• 한국터널지하공간학회 논문집
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• 제5권1호
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• pp.55-70
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• 2003

지상형 탄약저장시설은 폭발시 인명과 재산의 피해가 크고 외부공격에 대하여 취약하므로 안전성, 부지확보 및 유지관리에서 유리한 지하탄약고의 개발이 절실하다. 본 연구에서는 폭발시 안전성 및 수불장비의 동선을 고려한 지하탄약고 시설배치와 방폭시설의 국내 설계사례를 소개하였다. ${\bigcirc}{\bigcirc}$지하탄약고는 경암지역에 불연속면의 영향이 적도록 주응력방향과 거의 평행하게 3개소의 저장격실이 배치되도록 설계되었다. 또한 국방부 폭발안전기준을 만족하는 안전거리를 확보하였고, 탄약 수불장비의 동선 시뮬레이션을 통해 시설배치의 적절성을 검증하였다. 방폭시설은 임의 저장격실의 우발적 폭발시 발생하는 최대 폭풍압을 산정하여 연쇄폭발이 발생하지 않도록 인접격실의 보호를 위한 방폭문 및 방폭밸브 등을 설계하였고. 폭풍압의 저감을 위한 병목장치, 파편함정 등의 시설은 구조해석을 통해 국방부 폭발물안전기준을 만족하도록 규격을 결정하였다.

• Korean Chemical Engineering Research
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• 제55권5호
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• pp.629-637
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• 2017

식료품 가공 산업에서 분진폭발사고가 자주 발생하고 있으며 배관이나 장치 내의 화염전파에 의한 폭발피해가 증가하고 있다. 그러나 다양한 분체특성으로 인하여 활용 가능한 화재폭발특성자료가 적다는 문제가 있다. 사고발생 빈도가 높고 사회적 수요가 많은 설탕, 옥수수, 밀가루의 발화 위험성과 폭발특성을 실험적으로 조사하였다. 설탕, 옥수수, 밀가루 분진의 평균입경은 27.56, 14.76, $138.5{\mu}m$로 나타났으며 이러한 분체조건에서 열중량분석(TGA) 및 시차주사열량계(DSC)를 사용하여 발화온도를 조사하였다. 최대폭발압력($P_m$) 및 폭발지수는($K_{st}$) 각각 7.6, 7.6, 6.1 bar 및 153, 133, 61 [$m{\cdot}bar/s$]로서 분진폭발 위험성은 설탕이 가장 높고 밀가루가 가장 작았다. 또한 분진폭발 시의 화염전파로 인한 피해확대 위험성을 평가하기 위하여 분진화염전파의 소요시간을 계산하였으며 화염전파로 인한 폭발피해 위험성은 설탕, 밀가루, 옥수수 분진의 순으로 높았다.

• 한국가스학회지
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• 제17권5호
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• pp.81-86
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• 2013

분진폭발은 플라스틱류, 제약, 목재, 곡물 저장고, 고체연료 및 화학약품의 제조와 같은 다양한 산업에서 발생되고 있다. 본 연구에서는 폐목재를 재활용하여 Particle board를 생산하는 공정의 사이로 분진, 함머밀 분진 및 뉴송 분진을 선택하여 분진폭발 특성을 평가하였다. 실험은 20 L 구형 폭발용기를 이용하여 목재 부유분진의 최대폭발압력, 분진폭발지수, 폭발한하계, 및 최소 점화에너지를 측정하고, 평가하였다. 이들 연구결과는 Particle board를 생산하는 제조공정의 화재 폭발사고 예방을 위한 공정안전 정보로 활용할 수 있을 것이다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권4호
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• pp.346-352
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• 2005

