• Fire Science and Engineering
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• v.34 no.4
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• pp.107-114
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• 2020

With the development of the national industry, the importance of the elderly and children such as the elderly, disabled, and children is recognized. Similarly, the number of facilities for the elderly and children is increasing. Fires at facilities for the elderly and children cause heavy casualties. In response to these events, it is essential to activate fire alarms promptly and accurately and to secure evacuation routes. In this study, the laws and statistics related to facilities for elderly and children were reviewed, and problems with legal terms-such as elderly, children, others, unwanted alarm of fire alarm systems, blind spots of fire compartment standards, securing evacuation routes, and absence of standards for life safety rescue organizations-were identified. As an improvement measure, the legal definitions of similar terms-such as elderly, children, unwanted alarm checklist, and establishment of standards for fire prevention compartment-and introduction of other terms-evacuation elevators, the establishment of standards for life-safety rescue organizations, and provision of flame retardation objects for evacuees-were proposed.

• Fire Science and Engineering
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• v.33 no.4
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• pp.50-58
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• 2019

The prediction performance of B-RISK was evaluated for the fire behaviors of combustibles in a compartment using Fire Dynamics Simulator (FDS). First of all, to predict the heat release rate (HRR) for two combustible sets, the HRR for one combustible set and the design fire curve were used as input values for B-RISK. Comparing results of B-RISK calculations with experimental data for two combustible sets, it was found that B-RISK results predicted insufficiently for fire growth rate of experimental data but there was good agreement for maximum HRR and total HRR with the experimental data. And the B-RISK results were used for input values of FDS to evaluate the fire behaviors of B-RISK results. Comparing results of FDS calculations with experimental data, the simulation results showed that the temperature and concentrations of O₂, CO₂ in the fire growth phase were different from the experimental data. However, when using the B-RISK result for percentile 70%, the simulation results sufficiently predicted the overall fire behaviors.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.3
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• pp.235-244
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• 2007

In the case of the fire outburst within a partitioned space, it can disappear inside it through smoldering process if the fire cannot obtain sufficient imflammability. On the contrary, if it obtains it, the fire is not restricted within the room, spreading to the higher levels beyond outside windows and the compartment room. The method to prevent the fire spread through windows is considered to build a balcony or equip with sprinkler facilities. This case study is to identify which effects and controlibility a balcony brings about on the spread of fire through a full scale model experiment. In order to understand the effects of fire spread on the upper levels of the room on fire by changing the length of balcony, the temperature was measured, radiant heat was investigated, and products of combustion were analyzed. The result showed that when fire occured, longer length of the balcony, which linked to the outside wall of the apartments, led to the blocking of the fire spread, lower level of radiant heat, and significantly less transfer of toxic gases, and the driving force of the outburst of flame was identified as the attractive force due to the turbulence of uncombusted gases, which exist on the upper level of the outbursting flame.

• International Journal of High-Rise Buildings
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• v.7 no.4
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• pp.375-387
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• 2018

This paper presents a review on progressive collapse mechanism of steel framed buildings exposed to fire. The influence of load ratios, strength of structural members (beam, column, slab, connection), fire scenarios, bracing systems, fire protections on the collapse mode and collapse time of structures is comprehensively reviewed. It is found that the key influencing factors include load ratio, fire scenario, bracing layout and fire protection. The application of strong beams, high load ratios, multi-compartment fires will lead to global downward collapse which is undesirable. The catenary action in beams and tensile membrane action in slabs contribute to the enhancement of structural collapse resistance, leading to a ductile collapse mechanism. It is recommended to increase the reinforcement ratio in the sagging and hogging region of slabs to not only enhance the tensile membrane action in the slab, but to prevent the failure of beam-to-column connections. It is also found that a frame may collapse in the cooling phase of compartment fires or under travelling fires. This is because that the steel members may experience maximum temperatures and maximum displacements under these two fire scenarios. An edge bay fire is more prone to induce the collapse of structures than a central bay fire. The progressive collapse of buildings can be effectively prevented by using bracing systems and fire protections. A combination of horizontal and vertical bracing systems as well as increasing the strength and stiffness of bracing members is recommended to enhance the collapse resistance. A protected frame dose not collapse immediately after the local failure but experiences a relatively long withstanding period of at least 60 mins. It is suggested to use three-dimensional models for accurate predictions of whether, when and how a structure collapses under various fire scenarios.

• Fire Science and Engineering
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• v.24 no.3
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• pp.131-138
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• 2010

Experimental and numerical studies were conducted to investigate the thermal and chemical characteristics of heptane fires in a full-scale ISO 9705 room. Representative fire conditions were considered for over-ventilated fire (OVF) and under-ventilated fire (UVF). Fuel flow rate and doorway width were changed to create OVF and UVF conditions. Detailed comparisons of temperature and species concentrations between experimental and numerical data were presented in order to validate the predictive performance of FDS (Fire Dynamic Simulator). The OVF and UVF were explicitly characterized with distributions of temperature and product formation measured in the upper layer, as well as combustion efficiency and global equivalence ratio. It was shown that the numerical results provided a quantitatively realistic prediction of the experimental results observed in the OVF conditions. For the UVF, the numerically predicted temperature showed reasonable agreement with the measured temperature. The predicted steady-state volume fractions of $O_2$, $CO_2$, CO and THC also agreed quantitatively with the experimental data. Although there were some limitations to predict accurately the transient behavior in terms of CO production/consumption in the UVF condition, it was concluded that the current FDS was very useful tool to predict the fire characteristics inside the compartment for the OVF and UVF.

