• 제목/요약/키워드: gas explosions

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PIV Measurements on the Flame Initiation and Propagation under Gas Explosions by Electrostatic Discharge Energies in a Confined Chamber with an Obstacle (장애물이 있는 챔버 내부의 정전기 방전 에너지에 의한 가스 폭발시 초기화염과 화염전파 특성에 대한 PIV 계측)

  • Park, Dal-Jae;Lee, Seok-Hwan;Sung, Jae-Yong;Lee, Young-Soon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.9
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    • pp.682-687
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    • 2009
  • In order to investigate the effects of three different electrostatic discharge energies on gas explosions, a high-speed PIV system has been applied. The present study paid attention to the flame initiation by the gas explosions and its propagation at the existence of an obstacle within a chamber. Three different ignition energies such as 0.56 mJ, 52.87 mJ and 112.5 mJ were used. It is found that the ignition kernel is bent by the electrostatic discharge during the flame initiation. Tangential velocities of unburnt mixture ahead of initially propagating flame fronts are increased with increasing ignition energy, which makes the flame propagation faster before it reaches the obstacle. Although the flame speed was found to be less sensitive to the ignition energies, the flame developments were different. The effects of the energies on explosion pressures were also discussed.

Quantitative Risk Assessment for Gas-explosion at Buried Common Utility Tunnel (지하 매설 공동구 내부 가스 폭발에 대한 위험성 평가)

  • Jang, Yuri;Jung, Seungho
    • Journal of the Korean Institute of Gas
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    • v.20 no.5
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    • pp.89-95
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    • 2016
  • Keeping the gas pipelines in the common utility tunnel is useful because it has a lower risk of corrosion than conventional burial, and can prevent from excavating construction. But, explosions in common utility tunnels can cause greater damage from the blast overpressure compared to outdoor explosions, due to nature of the confined environment. Despite this fact, however, research on common utility tunnels has been limited to fire hazard and little has been studied on the dangers of explosions. This study developed scenarios of methane gas explosion caused by gas leak from gas piping within the common utility tunnel followed by unknown ignition; the study then calculated the extent of the impact of the explosion on the facilities above, and suggested the needs for designing additional safety measures. Two scenarios were selected per operating condition of safety devices and the consequence analysis was carried out with FLACS, one of the CFD tools for explosion simulation. The overpressures for all scenarios are substantial enough to completely destroy most of the buildings. In addition, we have provided additional measures to secure safety especially reducing incident frequency.

Numerical analyses for the structural assessment of steel buildings under explosions

  • Olmati, Pierluigi;Petrini, Francesco;Bontempi, Franco
    • Structural Engineering and Mechanics
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    • v.45 no.6
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    • pp.803-819
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    • 2013
  • This paper addresses two main issues relevant to the structural assessment of buildings subjected to explosions. The first issue regards the robustness evaluation of steel frame structures: a procedure is provided for computing "robustness curves" and it is applied to a 20-storey steel frame building, describing the residual strength of the (blast) damaged structure under different local damage levels. The second issue regards the precise evaluation of blast pressures acting on structural elements using Computational Fluid Dynamic (CFD) techniques. This last aspect is treated with particular reference to gas explosions, focusing on some critical parameters (room congestion, failure of non-structural walls and ignition point location) which influence the development of the explosion. From the analyses, it can be deduced that, at least for the examined cases, the obtained robustness curves provide a suitable tool that can be used for risk management and assessment purposes. Moreover, the variation of relevant CFD analysis outcomes (e.g., pressure) due to the variation of the analysis parameters is found to be significant.

Analysis of Explosion Energy related to the Cause of Tianjin Explosion Accident in China (중국 텐진항 폭발사고 원인과 관련된 폭발 에너지 분석)

  • Kwon, Sangki;Kim, Ha Yung
    • Explosives and Blasting
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    • v.34 no.1
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    • pp.1-10
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    • 2016
  • On August 12, 2015, two huge explosions were accidently happened in Tianjin port, China. The explosion energies of the two explosions were similar to those of TNT 3 tons and TNT 21 tons. Until now, the cause of the explosions was not clearly announced but some guesses of the cause were released. One of the possible cause of the explosion is the generation of explosive acetylene gas from the chemical reaction between $CaC_2$ and spraying water to extinguish fire happened at the storage site of different chemical compounds. The explosion of acetylene gas might ignite the explosion of 800 tons of ammonium nitrate. In this study, the explosion due to the scenario was analyzed in order to check that such a chemical reaction can produce the huge explosion observed at the Tianjin accident.

A Study on the Development of Early Acetone Gas Detection to Prevent the Acetone Leakage Accident (아세톤 누출사고 예방을 위한 아세톤 가스 조기감지 기술개발에 관한 연구)

  • Seung Jin Jeon;Youngbo Choi
    • Journal of the Korean Society of Safety
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    • v.38 no.2
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    • pp.30-35
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    • 2023
  • Acetone is a widely used Volatile Organic Compound (VOC) in industries and laboratories. However, acetone affects human health adversely and causes fires and explosions. Early acetone detection and improved personnel training in safety and emergency management are necessary to prevent acetone-related accidents. The multi-VOC acetone detectors used currently have a sensitivity and selectivity limit. In this study, we discovered that Pt-loaded iron oxide (a metal oxide semiconductor) conversely, has high detection and selectivity for very low-levels of acetone gas. The loaded Pt catalyzes the reaction between the sensing materials' surface and the oxygen molecules in the air; this optimizes acetone detection and can decrease acetone-related illnesses, fires and explosions.

Hazard Assesment of Dust Explosion Pharmaceutical Raw Material Powders (원료의약품 분진의 폭발 위험성 평가)

  • Kim, Won Sung;Lee, Keun Won;Woo, In Sung;Jeon, Sang Yong
    • Journal of the Korean Society of Safety
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    • v.33 no.2
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    • pp.39-44
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    • 2018
  • Dust explosions are occurring in a variety of industries. A dust explosion caused by a specific energy generates huge amount of energy in the ignition and releases decomposition gas. Damages can be increased since this released decomposition gas can cause second and subsequent explosions. In this study, the goal was to obtain practical information on what could affect the explosion by comparing the characteristics of two kinds of dusts with completely different chemical properties. Three kinds of dusts were measured and evaluated for explosion pressure, dust explosion index, explosion limit and minimum ignition energy. It is possible to grasp the characteristics of each dust and use it as useful accident prevention data in the production of raw material powder.

A Phenomenological Review on the Damage of Hot Gas Parts caused by Explosion of Gas Turbine Cooling System (가스터빈 내부 냉각계통 발화에 의한 고온부품 손상의 현상학적 고찰)

  • Yu, Won-Ju;Lee, Seong-Hyun
    • Proceedings of the Safety Management and Science Conference
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    • 2010.04a
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    • pp.81-95
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    • 2010
  • Gas turbines generating power operate in high temperature condition and use natural gas as fuel. For that reason, there are many cases where damage is done to the hot gas parts caused by the high temperature and many accidents occur like gas explosions, then various efforts are needed to maintain the hot gas parts and prevent accidents. It is difficult to find the root causes of damage to the hot gas parts from the gas explosion caused by gas leakage through rotor cooling air line from fuel gas heat exchanger during the shut down. To prevent gas turbine from damage, removal of gas leakage inside of gas turbine is required by purging the turbine before firing, improving the fuel gas heating system and installing alarm systems for detecting gas leakage from stop valve to turbine while the gas turbine has shut down.

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