The chemical characteristics, enzymatic saccharification, and ethanol fermentation of autohydrolyzed lignocellulosic material that was exposed to steam explosion were investigated using bagasse as the sample. The effects of the steam explosion on the change in pH, organic acids production, degrees of polymerization and crystallinity of the cellulose component, and the amount of extractive components in the autohydrolyzated bagasse were examined. The steam explosion decreased the degree of polymerzation up to about 700 but increased the degree of crystallinity and the micelle width of the cellulose component in the bagasse. The steam explosion, at a pressure of 2.55 MPa for 3 mins, was the most effective for the delignification of bagasse. 40 g/L of glucose and 20 g/L of xylose were produced from 100 g/L of the autohydrolyzed bagasse by the enzymatic saccharification using mixed cellulases, acucelase and meicelase. The maximum ethanol concentration, 20 g/L, was obtained from the enzymatic hydrolyzate of 100 g/L of the autohydrolyzed bagasse by the ethanol fermentation using Pichia stipitis CBS 5773; the ethanol yield from sugars was 0.33 g/g sugars.

• 한국군사과학기술학회지
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• 제23권1호
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• pp.43-51
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• 2020

In this study, numerical analysis was carried out on a complex pressure field of blast waves caused by the detonation of high explosives in various environments. The generated blast waves propagated in the air, upon the sudden release of high energy induced by the explosion. Reflected waves were created when the pressure waves encountered certain obstacles such as the ground or the walls of structures. The propagation of the blast waves and its interaction with the reflected waves were simulated. An adaptive mesh refinement was applied to improve the efficiency of distribution of computer resource, for the computational calculation of the blast wave propagation in a wide open space. In addition, the integration of the calculation domains for the explosive and air were considered when the maximum density of the explosive region was below critical value. The results were verified by comparison with the pressure time history from blast wave experiments performed under two topographical conditions.

• 대한기계학회논문집A
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• 제38권4호
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• pp.355-361
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• 2014

신규 원전에서 추진중인 외벽침수냉각 방식의 적용이 실패할 경우 노심용융물과 원자로공동 내유체의 상호작용으로 인해 증기폭발이 발생하며, 이는 격납건물 및 관통부 배관을 포함한 각 구조물의 건전성을 위협할 수 있다. 본 논문에서는 선행연구 분석결과를 토대로 증기폭발 현상을 모사할 수 있는 개선된 해석기법을 도출하고 알루미나 실험 모사를 통해 타당성을 확인하였다. 또한 동일한 기법을 원자로공동 해석에 적용하여 가상 파손위치에 따른 증기폭발 압력이력을 예측하였으며, 측면파손에 의한 최대압력 값이 하부파손에 의한 것보다 최대 70% 정도 높음을 보였다.

• 한국안전학회지
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• 제31권3호
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• pp.8-15
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• 2016

The purpose of this study is to design a model with the structural stability so as not to lose the operational function due to structural plastic or fail of a sliding blast door by blast pressure to this aim, a numerical simulation was performed using full-size experiments and M&S (Modeling & Simulation) of the sliding blast door. The sliding blast door ($W3,000{\times}H2,500mm$) under the blast load is in the form of a sliding type 2-way metal grill, which was applied by a design blast pressure (reflected pressure $P_r$) of 17 bar. According to the experimental results of a real sliding blast door under blast load, the blast pressure reached the sliding blast door approximately 4.3 ms after the explosion and lasted about 4.0 ms thereafter. The maximum blast pressure($P_r$) was 347.7 psi (2,397.3 kPa), it is similar to the UFC 3-340-02 of Parameter(91 %). In addition, operation inspection that was conducted for the sliding blast door after real test showed a problem of losing the door opening function, which was because of the fail of the Reversal Bolt that was installed to prevent the shock due to rebound of the blast door from the blast pressure. According to the reproduction of the experiment through M&S by applying the blast pressure measurement value of the full-size experiments, the sliding blast door showed a similar result to the full-size experiment in that the reversal bolt part failed to lose the function. In addition, as the pressure is concentrated on the failed reversal bolt, the Principal Tensile Failure Stress was exceeded in only 1.25 ms after the explosion, and the reversal bolt completely failed after 5.4 ms. Based on the result of the failed reversal bolt through the full-size experiment and M&S, the shape and size of the bolts were changed to re-design the M&S and re-analyze the sliding blast door. According to the M&S re-analysis result when the reversal bolt was designed in a square of 25 mm ($625mm^2$), the maximum pressure that the reversal bolt receives showed 81% of the principal tensile failure stress of the material, in plastic stage before fail.

