• Title/Summary/Keyword: $SF_6$가스

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An Experiment on Verification of Multi-Gas Tracer Technique for Air Exchange Rate Between Rooms (실간환기량 측정을 위한 멀티추적가스법의 검증실험)

  • Han, Hwa-Taik;Cho, Seok-Hyo
    • Proceedings of the SAREK Conference
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    • 2007.11a
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    • pp.99-104
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    • 2007
  • Tracer gas technique is widely used to measure the ventilation rates and/or ventilation effectiveness of building spaces. However, the conventional method using a single tracer gas can measure only outdoor air change rates in a single zone. This paper deals with the multi-gas tracer technique to measure air exchange rates between rooms. Interzonal air movements are important to characterize overall ventilation performance of complicated multi-zone buildings. Experiments are conducted in a simple two-room model with known airflow rates using tracer gases of SF6 and R134a. The concentration decays of two tracer gases are measured after simultaneous injections in each room. The governing equations are derived from the continuity and the mass balance of each room. The data reduction procedure are developed to obtain the inter-room airflow rates using the governing matrix inversion, and various data manipulation methods are tested, such as data shift, interpolation, smoothing, and etc, to improve the estimate and interpretation of the results.

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Fluid Dynamics Analysis and Experimental Trial to Improve the Switching Performance of Eco-friendly Gas Insulated Switch (친환경 가스개폐기 개폐성능 향상을 위한 유동해석 및 실험)

  • Yu, Lyun;Ahn, Kil-Young;Kim, Young-Geun;Cho, Hae-Yong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.21 no.9
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    • pp.42-49
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    • 2022
  • An underground electric switch is a high-voltage switch used in distribution network systems for a reliable power supply. Many studies are being conducted to expand the switch to use an eco-friendly gas using dry air instead of SF6 gas to reduce greenhouse gas emissions. In this study, a flow analysis model was established to improve the performance of an eco-friendly gas switch. The results were compared and reviewed through experiments. For the optimal arc grid design applied to the switch, the flow characteristics based on the flow path configuration and the changes in arcing time for each configuration were compared. Flow analysis can predict the switch flow distribution, and a comparative review of the flow path configurations of various methods is possible.

Analysis of Carbon Emissions According to Combustion of Surface Fuels (지표연료의 연소에 따른 탄소배출량 분석)

  • Park, Young Ju;Lee, Hae Pyeong;Kim, Min Jung;Kim, Hae Rim
    • 한국방재학회:학술대회논문집
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    • 2011.02a
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    • pp.192-192
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    • 2011
  • 교토의정서에서 지구온난화의 원인이 되는 온실가스로 $CO_2$, $CH_4$, $N_2O$, HFCs, PFCs, $SF_6$를 규제하고 있다. 규제하는 6대 온실가스 가운데 $CO_2$가 가장 대표적이며, 우리나라의 연료연소에 의한 $CO_2$ 배출량은 세계 10위로 기후변화 진행속도는 세계 평균속도보다 빠르게 진행되고 있다. 이러한 기후변화에 대응하기 위하여는 온실가스 배출로 인한 DB구축 연구가 선행되어야 하며, 산림부분에 있어서는 연료의 열적특성 구명 연구가 극도로 미진한 국내현실에서 기초 data 확보를 위한 연구가 시급한 실정이다. 따라서, 본 연구에서는 산불발생 시 온실가스 배출량의 DB를 구축하기 위하여 산불발생 시 배출되는 탄소배출량을 예측하고자 산림 가연물의 연소실험을 수행 하였다. 연소실험은 산림 연료 가운데 지표연료 10가지(소나무낙엽, 굴참나무낙엽, 소나무솔방울, 밤나무밤송이껍질, 방아풀, 주름조개풀, 칡, 엉겅퀴, 김의털, 고비)를 대상으로 콘칼로리미터 장비를 이용하여 이산화탄소와 일산화탄소 배출량을 분석하였다. 탄소배출량 실험에 앞서 지표연료들의 함수율을 측정한 결과, 10가지 지표연료 가운데 고사한 연료(낙엽, 솔방울, 밤송이)는 9~24% 정도, 생연료인 초본류 6가지는 181~484% 정도인 것으로 나타났으며, 솔방울과 밤송이의 경우 9~10%로 가장 수분을 적게 함유하고 있음을 알 수 있었다. 탄소배출량 분석 결과, 50g 중량에 대한 10가지 지표연료들의 이산화탄소 총배출량은 28~98g 정도, 일산화탄소 총배출량은 0.76~4.08g 정도 배출하는 것으로 나타나 연료별 차이를 보였으며, 특히, 고사한 연료와 생연료의 탄소배출량 차이는 큰 것으로 나타났다. 일산화탄소 총배출량은 고사한 연료(소나무낙엽, 굴참나무 낙엽, 소나무 솔방울, 밤나무 밤송이)는 3.24~4.08g 정도, 생연료 초본류 6가지(방아풀, 주름조개풀, 칡, 엉겅퀴, 김의털, 고비)는 0.76~2.73g 정도 배출하는 것으로 나타났다. 이산화탄소 총배출량은 함수율이 현저히 낮은 4가지 연료(소나무 낙엽, 굴참나무 낙엽, 소나무 솔방울, 밤나무 밤송이 껍질)들은 52~98g 정도, 함수율이 높은 6가지 초본류는 28~48g 정도의 이산화탄소를 배출하는 것으로 나타났다. 따라서, 고사한 연료인 소나무 낙엽, 굴참나무 낙엽, 소나무 솔방울, 밤나무 밤송이는 초본류 보다 상대적으로 이산화탄소와 일산화탄소 배출량이 많은 것으로 나타났으며, 특히, 소나무 솔방울은 가장 많은 이산화탄소와 일산화탄소를 배출하는 것으로 나타났다. 상대적으로 방아풀과 주름조개풀은 각각 28g과 35g으로 이산화탄소 배출량이 작은 것으로 나타났다. 따라서, 산불발생 시, 소나무의 솔방울은 10가지 지표연료 가운데 상대적으로 많은 이산화탄소와 일산화탄소를 배출할 것으로 사료된다.

