Mathematical modeling of nitrogen-pressurized Halon flow in fire extinguishing systems

2021 ◽  
Vol 122 ◽  
pp. 103356
Author(s):  
Aitor Amatriain ◽  
Gonzalo Rubio ◽  
Ignacio Parra ◽  
Eusebio Valero ◽  
David Andreu ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Fire Extinguishing ◽  
In Fire

scholarly journals A Study on the Effect of O2 Diffusion on the Retention Time of Inert Agents

2020 ◽  
Vol 10 (19) ◽  
pp. 6694
Author(s):  
GoonHo Kim ◽  
Ju-Hong Cha ◽  
Jee-Hun Jeong ◽  
Ho-Jun Lee
Keyword(s):  
Theoretical Model ◽  
Retention Time ◽  
Hold Time ◽  
Theoretical Models ◽  
Accurate Model ◽  
Fire Extinguishing ◽  
A Value ◽  
O2 Diffusion ◽  
In Fire ◽  
And Diffusion

Gaseous agents are widely used in fire extinguishing systems (FESs) when water extinguishing agents are unavailable. The extinguishing ability of the FES-gaseous agent is determined by the retention time (hold time) at which its concentration is maintained. In particular, the retention time of the inert agent is determined by the O2 inflow from the outside. However, current theoretical models for inert agents do not provide an accurate model for the diffusion of incoming O2. Specifically, because the theoretical equations do not include O2 diffusion or include too large a value, there is a large difference between the measured and theoretical retention times. Therefore, in this study, accurate O2 diffusion was verified through experimental and numerical analyses using three types of deactivators and reflected in the existing theoretical model. O2 diffusion was analyzed through the interface slope α and diffusion velocity vd. As a result, this proposed method can predict the retention time more accurately than existing theoretical models.

scholarly journals An Approach for the Analysis of the Accessibility of Fire Hydrants in Urban Territories

2019 ◽  
Vol 8 (12) ◽  
pp. 587
Author(s):  
Raminta Raškauskaitė ◽  
Vytautas Grigonis
Keyword(s):  
Risk Management ◽  
Information Systems ◽  
Geographic Information Systems ◽  
Data Collection ◽  
Information Technologies ◽  
Fire Risk ◽  
Fire Extinguishing ◽  
Urban Territories ◽  
Efficient Planning ◽  
In Fire

Globally, fire causes considerable losses that can be alleviated by taking appropriate actions facilitated by systems supported by geo-information technologies. This research focuses upon the development of an approach for planning urban infrastructures, and particularly in the accessibility of fire hydrants. Accessibility of fire hydrants’ infrastructure in urban territories is one of the key elements in fire risk management and public safety. The main result of the research is a comprehensive and structured Geographic Information Systems (GISs)-based dataset for the fast and more efficient planning of fire hydrants in urban territories. The proposed framework for data collection and processing was used to determine the distribution of hydrants, location of fire brigade stations and areas and to demonstrate the capabilities of the existing municipal fire extinguishing systems in Vilnius City, Lithuania. Later on, research on fire hydrants’ accessibility, analysis of the location of protected and unprotected urban territories and marking of unprotected buildings, was carried out. The resulting map of unprotected urban territories can be of great benefit for understanding fire risks and offering more effective ways for fire risk management.

Support for decision-making on the need to replace fire trucks in fire and rescue units

2021 ◽  
Vol 92 ◽  
pp. 106-115
Author(s):  
V. A. Aristarkhov ◽  
◽  
A. V. Rozhkov ◽  
Keyword(s):  
Mathematical Modeling ◽  
Service Life ◽  
System Analysis ◽  
Block Diagram ◽  
Operating Time ◽  
Technical Condition ◽  
Technical And Economic Analysis ◽  
Study Results ◽  
In Fire ◽  
Goals And Objectives

Introduction. A study of the fleet of fire trucks was conducted. The absence of a direct dependence of the operating time of a fire truck on its service life is confirmed on the basis of the analysis. A matrix of conditions for making a decision on the need to replace a fire truck is formed, taking into account the standard purpose of the fire truck, its service life, the actual technical condition described by the corresponding category of technical condition, as well as the date of termination of its release. A criterion for the need to replace a fire truck has been developed, as well as an algorithm for making a decision on the need to replace a fire truck in conditions of limited funding. Goals and objectives. The purpose of the article is to develop an algorithm for making a decision about the need to replace a fire truck. This goal allows us to solve the problem of justifying the need to replace the sample in the course of ensuring a given level of readiness of fire and rescue units. Methods. Methods of mathematical statistics, the theory of the importance of criteria, technical and economic analysis, mathematical modeling and system analysis were used to achieve the goal and solve the problems of the study. Results and discussion. A criterion for the need to replace a fire truck is developed, on the basis of which a block diagram of the algorithm for making a decision on the need to replace a sample is formed. Conclusion. The results obtained in the course of the work can be used in the development of programs (plans) for re-equipping fire and rescue units with modern fire trucks. Keywords: the criterion of the need for replacement, fire trucks, category by technical condition, service life

The Evolution of Gasses in Fire Suppression Systems to Promote Changes in Industrial Towards Global Sustainability

2021 ◽  
Vol 1025 ◽  
pp. 259-264
Author(s):  
Jum’azulhisham bin Abdul Shukor ◽  
Rahim Jamian ◽  
Azmi Hassan ◽  
Muhammad Al Hapis Abdul Razak
Keyword(s):  
Fire Suppression ◽  
Sudden Change ◽  
Montreal Protocol ◽  
Fire Extinguishing ◽  
Clean Agent ◽  
Key Issues ◽  
Greenhouse Effects ◽  
The Stability ◽  
Fundamental Equations ◽  
In Fire