• Fire Science and Engineering
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• v.26 no.5
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• pp.105-110
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• 2012

The present study investigates the effects of sprinkler spray on fire driven flow characteristics in a compartment based on numerical approach. The FDS (Fire Dynamics Simulator), a widely used fire field model, was used to simulate the fire induced flow and sprinkler spray and a series of grid independence tests have been performed to obtain the optimal grid size. In order to validate the result predicted by FDS model, the calculated results were compared with experimental results of Magnone et al.. The FDS model matches quite well to experiments in temperature profile and mass flux through doorway, however, the discrepancy between the FDS model and experiments increases with increasing water discharge rate. As with previous study, the FDS calculation also shows a decrease of mass flow rate of combustion products through doorway due to the sprinkler spray. This study can contribute to optimize the sprinkler system design and verify the validity of the fire field model with sprinkler spray.

• Fire Science and Engineering
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• v.32 no.6
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• pp.28-33
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• 2018

To measure the full scale fire test and heat release rate of bed mattresses according to the building compartment space, a fire test was performed using the Standard test method to determine the heat release rate of mattresses and mattress sets (KS F ISO 12949: 2011). Both test locations showed similar fire growth until approximately 3 minutes after burner ignition. After 3 minutes, the heat release rate in the test room was higher than the open calorimeter. For bed mattresses (SS), the maximum heat release rate in the open calorimeter was 735 kW and the maximum heat release rate in the test room was 992 kW. For bed mattresses (Q), the heat release rate in the test room increased more rapidly than the open calorimeter. The maximum heat release rate in the open calorimeter was 1,087 kW (346 s) and the maximum heat release rate in the test room was 2,127 kW (287 s). The difference between the maximum heat release rate and the measurement time according to the test location was confirmed.

• Fire Science and Engineering
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• v.24 no.5
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• pp.128-135
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• 2010

In this study, a mixture fraction analysis was performed to investigate the characteristics of chemical species production in compartment fires burning hydrocarbon fuels such as methane, heptane, and toluene. A series of fire experiments was conducted in the ISO 9705 standard room, and gas species concentration and soot fraction were measured at two locations in the upper layer of the compartment. The mass fractions of measured chemical species, such as unburned hydrocarbons (UHC), carbon monoxide (CO), carbon dioxide ($CO_2$), oxygen ($O_2$), and soot were presented as a function of mixture fraction and compared with state relationships based on the idealized reaction of hydrocarbon fuels. The mixture fraction analysis made it possible to rearrange hundreds of species measurements, which were done under various fire conditions and at two locations of the upper layer, in term of the unified parameter, i.e. the mixture fraction. The results also showed that inclusion of soot in the mixture fraction calculation could improve the performance of analysis, especially for the sooty fuels such as heptane and toluene.

• Fire Science and Engineering
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• v.32 no.1
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• pp.16-23
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• 2018

In a closed-compartment with various configurations, the correlation that can predict the maximum heat release rate (HRR) with the changes in internal volume and fire growth rate was investigated numerically. The volume of the compartment was controlled by varying the length ratio based on the bottom surface shape of the ISO 9705 fire room, where the ceiling height was fixed to 2.4 m. As a main result, the effect of a change in ceiling height on the maximum HRR was examined by a comparison with a previous study that considered the change in ceiling height. In addition, a more generalized correlation equation was proposed that could predict the maximum HRR in closed-compartments regardless of the changes in ceiling height. This correlation had an average error of 7% and a maximum error of 19% for various fire growth rates when compared with the numerical results. Finally, the applicability of the proposed correlation to representative fire compartments applied to the domestic performance-based design (PBD) was examined. These results are expected to provide useful information on predicting the maximum HRR caused by flashover in closed-compartments as well as the input information required in a fire simulation.

• Journal of the Korea Institute of Building Construction
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• v.14 no.2
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• pp.143-149
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• 2014

Recently, the structure system for apartment buildings in Korea has been changing from wall to post-beam structure. This study examines the fire resistance and sound insulation of light-weight dried wall, a component of post-beam structure. For the fire resistance and sound insulation in Korea, the Compartment wall of apartment house in the case of building regulation has regulations specify the detailed requirement of fire compartment walls in apartment, but do not specify that of interior walls. This study proposes the fire resisting rate of the interior wall into three grades in which the highest grade requires fire resistance of 30 minutes and also proposes the requirement of sound insulation performance into three grades in which the lowest grade requires 35dB.