Assessment of the Fire Dynamics Simulator for Modeling Fire Suppression in Engine Rooms of Ships with Low-Pressure Water Mist

2019 ◽  
Vol 56 (3) ◽  
pp. 1315-1352 ◽  
Author(s):  
Roberto Bellas ◽  
Miguel A. Gómez ◽  
Arturo González-Gil ◽  
Jacobo Porteiro ◽  
José L. Míguez
Keyword(s):  
Fire Suppression ◽  
Low Pressure ◽  
Water Mist ◽  
Fire Dynamics ◽  
Fire Dynamics Simulator ◽  
Pressure Water

scholarly journals Implementation of Low-Pressure Water Mist System for Fire Suppression inside a Model of Road Tunnel

2021 ◽  
Vol 9 (6) ◽  
pp. 184-188
Author(s):  
Hatem Sadek
Keyword(s):  
Fire Suppression ◽  
Low Pressure ◽  
Water Mist ◽  
Suez Canal ◽  
Maximum Temperature ◽  
Outer Diameter ◽  
Road Tunnel ◽  
The North ◽  
Pressure Water ◽  
Ventilation Fan

Previous studies have proven the performance of certain water mist system in general or in suppressing certain tunnel fires. The southern tunnel under the Suez Canal in the province of Ismailia length of 4 kilometers and 800 meters is serving the movement from Ismailia to Sinai through the Suez Canal old and new, while serving the northern tunnel movement from Sinai to Ismailia through the two channels. This tunnel in Ismailia is the largest in the world, with outer diameter of 12.6 meters, the internal 11,40 meters, the length of the tunnel is 4830 meters and reaches 6830 meters with the entrances and exits, the distance between the north and south tunnels 12 meters, and the maximum depth of the tunnel 45 meters down both Suez Canals. Since completing this project in the begin of 2019, this Tunnel did not experimentally test. This paper describes an experimental study of a low-pressure water-mist system (LPWMS) used in a scaled fire test conducted in a section of a scaled down road tunnel. The length, width, and height of the tunnel were 6 m, 2.4 m, and 2 m, respectively, which are in a ratio of 1:4 to the dimensions of an actual tunnel. The LPWMS used a pump pressure of 5.5 bar, and the system configuration was designed according to the pressure generated by the pump. Without a ventilation fan, the fire suppression time was 275 s, and amount of water required to fully suppress the fire was 696.67 L. When a ventilation fan was used, the maximum temperature location was moved from the center of the 6 m long tunnel toward the air inlet end of the tunnel (upstream). While this study will find the performance of the LPWMS in suppressing a fire in a small section of the Ismailia tunnel, determining the times spent and the amount of water consumed in the various stages of fire suppression, and in addition to studying the effect of the ventilation fan on These results and the location of the maximum temperature in the tunnel.

Fire Suppression by Water-Mist Sprays: Experimental and Numerical Analysis

2010 ◽  
Author(s):  
Paolo E. Santangelo ◽  
Paolo Tartarini ◽  
Beatrice Pulvirenti ◽  
Paolo Valdiserri ◽  
Andre´ W. Marshall
Keyword(s):  
Numerical Analysis ◽  
Fire Suppression ◽  
Test Chamber ◽  
Water Mist ◽  
Specific Reference ◽  
Test Case ◽  
Fire Dynamics ◽  
Suppression Mechanism ◽  
Thermal Transient ◽  
Combustion Tests

Water-mist systems have become a promising technology in the fire-fighting field over the last twenty years. The present work is aimed at employing the available knowledge on water-mist sprays in an experimental and numerical analysis of the suppression mechanism. Therefore, a water-mist system has been operated within a typical fire case. Most notably, this latter is constituted by a heptane pool fire: experiments have been carried out inside a test chamber, where a set of thermocouples has conveniently been placed to evaluate the thermal transient at different locations of interest. Some free-combustion tests have been run as a benchmark to validate combustion models. Then, a typical water-mist nozzle has been inserted and activated to realize control, suppression and potential extinction of the generated fire. The recognized FDS (Fire Dynamics Simulator) and Fluent® codes have been challenged in reproducing the test case: thermal transient and suppression time have been considered as parameters for validation. Therefore, the water-mist spray has been modeled and the already mentioned results about its characterization have been implemented as initial or boundary conditions. Moreover, the fire scenario has been modeled as well. A good agreement between experimental and numerical results has been obtained, even under some approximations, with specific reference to combustion mechanisms.

