• 조명전기설비학회논문지
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• 제29권8호
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• pp.63-69
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• 2015

This paper presents the surface flashover characteristics to simulate the poor contact between an anode and a solid dielectric in a $N_2/O_2$ mixture gas (8/2) under a non-uniform field. The surface flashover voltage of the $N_2/O_2$ mixture gas revealed the irregular tendency that was not in accordance with the Paschen's law with an increasing gap of the poor contact. In addition, the insulation performance of the $N_2/O_2$ mixture gas at 0.6MPa was comparable to that of $SF_6$ gas of 0.1MPa based on the insulation performance on the poor contact. These results are able to apply the insulation design of eco-friendly gas insulation switchgear considering the internal faults.

• 조명전기설비학회논문지
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• 제24권7호
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• pp.41-46
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• 2010

With the improvement of industrial society, high quality electrical energy, simplification of operation and maintenance, and ensuring reliability are being required. Also we request an urgent change from $SF_6$ gas to an environment-friendly gas insulation material. In this paper, the experiments of breakdown characteristics by pressure and gap change of $N_2/O_2$ mixture gas through a GIS (Gas Insulated Switchgear) model were described. This paper reviews basic data of the surface discharge characteristics for Teflon resin in not only pure $N_2$, $N_2:O_2$ mixture gas as being focused on environmentally-friendly insulating gas, but also $SF_6$. Also, insulation characteristics by breakdown voltage and surface discharge voltage of $N_2:O_2$ mixture gas in the experimental chamber were studied.

• 조명전기설비학회논문지
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• 제29권6호
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• pp.49-57
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• 2015

This paper presents the discharge characteristics and economic feasibility of a Dry $Air/O_2$ and a $N_2/O_2$ mixture gas in order to review $SF_6$ alternative. From AC discharge experiment in an quasi-uniform field, it was found that the optimal $N_2/O_2$ mixing ratio which breakdown voltage and surface flashover voltage were the highest was 70/30 and that the pressure dependence on the breakdown voltage was higher than that of the surface flashover voltage in the Dry $Air/O_2$ and the $N_2/O_2$ mixture gas. The mixing ratio (70/30) and the tendency of the pressure dependence were described in detail based on physical factors (impact ionization coefficient, electron attachment coefficient, secondary electron emission coefficient) involved in discharge mechanism and a electron source, respectively. In addition, the performance insulation and the economic feasibility of the Dry $Air/O_2$ and the $N_2/O_2$ mixture gas were discussed so that Dry $Air/O_2$ mixture gaswas more suitable than $N_2/O_2$ mixture gas to the $SF_6$ alternative.

• 조명전기설비학회논문지
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• 제26권3호
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• pp.9-15
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• 2012

In this paper, we deal with a surface discharge that caused an aggravation of the dielectric strength in the $N_2/O_2$ mixture gas, When composit dielectrics were formed from the use of a solid dielectric. It was found from this study that the surface discharge voltage was deeply involved in the mixture ratio of $O_2$, the electrical property of the solid dielectric, kind of the solid dielectric, an electric field at the triple junction and a medium effect. These results expect basic data that will be used to transmission and distribution power system equipment using the $N_2/O_2$ mixture gas.

• 한국산업융합학회 논문집
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• 제15권2호
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• pp.49-54
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• 2012

With the improvement of industrial society, the high quality electrical energy, simplification of operation and maintenance, ensuring reliability and safety are being required. This paper reviews a basic data of the surface discharge characteristics for teflon resin in not only pure $N_2$, $N_2:O_2$ mixture gas and Dry-Air as being focused on environmentally friendly insulating Gas also $SF_6$. Used electrodes are Knife to Knife. With the changing distance of electrodes and pressure, we can find it, surface discharge voltages and surface dielectric strengths, respectively. Surface discharge Voltages of $N_2:O_2=80:20$ mixture gas are more higher than the $N_2:O_2$ Mixture gases.

• 조명전기설비학회논문지
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• 제27권1호
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• pp.85-91
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• 2013

This paper studied surface discharge characteristics by a dielectric constant and diameter of solid dielectrics in $N_2/O_2$ mixture gas. Applied electric field strength at $N_2/O_2$ mixture gas was changed from the dielectric constant and diameter of the solid dielectrics, and insulation performance of the $N_2/O_2$ mixture gas determined surface discharge voltage. In each of the diameter at the solid dielectrics, the surface discharge voltage was increased by lengthening surface distance, whereas increasing rate of the surface discharge voltage was different from gas pressure. Thus, In this paper, main factors of surface discharge are as follows. 1) Insulation performance of $N_2/O_2$ mixture gas, 2) Dielectric constant of solid dielectrics, 3) Surface discharge path. It was clear that the surface discharge voltage depend on the main factors. These results will be applied to useful data for an eco-friendly composite insulation design.