• 한국안전학회지
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• 제38권2호
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• pp.44-51
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• 2023

With the recent increase in gas energy use, risk management for explosion accidents has been emphasized. Protective walls can be used to reduce damage from explosions. The KOSHA GUIDE D-65-2018 suggests the minimum thickness and height of protective walls, minimum reinforcement diameter, and maximum spacing of reinforcements for the structural safety of the protective walls. However, no related evidence has been presented. In this study, the blast load carrying capacity of the protective wall was analyzed by the pressure-impulse diagrams while changing the yield strength of the reinforcement, concrete compressive strength, reinforcement ratio, protective wall height, and thickness, to check the adequacy of the KOSHA GUIDE. Results show that failure may occur even with design based on the criteria presented by KOSHA GUIDE. In order to achieve structural safety of protective walls, additional criteria for minimum reinforcement yield strength and maximum height of protective wall are suggested for inclusion in KOSHA GUIDE. Moreover, the existing value for minimum reinforcement ratio and the thickness of the protective wall should be increased.

• 대한조선학회논문집
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• 제57권6호
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• pp.322-330
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• 2020

This study deals with underwater explosion (UNDEX) characteristics of various non-explosive underwater shock sources for the development of non-explosive underwater shock testing devices. UNDEX can neutralize ships' structure and the equipment onboard causing serious damage to combat and survivability. The shock proof performance of naval ships has been for a long time studied through simulations, but full-scale Live Fire Test and Evaluation (LFT&E) using real explosives have been limited due to the high risk and cost. For this reason, many researches have been tried to develop full scale ship shock tests without using actual explosives. In this study, experiments were conducted to find the characteristics of the underwater shock waves from actual explosive and non-explosive shock sources such as the airbag inflators and Vaporizing Foil Actuator (VFA). In order to derive the empirical equation for the maximum pressure value of the underwater shock wave generated by the non-explosive impact source, repeated experiments were conducted according to the number and distance. In addition, a Shock Response Spectrum (SRS) technique, which is a frequency-based function, was used to compare the response of floating bodies generated by underwater shock waves from each explosion source. In order to compare the magnitude of the underwater shock waves generated by each explosion source, Keel Shock Factor (KSF), which is a measure for estimating the amount of shock experienced by a naval ship from an underwater explosionan, was used.

• 한국가스학회지
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• 제15권4호
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• pp.7-14
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• 2011

20 L 구형 폭발시험장치와 시차주사열량계(DSC)를 사용하여 반응성 유기물 분진의 폭발 및 열분해 특성을 실험적으로 조사하였다. 그 결과 97 % Benzoyl peroxide(BPO), Phthalic anhydride(PA), 1-Hydroxybenzotri azol(HBT)의 폭발하한은 매우 낮은 농도인 10~15 g/$m^3$의 범위로 측정되어 착화위험성이 높은 것으로 나타났다. HBT, PA 및 97 % BPO의 폭발지수는 각각 251, 146, 80 [bar m/s]로서, HBT는 폭발등급 2에 해당한다. 또한 밀폐계 분진폭발의 화염전파 특성을 추정하기 위하여 용기면에의 화염도달시간과 폭발압력을 고려하여 화염전파속도를 예측하였다. 97 % BPO 및 HBT의 열분해 개시온도와 발열량은 각각 $107^{\circ}C$(1025 J/g), $214^{\circ}C$(1666 J/g)로 나타났는데, 이와같이 낮은 열분해 온도와 큰 발열량이 폭발특성에 영향을 주는 것으로 판단된다.