• Title/Summary/Keyword: fire effects

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A STUDY on FOREST FIRE SPREADING ALGORITHM with CALCULATED WIND DISTRIBUTION

  • Song, J.H.;Kim, E.S.;Lim, H.J.;Kim, H.;Kim, H.S.;Lee, S.Y
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1997.11a
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    • pp.305-310
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    • 1997
  • There are many parameters in prediction of forest fire spread. The variables such as fuel moisture, fuel loading, wind velocity, wind direction, relative humidity, slope, and solar aspect have important effects on fire. Particularly, wind and slope factors are considered to be the most important parameters in propagation of forest fire. Generally, slope effect cause different wind distribution in mountain area. However, this effect is disregarded in complex geometry. In this paper, wind is estimated by applying computational fluid dynamics to the forest geometry. Wind velocity data is obtained by using CFD code with Newtonian model and slope is calculated with geometrical data. These data are applied fer 2-dimentional forest fire spreading algorithm with Korean ROS(Rate Of Spread). Finally, the comparison between the simulation and the real forest fire is made. The algorithm spread of forest fire will help fire fighter to get the basic data far fire suppression and the prediction to behavior of forest fire.

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A Study of the Analysis of Water Tank Suitability for Forest Fire Extinction using Geographic Information System (GIS를 이용한 산불 진화용 저수탱크 적지 분석에 관한 연구)

  • Yi, Gi-Chul;Kim, Seung-Hwan;Nam, Jung-Chil;Park, Sung-Burm;Kang, Young-Jo;Ok, JinA
    • Journal of the Korean Association of Geographic Information Studies
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    • v.1 no.2
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    • pp.1-13
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    • 1998
  • The objective of this paper is to develop a cartographic model for water tank suitability for small forest fire extinction using GIS. Various digital maps were created using CAD & GIS for Amnam urban park, which is located in Seogu, Pusan city. The park had 4 small water tanks for fire extinction. The developed descriptive cartographic model identified the spatial effects of fire extinction due to the existing facilities. The prescriptive model to enhance spatial effects was developed for the determination and comparison of the effects of forest fire extinction due to the proposed facilities. This paper proved the techniques of GIS and cartographic modelling are significant for the suitability analysis of water tanks for small forest fire extinction.

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An Experimental Study of Fire Risk Characteristic by Extended Balcony of High-Rise Apartments in Fire (고층아파트 화재시 발코니 확장에 따른 화재 위험성에 관한 실험 연구)

  • Kim, Woo-Suk;Kim, Wha-Jung;Lee, Gwang-Won;Lee, Ji-Hee
    • Journal of the Korean Society of Safety
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    • v.27 no.2
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    • pp.65-71
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    • 2012
  • Changes in the styles of communities are leading of increases in the number of high-rise apartments and commercial-apartment structures. Tall high-rise structures, while presenting unique economies of scale and cost effectiveness, tend to be highly engineered and complex structures. In the event of a fire, this complexity in design also results in a complexity in the behavior of fire propagation and control. High-rise structures are among the most potentially dangerous due to the high population density in the building, and the inherent limitations on evacuation and on fire control services. One of the most critical points of fire propagation is the movement of fire through the outer wall structures. Controlling such propagation is essential in controlling the spread of the fire throughout the building itself, as well as controlling the potential for its spread to adjacent buildings. In this study, we will be examining the potential for fire control design and effects mitigation using a 1/4.5 scale model. The primary focus of the study will be the effects of extended balconies into the structure of high-rise apartments. The authors will also consider the effectiveness of reduced-scale model tests.

Analysis on the Effects of the Heat Loss Coefficient on the Operation Time of Sprinkler in Compartment Fire (구획 화재에서 스프링클러 열 손실계수 변화에 따른 작동 시간 분석)

  • You, Woo Jun
    • Fire Science and Engineering
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    • v.32 no.5
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    • pp.34-39
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    • 2018
  • In this study, the experiment conditions for the variation of heat release rate in compartment space were constructed to analyze the effects of fire spread and the operation time of sprinkler in accordance with the heat loss of the sprinkler's heat element. The compartment composed of fire board (width = 0.3 m, height = 0.5 m, length = 3.0 m), are manufactured to measure the temperature distributions in the inner space, the mass loss rate and heat release rate during the experiment of N-heptane pool fire test. Also, the operation time of sprinkler is analyzed with the installation of sprinkler and C-factor using Fire Dynamics Simulator Ver.6 under the experiment conditions. The results show that the operation time of sprinkler, which has RTI $100(m{\cdot}s)^{0.5}$ operating temperature $70^{\circ}C$, is 30 s~60 s for C-factor = 0 and 1, 62 s~92 s for C-factor = 3, and 120 s over for C-factor = 5, respectively.

