• 대한안전경영과학회지
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• 제16권4호
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• pp.379-389
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• 2014

Fire detectors are designed to minimize loss of life from a fire alarm system as an alarm to help evacuate more quickly until the completion of the evacuation alarm should be continued. the purpose of such alarms in order to achieve the characteristic fire heat release rate reaches a certain level, or when a certain time has elapsed, when the heat detector is to be alarms to answer. Requires a quick response, it is desirable to install the sensor as much as possible, but taking into account the cost of installation problems by engineering approach to minimize the quantity and rapidity of detection capability should be increased. In order to increase the rapidity of fire detectors in a room according to the height of the sensing period is to be maintained the optimum distance of the fire detector detects characteristics should be considered. Differential spot-type heat detectors installed domestic basis, depending on the type of sensor that can detect one sensor area is limited and less than 4m ceiling height regulations and simply double the number in excess of 4m and intended to be installed.

• 한국화재소방학회논문지
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• 제17권1호
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• pp.62-67
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• 2003

실제 건물화재에서 창문재료의 내화특성을 평가하기 위하여 건물화재실험이 수행되었다. 4 mx3.8mx2.4m 방에서 PVC 창문, 알루미늄 창문, AL+Wood 창문을 각각 설치하고 화원은 소파와 매트리스를 사용하였다. 창문은 아파트 베란다에 많이 사용하는 유리두께 6mm사이에 공기층 12 mm인 것을 사용하였다. 건물내부와 창문 주변의 온도분포를 살펴보기 위하여 총 32개 지점의 온도를 측정하였다. 실험결과 건물내의 온도분포, 창틀의 변화, 유리창의 파손 정도 둥을 조사하여 분석하였다.

• 한국화재소방학회논문지
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• 제23권5호
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• pp.103-109
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• 2009

본 연구에서는 환기부족 조건의 구획화재에 대하여 FDS(Ver. 5.2)를 이용하여 수치해석을 수행하였고 열적 특성 및 연소 가스 생성 특성에 대한 예측성능을 평가하였다. ISO-9705 표준화재실의 2/5 크기 모형에 대한 메탄 및 헵탄, 톨루엔 화재를 모사하였으며 고온 상층부의 온도, 연소가스 농도 등에 대하여 기존의 실험 결과와 비교하였다. 실험결과와의 비교를 통해 FDS가 천정의 온도와 과환기 조건의 혼합분율의 예측에 있어서 좋은 성능을 보임을 확인할 수 있었다. 그러나 화재 크기에 비해 산소의 유입량이 충분치 않은 환기부족 조건에서는 일산화탄소 및 그을름의 발생량을 실험값에 비해 크게 하향 예측하였다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.105-112
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• 2007

Recently developed raised floor heating system is not only capable of basic function to reduce noise between floors, but also is a multi-functional floor heating system enabling natural ventilation. The procedure of this system for natural ventilation is to import outdoor air through bottom space of the floor heating system, circulate indoor space and discharge it out of ceiling. In winter, powerless natural ventilation is possible with buoyancy effect caused by temperature difference between outdoor and indoor. And it also allows saving of energy by importing pre-heated air in bottom space of the floor heating system. To evaluate ventilation performance of this system, on-site measurement was conducted in 2 test laboratories, and the nominal air change rate was satisfied as 0.4$\sim$0.8 h-1 under the condition of outdoor temperature $5^{\circ}C{\sim}-5^{\circ}C$, which was evaluated as highly possible to be applied as a natural ventilation system in multi-family houses.

