulated switchgear (GIS). All electrode systems were filled with SF₆ gas at 0.5 MPa. PD pulses were detected using an oscilloscope and a data acquisition (DAQ) based on IEC 60270. To analyze the PD characteristics under AC and DC voltages, parameters such as discharge inception voltage (DIV), discharge extinction voltage (DEV), pulse magnitude, repetition rate, and T-F map were compared. From the experimental results, PD was revealed to have different characteristics under AC and DC, and these results may be useful for diagnosis of power facilities operated under HVDC.