• 한국안전학회지
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• 제32권5호
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• pp.20-24
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• 2017

In this study, we have performed the Cone Calorimeter test in accordance with ISO 5660-1 to check the combustion characteristics of building flooring materials. The fire risk of these materials were evaluated by construction code, KFI criteria and standards of flame retardant performance. When samples exposed to external heat flux, all samples consumed a lot of Oxygen for a long time. So heat release from sample burning continued so long. And also all samples produced so much smoke. Even though a few samples were satisfied with only peak heat release rate criteria, all 8 samples were not satisfied with criteria of peak heat release rate and total heat released together. The results of 5 min total heat released were $15.9MJ/m^2{\sim}5.9MJ/m^2$. It menas the results are more than 2~6 times higher than the criteria. The results of 10 min total heat released were $30.1MJ/m^2{\sim}100.8MJ/m^2$. It means the results are more than 3~12 times higher than the criteria. 6 of 8 samples were not satisfied with Dm.corr.(corrected maximum smoke density) criteria. The building flooring materials which we used for this test ignited very fast and the burning continued so long. It means these samples are susceptible to fire.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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• pp.77-84
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• 1997

Cone calorimeter measurements can be used for the calculation of effective material properties, which can be used as input parameters in modeling of fire. Main parameter measured in Cone calorimeter is heat release rate. Some other parameters as time to ignition, effective heat of combustion, mass loss rate or total heat released is also measured in Cone calorimeter. Total heat released is important from the point of view of total energy available in material in Fire situation. Cone calorimeter. measurements were done on several wood species (oak, beech, spruce, poplar). Measurements were provided at external irradiances 30, 50 and 65 ㎾/$m_2$ in horizontal orientation. Heat release rate data were evaluated and compared as a function of external irradiance for various species of wood. furthermore the influence of external irradiance on effective heat of combustion and total heat release was also evaluated for the period of flame combustion.

• 에너지공학
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• 제8권2호
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• pp.242-247
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• 1999

각종 산업단지 및 발전소에서 배출되는 막대한 양의 폐열을 회수하여 재활용하기 위하여 전국 7개 지역 11개 공단에 대한 폐열 특성분석을 실시하였다. 본 연구는 도시종합에너지시스템 연구의 일환으로 산업체 폐열을 배후도시의 주거 및 상업지역에 공급.이용 가능성을 검토하였다. 검토대상 공업단지의 조사된 폐열량은 148,913 TOE/년으로 나타났으며, 온도범위는 $0^{\circ}C$~20$0^{\circ}C$가 83%, 그리고 배가스 형태로 배출되는 폐열이 전체의 82%를 차지하는 것으로 나타났다. 이들 조사대상 공업단지 중 폐열량이 집중된 4개 지역 (대구공단, 울산 석유화학단지, 여천 석유화학단지 및 전주공단)에 대한 폐열특성도 상세하게 조사되었으며, 이들 공단의 조사된 폐열량은 114,402 TOE/년으로 조사된 총폐열량의 77%에 해당하며. 이중 배가스는 87%, 온도범위는 $0^{\circ}C$~20$0^{\circ}C$의 폐열이 대부분인 것으로 나타났다. 또한, 18.1 million TOE/년의 폐열이 화석연료를 사용하는 발전소로부터 발생되며, 이중 95%가 복수냉각기에서 배출되는 27$^{\circ}C$~34$^{\circ}C$ 범위의 저온폐열이며, 나머지 5%(894,800 TOE/년)가 연도 배가스 형태로 배출되고 있는 것으로 조사되었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.70-76
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• 2005

The interior materials of the urban subway car in operation are now being changed to new materials that meet the latest law in effect, the fire safety criteria of the urban railway vehicle. It was well known fact that the composite materials, that were applied to last subway car, were weak on the fire. Contrary to this materials, materials in work have good resistance to the fire. On the paper, To investigate the difference of fire safety level on the subway car, cone calorimeter was used to measure the heat release rate and total heat released according to the ISO 5660. A high radiative heat flux of 50kW/m2 was used to burn out all materials and to simulate the condition of fully developed fire case in the tests.