• 한국수소및신에너지학회논문집
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• 제21권4호
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• pp.278-285
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• 2010

The Sulfur-Iodine (SI) thermochemical hydrogen production process of a closed cycle consists of three sections, which are so called the Bunsen reaction section, the $H_2SO_4$ decomposition section and the HI decomposition section. To identify the role of oxygen that can be supplied to the Bunsen reaction section via the $H_2SO_4$ decomposition section, Bunsen reactions with a $SO_2,\;SO_2-O_2$ mixture and $SO_2-N_2$ mixture as feed gases were carried out using a stirred reactor in the presence of $I_2/H_2O$ mixture. As the results, the amounts of $I_2$ unreacted under the feed of mixture gases were higher than those under the feed of $SO_2$ gas only, and the amount of HI produced was relatively decreased. The results of Bunsen reaction using $SO_2-O_2$ mixture were similar to those using $SO_2-N_2$ mixture. It may be concluded that an oxygen in $SO_2-O_2$ mixture has a role as a carrier gas like a nitrogen in $SO_2-N_2$ mixture. The effects of oxygen were decreased with increasing temperature and decreasing oxygen content in $SO_2-O_2$ mixture.

• 멤브레인
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• 제21권1호
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• pp.22-29
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• 2011

중전기의 유지 보수 및 교체 과정에서 절연체로 사용된 $SF_6$ 가스는 교체 충전과 정제과정에서 유입되는 공기와의 아크 방전에 의해 많은 종류의 부산물($N_2$, $O_2$, $CF_4$, $SO_2$, $H_2O$, HF, $SOF_2$, $CuF_2$, $WO_3$ 등)이 발생된다. 부산물 중에서도 대부분을 차지하는 것이 $N_2$, $O_2$, $CF_4$이며, $SF_6$가스를 재사용하기 위해서는 이들을 효과적으로 분리 회수하는 공정이 필요하다. 주요 부산물인 $N_2$, $O_2$, $CF_4$와의 분리 효율 측면에서 분리막법은 기존의 흡착, 심냉법에 비하여 상대적으로 높은 효율을 보이고 있어 이에 대한 관심 또한 증가하고 있다. 따라서 본 논문에서는 중전기 산업에서 발생되는 $SF_6$ 가스 함유 농도 90 vol% 이상의 가스에 대하여 분리막법을 적용하여 $N_2$, $O_2$, $CF_4$와 $SF_6$ 가스의 온도와 배출유량의 변화에 따른 분리 회수 가능성을 관찰하였다. PSF와 PC 중공사 분리막을 이용하여 고농도 $SF_6$에 대한 분리 회수 실험 결과, PSF 분리막의 최대 회수율은 압력 0.3 MPa, 온도 $25^{\circ}C$, 배출유량 150 cc/min에서 92.7%를 나타내었으며, PC 분리막에서는 압력 0.3 MPa, 온도 $45^{\circ}C$, 배출유량 150 cc/min 일 때 74.8%의 최대 회수율을 나타내었다. 또한, 사용된 두 가지 분리막과 운전 조건에서 주요 부산물인 $N_2$, $O_2$, $CF_4$의 최대 제거율은 각각 약 80%, 74%, 그리고 58.9%가 관찰되었다. 이로부터 분리막 공정은 고농도 폐 $SF_6$ 가스에서 주요 부산물로부터 $SF_6$의 효과적인 분리 및 회수가 가능한 공정으로 적용할 수 있는 가능성을 파악 할 수 있었다.

• 조명전기설비학회논문지
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• 제23권5호
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• pp.96-100
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• 2009

산업사회의 발달과 더불어 신뢰성 높은 양질의 전기에너지와 운전 및 보수의 간편화, 계통 운용의 신뢰성, 안전성 확보가 요구되고 있다. 따라서 본 논문은 각종 전력설비에서 $SF_6$을 대체할 수 있는 친환경절연제로 연구되고 있는 $N_2-O_2$ 혼합가스($N_2:O_2=100$ : 0, 79 : 21, 60 : 40, 40 : 60) 절연파괴특성을 구명(究明)하여 이를 $SF_6$가스의 특성과 비교하였다. 이상의 연구 결과, 제조공기와 Dry-Air 절연특성을 구명함으로서 각종 전력응용 설비의 절연설계에 $SF_6$ 대신 친환경적인 모의공기를 사용 가능함을 본 연구에서 구명(究明)하였다. 제조공기를 이용한 친환경적인 절연재 사용으로 지구의 온난화현상 감소에 크게 기여할 것으로 기대된다.

• 한국분무공학회지
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• 제25권3호
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• pp.132-138
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• 2020

N₂O is hazardous atmosphere pollution matter which can damage the ozone layer and cause green house effect. There are many other nitrogen oxide emission control but N₂O has no its particular method. Preventing further environmental pollution and global warming, it is essential to control N₂O emission from industrial machines. In this study, the thermal decomposition experiment of N₂O gas mixture is conducted by using cylindrical reactor to figure out N₂O reduction and NO formation. And CHEMKIN calculation is conducted to figure out reaction rate and mechanism. Residence time of the N₂O gas in the reactor is set as experimental variable to imitate real SNCR system. As a result, most of the nitrogen components are converted into N2. Reaction rate of the N₂O gas decreases with N₂O emitted concentration. At 800℃ and 900℃, N₂O reduction variance and NO concentration are increased with residence time and temperature. However, at 1000℃, N₂O reduction variance and NO concentration are deceased in 40s due to forward reaction rate diminished and reverse reaction rate appeared.