A Study on the Durability of Fire Hoses of Fire Hydrants

Although the number of fires has not changed considerably in recent times, property damage and casualties due to fires are increasing every year. Maintaining the performance of fire-fighting facilities installed in buildings has been emphasized for maximizing human safety and minimizing property damage caused by fires. As a result, since 2017, the maintenance of fire extinguishers throughout their service life, has been mandated. In case of a fire, initial fire extinguishing and fire spreading prevention are crucial. There have been no available measures for the maintenance and verification of indoor fire hydrants and outdoor fire hydrant hoses used for extinguishing fires and preventing combustion expansion. This study was therefore intended to present measures for ascertaining the service life of these fire extinguishers, by evaluating their firefighting abilities through sample analysis and case analysis of the fire hoses. Research shows that the degradation of performance of the fire hoses becomes evident between 9 and 10 years, so that 10 years of service life is considered appropriate for the fire hoses.

Fire Spread Risk Assessment Process for Radiant Heat Flux of Flame Ejected from Opening in Fire

When a flashover occurs from a fire in a building compartment, the fire intensifies explosively and changes from a fuel-controlled fire to a ventilation-controlled fire. As a result, flames and unburnt gas are ejected from openings. The ejected unburned gas reacts violently with external oxygen to form a large-scale ejected flame, which causes the fire to expand to the upper layer. Moreover, the radiation of extreme heat to neighboring buildings contributes to fire spreading between buildings. In this study, a quantitative evaluation process was established to evaluate the thermal effect of radiant heat generated from an open fire on the exterior materials of facilities, assuming a fully developed fire.

AGENT-BASED FIRE-SPREADING MODEL IN A DENSE URBAN COMMUNITY

Metro Manila, home to twelve-million residents scattered in densely populated cities, grows its population at a rate of 1.21% annually. Areas of the metro occupied by residents falling under the poverty line have only been increasing in density per year, and have been prone to fire incidents. One such area, Barangay Addition Hills in Mandaluyong City, has fallen victim to two disastrous fires four years apart: in 2016 and 2020. This study aims to accurately model a portion of Barangay Addition Hills when a fire starts in one of the most densely populated blocks while observing firefighters responding to the incident. The agent-based model adapts features from (Wilensky, 2006)’s Fire model and is virtually simulated with the help of two-dimensional satellite images of the area. The fire-spreading algorithm incorporates solving the heat diffusion equation to determine ignition time of combustible materials per unit area. Firefighters have been incorporated into the model with the help of the Bureau of Fire Protection (BFP)’s Operational Procedures Manual to determine their expected behavior when responding to a fire alarm. Simulations were run on a per-incident basis to determine the total affected area, estimated affected families, and time for the fire to be put under control under varying densities, traffic conditions, firefighter response times and manpower.

Prediction of Forest Fire Spread Rate Using UAV Images and an LSTM Model Considering the Interaction between Fire and Wind

Modeling forest fire spread is a very complex problem, and the existing models usually need some input parameters which are hard to get. How to predict the time series of forest fire spread rate based on passed series may be a key problem to break through the current technical bottleneck. In the process of forest fire spreading, spread rate and wind speed would affect each other. In this paper, three kinds of network models based on Long Short-Term Memory (LSTM) are designed to predict fire spread rate, exploring the interaction between fire and wind. In order to train these LSTM-based models and validate their effectiveness of prediction, several outdoor combustion experiments are designed and carried out. Process data sets of forest fire spreading are collected with an infrared camera mounted on a UAV, and wind data sets are recorded using a anemometer simultaneously. According to the close relationship between wind and fire, three progressive LSTM based models are constructed, which are called CSG-LSTM, MDG-LSTM and FNU-LSTM, respectively. A Cross-Entropy Loss equation is employed to measure the model training quality, and then prediction accuracy is computed and analyzed by comparing with the true fire spread rate and wind speed. According to the performance of training and prediction stage, FNU-LSTM is determined as the best model for the general case. The advantage of FNU-LSTM is further demonstrated by doing comparison experiments with the normal LSTM and other LSTM based models which predict both fire spread rate and wind speed separately. The experiment has also demonstrated the ability of the model to the real fire prediction on the basis of two historical wildland fires.

Modelling Forest Fires Using Complex Networks

Forest fires have been a major threat to the environment throughout history. In order to mitigate its consequences, we present, in a first of a series of works, a mathematical model with the purpose of predicting fire spreading in a given land portion divided into patches, considering the area and the rate of spread of each patch as inputs. The rate of spread can be estimated from previous knowledge on fuel availability, weather and terrain conditions. We compute the time duration of the spreading process in a land patch in order to construct and parametrize a landscape network, using cellular automata simulations. We use the multilayer network model to propose a network of networks at the landscape scale, where the nodes are the local patches, each with their own spreading dynamics. We compute some respective network measures and aim, in further work, for the establishment of a fire-break structure according to increasing accuracy simulation results.

The wave algorithm used to determine the optimal indoor route for smoke divers in case of fire and fumigation

Introduction. One of the main objectives, pursued by the information analysis support extended to smoke divers, is the preparation of indoor routes. Technical capabilities, represented by advanced remote monitoring systems, provide a fire extinguishing manager with the necessary information about the point of fire origin and mathematical tools allow to predict fire spreading characteristics. The goal of this work is to develop an algorithm for the preparation of an optimal indoor route for smoke divers to support management decisions in the event of fire. To achieve this goal, it is necessary to develop the theoretical framework and implement it in a software programme.Theoretical foundations. The theory of cellular automata is employed in this paper to simulate the routes of smoke divers inside a building. A cellular automaton with a Moore neighborhood is applied. We use differential equations, similar to the Kolmogorov equations, to monitor the fire parameters.Results and discussions. A modified wave algorithm was developed to determine the optimal indoor route. The software tool was applied to simulate the route of gas divers. Coefficients of importance were applied in the process of mathematical modeling; they took account of the prioritized work to be performed by smoke divers.Conclusions. The results of the study suggest that the algorithm allows to identify the optimal itinerary, thereby enabling the decision maker, responsible for sending teams of smoke divers to the work performance location, to make a reasonable choice of the point of entry for the personnel and machinery, as well as their itinerary inside the building.

