• Fire Science and Engineering
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• v.27 no.5
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• pp.32-37
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• 2013

This paper suggested to revise unreasonable national fire safety codes of sprinkler system. Also proposed to modify the definition of "the gridded sprinkler system" and to add "the feed main" in terms of the definition of the pipes. In order to operate the regulations of discharge pressure of the sprinkler head efficiently, this paper checked the minimum criteria of pressure and flow for the pipe schedule sprinkler system of NFPA 13 and suggested to establish the similar minimum demand criteria. It proposed to be amended properly the pressure calculation formular in the pressure tank system and to use the correct K value due to change in pressure unit and to use the [bar] as a unit of pressure for the sake of using the existing K-factor etc.

• Fire Science and Engineering
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• v.20 no.2 s.62
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• pp.8-13
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• 2006

Numerical simulations were carried out for a fire in a clean room to confirm needs of a smoke control system and a sprinkler system, and to investigate a possible smoke spread-out. For a 1 MW methanol fire in a space of $39m{\times}13m$ floor and 4 m high, smoke spread-out was scrutinized for failure of the sprinkler system and/or the smoke control system. It was shown that the smoke control system removes smoke safely without the sprinkler system and that the sprinkler system is required to suppress smoke generation and spread of the fire, and to remove the smoke quickly. It was also confirmed that highly reliable sprinkler heads and automatic fire detection system are required for the sprinkler and smoke control systems.

• Fire Science and Engineering
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• v.28 no.2
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• pp.40-47
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• 2014

Design by means of the pipe schedule sprinkler system of NFSC 103 results in insufficient pressure and flow rate about 50% sprinklers of operating area. In order to solve the lack of pressure and flow rate, This paper compare and analyzed NFSC 103, National Fire Safety Code of Sprinkler System, with NFPA 13, Standard for the Installation of Sprinkler Systems, and suggested an alternative proposal. Changing the flow rate of each sprinkler from existing 80 L/min to 120 L/min, All of the operating sprinklers are fulfilled the minimum demands on 80 L/min and 1 bar. It is easy for everyone to design of the pipe schedule sprinkler system and it is optimum method that all sprinklers in design area are satisfied with minimum criteria.

• Nuclear Engineering and Technology
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• v.55 no.4
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• pp.1571-1584
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• 2023

In this study, a numerical analysis was performed as part of an international joint research project to reproduce a real cable tray fire that occurred in the heater bay area of the turbine building of a nuclear power plant. A sensitivity analysis was performed on various input parameters to derive results consistent with the sprinkler activation time obtained from the fire event analysis. For all sensitive parameters, the normalized sprinkler activation time correlated well with the power function of the normalized sprinkler height. A correlation equation was developed to identify the sprinkler activation time at any location when determining the slope or fire growth rate under the conditions assuming a linear or t-squared heat release rate (HRR) time curve. Various cable fire growth assumptions were used to determine which assumption was better to provide the prediction coincident with the information given from the fire event analysis in terms of the sprinkler activation time and total energy generated from cables damaged by fire. In the comprehensive analysis of all the sensitive parameters, the standard deviation of the input parameters increased as the sprinkler height decreased. Within the range of the sensitivity parameter values given in this study, when considering all sprinkler heights, the standard deviation of the cable model change was the largest and that of the overhang position change was the smallest.

• Journal of the Korean Professional Engineers Association
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• v.4 no.14
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• pp.49-65
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• 1971

• Journal of the Korean Society of Safety
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• v.32 no.4
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• pp.16-21
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• 2017

