Experimental investigation of explosion pressures and flame propagations by wall obstruction ratios and ignition positions

박달재,Young Soon Lee 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.2

Experimental studies were carried out to investigate the effects of different ignition source locations and wall obstructions in a partially opened chamber, 235 mm in height, with a 1,000×950 mm2 cross section and with a large top-venting of area of 1,000×320mm2. Four different ignition positions such as the bottom, side, corner and top,and three wall obstacles with blockage ratios ranging from about 10 to 30% were used. The comparisons between wall obstacles in the chamber showed that the dependence of overpressure on obstruction ratios was different compared with published experiments with a large L/D ratio enclosure. This may be linked to the characteristics of the chamber. The smallest wall obstacle caused the highest overpressure, while the largest one caused the lowest overpressure. The flame propagation and pressure development were highly sensitive to the ignition positions. The bottom ignition caused the highest overpressure, while the top ignition the closest to the vent opening caused the lowest overpressure.

[공인회계사] 분명한 목표의식과 철저한 준비가 있으면 반드시 합격한다!

박달재 회경사 2016 月刊 會計 Vol.24 No.11

Interactions between Propagating Flame Fronts and Obstacles in an Explosion Chamber with a H/L Ratio of 0.86

박달재 한국가스학회 2013 한국가스학회지 Vol.17 No.1

Experimental studies were carried out to investigate the interactions between the propagating flame fronts and different multiple obstacles within an explosion chamber. The explosion chamber is 600 mm in height, 700×700 mm2 in cross-section and has a H/L value of 0.86. Three different multiple obstacles with the blockage ratio of 0.43 were replaced within the chamber. The results showed that relatively higher local flame displacement speed was observed with the triangular obstacle while the lower was observed with the circular one. It was found that the local flame displacement speeds behind the obstacle were largely dependent on the obstacle types. It was also found that as the flame interacted with the flow field generated behind the obstacle,the probability density functions(PDFs) of the local flame displacement speed were extensively distributed toward higher speeds.

중·소규모 공정안전관리 사업장의 웹 전산시스템 개발

박달재,김영석 한국화학공학회 2022 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.60 No.3

중·소규모 사업장에서 중대산업사고가 발생되고 있는 원인 중 하나는 공정안전관리(PSM) 체계를 이해하고 적용하는데 관련 지식 및 정보 부족이다. 이를 해결하기 위해서는 PSM에 대한 실질적이며 지속적인 이행 수준을 확보하고추적관리를 통해 인적오류를 제거할 수 있는 프로토콜이 뒷받침되어야 하나 그동안 이에 대한 연구가 미흡하였다. 이에 본 연구에서는 고용노동부 고시의 규정과 전국 300인 미만 중·소규모 PSM 사업장 200여 개사를 대상으로 행정처분 위반 사례를 조사·분석하였다. 이를 기반으로 설비유지관리 웹프로그램을 개발하여 중·소규모 사업장의 인적오류제거를 통한 중대산업사고예방에 기여하고자 하였다. 본 연구를 통해 얻어진 주요 연구결과는 다음과 같다. 첫째, 프로그램 접근 편의성을 위해 스마트 기기에서 QR코드를 통해 웹에 접속하여 설비의 제원 검색 기능, 고장 사유, 사진을 확인함으로써 실시간 점검, 정비요청을 할 수 있게 하였다. 둘째, 변경 대상 파악, 위험성 평가, 작업자 교육, 가동전 점검을 프로그램과 연계하여 작업 시작 전부터 종료까지 모든 절차를 관리자가 추적관리 가능하도록 하였다. 셋째, 작업 완료 후 개선된 사진과 함께 수리, 시간, 비용 등을 등록하여 축적된 자료를 기반으로 설비의 수명 예측과 신뢰성을 검증하게 하였다. 이러한 연구결과는 중·소규모 PSM 사업장에게 실질적이고 체계적인 운영에 도움이 될 수 있으며 향후 정부 주도로 중·소규모 PSM 사업장을 대상으로 스마트팩토리 구축 시 설비유지관리 웹프로그램을 개발하여 보급하는데 유용하게 활용되리라 판단된다.