Systematic Review and Meta-Analysis of Efficacy and Safety of Fire Needling and Warm Needling on Acute Gout

  • Ji Hye Hwang;Aejin Song;Ho-Sueb Song
    • Journal of Pharmacopuncture
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    • v.25 no.4
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    • pp.301-316
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    • 2022
  • Objectives: This study aimed to evaluate the efficacy and safety of heat stimuli (e.g., fire needling, warm needling) in acupuncture for acute gout. Methods: Four international online databases (PubMed, Cochrane, Embase, and Chinese National Knowledge Infrastructure) were searched to identify randomized, controlled trials (RCTs) that used fire needling and warm needling for acute gout. The methodological quality of the RCTs was evaluated using the Cochrane risk-of-bias (RoB) tool. Thirteen RCTs (840 patients) were included and analyzed. Three evaluation tools (total effective rate, uric acid level, and pain score) were mainly used. Comparisons were made between Western medicine (WM) and i) fire needling or warm needling treatment alone, ii) fire needling and bloodletting combination treatment, iii) combination of fire needling, bloodletting, and herbal medicine, iv) warm needling (concurrently). Heat stimuli in acupuncture alone or in combination treatment were more effective in terms of the total efficacy rates, uric acid levels, and pain scores than WM alone. Results: In all the evaluation tools, the treatment effects in the fire needling alone or warm needling alone treatment group and the fire needling and bloodletting combination intervention group were significantly better than those in the WM control group. The warm needling and WM combination intervention groups also experienced significantly better treatment effects in terms of total efficacy rates and uric acid levels. Only the pain scores in the fire needling, bloodletting, and herbal medicine combination groups demonstrated significant improvement. Only four studies mentioned adverse reactions: one reported loss of appetite; three studies reported none. According to the Cochrane RoB tool, most studies showed either high or uncertain RoB. Conclusion: Heat stimuli during acupuncture could be effective for acute gout. However, as the included studies were regionally biased, more high-quality studies are needed to confirm the level of evidence.

Development of a Fire Human Reliability Analysis Procedure for Full Power Operation of the Korean Nuclear Power Plants (국내 전출력 원전 적용 화재 인간신뢰도분석 절차 개발)

  • Choi, Sun Yeong;Kang, Dae Il
    • Journal of the Korean Society of Safety
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    • v.35 no.1
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    • pp.87-96
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    • 2020
  • The purpose of this paper is to develop a fire HRA (Human Reliability Analysis) procedure for full power operation of domestic NPPs (Nuclear Power Plants). For the development of fire HRA procedure, the recent research results of NUREG-1921 in an effort to meet the requirements of the ASME/ANS PRA Standard were reviewed. The K-HRA method, a standard method for HRA of a domestic level 1 PSA (Probabilistic Safety Assessment) and fire related procedures in domestic NPPs were reviewed. Based on the review, a procedure for the fire HRA required for a domestic fire PSA based on the K-HRA method was developed. To this end, HRA issues such as new operator actions required in the event of a fire and complexity of fire situations were considered. Based on the four kinds of HFE (Human Failure Event) developed for a fire HRA in this research, a qualitative analysis such as feasibility evaluation was suggested. And also a quantitative analysis process which consists of screening analysis and detailed analysis was proposed. For the qualitative analysis, a screening analysis by NUREG-1921 was used. In this research, the screening criteria for the screening analysis was modified to reduce vague description and to reflect recent experimental results. For a detailed analysis, the K-HRA method and scoping analysis by NUREG-1921 were adopted. To apply K-HRA to fire HRA for quantification, efforts to modify PSFs (Performance Shaping Factors) of K-HRA to reflect fire situation and effects were made. For example, an absence of STA (Shift Technical Advisor) to command a fire brigade at a fire area is considered and the absence time should be reflected for a HEP (Human Error Probability) quantification. Based on the fire HRA procedure developed in this paper, a case study for HEP quantification such as a screening analysis and detailed analysis with the modified K-HRA was performed. It is expected that the HRA procedure suggested in this paper will be utilized for fire PSA for domestic NPPs as it is the first attempt to establish an HRA process considering fire effects.

