• Title/Summary/Keyword: Fire smoke

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Analysis of Optical Properties of Fire Smoke and Non-fire Smoke for Reduction of Nuisance Alarm (장애경보 방지를 위한 연소 연기입자와 비연소 연기입자의 광 특성 분석)

  • Jee, Seung-Wook
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.10
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    • pp.49-55
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    • 2014
  • This paper is basic study for development of an advanced photoelectric type smoke detector that has high reliability by reducing the occurrence of nuisance alarms. This paper was attempted to distinguish optical characteristics of the typical fire smoke particle and non-fire smoke particle. According to UL 268 standards, three types of test fires (the paper, the wood and the flammable liquid) were used in this paper for measurement of the fire smoke particles, and the water vapor and the cigarette smoke that were known as the main cause of the nuisance alarms were also used for the non-fire smoke particles. A smoke detection chamber was created, which was equipped with one light source and several light sensors for enabling simultaneous detection of light extinction and scattering, respectively. This paper analyzes the optical characteristics of each smoke particle using this chamber.

A evaluation study of a fire smoke diffusion delay device installed in a great depth underground double deck tunnel (대심도 복층터널에 설치 가능한 화재연기 확산지연장치 성능 평가 연구)

  • Shin, Tae-Gyun;Moon, Jung-Joo;Yang, Yong-Won;Lee, Yun-Taek
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.1
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    • pp.225-234
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    • 2018
  • Domestic urban areas are experiencing serious traffic congestion problems due to continuous population growth and increased traffic volume. In order to solve the problem of traffic congestion, the study of great depth underground double deck tunnels using underground space is being actively carried out in the urban areas. The characteristics of great depth underground double deck tunnels are low in cross section, so the spread of fire smoke is expected to spread faster than the road tunnel in case of fire. Therefore, it is necessary to provide a fire smoke delay device which delays the spread of fire smoke when a fire occurs in a tunnels. In the previous study, the diffusion effect was analyzed according to the blocking area when the fire smoke spread delay device was operated through the 3D CFD in the study of preventing the smoke spread in the case of the tunnel fire. A study on fire smoke diffusion delay device using spring elasticity which is excellent in applicability to a tunnel and economical value is studied. In this study, fire smoke spread delay system was developed to fire smoke delay was experimentally analyzed. Fire smoke delay effect of fire smoke delay device appeared. Therefore, it is considered that the can minimize the damage of the victims when installed in the great depth underground double deck tunnels.

How Visual-Field Obstruction from Fire Smoke Influences a Resident's Necessary Time to Reach Fire Escape and Evacuation Route in a High-rise Apartment Housing (연기발생으로 인한 시야장애가 초고층 공동주택 거주자의 피난계단실 진입시간과 피난경로에 미치는 영향)

  • Seo, Sang-Mok;Choi, Jun-Ho;Hong, Won-Hwa
    • Journal of the Korean housing association
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    • v.19 no.5
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    • pp.103-110
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    • 2008
  • The purpose of this study is to know how visual-field obstruction from fire smoke influences a resident's necessary time to reach fire escape and evacuation movement in a high-rise apartment housing. Generally, fire smoke not only gives visual-field obstruction and breath troubles to residents but interrupts their evacuation behavior. If a fire smoke layer is formed in the core department when evacuee enters at the evacuation staircase until, residents will be made to undergo a range of vision obstacle. In order to set a situation like that, participants wore eye bandage which had been made especially before the experiment. Also as a comparative standard, through no.1442 Japanese construction ministry notices about the building evacuation safety verification method, this study calculated smoke layer's dissent time and evacuation time. Then to compare with the former, the participants without an eye bandage joined a experiment once again. This study has understood how fire smoke effects on one's evacuation delay by analyzing residents' evacuation time to reach the staircase and movement route, however, in this study a toxic gas is not considered because it might threaten participants not to breathe.

A study on the fire smoke diffusion delay strategy in a great depth underground double deck tunnel junction (대심도 복층터널 교차로 화재연기 확산지연 방안 연구)

  • Shin, Tae-Gyun;Moon, Jung-Joo;Yang, Yong-Won;Lee, Yun-Taek;Han, Jae-Hee
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.21 no.1
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    • pp.115-126
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    • 2019
  • Recently, in order to solve the traffic congestion in urban areas and to improve the peripheral environment, research on the design and construction technology development of great depth underground double-deck tunnel is under way by using the underground space in the urban area. The network type double-deck tunnel is in the form of an intersection with a small cross section and a steep slope as per construction at the base of a flatland, so that the fire smoke spreads rapidly in case of fire, which is expected to cause damage of human life. Therefore, this study is analyzed the delay effect of fire smoke diffusion according to the installation and non - installation of delay system for fire smoke diffusion at the intersection. Fire fumes were delayed up to 270 seconds when the delay system for fire smoke diffusion was installed at the intersection and it is analyzed that the greater the operating area of the delay system for fire smoke diffusion, the more preventable the damage of human life of the intersection.