Experimental Studies on the Interaction Between a Propagating Flame and Multiple Obstacles in a Rectangular Chamber

박달재,안증진,이영순 한국가스학회 2008 한국가스학회지 Vol.12 No.1

Experimental investigations were performed to assess the influences of different multiple obstacles on flame propagation in a rectangular confinement. Three different multiple obstacles were used: circular, triangular and square cross-sections with blockage ratios of 15% and 30%. The same method described in Park et al. [13] to investigate the interaction between the propagating flame and the obstacle was applied. Before the freely propagating flame impinged on the obstacle, the flame propagation speed remains close to the laminar burning velocity, regardless of the obstacles used. The reported data revealed that the trend in increase of the local flame propagation speed is a result of the interaction between the obstacle and the propagating flame front behind the obstacle. The local speed was found to increase from a circular to a triangular and a square obstacle. The mean flame speed was found to be less dependent on both the obstacle types and the different blockage ratios used.

A comparison on predictive models of gas explosions

박달재,Young Soon Lee 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.2

A comparison on existing models of gas explosion predictions has been done. The advantages and drawbacks, and the possibilities and limitations of the different empirical, phenomenological, and computational fluid dynamics assessment models of gas explosions were discussed. Particular attention was paid to CFD models.

0.57의 L/D 비를 가지는 폭발챔버에서 전파하는 화염과 다중 장애물의 상호작용에 관한 실험적 연구

박달재 한국안전학회 2012 한국안전학회지 Vol.26 No.6

Experimental investigations were performed to examine the characteristics of propagating flame fronts around multiple bars within a rectangular chamber. The explosion chamber is 400 mm in height, 700×700 mm2 in cross‐section and has a large top‐venting area, Av, of 700×210 mm2. This results in a value of 0.44 for Av/V2/3 and a L/D value of 0.57. The multiple obstacles of length 700 mm with a blockage ratio of 30 % were placed within the chamber. Temporally resolved flame front images were recorded by a high speed video camera to investigate the interaction between the propagating flame and the obstacles. Results showed that the flame propagation speeds before the flame impinges onto the obstacle almost equal to the laminar burning velocity. As the propagating flame impinged on the obstacle, the central region of flame began to become concave, this resulted in the flame deceleration in the region. As the flame interacted with the modified flow filed generated behind the central obstacle, the probability density functions(PDFs) of the local flame displacement speed were extensively distributed toward higher speeds

위험물 취급설비 화재 사고결과 영향평가 프로그램 개발 방향

이경봉,유재환,이성우,이영순,김용수,박달재 (社團法人) 韓國火災 ·消防學會 1999 한국화재소방학회논문지 Vol.13 No.4

직사각형 폭발 챔버에서 화염전파와 직사각형 장애물의 상관관계

박달재 ( Dal Jae Park ),이태성 ( Tae Sung Lee ),이영순 ( Young Soon Lee ) 한국안전학회 2008 한국안전학회지 Vol.23 No.2

폭발챔버에서 전파하는 화염의 국부 거동

박달재 ( Dal Jae Park ),이영순 ( Young Soon Lee ) 한국안전학회(구-한국산업안전학회) 2011 한국안전학회지 Vol.26 No.2

다중 장애물을 가지는 폭발챔버에서 전파하는 화염과 국부 장애물의 상관관계를 조사하기 위하여 실험적 연구를 수행하였다. 폭발챔버 높이 235 mm, 단면적 1,000×950mm2, 벤트면적 1,000×320mm2를 가지는 폭발챔버를 제작하였으며, 30% blockage ratio를 가지는 장애물을 챔버내에 설치하였다. 전파하는 화염과 장애물의 상관관계를 조사하기 위해 고속카메라를 사용하였다. 고속카메라로 얻어진 화염 이미지로부터 장애물 주위의 국부 화염전파 거동은 2가지 다른 방법, 즉 전파하는 화염전면(flame front)의 각 pixel point에서 산정된 평균 화염전파속도와 연소면적 증가(incremental burnt area)/화염전면 길이(flame front length) 관점에서 분석하였다. 분석결과, 2가지 방법으로 얻은 결과는 거의 일치하는 경향을 나타났으며, 전파하는 화염이 장애물의 전면과 상호 작용할 때 화염속도는 급격히 증가하다가 장애물의 후단면에서 약간 감소하고, 화염이 장애물 후단에서 재결합될 때 다시 급격히 증가하였다. Experimental studies were carried out in an explosion chamber to investigate the influences of multiple cylinder obstacles on local flame propagation. The chamber dimension is 235 mm in height with a 1,000×950mm2 rectangular cross section and a large vent area of 1,000×320mm2. Multiple cylinder bars with obstruction ratio of 30% were used. In order to examine the interaction between the propagating flames and the obstacles, temporally resolved flame front images were recorded by a high speed video camera. The propagation behaviour of local flame fronts around the left obstacle was analyzed in terms of two different methods such as the incremental burnt area divided by the flame front length and the average of the local propagation velocity determined at each point along the flame front. It was found that two methods give good consistency.