Predicting the moment capacity of RC slabs with insulation materials exposed to fire by ANN

  • Erdem, Hakan
    • Structural Engineering and Mechanics
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    • v.64 no.3
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    • pp.339-346
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    • 2017
  • Slabs prevent harmful effects of fire that may occur in any floor. However, it is necessary to protect the slabs from fire. Insulation materials may be appropriate to protect reinforced concrete (RC) slab from elevated temperature. In the present study, a model has been developed in artificial neural network (ANN) to predict the moment capacity ($M_r$) of RC slabs exposed to fire with insulation material. 672 data were obtained for ANN model through author's prepared program. Input layer in model consisted of seven input parameters; such as effective depth (d), ratio of d'/d, thermal conductivity coefficient ($k_{insulation}$), insulation materials thickness ($L_{insulation}$), reinforcement area ($A_{st}$), fire exposure time ($t_{\exp}$), and concrete compressive strength ($f_c$). The predicted $M_r$ by ANN was consistent with the obtained $M_r$ by author. It is proposed to ease computational complexity in determining $M_r$ using ANN. The effects of using insulation material on the moment capacity in RC slabs were also investigated. Insulating material with low thermal conductivity has been found to be more effective for durability to high temperature.

Thermal Effects in the Pool Fire of Fuels(I) (석유류 POOL FIRE에 있어서의 열적인 영향(I))

  • 정국삼;강민호;이덕영
    • Journal of the Korean Society of Safety
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    • v.11 no.1
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    • pp.75-83
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    • 1996
  • This paper was concerned with pool fire about many used kerosene and diesel oil. In order to know the thermal effects of kerosene and diesel oil, temperature change in the pool fire of these fuels were obtained as a variation of combustion time and the tank's height and diameter by using the data acquisition system, And fuel combustion velocity were derived as a function of the diameter and wall thickness of tanks and combustion time. As a result, when the tank's height was 15㎝, the greater diameter the higher temperature rising regardless of tank's wall thickness and fuels. But, when the tank's height is 30㎝, temperature rising was not higher than 15㎝. Also, temperature rising in the pool fire of kerosene much higher than diesel oil. Kerosene's combustion velocity was about two times faster than diesel oil. And, kerosene's combustion velocity was increased according to the increasing of tank's diameter and combustion time. But, diesel oil's combustion velocity was a little increased or not. Surrounding temperature change of tank with the pool fire was obtained temperature distribution of 0∼35℃ according to the change of tank's diameter and distance from the tank's wall.

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Evaluating fire resistance of prestressed concrete bridge girders

  • Zhang, Gang;Kodur, Venkatesh;Hou, Wei;He, Shuanhai
    • Structural Engineering and Mechanics
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    • v.62 no.6
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    • pp.663-674
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    • 2017
  • This paper presents an approach for evaluating performance of prestressed concrete (PC) bridge girders exposed to fire. A finite element based numerical model for tracing the response of fire exposed T girders is developed in ANSYS. The analysis is carried out in three stages, namely, fire temperature calculation, cross sectional temperature evaluation, and then strength, deformation and effective prestress analysis on girders exposed to elevated temperatures. The applicability of the computer program in tracing the response of PC bridge girders from the initial preloading stage to failure stage, due to combined effects of fire and structure loading, is demonstrated through a case study, and validated by test data of a scaled PC box girder under ISO834 fire condition. Results from the case study show that fire severity has a significant influence on the fire resistance of PC T girders and hydrocarbon fire is most dangerous for the girder. The prestress loss caused by elevated temperature is about 10% under hydrocarbon fire till the girder failure, which can lead to the increase in deflection of the PC girder. The rate of deflection failure criterion is suggested to determine the failure of PC T girder under fire.