• 한국화재소방학회논문지
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• 제33권2호
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• pp.107-113
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• 2019

최근 지구 온난화 현상에 따라 낙뢰가 증가하고 있는 추세이며 산업시설과 인프라 설비에 사고 위험이 가중되고 있다. 특히 낙뢰가 정유 및 석유화학 공장의 시설물이나 저장탱크 등 인프라 설비에 떨어지는 경우 가동 중인 공장에 정전, 전자기기의 오동작이나 파손을 유발하거나 화재 폭발과 함께 동시 다발적이고 복합적인 재해를 초래하게 된다. 그러므로 낙뢰사고에 대한 체계적인 연구를 통하여 낙뢰에 대한 메커니즘의 이해 및 낙뢰에 의한 화재 폭발 발생 사례를 심층 분석하고, 조사 방법을 체계화하여 예방대책을 강구 할 필요가 있다. 본 연구는 낙뢰에 의해 석유화학공장의 폐수저장탱크 내부의 유증기가 폭발한 사례에 대해 사고 원인을 분석하고 그 원인에 따른 사전 예방대책을 제시하여 낙뢰에 의한 사고 발생을 예방하고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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• pp.296-298
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• 1991

When insulating oil was flowed through a pipe, the electrostatic charge in the oil was increased using inflammability oil, an electrostatic phnomena which may cause significantly problems as explosion must be circumvented by some methods. In this paper, Streaming insulating oil electrificated by streaming electrification of electrification pipe and standing insulating oil were affected under the high field strength, temperature of insulating oil, and concentration of surfactant. The electrical conduction was compared and analysed by these influence.

• 한국안전학회지
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• 제27권5호
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• pp.49-54
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• 2012

There is a possibility that electrical sparks may occur at discontinuities in metallic structures from distance of close to high power radio/radar transmitters. Voltage may be induced on these metallic structures by the radio-frequency transmitter. In this case, a person who comes into contact with these structure may be undergone a severe electrical shock. In this paper, assessment of the electrical shock and ignition hazards was investigated through experimental which are consisted radio transmitter and metallic loop-type structure in shield room. We measured that the induced voltage was highest at 61 MHz of transmission frequency, and confirmed the possibility of electric shock and explosion induced by a voltage or spark. But it is needed additional research where is opened site.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.1848-1849
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• 2006

The new robust controller design method is proposed for the flight control systems with model uncertainties. The proposed control system is a combination of the adaptive dynamic surface control (DSC) technique and the self recurrent wavelet neural network (SRWNN). The adaptive DSC technique provides us with the ability to overcome the "explosion of complexity" problem of the backstepping controller. The SRWNNs are used to observe the arbitrary model uncertainties of flight systems and all their weights are trained on-line. From the Lyapunov stability analysis, their adaptation laws are induced and the uniformly ultimately boundedness of all signals in a closed-loop adaptive system is proved. Finally, simulation results for a high performance aircraft (F-16) are utilized to validate the good tracking performance and robustness of the proposed control system.

• 대한안전경영과학회지
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• 제23권3호
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• pp.103-113
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• 2021

As the use of capacitors in electrical appliances and electrical control circuits increases, the related electrical fire is increasing. There are various parts such as resistors, coils, and capacitors that make up an electric circuit. Among them, the ignition of a capacitor with a temporary charging function is closely related to the structural characteristics of the capacitor. Capacitors can explode due to various reasons, and the high heat generated when they explode ignites the inflammable dielectric, which in turn burns the inflammable materials such as the surrounding electric wires and spreads into a fire. In this paper, the ignition mechanism is studied by conducting a reenactment experiment on the various probabilities that can be ignited in an electric capacitor, and the prevention measures to be applied to the fire prevention are presented.