scholarly journals A Numerical Analysis of the Fire Characteristics after Sprinkler Activation in the Compartment Fire

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3099 ◽  
Author(s):  
Ho Trong Khoat ◽  
Ji Tea Kim ◽  
Tran Dang Quoc ◽  
Ji Hyun Kwark ◽  
Hong Sun Ryou
Keyword(s):  
Experimental Data ◽  
Numerical Analysis ◽  
Fire Suppression ◽  
Compartment Fire ◽  
Fire Dynamics ◽  
Fire Dynamics Simulator ◽  
Safety Design ◽  
Smoke Layer ◽  
Fire Characteristics ◽  
Sprinkler Spray

Understanding fire characteristics under sprinkler spray is valuable for performance-based safety design. However, fire characteristics during fire suppression by sprinkler spray has seldom been studied in detail. In order to present a fire suppression model by sprinkler spray and determine the fire characteristics after sprinkler activation in a compartment, a numerical analysis was conducted using a fire dynamics simulator (FDS). A simple fire suppression model by sprinkler spray was calibrated by comparing ceiling temperatures from experimental data. An extinguishing coefficient of 3.0 was shown to be suitable for the fire suppression model. The effect of sprinkler spray on the smoke layer during fire suppression was explained, revealing a smoke logging phenomenon. In addition, the smoke, which spread under the influence of the sprinkler spray, was also investigated. The temperature, velocity, and mass flow rate of the smoke layer through the doorway was significantly reduced during fire suppression compared to a free burn case.

Physical Scaling of Fire Suppression by Water Mist

2001 ◽  
Author(s):  
G. Su ◽  
J. G. Quintiere ◽  
N. Schultz
Keyword(s):  
Heat Flux ◽  
Fire Suppression ◽  
Water Flow Rate ◽  
Water Mist ◽  
Full Scale ◽  
Scale Model ◽  
Safety Committee ◽  
Pressure Water ◽  
Full Scale Tests ◽  
Final Answer

Abstract The objective of the project is to develop water mist extinguishments design by scaling. The report describes the requirement and criteria of scaling fire, scale model, and the results of suppression for a developing water mist system design. The Maritime Safety Committee Draft Circular, MSC 914 is used as a basis test to evaluate a water mist design. A series of three full-scale tests related to MSC 914 were performed: fire only, fire with steel trailers, and fire with steel trailers and combustible commodities. A simulation was accordingly studied. Then, a scaled water mist design was tested in the scale model to find the characteristics needed for suppression in terms of pressure, water flow rate, droplet size, and the spray momentum. Based on these characteristics, a candidate nozzle will be selected for the full-scale MSC 914 test. The results so far show that the water mist system can effectively suppress the fire in scaled MSC 914 model. The full-scale MSC 914 is scheduled for September 2001. Therefore, the final answer is still pending until then. Scaling results are confirmed for temperatures, heat flux and flow for the MSC 914 fire without water add in.

Inhibition Effect of Thermally-Induced Fire in 21,700 Lithium-Ion Battery With Low-Pressure Twin-Fluid Water Mist

2021 ◽  
Vol 18 (2) ◽  
Author(s):  
Jun Guo ◽  
Haibin Wang ◽  
Yuanhua He
Keyword(s):  
Lithium Ion Battery ◽  
Fire Suppression ◽  
Fire Hazard ◽  
Flame Temperature ◽  
Lithium Ion ◽  
Low Pressure ◽  
Water Mist ◽  
Inhibitory Effects ◽  
Working Pressure ◽  
Thermally Induced

Abstract The fire hazard of lithium-ion batteries (LIBs) poses a serious threat to their transportation and use. The purpose of this study is to investigate the efficiency of low-pressure twin-fluid water mist (TFWM) on suppressing lithium-ion battery fires. Experiments were executed to research the effect of working pressures and release stages on extinguishing the fire. Aqueous vermiculite dispersion (AVD), a commercial agent that was specifically designed to extinguish battery fires, was chosen to compare with the fire suppression performance of TFWM under the same conditions. The results indicate that the type 21,700 LIB fires could be controlled by applying the water mist within 10 s. The cooling ability at various working pressures (0.4, 0.8, 1.0, and 1.2 MPa) demonstrated an increase in inhibitory effects as the working pressure increased, and the optimal pressure was 1.2 MPa. The results further show that the extinguishing ability of the TFWM was better than the AVD agent. When the water mist was applied at the optimal working pressure, the surface temperature, flame temperature and concentration of CO reduced more significantly, compared with the AVD agent. Therefore, the TFWM shows considerable merit as a candidate to fight LIB fires.

