• 제목/요약/키워드: Facility risk

검색결과 552건 처리시간 0.029초

수소 충전 시설 내 근로자를 위한 안전거리 선정 방법 개선에 관한 연구 (A Study on the Improvement of Selection Method of Safety Distance for Worker in Hydrogen Refueling Station)

  • 이효렬
    • 한국가스학회지
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    • 제27권4호
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    • pp.78-84
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    • 2023
  • 최근 이산화탄소배출 감축과 환경오염 물질 저감이 세계적인 이슈가 됨에 따라 규제를 강화하고 있다. 수송 부분에서는 사용 연료를 기존 화석 연료에서 수소 등 친환경 연료로 에너지 전환이 이루어지고 있다. 국내에서는 에너지 전환에 발맞춰 2040년까지 1,200기의 수소 충전소 구축을 목표로 하고 있어, 넓은 인화 범위를 가지는 고압 수소를 공급하는 충전소의 안전성 확보가 매우 중요하다. 본 논문에서는 충전소 사고 발생 시 충전소 내 근로자의 안전확보를 위해 국내 기준과 일본, 유럽 등의 수소 충전소 안전거리 기준 현황을 분석하여 안전거리 설정 가이드 라인을 제시하였다. 안전거리 설정 절차는 유럽의 EIGA 기준에 따라 설비별 사고 발생빈도와 TNO의 EFFECTS 소프트웨어를 활용한 피해 영향 분석을 통해 사망 확률이 3.5E-05 이하가 되는 안전거리를 산출하였다.

Lessons from constructing and operating the national ecological observatory network

  • Christopher McKay
    • Journal of Ecology and Environment
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    • 제47권4호
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    • pp.187-192
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    • 2023
  • The United States (US) National Science Foundation's (NSF's) National Ecological Observatory Network (NEON) is a continental-scale observation facility, constructed and operated by Battelle, that collects long-term ecological data to better understand and forecast how US ecosystems are changing. All data and samples are collected using standardized methods at 81 field sites across the US and are freely and openly available through the NEON data portal, application programming interface (API), and the NEON Biorepository. NSF led a decade-long design process with the research community, including numerous workshops to inform the key features of NEON, culminating in a formal final design review with an expert panel in 2009. The NEON construction phase began in 2012 and was completed in May 2019, when the observatory began the full operations phase. Full operations are defined as all 81 NEON sites completely built and fully operational, with data being collected using instrumented and observational methods. The intent of the NSF is for NEON operations to continue over a 30-year period. Each challenge encountered, problem solved, and risk realized on NEON offers up lessons learned for constructing and operating distributed ecological data collection infrastructure and data networks. NEON's construction phase included offices, labs, towers, aquatic instrumentation, terrestrial sampling plots, permits, development and testing of the instrumentation and associated cyberinfrastructure, and the development of community-supported collection plans. Although colocation of some sites with existing research sites and use of mostly "off the shelf" instrumentation was part of the design, successful completion of the construction phase required the development of new technologies and software for collecting and processing the hundreds of samples and 5.6 billion data records a day produced across NEON. Continued operation of NEON involves reexamining the decisions made in the past and using the input of the scientific community to evolve, upgrade, and improve data collection and resiliency at the field sites. Successes to date include improvements in flexibility and resilience for aquatic infrastructure designs, improved engagement with the scientific community that uses NEON data, and enhanced methods to deal with obsolescence of the instrumentation and infrastructure across the observatory.

Design and simulation of 500 MHz single cell superconducting RF cavity for SILF

  • Yanbing Sun;Wei Ma;Nan Yuan;Yulin Ge;Zhen Yang;Liping Zou;Liang Lu
    • Nuclear Engineering and Technology
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    • 제56권1호
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    • pp.195-206
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    • 2024
  • Shenzhen Innovation Light source Facility (SILF) is a 3.0 GeV fourth generation diffraction limited synchrotron light source currently under construction in Shenzhen. The SILF storage ring is proposed to use two 500 MHz single cell superconducting radio frequency (SRF) cavities to provide 2.4 MV RF voltage. In this study, we examined the geometric structure of mature CESR superconducting cavities and adopted a beam-pipe-type extraction scheme for high-order modes (HOM). One of the objectives of SRF cavity design and optimization in this study is to reduce Ep/Eacc and Bp/Eacc as much as possible to reduce power loss and ensure stable operation of the cavity. To reduce the risk of beam instability and thermal breakdown, the HOM and Multipacting (MP) are simulated. Moreover, the mechanical properties of the cavity are analyzed, including frequency sensitivity from pressure of liquid helium (LHe), stress, tuning, Lorentz force detuning (LFD), the microphone effect, and buckling. By comprehensive design and optimization of 500 MHz single-cell SRF cavities, a superconducting cavity for SILF storage ring was developed. This paper will detailed present the design and simulation.

