• Title/Summary/Keyword: 외부폭발

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A Study on the Correlation of MESG and Explosion Pressure (최대실험안전틈새(MESG)와 폭발압력의 상관관계에 대한 연구)

  • Hwang, Kyungyong;Shin, Woonchul;Lee, Taeck-Kie
    • Journal of the Korean Institute of Gas
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    • v.20 no.1
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    • pp.29-39
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    • 2016
  • Electrical apparatuses for use in the presence of explosive gas atmospheres have to be special designed to prevent them from igniting the explosive gas. Flameproof design implies that electrical components producing electrical sparks are contained in enclosures and withstand the maximum pressure of internal gas or vapours. In addition, any gaps in the enclosure wall have to designed in such a way that they will not transmit a gas explosion inside the enclosure to an explosive gas or vapours atmosphere outside it. In this study, we explained some of the most important physical mechanism of Maximum Experimental Safe Gap(MESG) that the jet of combustion products ejected through the flame gap to the external surroundings do not have an energy and temperature large enough to initiate an ignition of external gas or vapours. We measured the MESG and maximum explosion pressure of propane and acetylene by the test method and procedure of IEC 60079-20-1:2010.When the minimum MESG is measured, the concentration of propane, acetylene in the air is higher than the stoichiometric point and their explosion pressure is the highest value.

Collapse Simulations of High-Rise RC Building Using ELS Software and Application of Explosive Demolition Methods to Transition Process Analysis from Local Damage to Progressive Collapse (ELS를 이용한 고층 RC 빌딩의 붕괴해석 및 발파해체해석 기법의 국부손상-연쇄붕괴 전이과정 해석에 응용)

  • Kim, Hyon-Soo;Park, Hoon;Kim, Seung-Kon;Lee, Yeon-Gyu;Cho, Sang-Ho
    • Explosives and Blasting
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    • v.29 no.2
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    • pp.1-12
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    • 2011
  • Progressive collapse analyses of high-rise buildings subjected to abnormal loading such as fires, impacts, earthquakes, typhoon, bomb blasts etc. are intended. However it is difficult to perform collapse experiments of the real scale building to determine the capacity of the structure under an extreme loading events. In this study, collapse behavior of a 15 story RC structure building loaded by external explosion pressures were simulated using Extreme Loading Structures (ELS) software. The standoff distance between the RC building and explosives of 1500 kg was 1, 2, 5, 10, and 15 meters. The explosive demolition analysis techniques based on removal of partial support structures following blast scenario was adapted to investigate the transition process of progressive collapse-local damage.

가스폭발에 의한 폭풍압의 특성에 관한 연구

  • 박승일;오규형;이진영;라선종
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • 2002.11a
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    • pp.172-177
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    • 2002
  • 가스폭발 시 폭발 압력에 의해 건물의 일부 또는 전체적인 파괴와 함께 외부에 영향을 미치는 영향은 주로 폭풍파의 압력과 고온의 화염이다. 그 중에서도 폭풍압은 건물에서의 가스폭발 시 파열면을 통과한 급격한 압력 방출에 의해 생겨나는 물리적인 현상으로 그 충격은 때에 따라서 구조물을 붕괴시킬 만큼 크다. 폭발에 의해 발생되는 폭풍압에 의한 피해가 크기 때문에 과거부터 폭풍압에 대한 연구가 계속되어 왔다.(중략)

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Experimental Evaluation of Internal Blast Resistance of Prestressed Concrete Tubular Structure according to Explosive Charge Weight (프리스트레스트 콘크리트 관형 구조물의 폭발량에 따른 내부폭발저항성능에 관한 실험적 평가)

