• Proceedings of the KIEE Conference
• /
• 2008.10b
• /
• pp.382-383
• /
• 2008

현재 가정이나 산업용으로 사용하는 가스 화기나 보일러 등에서 가스 누출에 의한 화재사고나 폭발사고가 빈번하게 발생하고 있다. 가스 누출에 의한 사고는 오랜 시간 가스 누출 후 점화원에 의한 폭발이나 화재사고가 대다수를 차지한다. 일반적으로 천연가스를 사용하는 경우 상단부에 가스누출검지기를 설치하고 있다. 하지만 이러한 설치 위치는 대략적인 가스의 특성을 고려한 것이다. 본 연구에서는 가스 누출이 발생할 수 있는 누출위치를 가정의 가스레인지 화구와 밸브 연결부로 선정하고, 전산유체역학(CFD)을 이용하여 가스누출검지기의 시간에 따른 응답특성을 파악하여, 빠른 가스 검지를 위해 가스누출검지기 설치 위치를 최적화하였다. 본 연구의 결과를 기초로 가정이나 건물의 가스누출검지기출 설치할 경우, 가스가 누출되었을 때 신속한 검지를 통하여 위험을 알림으로서 가스폭발이나 사고를 미연에 방지할 수 있을 것이다.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.11a
• /
• pp.59-62
• /
• 2007

연료전지는 수소를 이용하여 전기를 생산하는 발전 시스템으로 운전 중 수소 누출과 폭발의 위험성을 항상 수반하고 있다. 따라서 안전성의 확보를 위해 연료전지 시스템 내부에서 수소 누출 시 유e동 특성으로 인한 특정 부근 농도 정체와 환기의 영향을 파악하는 것이 필요하다. 실험 장치와 전산유체역학 프로그램을 사용하여 챔버 내 수소의 유통 특성과 환기구에 따른 환기의 영향을 확인하였다. 수소의 누출 속도와 양에 따라 유동장의 형태는 크게 변하였으며 환기구의 위치와 크기는 특정 부근의 농도정체와 챔버 내 전체적인 수소 농도에 영향을 미침으로서 안정성을 확보하는 중요한 인자임을 알 수 있었다. 예측 결과를 실제 실험 모델과 비교하여 그 타당성을 검토하였으며 차후 가정용 연료전지 모듈의 환기구 설계에 적용할 수 있다.

• Journal of the Society of Disaster Information
• /
• v.20 no.1
• /
• pp.213-221
• /
• 2024

Purpose: The purpose is to find the optimal way to quickly block the leak in the event of a leak accident in a tank lorry transporting hydrochloric acid aqueous solution, a hazardous chemical, and to carry out effective disaster prevention work to minimize damage caused by the leak. Method: We organized the overall characteristics of hydrochloric acid and accidents that occurred during transportation by accident type and cause, and created a small tank that can be tested assuming a leak situation in a hydrochloric acid tanker, creating an environment similar to the leak situation, and leaking in various ways. I would like to experiment and organize blocking methods. Result: Through experiments, an effective leak blocking method was confirmed. We would like to summarize measures to quickly block a leak in the event of a leak and present the optimal disaster prevention plan that can be applied at the accident site. Conclusion: It has been confirmed that using a combination of adhesive tape and magnets is more effective in blocking leaks. Rapid response is possible by repeatedly training business emergency response teams and product transporters to appropriately select and respond to leak-blocking equipment. Additional research on various leak prevention methods is needed in the future.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2006.04a
• /
• pp.419-423
• /
• 2006

유류누출지역의 수리지질, 수리지화학 및 미생물 분석을 통하여 지층특성이 지하수 흐름, 수질 및 미생물 특성에 미치는 영향을 고찰한 결과 지표에서 심도 $1.8{\sim}3.5m$ 구간에 수십 cm에서 2m 정도의 두께를 갖는 투수성이 상대적으로 양호한 지층이 존재함을 확인할 수 있었다. 이러한 지층의 존재에 의하여 상하부의 지하수대의 수두차이가 현저함을 관측하였으며 유류 수송관에서 누출된 유류가 이 투수성 지층을 따라 이동하여 이 구간의 토양 및 지하수가 오염되었다고 판단할 수 있다. 지하수 수질은 이러한 지층의 특성에 따라 다른 이온성분 및 동위원소 특징을 보여주었으며 이는 다변량통계분석에 의해서도 확인할 수 있었다. 미생물 DGGE 분석결과 역시 유사한 특징을 보여주어 이러한 수리지화학, 수리지질 및 미생물 특징이 서로 밀접한 상관성을 보여줌을 확인할 수 있었다.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.6
• /
• pp.825-833
• /
• 2018

In this study, one calculated the range of damage to the combustion characteristics according to the composition of LNG and the size of leaking holes, and analyzed the damage effect in case of leakage accidents caused by pipe damage in the re-gasification process for the LNG supply system. In order to confirm the combustion characteristics according to LNG composition, there was no significant difference in the result of risk analysis by LNG-producing areas. However, the higher the methane content of the components, the lower the risk of flash fire, hazardous areas of overpressure due to explosion, and thermal radiation damage caused by jet fire. In addition, one investigated the effect of leakage, holes, and ruptures on the risk range and explosions according to the size of the pipe-leakage hole. Also, the influence of overpressure and the range of damage from radiant heat could be predicted. One confirmed the effect of LNG composition and pipe-leakage size on fire and explosion.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.5
• /
• pp.26-35
• /
• 2016

