• Title/Summary/Keyword: fire compartment

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Effects of Change in Heat Release Rate on Unsteady Fire Characteristics in a Semi-Closed Compartment (반밀폐된 구획에서 발열량 변화에 따른 비정상 화재특성)

  • Hwang, Cheol-Hong
    • Fire Science and Engineering
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    • v.26 no.2
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    • pp.75-83
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    • 2012
  • An experimental study was conducted to investigate the effects of change in heat release rate on unsteady fire characteristics of under-ventilated fire in a semi-closed compartment. A standard doorway width of the full-scale ISO 9705 room was modified to 0.1 m and the flow rate of heptane fuel was increased linearly with time using a spray nozzle located at the center of enclosure. Temperature, heat flux, species concentrations and heat release rate were continuously measured and then global equivalence ratio (GER) concept was adopted to represent the unsteady thermal and chemical characteristics inside the compartment. It was observed that there was a significant difference in unsteady behavior between global and local combustion efficiency, and the GERs predicted by ideal and measured heat release rate were also shown different results in time. The unsteady behaviors of temperature, heat flux and species concentrations were represented well using the GER concept. It was important to note that CO concentration was gradually decreased with the increase in GER after reaching its maximum value in the range of 2.0~3.0 of global equivalence ratio. In addition, the experimental data on unsteady thermal and chemical behaviors obtained in a semi-closed compartment will be usefully used to validate a realistic fire simulation.

A Comparative Analysis on the building Fire Protection Standards of Korea and Japan (한·일 건축물 방화구획 기준 비교분석)

  • Shin, Yeoung-Deok;Han, Ji-Woo;Lee, Byeong-Heun;Kwon, Young-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.05a
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    • pp.4-5
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    • 2019
  • Smoke and fire spread throughout the building as a result of problems in the fire prevention section of Uijeongbu Apartment Fire in 2015 and Jecheon Sports Center Fire in 2017 in Korea, causing a number of casualties. It is believed that the fire compartment standards need to be reviewed as the fire in recent buildings continues to show problems. In this study, a comparative analysis was conducted on the fire prevention zone standard with Japan to improve the fire compartmente standard in Korea.

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Analysis of Prediction Results and Grid Size Dependence According to Changes in Fire Area (화원면적 변화에 따른 격자 크기 의존도 및 예측결과 분석)

  • Yun, Hong-Seok;Hwang, Cheol-Hong
    • Fire Science and Engineering
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    • v.33 no.6
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    • pp.9-19
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    • 2019
  • In fire simulations for building fire safety evaluation, changes in the fire area and grid size can significantly influence the prediction results. Therefore, the effects of area changes of the fire source with identical maximum heat release rates on the prediction results of a compartment fire were investigated. The dependence of the prediction results on the grid size using the identical fire area was also examined. No significant changes were observed in the thermal and chemical characteristics of the fires with variable grid sizes, even though the fire area was changed when six or more grids were set based on the fire diameter. In addition, changes in the fire area caused significant differences in the prediction of major physical quantities associated with available safety egress time (ASET) within a compartment. However, the fire area changes did not considerably influence the overall fire characteristics outside the compartment after reaching a certain distance from the opening.

Prediction of Flash Over and Characteristics Operation of Sprinkler RTI in Compartme nt Fire (아파트형 공장 구획 공간 화재시 Flash Over 예측과 Sprinkler RTI 작동특성)

  • 진복권;정수일
    • Journal of the Korea Safety Management & Science
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    • v.5 no.1
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    • pp.1-12
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    • 2003
  • In this paper, computer simulation was used for researching into the estimate of flash over result from compartment fire and the characteristics operation of sprinkler RTI. Computing simulation, we analyzed and verified the path of the flame in compartment fire and the adaptation of sprinkler system concerned with sprinkler RTI.

An Experimental Study on Relationship Between Global Equivalence Ratio and Fire Characteristics in Full-Scale Compartment Fires (실제 규모의 구획화재에서 총괄당량비와 화재특성의 상관관계에 관한 실험적 연구)

  • Hwang, Cheol-Hong;Park, Chung-Hwa;Ko, Gwon Hyun;Lock, Andrew
    • Journal of the Korean Society of Combustion
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    • v.15 no.3
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    • pp.32-39
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    • 2010
  • An experimental study was conducted to investigate the relationship between global equivalence ratio(GER) and fire characteristics in an ISO 9705 room. Heptane fuel was burned with different fuel flow rates and doorway widths in order to force the room to be placed in different GER conditions. It was observed that after the onset of under-ventilated fire conditions, temperature and unburned fuel components such as CO and soot increased with increasing heat release rate (HRR), regardless of the doorway width. From the analysis of local mixture fraction, it was reconfirmed that the inclusion of soot production in the product composition was very important to predict accurately the chemical conditions inside the compartment, particularly for the under-ventilated fire conditions. In addition, the local equivalence ratio (LER) was directly proportional to the GER with a unit gradient regardless of doorway width when the soot production was included in the chemical products. This finding provided an important potential that the GER could be used to correlate the local thermal and chemical environment measured at the upper layer of a full-scale enclosure when soot was included.

