KS C IEC 60079-10-1 규격의 무시할 수 있는 정도와 누출특성에 관한 연구

조필래,이향직,백종배,Cho, Pil-rae,Lee, Hyang-jig,Baek, Jong Bae 한국안전학회 2020 한국안전학회지 Vol.35 No.2

When KS C IEC 60069-10-1(2015) standard is applied to estimate a hazardous area, the chart showing the relationship between a hazardous area distance and release characteristic is used as a guide to determine the extent of hazardous zones for various forms of release. Three release characteristic lines based on the three types of release as an unimpeded jet release with high velocity, a diffusive jet release with low velocity, and a release of heavy gases or vapours that spread along horizontal surfaces are given. As these characteristic lines have the low limit threshold, it is difficult to estimate the hazardous area distance when the value of release characteristic is under the low limit threshold. And KS C IEC 60079-10-1(2015) standard shows the concept for a zone of Negligible extent(NE) which can be considered as non hazardous area, but it is also difficult to apply the concept of a Negligible extent. The purpose of this paper is to suggest the guideline for the release characteristic to decide a hazardous area distance and the Negligible extent(NE) being considered as non-hazardous area when deciding a hazardous area distances by the KS C IEC 60079-10-1 standard.

회귀곡선을 이용한 단시간 노출에 대한 AEGL의 적용

이현진(Hyunjin Lee),정태준(Taejun Jeong),이향직(Hyang-Jig Lee),정창모(Changmo Jeong),고재욱(Jae-Wook Ko) 한국가스학회 2017 한국가스학회지 Vol.21 No.5

노후화 된 공정설비와 공장의 규모 확대 등 유해화학물질 사용량이 증가하고 있으며, 2013년부터 지속적으로 누출에 의한 사고가 발생하는 것을 확인할 수 있다. 장외영향평가에서 누출에 대한 끝점 농도는 ERPG 2로 나타내며, 안전보건공단의 가이드에서 시간에 따라 7분 미만에서 10분의 AEGL 2, 7분 이상 25분 미만일 때는 30분의 AEGL 2값을 사용한다. 기준이 되는 끝점 농도가 시간에 따라 모호하게 사용되고 있어, 사고 발생 시 문제를 야기할 것으로 생각이 된다. 이에 본 연구에서 회귀곡선을 통해 1~10분 사이의 AEGL 값을 도출하고, 동 시간의 Probit function의 0% Lethality 데이터와 비교하였으며, AEGL 결과 값을 사용하여 보다 명확한 시간에 따른 독성누출 평가에 활용될 것으로 생각된다. Thus, chemicals are managed under 9 related central government department and 16 relevant laws with program such as Process Safety Management and Offsite Consequence Analysis in korea. Guidelines for set the endpoint concentration for chemcals based on the ERPG-2 (Emergency Response Planning Guidelines-2) and AEGL-2 (Acute Exposure Guidelines Level-2). but ERPG and AEGL do not describe exposure for less than 10 minutes. because of this, each guidelines define criteria differently for short time less than 10 minutes exposure. This indefinite exposure criteria would give rise to a confusion in the chemical plants, and potentially lead to a critical decision making error when accidents happen. In an effort to apply guidelines with evenly-distributed initial time frame, AEGL concentrations within 10 minute exposure time were evaluated by examining statistical regression curves. The results were in good agreement with those from the Probit Function based on each AEGL grade to explain 3 different threshold levels of exposure effects. Resultant re-enforced guidelines for endpoint chemical concentrations are, therefore, to provide powerful tool to assess and manage the risk associated with any potential chemical accidents at an early stage.

CFD 시뮬레이션을 이용한 제한된 공간에서의 수소, LNG, LPG 폭발특성 비교

백주홍(Ju-Hong Baek),이향직(Hyang-Jig Lee),장창봉(Chang Bong Jang) 한국가스학회 2016 한국가스학회지 Vol.20 No.3