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Effect of Epoxy Dielectric Cooling on existing metal Porticoes in GIS (GIS내 금속이물 존재시 에폭시 절연코팅의 효과)

  • 곽희로;구교선;김영찬
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.17 no.2
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    • pp.95-101
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    • 2003
  • In this paper, partial discharges(PDs), lift off and breakdown voltage were measured when metal particles existed in a model GIS coated with epoxy resin on its bottom electrode, and the measured results were analyzed after comparing with the model DIS not coated. In order to presume the various fault case in GIS, we measured the experimental values with changing some experimental factors, such as the mixture ratio of SF$\_$6//N$_2$, the pressure of the gases, the kinds and diameter of the metal particles, and the coating thickness of the epoxy resin. As a result, the PDIV increased with the thickness of the epoxy resin, while the magnitude of PDs decreased at the same condition. The lift off voltages of steel alloy particles were higher than that of copper particles, and increased wit diameter of particles. Futhermore, the lift off voltages in the case of the electrode coated with epoxy resin were higher than that in the case of the uncoated one. In addition, the thicker the thickness of the epoxy resin was, the higher the breakdown voltage were. Thus, it was confirmed that the GIS coated with epoxy resin on its inner surface could be improved in insulation performance.

Isolation Effectiveness by Progressive Space Organization in Negative Pressured Isolation Unit (음압격리병실에 있어서 단계별 공간구성의 격리효과)

  • Kwon, Soonjung;Sung, Minki
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.22 no.4
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    • pp.79-86
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    • 2016
  • Purpose: The purpose of this study is to identify the effect of Progressive Space Organization (ante-rooms) in Negative Pressured Isolation Unit(NPIU) such as National and Regional Isolation Units in Korea in order to build basic data for the evidence based design of Airborne Infection Isolation Units which should prepare and respond effectively to the public health crisis due to the hazardous airborne infectious disease. Methods: 1) Gas(SF6) test and analysis on the 23 Korean Isolation Units under operation. 2) Assessment of the isolation level of the space components by checking the Gas concentration. 3) Analysis of the Isolation Effectiveness according to Space Organizational levels. Results: 1) The higher segregation level is, the lower Gas(SF6) concentration is. 2) Too many segregations(anterooms) of Isolation Unit are not efficient for the prevention of infectious bacillus spread. For example, 4 level of segregation has similar segregation effect to the 3 level of segregation. Implications: Many anterooms in front of the isolated patient bedroom will guarantee the safe environment against the danger of hazardous airborne nosocomial infection. On the other hand, too many segregations is inefficient, expensive, inconvenient, narrow(unflexible) and so on. This study can be used as basic data for further development of design guidelines of isolation units.

Analysis of Thermal Recovery Characteristics for $SF^6$ Gas-Blast Arc within Laval Nozzle (Laval Nozzle에 대한 $SF^6$ 아크의 열적회복특성 해석)

  • Song, Gi-Dong;Lee, Byeong-Yun;Gyeong-Yeop;Park, Jeong-Hu
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.51 no.9
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    • pp.522-529
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    • 2002
  • In this paper, computer simulations of the physical Phenomena occurring in the arc region before and after current zero were carried out to evaluate the thermal recovery characteristics of a Laval nozzle. A commercial CFD program "PHOENICS" is used for the simulation and the user-coded subroutines to consider the arcing phenomena were added to this program by the authors. The computed results were verified by the comparison with the test results presented by the research group of GE Co.(General Electric Company). In order to investigate the state of the arc region after current zero, the simulation was carried out with three steps. They are steady state arc simulation, transient arc simulation before current zero, and transient hot-gas flow simulation after current zero. The semi-experimental arc radiation model is adapted to consider the radiation energy transport and Prandtl's mixing length model is employed as the turbulence model. The electric field and the magnetic field were calculated with the same grid structure used for the simulation of the flow field. The post-arc current was calculated to evaluate the thermal recovery characteristics after current zero. Compared with the results obtained by GE Co., it has been found that the critical RRRV(ratio of rise of recovery voltage) will be determined previously by this study.his study.

