• Title/Summary/Keyword: Flame spread rate

Search Result 65, Processing Time 0.024 seconds

A Study on the Fire Characteristics of Aluminum Composite Panel by Large Scale Calorimeter (라지스케일 칼로리미터에 의한 알루미늄 복합패널 외장재의 연소특성에 관한 연구)

  • Yun, Jung-Eun;Min, Se-Hong;Kim, Mi-Suck;Choi, Sung-Bok
    • Fire Science and Engineering
    • /
    • v.24 no.2
    • /
    • pp.89-96
    • /
    • 2010
  • In this research, exterior material combustion experiment was really tested to evaluate fire risks of aluminium complex panel which is used a lot for building exterior material. As a result, We saw fast fire spreading of aluminium complex panel. The reason is polyethylene in aluminum complex panel combust spreading fast fire flame vertically. In this test, the highest heat release rate of aluminum complex panel was 1,144 kW and surface temperature which is measured by thermocouple went up to more than $903.3^{\circ}C$, that temperature is quite a higher than $660^{\circ}C$ which is aluminum melting temperature. So, fire of aluminum complex panel can be evaluated to give us severe damage both by fast fire spreading vertically and by fire spreading through openings internally. These results from real experiment will be able to use to predict fire spreading of aluminum complex panel by comparing to modeling materialization of aluminum complex panel in the future.

A Study on the Prediction of Fire Load in case of a Train Fire (철도 차량 화재시 화재강도 예측을 위한 연구)

  • Yang, Sung-Jin;Chang, Jung-Hoon;Gang, Chan-Yong
    • Proceedings of the KSR Conference
    • /
    • 2008.06a
    • /
    • pp.2101-2108
    • /
    • 2008
  • Most of train fires which occur in usual cases do not grow up significantly on a large scale enough to bring about casualties and harmful damages. However, the consequence of some train fire accidents can be devastating disaster so that it would be even recorded in history in unusual cases. Accordingly, such a probability of fire disaster cannot be ignored in aspect of the railway safety assesment. A scale of injury and damage is very difficult to predict and analyze. Because it is depend on various factors, i.e. fire load, burning period, facilities, environment condition, and so on. Thus, a prediction of fire load could be understood as a one methodology to estimate railway safety assesment. The summation method which is one of them is used to evaluate the overall fire load by assuming that sum of heat release rate per unit area or mass of each composite material equals the total. However, since the train fire is classified into a compartment fire in under-ventilation condition. The summation method do not estimate a fire load completely. In this journal, Various methods to predict fire load are introduced and evaluated. Especially the fire simulation tool FDS(Fire Dynamics Simulator)which is based on the CFD(Computational Fluid Dynamics) is introduced, too. Through the FDS simulation, numerical analyses for the fire load and flame spread are performed. Then, these results of the simulation are validated through the comparison study with the experimental data. Then, limitations and approximations including in simulation process are discussed. The future direction of research is proposed.

  • PDF

Fase Positive Fire Detection Improvement Research using the Frame Similarity Principal based on Deep Learning (딥런닝 기반의 프레임 유사성을 이용한 화재 오탐 검출 개선 연구)

  • Lee, Yeung-Hak;Shim, Jae-Chnag
    • Journal of IKEEE
    • /
    • v.23 no.1
    • /
    • pp.242-248
    • /
    • 2019
  • Fire flame and smoke detection algorithm studies are challenging task in computer vision due to the variety of shapes, rapid spread and colors. The performance of a typical sensor based fire detection system is largely limited by environmental factors (indoor and fire locations). To solve this problem, a deep learning method is applied. Because it extracts the feature of the object using several methods, so that if a similar shape exists in the frame, it can be detected as false postive. This study proposes a new algorithm to reduce false positives by using frame similarity before using deep learning to decrease the false detection rate. Experimental results show that the fire detection performance is maintained and the false positives are reduced by applying the proposed method. It is confirmed that the proposed method has excellent false detection performance.

A Review and Analysis of the Thermal Exposure in Large Compartment Fire Experiments

  • Gupta, Vinny;Hidalgo, Juan P.;Lange, David;Cowlard, Adam;Abecassis-Empis, Cecilia;Torero, Jose L.
    • International Journal of High-Rise Buildings
    • /
    • v.10 no.4
    • /
    • pp.345-364
    • /
    • 2021
  • Developments in the understanding of fire behaviour for large open-plan spaces typical of tall buildings have been greatly outpaced by the rate at which these buildings are being constructed and their characteristics changed. Numerous high-profile fire-induced failures have highlighted the inadequacy of existing tools and standards for fire engineering when applied to highly-optimised modern tall buildings. With the continued increase in height and complexity of tall buildings, the risk to the occupants from fire-induced structural collapse increases, thus understanding the performance of complex structural systems under fire exposure is imperative. Therefore, an accurate representation of the design fire for open-plan compartments is required for the purposes of design. This will allow for knowledge-driven, quantifiable factors of safety to be used in the design of highly optimised modern tall buildings. In this paper, we review the state-of-the-art experimental research on large open-plan compartment fires from the past three decades. We have assimilated results collected from 37 large-scale compartment fire experiments of the open-plan type conducted from 1993 to 2019, covering a range of compartment and fuel characteristics. Spatial and temporal distributions of the heat fluxes imposed on compartment ceilings are estimated from the data. The complexity of the compartment fire dynamics is highlighted by the large differences in the data collected, which currently complicates the development of engineering tools based on physical models. Despite the large variability, this analysis shows that the orders of magnitude of the thermal exposure are defined by the ratio of flame spread and burnout front velocities (VS / VBO), which enables the grouping of open-plan compartment fires into three distinct modes of fire spread. Each mode is found to exhibit a characteristic order of magnitude and temporal distribution of thermal exposure. The results show that the magnitude of the thermal exposure for each mode are not consistent with existing performance-based design models, nevertheless, our analysis offers a new pathway for defining thermal exposure from realistic fire scenarios in large open-plan compartments.

Experimental Study on the Effects of Combustion Products on the Human Body and Suggestion of Law Revision (흡음재의 연소 생성물이 인체에 미치는 영향에 대한 실험적 연구 및 법률 개정 제언)

  • Kang, Jung Ki;Choi, Don Mook
    • Fire Science and Engineering
    • /
    • v.33 no.4
    • /
    • pp.28-34
    • /
    • 2019
  • Regardless of the ignition source, the main factors affecting the spread of flames to the human body are combustibles. The sound absorption material, which is the finishing material used in music institutes and karaoke rooms, consists of polyurethane that generates a large amount of toxic gas with a high amount of combustion gases during a fire. Still, the current law does not require the use of impregnated finishing materials for tutoring services with less than 100 users. In this study, the rate of flame diffusion was measured using the MultiRaelite composite gas measuring instrument (target substance VOC, HCHO, SO2, CO2, CO, HCN, and NO2) for the collection of sound-absorbing materials installed in the actual music academy. The results showed that the toxic gas found in this experiment exceeded the allowable concentration of TWA (Time Weighted Average) and STEL (Short Term Exposure Limit). In addition, a comparative combustion test of the general sound absorber and non-combustion sound absorbing materials on the market showed wide differences in ignition and diffusion. Therefore, based on the results of the experiment, private institutes with less than 100 users should be mandated to use non-combustion sound absorbing materials.