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This study aims to identify the key design factors of a large-scale calorimeter and evaluate the accuracy of the simulation results using the Fire Dynamics Simulator (FDS) program. The design specifications of a domestic large-scale calorimeter were analyzed to determine the modeling and input conditions for the simulation. The simulation results of temperature, mass flow rate, and oxygen concentration reduction inside the duct were compared with the experimental results for heptane pool fires with diameters of 1.1 m, 1.24 m, and 1.44 m, respectively. To validate the accuracy of the simulation results, the deviations, calculated using FDS for the heat release rate as the experimental value, were found to be 19.12%, 11.86%, and 0.22% for temperature, mass flow rate, and oxygen concentration, respectively. Ultimately, the results of the heat release rate inside the duct obtained by the oxygen consumption method with FDS were found to be consistent with the experimental value, within 2.58%. However, the deviation of oxygen concentration is reduced as the deviation of mass flow rate increases for a constant heat release rate. This implies that for more accurate analysis, the heat loss and shape factors in the duct should be considered.

In this study, fundamental research was conducted to analyze the correlation between the main design factors of large-scale cone-calorimeters and the heat release rate. The specifications for designing cone-calorimeters of 1 MW or higher, which have been constructed in foreign research institutes, were investigated. In addition, the relationship between the total amount of smoke generated in the plume and the heat release rate determined via the oxygen consumption method was reviewed. The temperature variation inside the duct and the oxygen concentration could be decreased as the height and size of the hood increased. These results could have an important effect on the mass flow rate and oxygen consumption coefficient when calculating the heat release rate. To accurately determine the heat release rate of a large cone-calorimeter is determined, further research is necessary to analyze the design factors considering not only the blowing capacity but also the shape of the hood and height from the fire source.

This study was conducted to develop a preprocessing method that generates a computational geometry for a wildland fire simulation based on topographic data. The computational domain comprised an area of 2 km × 2 km with a height of 1.2 km, including the terrain geometry and atmosphere, in Palgongsan Natural Park near the Gatbawi district. BLENDER 2.92, an open-source 3D computer graphics software tool, was used to create the terrain surface and 3D solid objects based on the data of a digital elevation model, considering the spatial resolution of 90 m provided by the SRTM of the NASA. The level-set method of the FDS model was used to track the wildland fire spread, assuming that the speed of the wind from the east was 10 m/s. The calculated result of the fire spread was dependent on the grid size of the computational mesh and the voxel size of the 3D solid objects.

The aim of this study is to investigate the gas temperature and velocity during sprinkler activation considering the fire growth scenario based on the thermal response model of the sprinkler. The fire source is assumed to have time square fire growth scenarios with a maximum heat release rate of 3 MW. Eight types of standard and fast-response sprinkler heads with an operating temperature range of 65–105 ℃ and a response time index range of 25–171 m1/2s1/2 were adopted. The temperature difference between the gas stream and the sensing element of the sprinkler head decreased as the fire growth slowed down, and the RTI value decreased. The overall gas temperature and velocity conditions predicted using the FDS model at sprinkler activation were in reasonable agreement with those of standard test conditions of the sprinkler head response. However, the sprinkler head could be activated at lower limits of gas temperature and velocity under the current test conditions for a slowly growing fire scenario.

The energy released by various burning material has a wide range of its magnitude and transient characteristics, the measurement of the heat release rate(HRR) has been considered as one of the most challenging issue among the parameters related to fire. This study compares the measured HRR calculated by the oxygen consumption (OC) method and the carbon dioxide generation (CDG) method using a laboratory-scale fire calorimeter. The feasibility of the CDG method is examined by analyzing the relative error. The relationship between the oxygen depletion factor and CO2 mass flow rate, which is a key parameter in HRR calculations, showed strong linearity at 6 % for the methane burner fire. The contribution of HRR by CO was less than 7% compared with the of HRR by CO2 in the CDG calculation method. The linearity of the OC and CDG methods with respect to HRR of the referenced methane burner in a quasi-steady state was less than 1%; this indicates that the CDG method can be utilized as a complementary method in heat release rate measurement.

본 연구는 필드모델에서 소모된 연료에 기초하여 화학적 화염높이를 산정하기 위한 방법을 검토하고자 한다. 높이 방향으로 HRRPUL의 누적값과 연료농도에 따른 계산 알고리즘을 FDS 해석결과에 적용하였으며 평균화학적 화염높이는알고리즘을 적용한 순간화염높이의 시간평균을 통해 산정하였다. 연료농도에 기초한 평균화염높이는 HRRPUL의 누적값에 의해 계산된 화염높이와 10% 이내의 상향예측범위에서 일치된 결과를 보였다. 이러한 연구는 전산화재해석모델에서정량적인 화염높이를 산정하고 보다 상세한 화재거동특성을 이해하는데 기여하고자 한다.ABSTRACTThe present study has been conducted to estimate the chemical flame height based on fuel consumption in fire fieldmodel. The calculation algorithms based on cumulative fraction of HRRPUL and fuel concentration along the z axis wereapplied to the results predicted by Fire Dynamics Simulator (FDS) version 6.3.2 and the mean chemical flame height wasobtained by time averaging of instantaneous flame height with the algorithms. The mean flame height calculated by fuelconcentration was quite well matched with that of cumulative value of HRRPUL within 10% over-prediction. This studycontribute to a more detailed understanding of fire behavior and quantitative evaluation of flame height in the computa-tional fire model.Keywords : Flame height, Field model, Fire dynamics simulator, Heat release rate

