Calculated assessment of effectiveness of class B fire suppression using automatic fire sprinkler systems

2021 ◽  
Vol 30 (3) ◽  
pp. 88-98
Author(s):  
L. T. Tanklevskiy ◽  
A. A. Tarantsev ◽  
I. A. Babikov ◽  
D. V. Polyakov
Keyword(s):  
Response Time ◽  
Fire Suppression ◽  
Sprinkler System ◽  
Assessment Model ◽  
Convection Flow ◽  
Fire Extinguishing ◽  
Sprinkler Systems ◽  
Heat Detector ◽  
Class B ◽  
Fire Sprinkler

Introduction. The problem of timely activation of fire sprinkler systems is highly relevant for effective fire suppression before the critical moment, when calculated values applied to extinguish the fire, become ineffective. A number of works address the problem of effective application of the fire sprinkler system to Class A fires. The application of such methods to Class B fires has not yet been considered.The model simulating a fire in a room with an automatic fire extinguishing system. The response time assessment model, developed by the co-authors for an automatic water-consuming fire sprinkler system, allows to identify the velocity of flame spreading over the surface of an HFL/CL spillage and the temperature rise rate in the ceiling area in the case of a B class fire.A sprinkler is triggered by the bulb bursting caused by the thermal effect produced by the ascending convection flow. A model has been developed to determine the response time of a fire sprinkler system exposed to the effect of a heat flow, caused by the Class B fire, on a heat-sensitive sprinkler bulb.Activation of a fire sprinkler system by the rate-of-rise heat detector. A model, designated for determining the activation time of a rate-of-rise heat detector, was developed.Examples. A number of examples, illustrating the response time of traditional, deluge, and forced launch fire sprinkler systems, are provided in the article.Conclusions. The obtained formula allows to quickly check the applicability of different types of fire sprinkler systems to ensure the effective protection of premises in which class B fires may break out.

Analysis of Water Jet Trajectory of Auto-Targeting Fire Sprinkler System in Interior Large Space

2012 ◽  
Vol 490-495 ◽  
pp. 171-175
Author(s):  
Ming Long ◽  
Guo Liang Hu ◽  
Zhong Li
Keyword(s):  
Sprinkler System ◽  
Large Space ◽  
Working Pressure ◽  
Fire Extinguishing ◽  
Jet Trajectory ◽  
Working Principle ◽  
Design Requirements ◽  
The Relationship ◽  
Trajectory Equation ◽  
Fire Sprinkler

Auto-targeting fire sprinkler system is an intelligent fire extinguishing equipment that used in interior large space. An auto-targeting fire sprinkler system was designed; the compositions and working principle were also expounded in detail. The water trajectory equation was deduced and simulated by Matlab software according to the principle of particle kinematics, ballistics, and fluid mechanics. The relationship among working pressure, pitch angle, installation height and jet range, flow landing speed was analyzed. The results show that the fire sprinkler system can satisfy the design requirements, and the water trajectory equation basically concides with the actual situation, which can provide some theoretical references for the fire precision location.

scholarly journals RELIABILITY ANALYSIS OF FIRE SUPPRESSION SYSTEMS

2019 ◽  
pp. 127
Author(s):  
Dejan Ristić ◽  
Milan Blagojević ◽  
Nermin Haznadarević ◽  
Milena Simić
Keyword(s):  
Reliability Analysis ◽  
Fire Suppression ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Sprinkler System ◽  
System Failure ◽  
Event Tree ◽  
Fire Extinguishing ◽  
Alarm Systems ◽  
In Fire

The methods of fault tree and event tree are well-known methods for reliability analysis of technical systems. However, these methods are rarely applied in fire protection systems including fire alarm systems and fire extinguishing systems. The aim of this paper is to use the hypothetical values of event probability, obtained through qualitative fault tree analysis, in order to obtain results that would indicate which individual events cause sprinkler system failure and which events are the most significant for, or contribute the most to, sprinkler system failure.