Analysis of the Causes of Accidents Related to 3 Phase 170 kV Gas Insulated Switchgears(GIS) and Preventive Measures (3상 170 kV 가스절연개폐장치(GIS)의 사고 원인 분석 및 예방 대책)

  • Choi, Chung-Seog
    • Journal of the Korean Society of Safety
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    • v.26 no.4
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    • pp.41-46
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    • 2011
  • The purpose of this paper is to analyze the causes of accidents related to the 3 phase 170 kV gas insulated switchgear of a power system collected from accident sites to secure data for the prevention of similar accidents and provide important points of view regarding diagnosis for the prevention of accidents involving gas insulated switchgears. The analysis results of the causes of accidents involving gas insulated switchgears showed deformation of the manipulation lever installed at the S-phase, disconnection of the insulation rod connection, melting of the upper conductor, a damaged tulip, damage to the lower spacer and the spacer at the breaker, etc. It is believed from this result that the potential for accidents has expanded due to accumulated energy as a result of repeated deterioration. The carbonization depth of a GIS was formed near the screw (T2, T3) used to secure the lower pole of the S-phase tulip. It is not known what has caused the screws to be extruded and melted. However, it is thought that an unbalanced electromagnetic force, micro-discharge, surface discharge, etc., have occurred at that point. In addition, even though 16 years have passed since its installation, there was no installation defect, act of arson, accidental fire, etc. General periodical inspection and diagnosis failed to find the factors causing the accidents. As a system contained in a closed metal container, it has a high risk factor. Therefore, it is necessary to design, install and operate a GIS in accordance with the standard operational procedure (SOP). In addition, it is necessary to apply conversion technology for periodical SF6 gas analysis and precision safety diagnosis. It is expected that tracking and managing these changes in characteristics by recording the results on the history card will provide a significant accident prevention effect.

Steady State Hot Gas Flow Analysis for Nozzle Model Considering Nozzle Ab (노즐용삭을 고려한 노즐모델의 정상상태 열가스 유동해석)

  • Lee, B.Y.;Song, K.D.;Park, K.Y.
    • Proceedings of the KIEE Conference
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    • 2002.07b
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    • pp.622-624
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    • 2002
  • This paper describes a method for steady state hot gas flow analysis considering nozzle ablation for the nozzle of $SF_6$ gas circuit breaker. In order to take account of the effect of ablated nozzle material on the hot gas flow. the PTFE mass concentration equation is added to the established equations for hot gas flow analysis. The steady state simulations were carried out under the condition of DC current flows and the results are presented.

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Characteristics of Narrow Band Radio Electro-Magnetic Wave for Distance of Measurement (측정 거리에 따른 협대역 방사전자파 특성)

  • Yoon, D.H.;Park, K.S.;Lee, H.C.;Choi, Y.H.;Yoon, B.H.;Choi, S.T.;Park, W.J.;Lee, K.S.
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.1814-1816
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    • 2004
  • 현장에서 많이 사용되고 있는 GIS에 결함이 발생하면 치명적인 사고로 진전될 수가 있다. 본 논문은 모의 GIS내 도전성 금속이물질 존재 시 발생되는 부분방전 신호를 절연진단 방법중 하나인 UHF법을 이용하여 부분방전 시 방사되는 방사전자파의 스펙트럼을 분석해서 방사전자파의 거리에 따른 감쇄율을 측정하였다. 이러한 연구는 현장 GIS 및 $SF_6$ 가스절연 전력설비에서 금속이물질에 의해 발생되는 방사전자파 측정에 중요한 역할을 할 것으로 사료된다.

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UHF PD Systems of LGIS (LG산전 UHF 부분방전 시스템)

  • Lee, Chang-Jun;Lee, Hee-Cheoul;Park, Jong-Wha;Kang, Won-Jong;Kang, Yoon-Sik
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.1888-1890
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    • 2004
  • 현대사회에 들어서면서, 전력수요의 중가와 전력기기산업의 고집적화에 따라 사고시에 발생하는 파급효과가 대형화되는 추세에 있다. 따라서 이를 미연에 방지하기 위한 연구가 각 분야에 걸쳐 활발하게 진행되고 있다. 이에 당사에서는 초고압 계통에서 사용되는 SF6가스 절연 GIS(Gas Insulated Switchgear) 및 Oil-Transformer에서의 부분방전 측정/분석을 위하여 UHF/AE를 이용한 on-line/portable 측정 시스템을 개발하였다. 본 논문에서는 개발/상용화 되어 field에서 사용되고 있는 시스템의 전반에 대하여 설명한다. 또한 철재 선진사와 공동 진행중인 Risk Assessment에 대하여 언급하였다.

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