Impingement wastage experiment with SUS 316 in a printed circuit steam generator

  • Siwon Seo;Bowon Hwang;Sangji Kim;Jaeyoung Lee
    • Nuclear Engineering and Technology
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    • 제56권1호
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    • pp.257-264
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    • 2024
  • The sodium cooled fast reactor (SFR) is one of the Gen-IV reactors with the most operating experience accumulated. Although the technology level is the most mature among the Gen-IV reactors, there is still a safety problem that has not been solved, which is the sodium-water reaction. Since sodium and water are separated only by a heat transfer tube with a thickness of only a few mm, there is inherently a risk of a sodium-water reaction (SWR) accident in the SFR. In this study, it is attempted to quantitatively evaluate the resistance of SWR accidents by replacing the shell and tube steam generator with printed circuit steam generator (PCSG) as a method to mitigate the SWR accident. To do this, a CATS-S (Compact Accident Tolerance Steam Generator-SWR) facility was designed and built. And for the quantitative evaluation of accident resistance, a methodology for measuring the impingement wastage rate was established. As a result of this research, the impingement wastage rate caused by SWR generated in a PCSG was measured first time. It was confirmed that the impingement wastage phenomenon was suppressed in the PCSG, and the accident resistance was higher than that of the SWR through comparison with the experimental results performed in the existing shell and tube steam generator. In conclusion, a PCSG is more resistant to impingement wastage as a result of the SWR accident than existing shell and tube steam generators, and it is estimated that a PCSG can mitigate SWR accidents, an inherent problem of SFR.

도전성 고무 매트를 이용한 수소 기반 시설에서 제전 신뢰성 향상 (Conductive Rubber for Enhanced Safety in Hydrogen-based Facilities from Electrostatic Discharge)

  • 이수운;고재환;송지원;김찬우;김충일;김해술;허만억;정재형;송형준
    • 한국안전학회지
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    • 제39권1호
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    • pp.9-15
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    • 2024
  • Hydrogen-based electricity and transportation systems are widely recognized as sustainable power sources. However, the low ignition energy of hydrogen, only 1/10th that of conventional fossil fuels, poses a safety concern involving the risk of ignition due to electrostatic discharge from facility workers. Therefore, anti-static systems are imperative for hydrogen-based electricity facilities. To address this, we propose a reliable conductive rubber mat (CRM) to ensure the safety of these facilities. Unlike conventional anti-static floors that utilize conductive paint (CP), the CRM features a uniform distribution of conductive components in chemically and mechanically stable rubber. As a result, the CRM is unyielding to polar solvents (such as ethanol and hydrosulfuric acid) and non-polar solvents (like mineral oil) without increasing its resistance. Moreover, the CRM can withstand mechanical stress. Consequently, the human-body voltage of workers on the CRM would be sufficiently low enough to protect them from hydrogen explosions, thereby enhancing overall safety.

카본제조 부생가스 배출 안전성에 관한 연구 (A Study on the Safety of Carbon Manufacturing By-product Gas Emissions)

  • 주종율;정필훈;김상길;이성은
    • 대한안전경영과학회지
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    • 제26권1호
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    • pp.99-106
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    • 2024
  • In the event of an emergency such as facility shutdown during process operation, the by-product gas must be urgently discharged to the vent stack to prevent leakage, fire, and explosion. At this time, the explosion drop value of the released by-product gas is calculated using ISO 10156 formula, which is 27.7 vol%. Therefore, it does not correspond to flammable gas because it is less than 13% of the explosion drop value, which is the standard for flammable gas defined by the Occupational Safety and Health Act, and since the explosion drop value is high, it can be seen that the risk of fire explosion is low even if it is discharged urgently with the vent stock. As a result of calculating the range of explosion hazard sites for hydrogen gas discharged to the Bent Stack according to KS C IEC 60079-10-1, 23 meters were calculated. Since hydrogen is lighter than air, electromechanical devices should not be installed within 23 meters of the upper portion of the Bent Stack, and if it is not possible, an explosion-proof electromechanical device suitable for type 1 of dangerous place should be installed. In addition, the height of the stack should be at least 5 meters so that the diffusion of by-product gas is facilitated in case of emergency discharge, and it should be installed so that there are no obstacles around it.