Numerical Simulation and Experimental Study on Water Mist Fire Suppression for Cooking Fog Discharge Pipe

2014 ◽  
Vol 915-916 ◽  
pp. 356-361
Author(s):  
Zheng Wen Xie
Keyword(s):  
Design Method ◽  
Fire Suppression ◽  
Orthogonal Design ◽  
Water Mist ◽  
Simulation Software ◽  
Droplet Radius ◽  
Test Analysis ◽  
Injection Angle ◽  
Fire Extinguishing ◽  
Flow Quantity

FDS simulation software was used to establish the full size lampblack physics model of single wind pipe, using the orthogonal design method design of analog calculation conditions, research in the nozzle pressure, the droplet radius, nozzle, flow quantity and injection angle parameters under different conditions of water mist fire extinguishing effect. Based on a full-scale combustion and water mist fire extinguishing experiment, the water mist fire suppression was observed and test analysis etc, to better understand the flue water mist fire extinguishing feasibility, provides the theory basis for the design of efficient, reliable flue fire extinguishing system.

scholarly journals Experimental Study on Fire Sources for Full-Scale Fire Testing of Simple Sprinkler Systems Installed in Multiplexes

Fire ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 8
Author(s):  
Jeonghwa Park ◽  
Jihyun Kwark
Keyword(s):  
Large Scale ◽  
Fire Suppression ◽  
National Fire Protection Association ◽  
Control Performance ◽  
Fire Testing ◽  
Fire Control ◽  
Wood Crib ◽  
Fire Source ◽  
Sprinkler Systems ◽  
Cotton Wick

Fires are accidents that can cause numerous human casualties in multiplexes. The simple sprinkler systems applied in South Korea employ sprinklers to protect people against residential fires, as specified by the National Fire Protection Association (NFPA) standard 13D. Therefore, it is necessary to evaluate the fire control performance of multiplexes, which are at a greater risk than residential facilities. This study aims to verify the fire control performance of simple sprinklers in multiplexes and to develop a fire source that can be used as a protocol for testing fire suppression methods. The fire source was evaluated by using a 3 MW large-scale calorimeter (ISO 13784). The proposed fire source for multiplexes was applied in various forms according to the application methods, with ignition sources including cotton wick, wood crib, and heptane, and then the fire tests were conducted.

scholarly journals Machinery Space Fire Fighting – Modern Alternatives

2018 ◽  
Author(s):  
T Goode
Keyword(s):  
Fire Suppression ◽  
Health And Safety ◽  
Alternative Methods ◽  
Royal Navy ◽  
Safety Issues ◽  
Fire Extinguishing ◽  
Small Craft ◽  
Accidental Discharge ◽  
Fire Suppressant ◽  
Machinery Space

Machinery spaces in the majority of Royal Navy (RN) vessels use carbon dioxide (CO2) as the primary fire suppressant. While CO2 is very effective for firefighting, particularly in machinery space application, it is harmful to life in the concentrations required for effective fire suppression; exposure to concentrations greater than 15% can cause death within sixty seconds. The use of CO2 and similar fire suppressant systems in machinery spaces presents a risk due to the potential exposure of personnel. This may occur in a fire scenario where personnel are unable to escape the affected compartment, if there is a leak in the system, or due to accidental discharge. These risks are typically mitigated through physical means and procedural controls. However, in the hierarchy of safety controls the primary means should always be the elimination of the hazard. Babcock Energy and Marine undertook a study for the United Kingdom Ministry of Defence (MoD) into alternative methods of firefighting on Royal Navy minor warship machinery spaces with the safety of personnel considered a key requirement. The study identified five alternatives to CO2 available on the market. One particular aerosol fire suppression system was found to be superior to the others for application in small craft. This system is not toxic, non-ozone depleting and leaves almost no residue after application to the affected space, enabling re-entry (provided that the space has been ventilated to remove the products of combustion). The study concluded that traditional methods of fire suppression should be reconsidered across all small craft due to the health and safety issues associated with CO2 and the availability of improved alternatives. This paper considers the use of traditional firefighting systems on naval vessels in light of 21st century health and safety regulations. An assessment of current fire extinguishing agents is presented followed by a case study to determine the most appropriate solution for a minor warship concept with a particular aerosol system being justified as the preferred option. The paper also considers if the same conclusions would be reached for major warships or if the difference in scale results in an alternative solution.