New techniques and a new approach to the effective extinguishing of fully developed fires in enclosed spaces

2016 ◽  
Vol 8 (1) ◽  
pp. 213-224
Author(s):  
Norbert Tuśnio ◽  
Paweł Wolny
Keyword(s):  
Fire Suppression ◽  
Radiant Heat ◽  
Fire Service ◽  
Water Mist ◽  
Abrasive Waterjet ◽  
Water Spray ◽  
Fire Extinguishing ◽  
Pressure Water ◽  
Fire Area ◽  
In Fire

An example of modern water mist extinguishing technology is presented in the article. Water mist systems are firefighting systems which uses very fine water sprays. The smallest water droplets allow a water mist to control, suppress or extinguish fires by cooling both the flame and hot gases by evaporation, displacing oxygen by evaporation and reducing radiant heat through the small droplets themselves. The effectiveness of water mist systems in fire suppression depends on its spray characteristics, which include the droplet size and distribution, flux density and spray dynamics, phase of fire development, fire size and the ventilation conditions. The COBRA (known as PyroLance in USA) systems presented use of a cutting extinguisher is a fire extinguishing technique that combines abrasive waterjet cutting with water spray extinguishing, through a single handpiece or nozzle. The firefighter approaches the fire from outside the main fire area, then uses the cutting action to drill a small hole through a barrier such as a door, wall, roof or floor. Switching to a water spray then allows the fire to be fought, as with a conventional fog nozzle. An analysis of the benefits of using high-pressure water mist in conjunction with new firefighting tactics is described. State Fire Service should aim to minimize water consumption and thus reduce the post-fire losses, take care of environmental protection and improve safety conditions for firefighters.

scholarly journals Low pressure water-mist nozzle with a swirl worm screw inserts

2018 ◽  
Vol 245 ◽  
pp. 11001 ◽  
Author(s):  
Nadezhda Kropotova ◽  
Alexander Arakcheev ◽  
Leonid Tanklevskiy ◽  
Anton Tanklevskiy
Keyword(s):  
Design Research ◽  
Research Work ◽  
Low Pressure ◽  
Water Mist ◽  
Application Efficiency ◽  
Fire Extinguishing ◽  
Pressure Water ◽  
Improved Design ◽  
Fire Extinguishing System ◽  
Pressure Nozzle

The article contains the main results of the creation of a nozzle of improved design research work. To improve application efficiency of low-pressure nozzle of water mist in automatic fire-extinguishing system (AFS), the construction of centrifugal nozzles with swirl worm screw inserts was changed. The construction features of this sprayer, methods of its testing and obtained results these tests characteristics are presented.

scholarly journals Examination on Effects of Spray Characteristics of Water Mist on Thermal Radiation Attenuation Using Fire Dynamics Simulator

2021 ◽  
Vol 35 (1) ◽  
pp. 1-10
Author(s):  
Jae Geun Jo ◽  
Chi Young Lee
Keyword(s):  
Numerical Simulation ◽  
Thermal Radiation ◽  
Droplet Size ◽  
Flow Rate ◽  
Water Mist ◽  
Spray Angle ◽  
Fire Dynamics ◽  
Spray Characteristics ◽  
Radiation Attenuation ◽  
Fire Dynamics Simulator

In this study, numerical simulations to investigate the effects of the spray characteristics of water mist on thermal radiation attenuation were performed using fire dynamics simulator (FDS). The droplet size, flow rate, and spray angle of the water mist were 100-300 µm, 1-3 L/min, and 60-180°, respectively. As the droplet size decreased and flow rate increased, the thermal radiation attenuation increased. When the spray angles decreased and increased behind the near nozzle center and behind a certain remote distance from the nozzle center, respectively, the thermal radiation attenuation increased. The peak thermal radiation attenuation increased with decreases in droplet size and spray angle and an increase in flow rate, whereas the average thermal radiation attenuation increased with a decrease in droplet size and increases in flow rate and spray angle. Under the numerical simulation conditions of this study, the peak and average thermal radiation attenuations were significantly altered by the ratios of droplet size and flow rate and by that of flow rate, respectively. However, their variations with the ratio of spray angle were the smallest.

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