The present study has been conducted to analyse the effects of various pool diameters on the measurement of heat release rate (HRR) of heptane fire using large scale cone calorimeter (LSC). The burning rate which is the major parameter for HRR compared with the previous model suggested by A. Hamins. The combustion efficiency for heptane by oxygen consumption method is about 91%, which is almost same with the previous results of 92% suggested by J. Gore. The convective HRR by enthalpy consumption method was 54% lower than HRR by oxygen consumption method. This results are practical use for establishing the reliability of heat release rate for fire experiment.

건축물의 성능위주 소방설계의 활용성 및 신뢰성을 향상시키기 위해서는 다양한 화재실험 및 조사 등을 통해 가연물의 연소물성에 관한 광범위하고 다양한 데이터베이스가 필요하다. 본 연구에서는 건축물의 성능위주 소방설계에 활용하기 위해 건축물의 내장용 판재 2종과 내장용 루버 3종을 대상으로 연소시험을 실행하여 연소발열특성 등을 파악하였다.또한 내장용 판재는 그 두께에 따라 최대열방출률 등 연소발열성상에 차이가 발생할 가능성이 있으므로 판재의 두께에따라 연소시험을 수행하였다. 실험결과 내장재 판재 및 루버의 단위연소량당 평균발열량은 15.3 MJ/kg~16.9 MJ/kg이었고, 내장용 판재의 평균최대열방출률과 평균최대이산화탄소 농도는 판재의 두께에 따라 차이가 있는 것이 확인되었다.ABSTRACTIt is necessary to enhance its availability and reliability of performance based fire design of building with various typeof database such as experiments, survey and fire properties and so on. In order to utilize to the performance based firedesign, the present study has been performed a series of experiments to investigate the burning characteristics of buildingmaterials for two types of interior board and three types of interior louver. The burning test has been also conducted fordifferent thickness because it may show different characteristics of burning behavior such as flame spread rate and flamepropagation time. The result shows that the effective heat release per unit mass of interior materials were almost constantwith 15.3~16.9 MJ/kg regardless of its thickness while the peak heat release rate and maximum CO

성능위주 소방설계(PBD)의 과정에서 화재 및 피난모델링의 신뢰성을 확보하기 위해서는 화재감지기 모델의 높은 예측성능이 필수적으로 요구된다. 본 연구의 목적은 대표적인 화재모델인 FDS에 적용되고 있는 정온식 열감지기의 정확한작동 개시시간을 예측하기 위한 입력정보를 측정하는 것이다. 이를 위해 화재감지기의 장치특성을 측정할 수 있는 FireDetector Evaluator (FED)가 사용되었으며, 국내에서 적용되는 2개의 써미스터 방식(Thermistor types)과 1개의 바이메탈 방식(Bimetal type)의 스포트형 정온식 열감지기가 연구대상으로 고려되었다. 화재모델링을 위해 요구되는 감지기의작동 개시온도 및 반응시간지수(Response Time Index)가 측정되었으며, 이때 RTI는 감지기의 설치위치를 고려하여 천장제트기류(Ceiling jet flow)와 수직제트기류(Vertical jet flow)에 대하여 측정되었다. 측정된 장치물성을 이용한 화재모델링 결과는 실규모 구획화재실험 결과와 비교·검증되었다. 그 결과 수치적으로 예측된 감지기의 작동 개시시간은 실험결과를 적절히 잘 예측함을 확인하였다.ABSTRACTThe high predictive performance of fire detector models is essentially needed to assure the reliability of fire and evacua-tion modeling in the process of Performance-Based fire safety Design (PBD). The main objective of the present study isto measure input information in order to predictive the accurate activation time of fixed temperature heat detectorsadopted in Fire Dynamics Simulator (FDS) as a representative fire model. To end this, Fire Detector Evaluator (FDE)which could be measured the device properties of detector was used, and the spot-type fixed temperature heat detectors oftwo thermistor types and one bimetal type were considered as research objectors. Activation temperature and ResponseTime Index (RTI) of detectors required for the fire modeling were measured, and then the RTI was measured for ceilingjet flow and vertical jet flow in consideration of the install location of detectors. The results of fire modeling using mea-sured device properties were compared and validated with the experimental results of full-scale compartment fires. It wasconfirmed that, in result, the numerically predicted activation time of detector showed reasonable agreement with themeasured activation time.