The historical development of fire suppression technology evolved in the 1930s since the application of Halons as a fire extinguishing agent. The fire may cause tremendous losses to organizations. It affects the chain of businesses and the stability of the economic growth of a country. The key issues of greenhouse effects and safety and health as well contributes to the sudden change of the technology of fire extinguishing systems. The establishment of the Montreal Protocol and Kyoto Protocols controls the producers to develop, supply and use of environmentally hazardous gasses worldwide. Hence, promote global sustainable for upcoming generations. This paper is highlighting the reasons gas type fire extinguishing agents extensively used substituting conventional methods against fire. The fundamental equations of Ozone Depleting Potential and Global Warming Potential were properly discussed to show how severe these gasses exposed to the environment. The effectiveness of these gases as a clean agent in extinguishing the fire may convince prospect users to carry out the decision of changes. Potential extinguishing agents will be deliberated to investigate their needs as new fire suppression agents. It will be then to be suggested and recommended for further studies.

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 Application of a novel a core-shell microstructured nanocomposites as a fire extinguishant using seawater

2021 ◽  
Vol 237 ◽  
pp. 01009
Author(s):  
Hao Liu ◽  
Tianwei Zhang ◽  
Cunwei Zhang ◽  
Lei Xiao ◽  
Qiang Liang
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Water Shortage ◽  
Core Shell ◽  
Dry Powders ◽  
The Core ◽  
Fire Extinguishing ◽  
External Shell ◽  
Treatment Technologies ◽  
In Fire

Water has unsurpassed capabilities in fire extinguishing. However, water scarcity is rapidly increasing in many regions and water shortage problems have led to find either new water resources or improve seawater treatment technologies. In this study, a new environment-friendly and high-efficiency powdered fire extinguishing agent with a core-shell structure is designed. The designed extinguishing agent is a colloidal powder with a 92% liquid content and is prepared through physical modification and high-speed shearing. Fumed silica is used for the external shell due to its chemical inertness, whereas seawater is used as the core due to its high extinguishing efficiency. Results show that the size of the prepared agent ranged between 100–200μm. The two fire extinguishing experiments of different scales demonstrate that the employing inorganic salts with seawater as the core can significantly increase the efficiency of the new powder in extinguishing gasoline and diesel fire compared with ultrafine and common ABC dry powders. The suppression mechanism of action is caused by the combined flame chemical and pyrolysis theories of the potassium compounds. This study would be of great theoretical significance and application value for improving the application scope of the seawater.

scholarly journals An integrated approach for fire extinguishers selection with DEMATEL and TODIM methods

2021 ◽  
Vol 9 (4) ◽  
pp. 1696-1707
Author(s):  
Mesut Ulu ◽  
Hasan Şahin
Keyword(s):  
Integrated Approach ◽  
Significant Loss ◽  
Industrial Facilities ◽  
Fire Extinguishing ◽  
Agent Selection ◽  
Todim Method ◽  
The Right ◽  
In Fire ◽  
Selection Of ◽  
Fire Extinguishers

Fire is a type of disaster that has caused significant loss of property and life from past to present. If the necessary measures are not taken, they cause serious property damage, interruption of processes, death and injury. Especially in industrial facilities, the density of flammable, explosive and hazardous chemicals, chimneys, hot surfaces, static electricity and electrical hazards, hot work increases the risk of fire. Therefore, necessary precautions should be taken. The choice of extinguisher device, which includes both passive and active precaution in fire safety, provides the correct intervention in case of possible fire. In case of being a fire, it is necessary to quickly and easily extinguish without damaging the system. For this reason, choosing the right extinguisher is important. In this study, effective criteria were determined by negotiating with supplier companies for the selection of suitable fire extinguishers. After scoring for the criteria, the weights of the criteria were determined by DEMATEL method. With TODIM method, appropriate fire extinguishing agent selection and sequencing were made.

scholarly journals Anti-freeze Application in Fire Extinguishing Facility Piping for a Warehouse Building

2020 ◽  
Vol 20 (1) ◽  
pp. 233-237
Author(s):  
Min Hyuk Yang ◽  
So Jin Yang ◽  
Woon Hyung Kim
Keyword(s):  
Flow Velocity ◽  
Flow Rate ◽  
Temperature Rise ◽  
Freezing Point ◽  
Effect Of Temperature ◽  
Circulation Method ◽  
Friction Heat ◽  
Fire Extinguishing ◽  
Protection Method ◽  
In Fire

This study aims to test the effect of temperature-rise on fire extinguishing facility piping by means of the flow method using an antifreeze solution and the circulation method by the heat of the pump to secure. The results of the experiment showed that the insides of the pipe freeze at -7 ℃ at a concentration of 20% antifreeze and -4 ℃ at 10%. When tested with the flow velocity of the antifreeze maintained at 1 m/s and concentrations of 20%, 10%, and 0%, the temperatures rose by 1.8 ℃, 0.6 ℃, and 1.7 ℃, respectively. At a velocity of 2 m/s, the temperatures rose by 2.1 ℃, 3.1 ℃, and 0.9 ℃. In addition, the circulation method test, by operating of the pump, increased the temperature by 1.2 ℃ with a pressure of 0.9 kgf/cm<sup>2</sup> and flow rate of 120 LPM. The pressure of 2.5 kgf/cm<sup>2</sup> and flow rate of 200 LPM increased the temperature by 2.7 ℃. Finally, a novelfreeze protection method was proposed to maintain the setup above freezing point due to the friction heat generated between the impeller of the pump and water.

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