• Fire Science and Engineering
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• v.29 no.2
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• pp.84-91
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• 2015

The purpose of this study is to suggest the reasonable model of the caliber in suction nozzle, the pressure of suction nozzle, and the flow rate about foam system of line proportioner type using in the pumpcar. To test this, the experimental study was accomplished on the ground of the standards for the Performance Certification and Product Inspection of Foam Fire-extinguishing Chemical Mixing Machine. Aqueous Film Forming Foam in 3% and pipe type air foam nozzle with line proportioner FE 40 type were used. Test result showed that the pressure of suction nozzle within the limits between 0.25 MPa and 0.35 MPa was appropriate when the caliber in suction nozzle is 4 mm. Also, the pressure of suction nozzle within the limits between 0.45 MPa and 0.60 MPa was appropriate in the higher pressure than 4 mm when the caliber in suction nozzle is 5 mm.

• Fire Science and Engineering
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• v.33 no.4
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• pp.77-82
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• 2019

Fire extinguishing systems are essential equipment in all indoor facilities to address unexpected fire scenarios, and appropriate fire extinguishing agent should be used depending on the place and object to protect. Among these, gaseous fire-extinguishing systems are used to protect electronic equipment. Therefore, inert gases that do not undergo chemical reactions are used mainly in those systems. On the other hand, recently, owing to the high integration of electronic equipment, there are some cases, in which large noise generated from gaseous systems damage the electronic equipment. In this study, numerical analysis of the discharge noise with various nozzle contraction angles was carried out to improve the gas fire extinguishing system. Numerical analysis was carried out using ANSYS FLUENT ver 18.1. The causes of the noise were elucidated using the swirl distribution. The noise level of the modified model was reduced by approximately 6 dB compared to the reference model, which is similar to the result of a previous study, confirming the validity of the method.

• Fire Science and Engineering
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• v.33 no.3
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• pp.37-43
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• 2019

In this study, ethanol pool fire extinguishing experiments were conducted using a twin-fluid nozzle. Ethanol pool fires, 5.027×10^-3 ㎡ and 1.131×10^-2 ㎡ in size (80 mm and 120 mm in fuel pan diameter, respectively), were tested, and the flow rates supplied to the twin-fluid nozzle for fire extinguishing were 156-483 g/min and 20-70 L/min for water and air, respectively. The heat release rate increased with increasing fire source area, and heat release rates of 5.027×10^-3 ㎡ and 1.131×10^-2 ㎡ in size were measured to be 1.01 kW and 5.51 kW, respectively. For both fire source cases in the present experimental range, regardless of the water flow rates, the ethanol fires were extinguished successfully under the high air flow rate condition (e.g., above 40 L/min). On the other hand, under all water flow rate conditions, the fire extinguishing time and water consumption decreased with increasing air flow rate, which were approximately 23 s and 185 g under high air flow rate conditions (e.g., above 50 L/min), respectively. Based on the water consumption per heat release rate, the present experimental data were compared with the previous ones using a single-fluid nozzle, and it was found that the twin-fluid nozzle could extinguish a fire with a lower water consumption than a single-fluid one.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.4
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• pp.392-398
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• 2009

Theoretical thrust equations for the diverse nozzle expansion condition were derived. By using the obtained thrust equations, parametric studies were carried out to estimate the effect of pressure exponent, minimum operation pressure, ambient pressure and extinguishment pressure on thrust modulation performance in pintle-nozzle solid rocket motors. Analysis results showed that thrust turndown ratio can be easily attained by small nozzle-throat area variation at high pressure exponent, low minimum operation pressure, high ambient pressure and high extinguishment pressure condition. At those conditions, the highest chamber pressure to obtain the intended thrust turndown ratio can be minimized.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.11a
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• pp.167-168
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• 2013

본 연구에서는 미분무수시스템의 소화성능을 향상하기 위하여 노즐을 개발하고, 첨가제를 혼합하여 보다 높은 소화성능을 갖는 미분무수시스템을 개발하였다. 개발된 미분무수시스템의 소화성능을 분석하기 위하여 FM 5560(Approval Standard for Water Mist Systems)에 규정되어 있는 화재실험챔버를 이용하여 실험을 실시하고 소화성능을 분석하였다. 그 결과 본 연구의 미분무수시스템은 소화성능이 우수한 것으로 나타났다.

• Fire Science and Engineering
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• v.16 no.2
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• pp.59-69
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• 2002

The conventional fire extinguishing gas-agent system has a configuration in which the gas-agent comes out of a cylindrical container having vertically settled shape. However, in this study a horizontally installed container of a piping shape having a cylinder of the same shape with a cylinder valve and a discharge nozzle was used, and the relationship between orifice size of nozzle and discharge rate of gas-agent was investigated through various experiments including the measurement of discharge rate under different ambient-temperature conditions. In such experiments, HCFC Blend A was used without super-pressurization by nitrogen. From this research, it was observed that statutory discharge duration of 10 seconds can be met if the relatively large size of the valve and the nozzle orifice were properly selected.

• Fire Protection Technology
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• s.33
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• pp.27-34
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• 2002

• Fire Protection Technology
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• s.36
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• pp.26-33
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• 2004

• Fire Science and Engineering
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• v.26 no.1
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• pp.1-9
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• 2012

Since accommodation, public space and service areas where people stay for all day occupy about 70% of a huge cruise ship, they have to be protected from the fire. International Maritime Organization has resolved that a water mist system should be equipped in this cruise ship according to SOLAS II-2 Reg. 10.6 and FSS code Ch. 7. The water mist system consists of mist nozzles, pressure vessels, section valves and pump unit etc. In particular, the water mist nozzles should be recognized by fire tests in accordance with IMO Res. MSC 265(84). In this study, the fire tests for cabin, corridor, public space and storage area have been conducted to develop the water mist nozzles appropriate to the regulation. Totally 5 types of nozzles were developed and have satisfied the whole performance requirements.

• Fire Science and Engineering
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• v.34 no.2
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• pp.147-155
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• 2020

This paper presents a study on the development of a fire extinguishing agent and extinguishing system for an energy storage system (ESS) fire. The fire extinguishing agent designed to extinguish an ESS fire is a highly permeable fire extinguisher that reduces the surface tension and viscosity while bringing about cooling action. This is the main extinguishing effect of this type of wetting agent, which displays the characteristics of fire extinguishing agents used for penetrating the battery cells inside the ESS module. For the fire extinguishing system, a local application system was designed to suppress fire on a rack-by-rack basis. A 360° rotating nozzle was inserted into the rear hall of the ESS module, and general nozzles were installed in the rack to maximize the fire extinguishing effect. The fire extinguishing agent was strongly discharged by virtue of the gas release pressure. Experiments on fire suppression performance with ESS module 1 unit and module 3 units showed that all visible flames were extinguished in 8 s and 9 s, respectively, by the fire extinguishing agent. In addition, based on confirming reignition for 600 s after the fire extinguishing agent was exhausted, it was confirmed that the ESS fire was completely extinguished without reignition in all fire suppression performance experiments.