  • Choi, Ji Hun;Choi, Seung Jai;Yang, Dal Hun;Kim, Jang-Ho Jay
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.39 no.3
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    • pp.369-380
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    • 2019
  • When a extreme loading such as blast is applied to prestressed concrete (PSC) structures and infrastructures for an instantaneous time, serious property damages and human casualties occur. However, a existing design procedure for PSC structures such as prestressed containment vessel (PCCV) and gas storage tank do not consider a protective design for extreme internal blast scenario. Particularly, an internal blast is much more dangerous than that of external blast. Therefore, verification of the internal blast loading is required. In this paper, the internal blast resistance capacity of PSC member is evaluated by performing internal blast tests on RC and bi-directional PSC scaled down specimens. The applied internal blast loads were 22.68, 27.22, and 31.75 kg (50, 60, and 70 lbs) ANFO explosive charge at 1,000 mm standoff distance. The data acquisitions include blast pressure, deflection, strain, crack patterns, and prestressing force. The test results showed that it is possible to predict the damage area to the structure when internal blast loading occurs in PCCV structures.

A Study on the MESG of Flammable Ternary Gas Mixtures (3성분계 인화성 혼합가스의 MESG에 관한 연구)

  • Hwang, Kyungyong;Byeon, Junghwan;Rhee, Kyunam;Lee, Taeck-Kie
    • Journal of the Korean Institute of Gas
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    • v.20 no.3
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    • pp.30-37
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    • 2016
  • Electrical apparatuses for use in the presence of flammable gas atmospheres have to be specially designed to prevent them from igniting the explosive gas. Flameproof design implies that electrical components producing electrical sparks are contained in enclosures and withstand the maximum pressure of internal gas or vapours. In addition, any gaps in the enclosure wall have to designed in such a way that they will not transmit a gas explosion inside the enclosure to an explosive gas or vapours atmosphere outside it. In this study, we explained some of the most important physical mechanism of MESG(Maximum Experimental Safe Gap) that the jet of combustion products ejected through the flame gap to the external surroundings do not have an energy and temperature large enough to initiate an ignition of external gas or vapours. We measured the MESG and maximum explosion pressure of ternary gas mixtures(propane-acetylene-air) by the test method and procedure of IEC 60079-20-1:2010. As a result, the composition of propane gas that has lower explosive power than acetylene gas in the ternary gas mixtures makes greater effects on MESG and explosion pressure.

Hauling time prediction of the muck generated by a blasting around a tunnel (터널 주변 폭발로 인해 발생된 버력의 처리시간 예측)

  • You, Kwang-Ho;Son, Myung-Kyun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.15 no.1
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    • pp.33-47
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    • 2013
  • When a bomb explodes near a tunnel, generated muck should be quickly moved outside for rehabilitation of the tunnel. In this study, the amount of muck generated by an explosion was estimated and a methodology was presented for the prediction of the muck hauling time. To this end, 3D-meshes were made by using SoildWorks and blasting analyses were performed by using AUTODYN. A method was suggested to calculate theoretically the amount of muck which inflows into a tunnel based on the relationship between the tunnel and the fragmentation zone obtained from the analysis results. Also, muck hauling times were predicted based on the selection of construction equipment and the results were compared and analyzed. As a result, it was convinced that the amount of muck flowing into the tunnel could be effectively calculated by classifying the relationship between a tunnel and the fragmentation zone into 4 cases and using the mensuration by parts. Also it was confirmed that the closer blasting location is to the portal and the excavation surface of a tunnel, and the more blasting location deviates from the center line of the tunnel, the lesser amount of muck occurs and thus the muck hauling time decreases as well.

A Study on the Identification Technique and Prevention of Combustion Diffusion through ESS (Energy Storage System) Battery Fire Case (ESS (에너지 저장장치) 배터리 화재사례를 통한 감식기법 및 연소 확산방지에 관한 연구)

  • Lee, Jung-Il
    • Journal of the Society of Disaster Information
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    • v.16 no.2
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    • pp.383-391
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    • 2020
  • Purpose: To identify internal self ignition and ignition caused by external flames in energy storage rooms, and to analyze the difference between ignition due to overheating and ignition caused by external heat sources. Method: membrane melting point measurement, battery external hydrothermal experiment, battery overcharge experiment, comparative analysis of electrode plate during combustion by overcharge and external heat, overcharge combustion characteristics, external hydrothermal fire combustion characteristics, 3.4 (electrode plate comparison) / 3.5 (overcharge) /3.6 (external sequence) analysis experiment. Result: Since the temperature difference was very different depending on the position of the sensor until the fire occurred, it is judged that two temperature sensors per module are not enough to prevent the fire through temperature control in advance. Conclusion: The short circuit acts as an ignition source and ignites the mixed gas, causing a gas explosion. The electrode breaks finely due to the explosion pressure, and the powder-like lithium oxide is sparked like a firecracker by the flame reaction.