The sprinkler system is a basic fire extinguishing system that uses water as an extinguishing agent. In order to evaluate the fire extinguishing performance of the sprinkler system, information such as the discharge angle, discharge speed, discharge pressure, flow rate, and water droplet size of the installed head are required. However, there is a lack of research on droplets size compared to other requirements. In this study, to evaluate the extinguishing characteristics of sprinkler system, the droplet size distribution was measured for various types of sprinkler heads actually used. The size of the droplet was measured using laser diffraction method. The 50% cumulative volume distribution ($D_{v50}$) according to discharge coefficient(K factor) was $540{\mu}m{\sim}695{\mu}m$ for K50, $542{\mu}m{\sim}1,192{\mu}m$ for K80, $980{\mu}m{\sim}1,223{\mu}m$ for K115 and $1,188{\mu}m{\sim}1,234{\mu}m$ for K202. Based on the measured results, the vaeiance of the droplet particle distribution and the distribution ($D_{v50}$) according to discharge coefficient(K factor) was $540{\mu}m{\sim}695{\mu}m$ for K50, $542{\mu}m{\sim}1,192{\mu}m$ for K80, $980{\mu}m{\sim}1,223{\mu}m$ for K115 and $1,188{\mu}m{\sim}1,234{\mu}m$ for K202. Based on the measured results, the vaeiance of the droplet particle distribution and the Rosin-Rammler index value are presented. As a result of the fire simulation with FDS, it was confirmed that the performance difference occurs according to the water droplet size distribution even when the same amount of water is used. Therefore, the extinguishing performance of the sprinkler system should be evaluated considering the droplet size distribution according to the sprinkler head type.

• Fire Science and Engineering
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• v.27 no.3
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• pp.14-19
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• 2013

National Fire Safety Code 103 regulates that all operating sprinkler in design area must be discharged 1 bar or more pressure and release 80 lpm or more flow rate as minimum criteria. NFSC103 also provides that the number of operating sprinkler in design area is 10, 20, 30 according to the building classification and the total flow rate is 800, 1,600, 2,400 lpm depending on 80 lpm per sprinkler. If sprinkler system is designed as above provisions, the pressure and the flow rate accordingly become smaller than the minimum criteria about 50 % sprinklers. It results in serious consequence that the purpose of sprinkler system as initial fire reaction equipment is failure. In order to solve these problems, It is desirable that Performance-based fire protection design, hydraulic calculation, is carried out to all sprinkler system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.43-48
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• 2010

In this paper, structural analysis was conducted by designing a ultra low volume sprinkler applied to spray liquid and applying a ANSYS commercial code for three dimensional finite element method to the ultra low volume sprinkler. Based on this numerical structural analysis, stress, strain and total deformation were obtained and the structure improvement of the ultra low volume sprinkler was made along with improved productivity and shorten design period.

• Fire Science and Engineering
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• v.15 no.2
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• pp.46-52
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• 2001

To evaluate the usability of compartment fire models for predicting sprinkler response time, fire experiment was conducted and measured sprinkler response time. The experimental data was compared with zone model "FASTLite"and field model "FDS"and field Model "SMARTFIRE" A Compartment fire conducted in a 2.4 m by 3.6 m by 2.4 m ISO 9705 room and measured H.R.R was approximately 100.3 kW. In test, Sprinkler activation temperature used is $72^{\circ}c$ and responded at 198s. The output of FASTLite, SMARTFIRE and, FDS for this fire scenario were 209s, 183s, and 192s, respectively. As a results, prediction using FDS model approached to that of test very closely and other models showed good approximated results also.

• Journal of the Korean Society of Safety
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• v.5 no.3
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• pp.51-55
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• 1990

This study describes the engineering approach adopted to investigate sprinkler head during the early stage of a fire when they are subjected to convective heating and low gas velocities. Comparions are made between the parameters derived using basic methods, ie. ramp test, for evaluating sprinkler parameters(time constant, response time index) is illustrated. Evidence is presented that the propotion of heat loss by conduction from a sprinkler element may very typically employed in the rate of rise test. This fact alone may justfy the precautionary need to perform a limited number of rate of rise tests to confirm a sprinklers capacity to function correctly in reasonably unfavourable yet realistic conditions. The work is aimed primarily at meeting the needs of sprinkler industry.