배터리 시뮬레이터를 이용한 리튬이온 배터리와 납축전지 특성분석 (Characteristic Analysis of Lithium-ion Battery and Lead-acid Battery using Battery Simulator)

  • 윤용호
    • 한국인터넷방송통신학회논문지
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    • 제24권2호
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    • pp.127-132
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    • 2024
  • 최근 이차전지는 다양한 산업 분야에서 사용되고 있다. 특히 소형 및 경량의 특성으로 스마트폰, 노트북, 태블릿 등 다양한 휴대용 전자기기에서 높은 에너지 밀도와 충·방전 효율을 토대로 전기자동차와 에너지저장시스템(Energy Storage System, ESS)의 핵심 부품으로 사용되고 있다. 하지만 이차전지의 과도한 충·방전에 따른 수명감소, 파열, 손상, 화재 등의 문제점이 발생하고 있다. 따라서 BMS(Battery Management System)를 통하여 과도한 충·방전을 보호하고 성능을 향상시킨다. 하지만 실제 리튬이온 배터리를 사용하여 BMS의 차단 및 보호범위 설정하는 데 있어서 이차전지의 수명감소, 파열, 손상, 화재의 문제점이 따른다. 따라서 본 논문에서는 배터리 충방전기와 시뮬레이터를 활용하여 이차전지 중 사용이 높은 리튬이온 배터리와 납축전지의 충전 및 방전 특성을 살펴본다.

베이지안 확률 기반 범죄위험지역 예측 모델 개발 (Crime Incident Prediction Model based on Bayesian Probability)

  • 허선영;김주영;문태헌
    • 한국지리정보학회지
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    • 제20권4호
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    • pp.89-101
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    • 2017
  • 범죄는 장소나 건축물 용도에 따라 발생빈도와 유형이 다르고, 그 장소를 이용하는 사람들의 특성 및 공간 구조 차이에 의해 다양하게 발생한다. 따라서 공간 및 지역특성을 포함한 공간 빅데이터를 활용하여 지역을 분석해 보면 범죄예방 전략을 마련할 수 있다. 아울러 빅데이터와 지능 정보화시대의 도래에 따라 예측적 경찰활동이 새로운 경찰활동의 패러다임으로 등장하고 있다. 이에 보편적인 지방도시 J시를 대상으로 3개년 동안의 7,420건의 실제 범죄사례를 바탕으로 도시공간의 물리 환경적인 특성을 분석하여 범죄발생공간을 규명하고, 위험지역을 예측해 보고자 하였다. 분석에는 다양한 빅데이터 중 범죄를 유발하는 도시 공간 내 물리 환경적 요소에 한하여 공간 빅데이터를 구축하여 공간회귀분석을 실시하였다. 다음으로 분석결과 도출된 가로폭, 평균 층수, 용적율, 1층 사용용도(제2종 근린생활시설, 상업시설, 유흥시설, 주거시설)을 변수로 베이지안확률 기반 범죄발생 위험성 예측 모형(CIPM: Crime Incident Prediction Model)을 개발하였다. 개발된 모델은 실제 범죄발생 지역과의 중첩분석 및 모델의 정확도를 판단하는 Roc curve 분석을 통해 AUC 값이 0.8로 모델이 적합한 것으로 나타났다. 개발된 모델을 토대로 사례지역의 범죄 위험도를 분석한 결과 범죄발생은 상업 및 유흥시설이 밀집된 지역과 건물층수가 높은 지역, 그리고 상업 및 유흥시설과 주거가 혼재해 있는 블록이 범죄발생 확률이 높은 것으로 나타났다. 본 연구는 단순히 범죄의 공간적 분포와 범죄발생 영향요인을 탐색하는 기존의 연구와 달리 범죄발생 예측모델을 확률론적 관점에서 개발하는 영역으로 한 단계 진전되었다는 점에 의의가 있다.