Automation System of Explosion-Proof Panel Condition (방폭 패널 컨디션 자동화 시스템(1))

  • Hwang, Dae-Hyeon;Choi, Kwang-Il;Bae, Young-Chul
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.2
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    • pp.253-258
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    • 2020
  • Petrochemical industry complex in Korea always has high riskiness due to explosive and inflammable gases. To prevent these explosion, most facility of petrochemical industry complex requires the performance of explosive proof. The control panel, which is used as explosive proof, has been used the air injection method by manually from outside to constantly keep the temperature and pressure between inside and outside of the panel. In this paper, we propose the automatic temperature controller, which performs automatic heating and cooling according to temperature inside the panel in order to control temperature automatically.

Design of Integration Controller of Explosive Proof Panel (방폭 패널 통합 제어기 설계)

  • Bak, Gwi-Man;Bae, Young-Chul
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.2
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    • pp.267-272
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    • 2020
  • Currently, the petrochemical industry complex always has remained with the explosive riskiness due to explosive and inflammable gases. In order to prevent explosion, all kind of equipment or facility including controller and its panel requires explosive proof. The control panel, which is currently used as explosive proof, has been used as the air injection method by manually from outside to constantly keep the temperature and pressure between inside and outside of the panel. In this paper, we propose the design of integrated controller of explosive proof panel which can control pressure and temperature automatically.

The cause analysis of explosion on bushing of 154 kV cable (154 kV급 절연부싱에서의 폭발사고 원인분석)

  • Shong, Kil-Mok;Bang, Sun-Bae;Kim, Chong-Min;Kim, Young-Seok;Choi, Myeong-Il
    • Congress of the korean instutite of fire investigation
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    • 2011.04a
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    • pp.137-160
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    • 2011
  • 본 사고분석을 통해 154 kV 절연부싱에서의 폭발사고에 대한 원인을 규명하였다. 결과적으로, 절연부싱의 사양은 국제표준에 적합하였다. 사고당일 기록된 자료에 의하면 R상과 S상에서 거의 동시에 지락사고가 발생하였으며, 지락지속시간은 약 75 ms로써 사고의 영향을 준 시간은 약 67 ms인 것으로 나타났다. R상은 아크에 의한 탄화 흔적, S상은 아크에 의한 탄화흔적과 외부열에 의한 탄화흔적, T상은 외부열에 의한 탄화흔적, 용융흔적은 R상과 S상의 케이블접속부와 플랜지에서 각각 발생하였다. S상의 절연부싱을 이용하여 탄화패턴 중 아크에 의한 것과 일반 열에 의한 것을 분류하여 연면방전이 발생한 것을 입증하였다. 사고추정 시나리오는 현장조사과정에서 나타난 현상과 목격자 진술, 사고원인 분석자료 등을 토대로 하여 작성되었다. 따라서 사고추정을 통해 분석된 자료는 아크생성단계, 열폭주 단계, 폭발단계, 화재단계로 구성하였다. 사고원인 가능성은 사고의 원인, 형태, 영향을 통해 나타난 연결고리를 검토하여 가능성이 낮은 부분을 배제하는 방식으로 진행되었다. 절연부싱의 사고원인은 표면의 오염물질 부착 가능성이 가장 높았다. 이를 근거로 하여 제조, 시공, 관리적 측면에서의 방지대책을 고려하는 것이 바람직할 것으로 판단된다.

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