• International Journal of Aeronautical and Space Sciences
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• 제3권1호
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• pp.95-104
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• 2002

Numerical solution of the full Navier-Stokes equation as well as the energy equation has been obtained for the unsteady natural convection in a rectangular enclosure. One side wall was maintained at very high temperature simulating fires. Especially the effect of surface radiation was taken into account. While the enclosed air was assumed to be transparent, the internal walls directly interacted one another through the surface radiation. Due to a significant temperature difference in the flow field, the equation of state was used instead of the Boussinesq approximation. It was found that the rapid heating of the adiabatic ceiling and floor by the incoming radiation from the hot wall made the evolution at thermo-fluid field highly unstable in the initial period. Therefore, the secondary cells brought about at the floor region greatly affected the heat transfer mechanism inside the enclosure. The heat transfer rate was augmented by the radiation, resulting in requiring less time for the flow to reach the steady state. At the steady state neglecting radiation two internal hydraulic jumps were clearly observed in upper/left as well as in lower/right comer. However, the hydraulic jump in the lower/right comer could not be observed for the case including radiation due to its high momentum flow over the bottom wall. Radiation resulted in a faster establishment of the steady state phenomena.

• 터널과지하공간
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• 제12권2호
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• pp.92-98
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• 2002

본 연구에서는 제트팬이 설치된 터널에서 화재발생시 연기의 거동을 해석하기 위하여 축소실험을 실시하였다. Froude 상사를 사용하여 1/20로 축소된 모형터널에서 실험을 실시하였으며 가연물질로는 휘발유를 사용하였다. 지름이 6.6∼ 12.5 cm의 화원을 사용하였으며 발열량은 7.714∼4.77 kW이다. 2.5 kW이하의 화재시 팬을 가동함으로 인하여 역기류가 팬 상류 약 40cm 이상 감소하였으며 팬 하류에서는 효과적으로 연기를 제어하였다. 팬 상류에서는 팬을 가동하지 않은 경우에 비해 연층은 하강하고 온도는 감소하였으나 터널 하부에서는 온도가 증가하였다.

• Geosystem Engineering
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• 제21권5호
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• pp.282-290
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• 2018

The onset of extreme fire behaviour in a mine drift with longitudinal ventilation was analysed. A fire in a mine drift with continuous fuel load, involving several separate fires may lead to flames tilted horizontally and filling up the entire cross section. This will lead to earlier ignition, higher fire growth rate, higher fire spread rate and a severe fire behaviour. The focus has been on what changes take place at the onset and signs of the impending phenomenon. It was found that the fire gas temperature at the ceiling level provided a poor indicator. At the downstream far-field region of the fire, the sudden temperature increase at the lowest levels of the cross section and the sudden increase in flow velocities would provide signs of extreme fire behaviour. The corresponding full-scale heat release rates of the experiments at the onset of extreme fire behaviour were found to be very high for mining applications but not necessarily for tunnel fires. The heat release rate threshold for a mine drift with smaller cross-sectional dimensions would decrease considerably, increasing the likelihood of occurrence. The distance between the fuel items will play an important role during the initiation of horizontal flames.

• 대한건축학회논문집:구조계
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• 제33권12호
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• pp.99-106
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• 2017

Recently, the condensation and mold problems of apartment buildings has been growing due to high insulation and high air-tightness performance for energy saving. Most of all, occupants in residential buildings has suffered from property damages due to the condensation and mold of built-in furniture. Condensation at built-in furniture were generally found in winter at the of furniture's back panels, adjacent surfaces of wall, floor and ceiling. The aim of paper is to analyze the characteristics of adjacent area around built-in furniture's condensation problem and the thermal environment around the built-in furniture in winter through the field measurements at apartment buildings. In this research, the thermal conditions and surface temperature around the built-in furniture were measured during winter season. In this research, we analyzed thermal conditions for built-in furniture which were applied and not applied auxiliary heating device. In results, it is important to consider increasing surface temperature for using heater and decreasing absolute humidity due to the occupants' behavior around built-in furniture for preventing condensation.