• 한국안전학회지
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• 제24권4호
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• pp.96-103
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• 2009

This study was fulfilled to investigate the forest fire risk of forest fuels based on the combustion characteristics of living leaves of coniferous trees and broadleaf trees naturally growing in Youngdong areas of Gangwon Province by using cone calorimeter and smoke density chamber. According to the result, Pinus densiflora and Pinus rigida among coniferous trees released a greater amount of heat release than other kinds. The total smoke release varied depending on the species, whereas Pinus koraiensis showed the largest amount of smoke release. With regard to maximum smoke density, it was much higher in coniferous trees than in broadleaf trees. With regard to smoke temperature, Pinus densiflora showed the lowest compared to other kinds up until 200s from the ignition, but all most trees uniformly maintained constant temperature of about $70^{\circ}C$ after 200s. The concentrations of CO and $CO_2$ release were drastically increased at about 150s and then gradually decreased thereafter. Pinus densiflora showed a bit higher CO release than broadleaf trees, but there was no distinct difference in $CO_2$ release among tress.

• 한국화재소방학회논문지
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• 제24권5호
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• pp.115-121
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• 2010

이 연구에서는 암모늄염을 처리한 리기다 소나무의 연소성을 시험하였다. 실온에서 3종류의 암모늄염 즉, 황산암모늄, 제1인산암모늄, 그리고 제2인산암모늄의 20wt% 수용액에 각각 리기다 소나무를 함침시켜 건조시킨 후 콘칼로리미터(ISO 5660-1)를 이용하여 그의 연소성을 시험하였다. 암모늄염으로 처리한 시험편은 처리하지 않은 시험편에 비하여 그의 연소성을 감소 시켰다. 이것은 연소 억제성이 순수 리기다 소나무 시험편에 처리한 암모늄염 때문에 향상된 것으로 생각된다. 또한 암모늄염으로 처리한 시험편은 처리하지 않은 시험편에 비해 낮은 최대열방출률과 낮은 총방출열량을 나타내었다.

• Journal of Mechanical Science and Technology
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• 제18권3호
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• pp.407-418
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• 2004

Prandtl-Meyer expansion flow with homogeneous condensation is investigated experimentally and by numerical computations. The steady and unsteady periodic behaviors of the diabatic shock wave due to the latent heat released by condensation are considered with a view of technical application to the condensing flow through steam turbine blade passages. A passive control method using a porous wall and cavity underneath is applied to control the diabatic shock wave. Two-dimensional, compressible Navier-Stokes with the nucleation rate equation are numerically solved using a third-order TVD (Total Variation Diminishing) finite difference scheme. The computational results reproduce the measured static pressure distributions in passive and no passive Prandtl-Meyer expansion flows with condensation. From both the experimental and computational results, it is found that the magnitude of steady diabatic shock wave can be considerably reduced by the present passive control method. For no passive control, it is found that the diabatic shock wave due to the heat released by condensation oscillates periodically with a frequency of 2.40㎑. This unsteady periodic motion of the diabatic shock wave can be completely suppressed using the present passive control method.

• 한국전산유체공학회지
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• 제20권1호
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• pp.65-76
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• 2015

In this study, the natural convection phenomenon of the air side and the forced convection phenomenon of the oil side were simulated in the radiator through a 3-D numerical analysis, and the total heat released by the oil side into the radiator heating plate and then to the air side was evaluated. Also, a quantitative analysis was carried out on the effect of each thermal resistance on the overall heat transfer coefficient through a 1-D thermal circuit analysis on the heat transfer mechanisms of the radiators considered in this study. In addition, for the diverse shapes of the heating plates considered in this study, the pressure drops of the oil side were quantitatively compared and evaluated. The temperatures at the air side and the oil side outlets of the radiators with 8 different fin shapes considered in this study had almost similar values showing a difference of +/-3% and, accordingly, the total heat transfer also showed similar heat dissipation performance in all the models. As a result of the 1-D thermal circuit analysis, in all the models considered in this study, while the thermal resistance of the air side accounted for 92% to 96% of the total, that of the oil side was 5 to 7%, and that of the heating plate showed a very small value of 0.02%.