Algorithm for Detection of Fire Smoke in a Video Based on Wavelet Energy Slope Fitting

  • Zhang, Yi;Wang, Haifeng;Fan, Xin
    • Journal of Information Processing Systems
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    • v.16 no.3
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    • pp.557-571
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    • 2020
  • The existing methods for detection of fire smoke in a video easily lead to misjudgment of cloud, fog and moving distractors, such as a moving person, a moving vehicle and other non-smoke moving objects. Therefore, an algorithm for detection of fire smoke in a video based on wavelet energy slope fitting is proposed in this paper. The change in wavelet energy of the moving target foreground is used as the basis, and a time window of 40 continuous frames is set to fit the wavelet energy slope of the suspected area in every 20 frames, thus establishing a wavelet-energy-based smoke judgment criterion. The experimental data show that the algorithm described in this paper not only can detect smoke more quickly and more accurately, but also can effectively avoid the distraction of cloud, fog and moving object and prevent false alarm.

Numerical Simulation on Smoke Movement in Multi-Compartment Enclosure Fires under Pressurized Air Supply Conditions (급기가압 조건에서 복합 구획 공간 화재의 연기 거동에 대한 수치해석 연구)

  • Ko, Gwon Hyun
    • Fire Science and Engineering
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    • v.32 no.6
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    • pp.15-21
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    • 2018
  • This study examined the flow characteristics of fire smoke under pressurized air ventilation conditions by carrying out fire simulations on multi-compartment enclosure, including room, ancillary room and stair case. Fire simulations were conducted for the air-leakage test facility, which was constructed to measure the effective leakage area and aimed to improve the understandings of fire and smoke movement by analyzing the overall behaviors of fire smoke flow and pressure distributions of each compartment. The simulation results showed that the heat release rate of the fires was controlled sensitively by the amount of air supplied by the ventilation system. An analysis of the velocity distributions between the room and ancillary room showed that fire smoke could be leaked to the ancillary room through the upper layer of the door, even under pressurized air supply conditions. From these results, it was confirmed that the fire size and spatial characteristics should be considered for the design and application of a smoke control system by a pressurized air supply.

Fire-Smoke Detection Based on Video using Dynamic Bayesian Networks (동적 베이지안 네트워크를 이용한 동영상 기반의 화재연기감지)

  • Lee, In-Gyu;Ko, Byung-Chul;Nam, Jae-Yeol
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.4C
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    • pp.388-396
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    • 2009
  • This paper proposes a new fire-smoke detection method by using extracted features from camera images and pattern recognition technique. First, moving regions are detected by analyzing the frame difference between two consecutive images and generate candidate smoke regions by applying smoke color model. A smoke region generally has a few characteristics such as similar color, simple texture and upward motion. From these characteristics, we extract brightness, wavelet high frequency and motion vector as features. Also probability density functions of three features are generated using training data. Probabilistic models of smoke region are then applied to observation nodes of our proposed Dynamic Bayesian Networks (DBN) for considering time continuity. The proposed algorithm was successfully applied to various fire-smoke tasks not only forest smokes but also real-world smokes and showed better detection performance than previous method.

A Study for Pressure Difference and Critical Velocity by Pressurization of Elevator Shaft at High Rise Apartment (고층 공동주택의 승강로가압을 이용한 차압 및 방연풍속에 관한 연구)

  • Park, Kyung-Hwan;Yoon, Myong-O
    • Fire Science and Engineering
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    • v.25 no.4
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    • pp.89-93
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    • 2011
  • It is not recommended that elevator use for egress at (super) high rise buildings because elevator shaft main roles to spread of fire smoke. But in North America used to protect this area by elevator shaft pressurization. These tests are performed at high rise apartment to verify that elevator shaft pressurization can protect to spread of fire smoke or not. and verify to used for egress at fire. Pressurization at elevator shaft make pressure difference of 50 Pa all floor at 150 CMM because this method have low friction loss from air flow. Also when dwelling door and elevator door are opened that critical velocity is performed to protect of back-layering from fire room for escape routs by 180 CMM. Therefore through out these pressurization tests by elevator shaft are estimated to have less overpressure because supply air difference are low between to satisfy critical velocity at one door opened and maintain to pressure difference all doors closed. Finally we verified that disable or residual people can use elevator for egress at fire by elevator shaft pressurization.

A Comparative Study on the Toxicity Evaluation for Fire Smoke by FDS (FDS를 이용한 화재시 연소가스의 독성평가에 관한 비교 연구)

  • Jeong, Beom Jin;Lee, Keun Won
    • Journal of the Korean Institute of Gas
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    • v.19 no.1
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    • pp.38-44
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    • 2015
  • FDS (Fire Dynamics Simulator) is the most widely used computational fluid dynamics software in the fire safety engineering community, and it is applicable to various evaluations of fire growth and its effects. This study made use of a range of outputs from FDS simulation to predict FED (Fractional Effective Concentration) and FEC (Fractional Effective Concentration) levels which are often adopted to evaluate toxicity of fire smoke. As it is not possible to calculate these values directly from outputs of FDS, it was necessary to produce them by means of additional calculation procedures incorporating results of evacuation simulation. In this study, the latest version of FDS, which was recently updated in November 2013, was utilized for the purpose of quantitative comparison with the old version of FDS. As a result, it was found that they make about 10 percent difference on average in predicting FED and FEC levels for the cable fire case study.