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Heat release rate measured in the fire experiment with PET plastic bottles in cardboard boxes. Reproduced from [79].
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VTT Working Papers 139 For construction design fire safety is one of the key requirements. Fire loads, which define the possible fires that can occur, need to be known both in magnitude and quality. This report describes design fires appropriate for use in Fire Safety Engineering (FSE) design in general and thus applicable also for building with wo...
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The presented article deals with the thermally modified spruce wood fire risk assessment. The assessment was based on comparison of heat release rate and carbon monoxide yield from thermally modified and thermally unmodified samples. The heat release rate and carbon monoxide yield were determined by the means of cone calorimeter at two different he...
Ignition is the initial stage of burning the materials. Consequent flame spread over the materials, heat release rate, fire spread across the rooms, and other issues for building fires all depend on that. Ignition of cellulose materials is commonly classified as smoldering or glowing ignition (self-heating ignition) and flaming ignition including p...
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... Sehingga dalam penelitian ini, penyebab kebakaran diskenariokan sesuai dengan penelitian tersebut dengan nilai pelepasan panas atau Heat Release Rate Per Area (HRRPUA) sebesar 50 kW/m 2 . Nilai HRRPUA tersebut merupakan paparan panas yang paling umum digunakan sebagai paparan api yang khas [19] . Asumsi luas bidang yang terbakar pada penelitian ini adalah sebesar 2,4 m 2 . ...
The study of “Lifeboat placement effectiveness” which was applied to the evacuation process of passenger ships should be based on the regulation of IMO MSC.1/Circ.1533. The analysis of the evacuation duration was important considering the high number of fatalities in shipping accidents based on KNKT data, as many as 686 people died in the last 7 years. This study analyzed the duration of evacuation using a simulation method based on “Agent Based Modelling Simulation” with the purpose to obtain a modeling framework to simulate the evacuation process to the lifeboat in 3 dimensions. Simulations were applied to 4 cases with 2 different lifeboat positions. The results of the analysis showed that the total value of the evacuation duration for lifeboats placement on the navigation deck which was placed close to the main stair of the exit route was leading than the placement in the existing position, which as case 1 lead by 1 minute, case 2 lead by 1 minute 2 seconds, case 3 lead by 23 seconds, and case 4 a lead by 17 seconds. The calculation also showed that the total evacuation duration in each case was valued at 60 minutes, which met the IMO MSC.1/Circ.1533 standard.
... Example of What -If Analysis[8] ...
... The simulation of heat transfers with simplified assumptions allows the choice of potential hybrid steel-wood beam configurations, which it would be interesting to test experimentally, to verify the behaviour in a fire situation. Besides, the influence of moisture content can be taken into account in the case of the specific heat capacity according to several authors as Cachim & Franssen [28], Hietaniemi & Mikkola [29], these authors claim that the lower value of the moisture causes lower values of the specific heat capacity until the time of the vaporization of water. ...
Steel-timber hybrid structures are becoming more and more common in the construction industry. They offer high practical advantages as sustainable solutions with high load-bearing capacities and fire resistance. Wood is occasionally used as a passive protection for steel to maintain its mechanical strength as long as possible with the aim to prevent structural collapse under fire. This paper aims to analyse the thermal behaviour of hybrid steel-timber elements through experimental tests and numerical modelling. The fire tests were performed on various steel-timber combinations using T and I steel cross-sections with various wood species. A high-temperature furnace of up to 1200 °C built in the laboratory was used. The results show that wood provides a significant protection to the steel cross-section, mainly to the fully encapsulated IPE profile. Wood performed as an insulating material that significantly reduced the temperature rise in steel. The experimental results are compared to those obtained through thermal simulations using Abaqus software. The comparison shows that the numerical model can be used to evaluate the temperature increase in the steel element protected by timber in high-temperature conditions.
... Afterward, a burning surface with dimensions of 0.6 × 0.8 × 0.25 3 was defined and the value of 500 2 � was set as a parameter of the Heat Release Rate Per Unit Area (HRRPUA). This value corresponds to an object made of wood, plastic, and cellulose, like a sofa (Hietaniemi and Mikkola, 2010). ...
High-rise buildings, with high number of population, have always been among the concerns discussed in urban crisis management. One of the crucial aspects of high-rise buildings is having a proper and timely action plan for evacuation in the case of emergencies such as fires. The spread and progression of fire smoke in high-rise buildings are affected by the architectural design of the building, and having a three-dimensional (3D) model of high-rise buildings can play key role in damage reduction in such cases. This paper, first presents a method for 3D smoke emission based on utilizing 2D cadastral data to generate a 3D model of the buildings. Then, in step of smoke fire emission simulation, the influence of different smoke movement paths such as the entrance/exit doors, windows, smoke barrier, stairs, and elevators, are examined in different scenarios. Next, the emergency evacuation of occupancies with different behavioral and physical characteristics is simulated. The results indicate that 2D cadastral data of apartments can be employed as a suitable source to create 3D models of high-rise buildings, and allows to examine the emergency evacuation of residents by including the smoke simulation spread in the building.
... created in the US by the National Institute of Standards and Technology (NIST) [16]. FDS currently has several thousand users and, in this field, is the best-verified of all simulation programs [17][18][19]. Due to the above, the FDS was chosen for the simulations presented below. All the simulations were prepared in 3D models of the enclosure, using the FDS, in which the large eddy simulation (LES) turbulence model is implemented for the airflow phenomena modeling. ...