화석연료의 의존도를 줄이고자 대체에너지 연구가 활발하게 이루어지고 있는 현재, 산업에서 가장 많이 사용하고 있는 대체에너지 중 하나가 수소이다. 수소의 수요는 매년 꾸준히 증가하고 있으며, 수소의 생산 및 이송을 위한 설비도 늘어나고 있는 실정이다. 이에 따른 수소설비에서 중대사고가 발생할 확률 또한 증가할 것으로 예상된다. 또한 산업현장에서 가장 사고를 많이 초래하는 물질은 LPG 61%, 수소 12%, LNG 10%로 세 가지 가연성가스의 사고 빈도는 높은 축에 속한다. 따라서 산업용으로 많이 사용되며 사고다발성 가연성 가스인 수소, LNG, LPG가 제한된 공간에서 폭발했을 때의 폭발위험성에 대하여 CFD 시뮬레이션을 이용하여 계산을 하였고, 그 결과들을 기반으로 비교분석하여, 제한된 공간에서의 각 가스별 폭발에 대한 위험성을 검토하였다. The demand for hydrogen is steadily increasing every year, and the facilities to produce and transfer hydrogen are being increased as well. Therefore, the possibility of a critical accident at hydrogen is expected to increase. Furthermore, the materials most likely to cause accidents at industrial sites are LPG 61%, hydrogen 12%, and LNG 10%, and the frequency of accidents due to these three combustible gases is relatively high. Thus, a CFD simulation was used to compute the explosion risk of danger-frequent combustible gases - hydrogen, LNG, and LPG - within a limited space, and the outcomes were compared and analyzed to review the risk of explosion of each gase within a limited space.

CFD 모델링을 이용한 화학공장의 안전거리 산정 방법론에 관한 연구

백주홍 ( Ju Hong Baek ),이향직 ( Hyang Jig Lee ),장창봉 ( Chang Bong Jang ) 한국안전학회(구 한국산업안전학회) 2016 한국안전학회지 Vol.31 No.3

As the simple empirical and phenomenological model applied to the analysis of leakage and explosion of chemical substances does not regard numerous variables, such as positional density of installations and equipment, turbulence, atmospheric conditions, obstacles, and wind effects, there is a significant gap between actual accident consequence and computation. Therefore, the risk management of a chemical plant based on such a computation surely has low reliability. Since a process plant is required to have outcomes more similar to the actual outcomes to secure highly reliable safety, this study was designed to apply the CFD (computational fluid dynamics) simulation technique to analyze a virtual prediction under numerous variables of leakages and explosions very similarly to reality, in order to review the computation technique of the practical safety distance at a process plant.

ALOHA 프로그램을 이용한 도시가스 배관의 누출 모델링 최적화

조필래(Pil-rae Cho),이향직(Hyang-jig Lee),백종배(Jong Bae Baek) 한국위험물학회 2020 한국위험물학회지 Vol.8 No.2

Since the Process Safety Management(PSM) by Occupational Safety and Health Act has been introduced in Korea, the consequence analysis of chemical release has been actually implemented. The purpose of this paper is to suggest the guideline for the release modeling of natural gas piping. Applicable programs for the release modeling of gas pipeline are ALOHA, PHAST, etc. but ALOHA is the most reasonable program because of the benefit of cost-free and easiness to use. As the release rate in gas pipeline is largely depended on length of pipeline, it is very important to select the appropriate length of pipeline. As lots of company apply length of pipeline as the length between a gas governor and a gas burner, the result of these modeling can be different from an actual situation that is pressurized by the pipeline system of gas supplier. This paper studied the method to decide the length of pipeline by the comparison of the release rate between the infinite end piping connected to tank and closed off piping by using ALOHA program. And this paper also studied the modeling means for the low pressure pipeline under 2 atm(absolute) in pressure being not applied with the Gas pipe option of ALOHA.

인화점 기반의 KS C IEC 60079-10-1:2015 표준의 인화성 액체 적용에 관한 연구

조필래(Pil-rae Cho),이향직(Hyang-jig Lee),백종배(Jong Bae Baek) 한국위험물학회 2020 한국위험물학회지 Vol.8 No.2

This paper is written to suggest the guideline for the flash point of flammable liquids when the KS C IEC 60079-10-1:2015 standard is applied for the hazardous area classification. Flammable liquid is defined as “liquid capable of producing a flammable vapour under any foreseeable operating conditions” in the KS C IEC 60079-10-1:2015 standard and an example of the flammable liquid is shown as the liquid that is handled at temperatures close to or above its flash point. Therefore the relationship between flash points and flammable liquids is not clear. Occupational safety and health act in Korea, Ministry of Employment and Labor notification(No. 1993-19), NFPA 497, API RP 505 and EI 15 are reviewed to compare the flash points for the application of the hazardous area classification and the guideline for flash points is suggested.