The Experimental Study on the Fire Suppression Effectiveness of Water Mist with the FeCl2 Additives

2013 ◽  
Vol 790 ◽  
pp. 53-56
Author(s):  
Chen Jian ◽  
Xu Yan Ying ◽  
Wang Na
Keyword(s):  
Experimental Study ◽  
Fire Suppression ◽  
Water Mist ◽  
Experimental Results ◽  
Additive Concentration ◽  
Experimental Conditions ◽  
Fire Source ◽  
Fire Extinguishing ◽  
Nozzle Position

This paper presents an experimental study of fire suppression effectiveness with water mist containing FeCl2 additives.The investigation focuses on suppression effectiveness under various FeCl2 additives concentrations,working pressures and nozzle different height above the fire source . The experimental results show that: there is a significant impact on fire suppression effectiveness when adding FeCl2 to water mist. There is an optimum additive concentration of extinguishing fire, corresponding to the shortest extinguishing time, the least amount of water, the highest efficiency of extinguishing fire. The nozzle working pressures and nozzle position have effect on the performance of the water mist extinguishing: the greater the pressure is, the shorter water mist fire extinguishing time is. Under the same experimental conditions, the closer the water mist nozzles are to the oil pan, the shorter extinguishing time is.

Residential Flashover Prevention with Reduced Water Flow: Phase 2

2021 ◽  
Author(s):  
Nicholas Dow ◽  
◽  
Daniel Madrzykowski
Keyword(s):  
Water Flow ◽  
Fire Suppression ◽  
Water Flux ◽  
Sprinkler System ◽  
Low Flow ◽  
Fire Growth ◽  
Solid Cone ◽  
Prevention System ◽  
Discharge Density ◽  
Reduced Water

The purpose of this study was to investigate the feasibility of a residential flashover prevention system with reduced water flow requirements relative to a residential sprinkler system designed to meet NFPA~13D requirements. The flashover prevention system would be designed for retrofit applications where water supplies are limited. In addition to examining the water spray's impact on fire growth, this study utilized thermal tenability criteria as defined in UL 199, Standard for Automatic Sprinklers for Fire-Protection Service. The strategy investigated was to use full cone spray nozzles that would discharge water low in the fire room and directly onto burning surfaces of the contents in the room. Where as current sprinkler design discharges water in a manner that cools the hot gas layer, wets the walls and wets the surface of the contents in the fire room. A series of eight full-scale, compartment fire experiments with residential furnishings were conducted with low flow nozzles. While the 23~lpm (6~gpm) of water was the same between experiments, the discharge density or water flux around the area of ignition varied between 0.3~mm/min (0.008~gpm/ft**2) and 1.8~mm/min (0.044~gpm/ft**2). Three of the experiments prevented flashover. Five of the experiments resulted in the regrowth of the fire while the water was flowing. Regrowth of the fire led to untenable conditions, per UL 199 criteria, in the fire room. At approximately the same time as the untenability criteria were reached, the second sprinkler in the hallway activated. In a completed system, the activation of the second sprinkler would reduce the water flow to the fire room, which would potentially lead to flashover. The variations in the burning behavior of the sofa resulted in shielded fires which led to the loss of effectiveness of the reduced flow solid cone water sprays. As a result of these variations, a correlation between discharge density at the area of ignition and fire suppression performance could not be determined given the limited number of experiments. An additional experiment using an NFPA~13D sprinkler system, flowing 30~lpm (8 gpm), demonstrated more effective suppression than any of the experiments with a nozzle. The success of the sprinkler compared with the unreliable suppression performance of the lower flow nozzles supports the minimum discharge density requirements of 2~mm/min (0.05~gpm/ft**2) from NFPA~13D. The low flow nozzle system tested in this study reliably delayed fire growth, but would not reliably prevent flashover.

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