As a potential clean energy resource, the production and consumption of hydrogen gas are expected to gradually increase, so that hydrogen related studies are also increasing. The thermal and chemical properties of hydrogen result in its high flammability; in particular, there is a high risk if leaks occur within an enclosed space. In this study, we applied the computational fluid dynamics method to conduct a numerical study on the leakage behavior of hydrogen gas and compared these numerical study results with an experimental study. The leakage hole diameter was selected as an important parameter and the hydrogen gas dispersion behavior in an enclosed space was investigated through various analytical methods. Moreover, the flammable regions were investigated as a function of the leakage time and leakage hole size. We found that the growth rate of the flammable region increases rapidly with increasing leakage hole size. We also investigated the relation between the mass flow rate and the critical time when the hydrogen gas reaches the ceiling. The analysis of the monitoring points showed that the hydrogen gas dispersion behavior is isotropic and independent of the geometry. We found that the concentration of gas in an enclosed space is affected by both the leakage flow rate and amount of gas accumulated in the enclosure.

• Journal of the Korean Institute of Gas
• /
• v.26 no.4
• /
• pp.27-35
• /
• 2022

When LPG leaks from the storage tank, the gas try to sink to the ground because LPG is heavier than air. The gas easily creates vapor clouds causing aggressive accidents in no airflow. Therefore, It is important to prevent in advance by analyzing the damaged range caused from LPG leakage and vapor clouds. So, this study analyzed the range of damaged by LPG leakage and vapor clouds with consideration of the cold air flow which is generated by the topographical characteristics and the land use status at night time in the Jeju Hagari. As a result of the cold air flow using KLAM_21, about 2 m/s of cold air was introduced in from the southeast due to the influence of the terrain. The range of damaged by LPG leakage and vapor cloud was analyzed using ALOHA. When the leak hole size is 10 cm at the wind speed of 2 m/s, the range corresponding to LEL 60 % (12,600 ppm) was 61 m which range is expected to influence in nearby residential areas. These results of this study can be used as basic data to prepare preventive measures of accidents caused by vapor cloud. Forward, it is necessary to apply CFD modeling such as FLACS to check the vapor cloud formation due to LPG leakage in a relatively narrow area and to check the cause analysis.

• Applied Chemistry for Engineering
• /
• v.9 no.2
• /
• pp.268-272
• /
• 1998

Water leak phenomena in the liquid sodium which is a coolant of liquid metal reactor, were investigated by carrying out sodium-water reaction experiment. It was confirmed that sodium and water react each other by the analysis of material composition of aspecimen at the end of experiment. When steam of $100kg/cm^2$ was passed through the leak path of the specimen for 4 hours, reaction products from sodium-water reaction were observed on the leak site. However, re-opening phenomena were not observed at this condition. It was interpretted that the reaction product precipitated on leak path and thermal transient caused self-plugging and re-openning phenomena, respectively.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 2003.05a
• /
• pp.185-190
• /
• 2003

산업체 등에서 사용되고 있는 가스들중에서 일반적인 가스들과는 달리 위험한 가스(heavy gas)들은 누출사고시에 이들 고유한 확산과 계층화(stratification)방식에 의해 높은 위험성을 유발시키고 있다. 이러한 가스의 누출확산사고들과 일반적인 가스누출사고들의 비교는 그 사실들을 증명해주고 있다. 이런 사실에 의해 위험한 가스확산에 대한 실험과 고유특성을 고려한 확산모델의 개발이 여러 관점에서 진행되고 있으며, 이들의 중요성은 이미 세계적으로 의미를 부여하고 있다.(중략)

• Applied Chemistry for Engineering
• /
• v.10 no.8
• /
• pp.1155-1160
• /
• 1999

The screening methodology modeling, dispersion modeling procedures for continuous and instantaneous releases of the gas phase flow from the storage tank and pressure relief valve were considered. This study was performed to develop the screening methodology for prediction and control of hazardous/toxic gas releases by estimating the 1-hr average maximum ground-level concentration of $Cl_2$ gas vs. downwind distance by incorporating source term model including the general/physical properties of released material and release mode of the $Cl_2$ storage tank of the chemical plant facilities, dispersion model, and meteorological/topographical data into the TSCREEN model. As the results of the study, it was found that dispersion modes of the dense gas were affected by the state of the released material, the released conditions, physical-chemical properties of released material, and the released modes (continuous and instantaneous releases), and especially largely affected by initial (depressurized) density of the released material and release emission rate as well as the wind velocity. Especially, this study was considered to release hazardous material as meteorological data. It was thought that this screening methodology can be useful as a preliminary guideline for application of the refined analysis model by developing the generic sliding scale methodology for various senarios selected.