• Safety and Health at Work
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• 제14권2호
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• pp.215-221
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• 2023

Background: There is little information about the airborne hazardous agents released during the heat treatment when manufacturing a welding material. This study aimed to evaluate the airborne hazardous agents generated at welding material manufacturing sites through area sampling. Methods: concentration of airborne particles was measured using a scanning mobility particle sizer and optical particle sizer. Total suspended particles (TSP) and respirable dust samples were collected on polyvinyl chloride filters and weighed to measure the mass concentrations. Volatile organic compounds and heavy metals were analyzed using a gas chromatography mass spectrometer and inductively coupled plasma mass spectrometer, respectively. Results: The average mass concentration of TSP was 683.1±677.4 ㎍/m³, with respirable dust accounting for 38.6% of the TSP. The average concentration of the airborne particles less than 10 ㎛ in diameter was 11.2-22.8×10⁴ particles/cm³, and the average number of the particles with a diameter of 10-100 nm was approximately 78-86% of the total measured particles (<10 ㎛). In the case of volatile organic compounds, the heat treatment process concentration was significantly higher (p < 0.05) during combustion than during cooling. The airborne heavy metal concentrations differed depending on the materials used for heat treatment. The content of heavy metals in the airborne particles was approximately 32.6%. Conclusions: Nanoparticle exposure increased as the number of particles in the air around the heat treatment process increases, and the ratio of heavy metals in dust generated after the heat treatment process is high, which may adversely affect workers' health.

• Advances in nano research
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• 제16권2호
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• pp.127-140
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• 2024

Upon direct/indirect exposure to flame or heat, composite structures may burn or thermally buckle. This issue becomes more important in the natural fiber-based composite structures with higher flammability and lower mechanical properties. The main goal of the present study was to obtain an optimal eco-friendly composite system with low flammability and high thermal buckling resistance. The studied composite consisted of polypropylene (PP) and short abaca fiber (AF) with eggshell powder (ESP) and halloysite clay nanotubes (HNTs) additives. An optimal base composite, consisting of 30 wt.% AF and 70 wt.% PP, abbreviated as OAP, was initially introduced based on burning rate (BR) and the Young's modulus determined by horizontal burning test (HBT) and tensile test, respectively. The effects of adding ESP to the base composite were then investigated with the same experimental tests. The results indicated that though the BR significantly decreased with the increase of ESP content up to 6 wt.%, it had a very destructive influence on the stiffness of the composite. To compensate for the damaging effect of ESP, small amount of HNT was used. The performance of OAP composite with 6 wt.% ESP and 3 wt.% HNT (OAPEH) was explored by conducting HBT, cone calorimeter test (CCT) and tensile test. The experimental results indicated a 9~23 % reduction in almost all flammability parameters such as heat release rate (HRR), total heat released (THR), maximum average rate of heat emission (MARHE), total smoke released (TSR), total smoke production (TSP), and mass loss (ML) during combustion. Furthermore, the combination of 6 wt.% ESP and 3 wt.% HNT reduced the stiffness of OAP to an insignificant amount by maximum 3%. Moreover, the char residue analysis revealed the distinct differences in the formation of char between AF/PP and AF/PP/ESP/HNT composites. Afterward, dilatometry test was carried out to examine the coefficient of thermal expansion (CTE) of OAP and OAPEH samples. The obtained results showed that the CTE of OAPEH composite was about 18% less than that of OAP. Finally, a theoretical model was used based on first-order shear deformation theory (FSDT) to predict the critical bucking temperatures of the OAP and OAPEH composite plates. It was shown that in the absence of mechanical load, the critical buckling temperatures of OAPEH composite plates were higher than those of OAP composites, such that the difference between the buckling temperatures increased with the increase of thickness. On the contrary, the positive effect of CTE reduction on the buckling temperature decreased by raising the axial compressive mechanical load on the composite plates which can be assigned to the reduction of stiffness after the incorporation of ESP. The results of present study generally stated that a suitable combination of AF, PP, ESP, and HNT can result in a relatively optimal and environmentally friendly composite with proper flame and thermal buckling resistance with no significant decline in the stiffness.