Practice of Using Fire-safety Sleeve for Free Flow Conduits of the Engineering Systems Made of Polymer Materials

To exclude the possibility of fire spreading through the utility lines of buildings and structures, various technical means are used that meet the normative established characteristics. As part of the intersection nodes of the enclosing building structures of sewage and water disposal systems, fire-safety sleeves are used, which ensure the limit of fire spreading to adjacent rooms through the node crossed by the pipeline. The use of fire-safety sleeves for these utility lines is only possible for free flow conduits of the systems made of polymer materials (polypropylene, polyethylene, polyvinyl chloride, etc.). For different types of the pipelines, other technical solutions are used to limit the spread of fire. The principle of fire-safety sleeves operation is to completely cover the intersecting mounting opening of the building structure in the shortest possible time and prevent the transfer of flame and combustion products to adjacent rooms. The efficiency of the operation of fire-safety sleeve and the preservation of its fire-technical characteristics for a given time depends on the following factors: correct installation carried out in accordance with the established instructions; design of fire-safety sleeves; physical and chemical properties of the material used for thermally expanding sleeve liner; material of a polymer pipeline. Statistics of the conducted tests show that the maximum fire resistance limits are typical for intersection nodes with polymer pipelines having diameter from 32 to 110 mm. For the pipelines with a diameter of 160 mm and more, it is very difficult to achieve similar fire-technical characteristics due to the large area of the overlapping mounting openings and the increased inertia of a fire-safety sleeve actuation.

Fire Risk Situation Analysis in the Nimtoli Area of Old Dhaka

Assessment of the fire risk situation of Nimtali area by using eight indicators related to the fire source, fire spreading and evacuation during fire incidents was conducted. The results revealed that none of the buildings has emergency exits, fire protection measures, fire hydrant and provision of a fire drill. The area is densely populated. Most of the buildings are mixed-used and have no space in between. Electrical cables are haphazardly hanging from poles. Access roads are incredibly narrow. By analyzing eight indicators, it is found that the entire Nimtoli area is still at risk of fire hazard. Within Nimtoli, 32% area is at high risk, and 45% is at moderate risk of fire hazard. Proper fire safety measures and safety inspection, regular maintenance of utility lines, awareness about fire hazards among the dwellers, proper implementation of Bangladesh national building code (BNBC) and regulation of mixed-use of buildings can drastically reduce the fire risk in the urban area of Bangladesh. J. Asiat. Soc. Bangladesh, Sci. 46(1): 91-102, June 2020

Consistent modelling of material weight loss and gas release due to pyrolysis and conducting benchmark tests of the model—A case for glovebox panel materials such as polymethyl methacrylate

It is necessary to consider how a glove box’s confinement function will be lost when evaluating the amount of radioactive material leaking from a nuclear facility during a fire. In this study, we build a model that consistently explains the weight loss of glove box materials because of heat input from a flame and accompanying generation of the pyrolysis gas. The weight loss suggests thinning of the glove box housing, and the generation of pyrolysis gas suggests the possibility of fire spreading. The target was polymethyl methacrylate (PMMA), used as the glove box panel. Thermal gravimetric tests on PMMA determined the parameters to be substituted in the Arrhenius equation for predicting the weight loss in pyrolysis. The pyrolysis process of PMMA was divided into 3 stages with activation energies of 62 kJ/mol, 250 kJ/mol, and 265 kJ/mol. Furthermore, quantifying the gas composition revealed that the composition of the pyrolysis gas released from PMMA can be approximated as 100% methyl methacrylate. This result suggests that the released amount of methyl methacrylate can be estimated by the Arrhenius equation. To investigate the validity of such estimation, a sealed vessel test was performed. In this test, we observed increase of the number of gas molecules during the pyrolysis as internal pressure change of the vessel. The number of gas molecules was similar to that estimated from the Arrhenius equation, and indicated the validity of our method. Moreover, we also performed the same tests on bisphenol-A-polycarbonate (PC) for comparison. In case of PC, the number of gas molecules obtained in the vessel test was higher than the estimated value.

Forest Fire Spreading Using Free and Open-Source GIS Technologies

Forest fires are one of the most dangerous events, causing serious land and environmental degradation. Indeed, besides the loss of a huge quantity of plant species, the effects of fires can go far beyond: desertification, increased risk of landslides, soil erosion, death of animals, etc. For these reasons, mathematical models able to predict fire spreading are needed in order to organize and optimize the extinguishing interventions during fire emergencies. This work presents a new system to simulate and predict the movement of the fire front based on free and open source Geographic Information System (GIS) technologies and the Rothermel surface fire spread model, with the adjustments made by Albini. We describe the mathematical models used, provide an overview of the GIS design and implementation, and present the results of some simulations at Etna volcano (Sicily, Italy), characterized by high geomorphological heterogeneity, and where the native flora and fauna may be preserved and perpetuated. The results consist of raster maps representing the progress times of the fire front starting from an ignition point and as a function of the topography and wind directions. The reliability of results is strictly affected by the correct positioning of the fire ignition point, by the accuracy of the topography that describes the morphology of the territory, and by the setting of the meteorological conditions at the moment of the ignition and propagation of the fire.