• 한국조경학회지
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• 제40권6호
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• pp.190-197
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• 2012

본 연구는 저관리 경량형 옥상녹화의 열수지를 정량화하기 위하여 모의실험을 수행하였다. 콘크리트블록을 이용하여 가로 $1.2m{\times}$세로 $1.2m{\times}$높이 1m의 모의실험구 2개를 제작하여 하나는 한국잔디를 식재한 토심 10cm의 옥상녹화 실험구로 하였으며, 옥상녹화를 실시하지 않은 나머지 하나는 대조구로 하였다. 2012년 6월 6일~7일에 기온, 상대습도, 풍향, 풍속 등 외부 기상환경, 증발산량, 옥상녹화와 대조구인 콘크리트의 표면과 천장면의 온도, 열류량, 열수지를 측정하였다. 6일과 7일의 일최고기온은 각각 $29.4^{\circ}C$와 $30^{\circ}C$로 초여름 날씨로는 매우 무더웠다. 6일과 7일의 일증발산량은 각각 $2,686.1g/m^2$과 $3,312.8g/m^2$이었으며, 일사량이 증가함에 따라 증발산량도 증가하였다. 외부 기온이 가장 높은 시간일 때의 옥상녹화 표면과 대조구 표면의 온도차이를 비교해 보면 대조구 표면이 $5.5^{\circ}C$(6일)와 $2.2^{\circ}C$(7일) 더 높은 것으로 나타났다. 옥상녹화 천장과 대조구 천장의 온도차이를 비교해 보면 $13.1^{\circ}C$(6일)와 $14.2^{\circ}C$(7일)로 나타나 옥상녹화에 의한 실내온도저감효과가 매우 큰 것으로 나타났다. 옥상녹화와 대조구인 콘크리트 표면의 열수지를 분석한 결과, 옥상녹화는 순복사량과 잠열량이 많은 비율을 차지하고 있었으나 대조구는 현열량과 전도열량의 비율이 높았다. 즉, 옥상녹화는 한국잔디와 식재토양에 의한 증발산으로 열을 식혀주는 잠열의 비율이 높은 반면에 대조구인 콘크리트 표면은 식물이 식재되어 있지 않기 때문에 열을 식혀주는 잠열은 $0W/m^2$인 반면에 주위 온도를 증가시키는 현열량과 건물내로 전달되는 전도열량의 비율이 높아 표면과 천장면의 온도를 상승시켰다. 본 연구는 옥상녹화의 온도저감과 열수지 해석을 시도했다는 점에서는 매우 의의가 크다고 할 수 있지만, 옥상녹화는 토심과 토양배합비, 식물종, 계절 등 여러 변수에 따라 온도저감효과가 다르게 나타날 수 있기 때문에 이에 대한 후속연구가 필요하다.

• 한국동물위생학회지
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• 제38권3호
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• pp.195-198
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• 2015

Mannheimia haemolytica is an opportunistic bacterium that is widely recognized among the bovine respiratory disease (BRD) complex in cattle. Five Hanwoo with a history of fever, anorexia and dyspnea were died within 2 days in a the middle of summer. Four cattle were pregnant. The cattle house were located in mountainous area but the window for air ventilation was open only one side. In addition, the fecal material for fermentation was located indoor. Air ceiling fan did not work. The indoor temperature was $40^{\circ}C$. After working on air fan, the indoor temperature was still $36^{\circ}C$. On necropsy, there was fibrinous pleuritis with a rich yellowish pleural fluids in the thorax. The cross-section of the lung showed lobar fibrinonecrotic pneumonia with expanded interlobular septa by edema and fibrin. Microscopically, parenchymal necrosis with dense layer of inflammatory cells were observed surrounding interlobular septum. Fibrin and inflammatory cells were filled in the alveoli. Bacteriological cultures of pulmonary tissue showed growth of M. haemolytica. This pneumonia case in Hanwoo suggests that environmental stressors such as high temperature, insufficient air ventilation, and pregnancy be the cause of mannheimoisis. Control of environmental stressor, such as temperature indoor is necessary to prevent BRD caused by M. haemolytica.