Application Study of Design Fire Curves for Liquid Pool Fires in a Compartment (구획실 내 액체 풀화재에 대한 디자인 화재곡선 적용 연구)

  • Baek, Bitna;Oh, Chang Bo;Lee, Eui Ju;Nam, Dong-Gun
    • Fire Science and Engineering
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    • v.31 no.4
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    • pp.43-51
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    • 2017
  • In this study, new design fire curves were suggested for the utilization in fire simulations. Numerical simulations with the Fire Dynamics Simulator (FDS) were performed for the n-octane and n-heptane pool fires in the ISO 9705 compartment to evaluate the prediction performance of the previous quadratic, exponential design fire curves and newly suggested ones. The numerical results were compared with the experimental temperature and concentrations of $O_2$ and $CO_2$. The numerical results with the previous quadratic and exponential curves showed slow increase and decrease trend than experiments. However, the numerical results with the newly suggested 2 design fire curves showed more similar variation trend in temperature, $O_2$ and $CO_2$ concentrations than the quadratic and exponential curves. It was found that the newly suggested design fire curves can be possibly used in the numerical simulation of fires in a practical respect.

A Study of Numerical Reproducibility for the Backdraft Phenomena in a Compartment using the FDS (FDS를 이용한 구획실 백드래프트 현상의 수치적 재현성에 관한 연구)

  • Park, Ji-Woong;Oh, Chang Bo;Choi, Byung Il;Han, Yong Shik
    • Journal of the Korean Society of Safety
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    • v.28 no.6
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    • pp.6-10
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    • 2013
  • A numerical reproducibility of the backdraft phenomena in a compartment was investigated. The prediction performance of two combustion models, the mixture fraction and finite chemistry models, were tested for the backdraft phenomena using the FDS code developed by the NIST. The mixture fraction model could not predict the flame propagation in a fuel-air mixture as well as the backdraft phenomena. However, the finite chemistry model predicted the flame propagation in the mixture inside a tube reasonably. In addition, the finite chemistry model predicted well the backdraft phenomena in a compartment qualitatively. The flame propagation inside the compartment, fuel and oxygen distribution and explosive fire ball behavior were well simulated with the finite chemistry model. It showed that the FDS adopted with the finite chemistry model can be an effective simulation tool for the investigation of backdraft in a compartment.

Numerical Study on Convective Heat Transfer in a Compartment Fire - I. Evaluation of Numerical Method and Natural Convection- (실내화재에 있어서의 대류열전달에 관한 수치연구 - I. 수치법 검증과 자연대류-)

  • 박외철;고경찬
    • Journal of the Korean Society of Safety
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    • v.14 no.2
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    • pp.26-31
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    • 1999
  • In a compartment fire, convective heat transfer dominates spread of the fire and smoke movement before flash-over occurs, and natural convection is very important in particular when there are no openings. The finite volume method with SIMPLE algorithm was applied to a square cavity similar to a compartment without an opening. The objectives of this study are to evaluate the method and to simulate natural convection from a hot body in the cavity. The results without the hot body showed an excellent agreement with those of previous studies. Streamlines, isotherms and Nusselt numbers were computed for different Rayleigh numbers.

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Validation of FDS for Predicting the Fire Characteristics in the Multi-Compartments of Nuclear Power Plant (Part II: Under-ventilated Fire Condition) (원자력발전소의 다중 구획에서 화재특성 예측을 위한 FDS 검증 (Part II: 환기부족화재 조건))

  • Mun, Sun-Yeo;Hwang, Cheol-Hong;Park, Jong Seok;Do, Kyusik
    • Fire Science and Engineering
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    • v.27 no.2
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    • pp.80-88
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    • 2013
  • The validation of Fire Dynamics Simulator (FDS) was conducted for the under-ventilated fire in well-confined multi-compartments representative of nuclear power plant. Numerical results were compared with experimental data obtained by the OECD/NEA PRISME project. The effects of the numerical boundary conditions (B.C.) in ventilated system and the flame suppression model applied within FDS on the thermal and chemical environments inside the compartment were discussed in details. It was found that numerical B.C. on the vent flow resulting from over-pressure at ignition and under-pressure at extinction should be considered carefully in order to predict accurately the species concentrations rather than temperatures and heat fluxes inside the multi-compartment. The default information of suppression model applied within FDS resulted in artificial phenomena such as flame extinction and re-ignition, and thus the FDS results on the under-ventilated fire showed good agreement with the experimental results as the modified suppression criteria of the fuel used was adopted.