• 한국안전학회지
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• 제5권1호
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• pp.57-66
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• 1990

The purpose of this study is to investigate electrostatic charge condition and possibility of electrostatic hazards in case of putting on synthetic smocks and antistatic garments for the purpose of prevention of electrostatic hazards due to a human body electrical charge. It is shown in case of a synthetic smocks, electrostatic voltage by friction is about 2,900 (V), half life period is 12 second, and electrostatic charge is 1.4―1.8 ($\mu$ C). When putting on a synthetic smocks, electrostatic voltage is 2,500―2,800(V). When putting on a jumper of chemical fiber, electrostatic voltage is 8,000(V) . It is, therfore, possible to cause a electrostatic hazards. It is also shown in case of a antistatic garments, electrostatic voltage by friction is 87(V) ―280(V) (washing 90 times), half life period is 3―5 second, and electrostatic charge is 0.24―0.28($\mu$ C) which is much lower than 0.6($\mu$ C) limitation of fire and explosion occurance. When putting on a antistatic garments, electrostatic voltage is 10(V) ―125(V). In conclusion, it is shown when putting on a antistatic garments it is possible to prevent a electrostatic hazards such as fire or explosion due to human body, to prevent a destruction of semiconductor elements and capacity decline, and to prevent a misoperation of automation facilities and semiconductor electric and electronic products.

• 한국전자통신학회논문지
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• 제15권2호
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• pp.253-258
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• 2020

우리나라의 석유화학산업단지는 폭발성 가스와 가연성 가스로 인하여 언제나 폭발 위험성이 높다. 이러한 폭발을 방지하기 위한 방법으로 석유화학산업단지의 대부분 설비에 방폭 성능을 요구하고 있다. 방폭용으로 현재 사용하고 있는 제어기 패널은 패널의 내부와 외부의 압력(양압)과 온도를 일정하게 유지를 위해 외부에서 수동으로 공기를 주입하는 방식을 사용하고 있다. 이에 본 논문은 자동으로 온도를 제어할 수 있도록 패널 내부의 온도에 따라 가열과 냉각을 자동으로 수행하는 자동 온도조절기를 제안한다.

• 한국안전학회지
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• 제33권4호
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• pp.21-29
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• 2018

In many companies handling flammable liquids, explosion-proof electrical equipment have been installed according to the Korean Industrial Standards (KS C IEC 60079-10-1). In these standards, hazardous area for explosive gas atmospheres has to be classified by the evaluation of the evaporation rate of flammable liquid leakage. The evaporation rate is an important factor to determine the zones classification and hazardous area distance. However, there is no systematic method or rule for the estimation of evaporation rate in these standards and the first principle equations of a evaporation rate are very difficult. Thus, it is really hard for industrial workplaces to employ these equations. Thus, this problem can trigger inaccurate results for evaluating evaporation range. In this study, empirical models for estimating an evaporation rate of flammable liquid have been developed to tackle this problem. Throughout the sensitivity analysis of the first principle equations, it can be found that main factors for the evaporation rate are wind speed and temperature and empirical models have to be nonlinear. Polynomial regression is employed to build empirical models. Methanol, benzene, para-xylene and toluene are selected as case studies to verify the accuracy of empirical models.

• 한국지형학회지
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• 제25권1호
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• pp.97-113
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• 2018

Low-frequency geological natural disaster events such as Pohang earthquake have been occurred. As a results, there's a growing recognition on the importance of education and training for low frequency geological disasters in Korea. In spite of many years of scientific researches on volcanic disaster prevention and preparedness on Baekdusan volcano, the results do not provide the proper scenario for the training for volcanic ash event. Fall 3D volcanic ash diffusion model was run based on wind field data for the last five year, assuming Aso Mountain's explosion with volcanic explosion index 5 for seventy two hours. The management criteria values for proper actions in the previous studies were applied to make a scenario for thirteen groups of the disaster response teams such as train transportation, water supply, electrical facilities and human health. The models on the relationship between education and training for disaster prevention and response were suggested to fulfill the scientific and practical training at local level.

• 한국수소및신에너지학회논문집
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• 제34권6호
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• pp.734-740
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• 2023

Hydrogen emphasis on safety management due to its high potential for accidents from wide explosive limits and low ignition energy. To prevent accidents, appropriate explosion-proof electrical equipment with installed to safe management of ignition sources. However, designing all facilities with explosion-proof structures can significantly increase costs and impose limitations. In this study, we optimize the barrier to effectively control the initial momentum in case of hydrogen release and form the control room as a non-hazardous area. We employed response surface method (RSM), the barrier distance, width and height of the barrier were set as variables. The Box-Behnken design method the selection of 15 cases, and FLACS assessed the presence of hazardous area. Analysis of variance (ANOVA) analysis resulting in an optimized barrier area. Through this methodology, the workplace can optimize the barrier according to the actual workplace conditions and classify reasonable hazardous area, which is believed to secure safety in hydrogen facilities and minimize economic burden.