Industrial power plant buildings differ from all other types of buildings, mainly due to their significant heights and volumes without internal floor sections, exceptionally heat gains during daily work, and potentially high fire risk. Those buildings consist of boiler and turbine houses with multilevel stairways. This complicated architecture creates an extraordinary natural thermal stack effect, causing special ventilation and smoke control systems requirements, adapted to their specific structures and internal conditions. The paper demonstrates a proposal for optimal thermal smoke control ventilation solutions in industrial power plant buildings designated on the basis of performance-based calculations and confirmed by CFD simulations. It demonstrates the possibilities of using daily ventilation in the boiler houses in a function of smoke control systems in the event of a fire and defines fundamental rules for designing the system. Additionally, a new method of sufficient staircase (pylons) protection with a modified pressurization system is proposed.
... In separate work, Hietaniemi and Mikkola [220] collated information on a series of office workstation experiments by Madrzykowski [221], Madrzykowski and Watson [222], Kakegawa et al. [223], Ohlemiller et al. [224], where it was summarised that the maximum HRRPUA for these experiments ranged from 820 kW/m 2 to 1,799 kW/m 2 with an average maximum (̇" ̅̅̅̅ ) of 1,156 kW/m 2 . In some instances, the HRRPUA represented a value averaged across the area of an entire burning enclosure (for example a 6.3 m by 6.3 m room for Kakegawa et al. [223]), and in others it related to the burning area of a single cubicle, or to the burning area of single items only. ...
... Hietaniemi and Mikkola [220] simulated a series of residential fires, adopting statistical distributions for mass and the heat of combustion of furniture items located in hypothetical residential room layouts. Furniture items included sofas, armchairs, coffee tables, televisions, etc. ...
... Using the results of the simulations, Gumbel distributions were proposed which differed depending on the room of fire origin. The distribution parameters (α, β) for these distributions, as well as the average fire load density and equivalent HRRPUA, are given in [220]. ...
... As explained above, the fire scenario in this study is assumed that the initial material burned is pvc pipe with Heat Release Per Area (HARRPUA) value is50 kW⁄m 2 . The heat exposure are considered as the advisable value to be used in the methodology [8]. ...
... The fuel loads were arranged as per the typically observed practice of storing raw materials in RMG storage area. The heat release rate per unit area for nylon was considered to be 1200 kW/m 2 (Hietaniemi and Mikkola, 2010), which was released from a combined nylon surface area of 1281.93 m 2 . The corresponding reaction for nylon was determined from the SFPE handbook (Hurley et al., 2016) and related guidelines with a carbon monoxide yield and soot yield of 0.038 and 0.075, respectively. ...
A coupled CFD modelling for fire growth and evacuation modelling is conducted to evaluate the fire safety performance of a multistoried ready-made garments (RMG) building. The geometric and architectural features, occupant density, and other features of the factory are selected to represent those of a standard RMG building in Bangladesh. The smoke propagation and evacuation scenarios are selected to resemble some of the typical and often overlooked unsafe practices, such as open fire-doors, obstacle in the egress routes, and reduced exit numbers, observed in the RMG sector in Bangladesh. The effects of these practices are examined separately and in different combinations to obtain a comprehensive understanding of their effect on the occupant safety. It is observed that when there is no compartmentation in place near the stairway (resembling open fire doors), different areas of the building become untenable very quickly. If all the unsafe practices are considered at the same time (open fire door, obstructed egress route, and reduced number of exits), about 6% (334 out of a total of 5381) of the occupants fail to evacuate safely. This happens due to the reduction in visibility in smoke below the threshold that permits safe escape, considering the physiological and psychological effects of smoke on the way-finding ability and escape behavior of the occupants. The critical issue of the possible effects of these unsafe or non-standard practices in the garment factories on the safety of the workers has not been addressed in a systematic manner before. Therefore, the findings of this study can be useful in assessing the potential consequences of a fire-hazard due to the unsafe workplace practices even in the standard RMG buildings complying with relevant building codes.
... Such a case study, where CFD based based fire model FDS has been used for PBD of stairwell smoke extraction system in a model high-rise building, is described in the next section. (Hadjisophocleous and Jia, 2009, Hietaniemi and Mikkola, 2010, Shen et al., 2008, Yuen et al., 2014, NFPA92, 2018: ...
... 1 The fire consequence assessment in performance-based fire safety design commonly relies on design fires that describe the evolution of the heat release rate over time, based on the expert judgment or a synthesis of relevant experiments. 2 A material model that couples the heat transfer and pyrolysis kinetics within the wood material has a potential to replace the fundamental input assumption by prediction. In such a model, heat release is controlled by the chemical kinetics and the surrounding conditions, thus in our opinion allowing for a more realistic calculation of fires in wooden enclosures. ...
Performance‐based design of the timber structures' fire resistance is often based on the reduced cross section and thus relying on empirical and numerical assessment of the charring propagation. The current work aims to construct models for the pyrolysis of spruce and pinewoods to allow coupled simulations of the cross‐section reduction and burning rate in fire models. Kinetic models are formulated based on thermogravimetric data and supported by the heats of pyrolysis and combustion measurements by differential scanning calorimetry and microscale combustion calorimetry, respectively. The results from these small‐scale measurements are consistent with each other, and the heats of pyrolysis and combustion are determined for the wood primary components by fitting the simulations to the experimental results. Heat release models are constructed based on the small‐scale tests, and cone calorimeter experiments are used for the estimation of the physical properties and for the heat release model validation.