Systemic analysis 방법을 활용한 국내 학교급식 위생의 주요 영향 인자 분석 연구(2005-2014) (Systemic Analysis on Hygiene of Food Catering in Korea (2005-2014))

  • 민지현;박문경;김현정;이종경
    • 한국식품위생안전성학회지
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    • 제30권1호
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    • pp.13-27
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    • 2015
  • Systemic analysis 기법을 이용하여 국내 학교급식의 위해관리를 위한 정보를 제공하고자 학교급식 위생 관련 문헌분석을 실시하였다. 단체급식 및 위생 분야 키워드 47개를 도출한 후, DBpia 검색엔진을 통하여 도출된 키워드를 입력하여 최근 10년간(2005-2014) 생산된 총 1,177개 논문을 검색하였다. 이후 관련논문을 수집하고 전문가리뷰를 통하여 최종 142개 논문을 선정하였다. 시설별, 이해당사자별, 외부요인, 내부요인, 직접적 요인, 간접적 요인으로 나눠 문헌을 분석하였다. 시설별로 학교(64편)가 산업체(5편)나 병원(3편)보다 단체급식 위생 관련문헌이 많았다. 학교급식의 주요요인을 분석한 결과 시스템/시설/설비(15편), 위생교육(12편), 생산/납품업체(6편), 식재료(4편), 복합적 요인(9편)이었다. 학교급식 위생관련 요인을 환경적 요인, 인적 요인, 식재료 요인, 고용 및 직무요인으로 구분하였다. 이해당사자별로 영양사, 조리종사원, 학생, 교직원, 식재료 납품업체 등으로 구분하여 분석하였다. 첫 번째, 환경적 요인으로 시설 설비 영역과 시스템 영역으로 구분하였다. 시설 설비 영역에서 대상이 영양사인 경우 급식시설의 명확하지 않은 구획 및 구분, 다량조리기기의 부족으로 인한 음식 온도관리 미흡, 위생관리를 위한 기기 구비율 저조, 조리실 온 습도 관리 미흡 등이 문제점으로 지적되었다. 대상이 학생인 경우에는 교실배식 환경을 문제로 꼽았다. 시스템 영역에서는 영양사가 대상인 경우 학교 내 구성원 간 HACCP 시스템 팀의 낮은 협력정도가 문제로 지적되었다. 조리사/조리종사원이 대상인 경우에는 과도한 업무량과 높은 노동 강도, 급식소 안전 관련 근무 조건의 열악함이 문제가 되었다. 학부모를 대상으로 조사한 결과에서는 학교급식 모니터 제도의 활동이 저조한 것이 문제로 파악되었다. 두 번째, 인적 요소 측면에서는 "위생교육 부족"이 가장 큰 문제점으로서, 교육대상이 조리종사원인 경우 형식적인 위생교육, HACCP 관련 교육 미흡, 낮은 개인위생관리수행이 문제가 되었다. 대상이 학생인 경우에는 위생교육 경험이 적고, 위생교육의 적용 및 효과가 낮은 것으로 나타났다. 세 번째, 식재료 요소 측면에서 원재료 자체의 위생문제와 신선편이식품 전처리 식재료의 불신이 문제로 파악되었다. 한편, 생산 납품업체 관련 납품업체 배송차량 관리 미흡, 생산 납품업체 직원의 위생관리, HACCP 비인증업체의 위생관리가 문제로 지적되었다. 마지막으로 고용 및 직무 요소 측면에서 영양사와 조리종사원의 고용형태, 연봉수준은 직무만족도 및 직무몰입도에 영향을 주는 것으로 나타났으며, 직무스트레스는 직무수행, 나아가 학교급식 위생에도 영향을 줄 수 있다는 것이 확인되었다. 학교급식 위생의 원인 분석을 통하여 향후 정부는 예산확보, 현장조사, 인증시스템 제도 마련, 근무 조건 개선, 위생훈련 및 점검 강화, 전문가에 의한 위생컨설팅 및 급식장 설계 컨설팅을 강화할 필요가 있다. 본 연구는 향후 급식위생안전 개선을 위한 교육 자료 및 관련 기술 개발에 활용할 수 있다.

설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2013)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
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    • 제26권12호
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    • pp.605-619
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    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.