Fire Safety Science最新文献

{"title":"Compartment fire temperature : a new simple calculation method","authors":"U. Wickström, Alexandra Byström","doi":"10.3801/IAFSS.FSS.11-289","DOIUrl":"https://doi.org/10.3801/IAFSS.FSS.11-289","url":null,"abstract":"In this paper a new simple calculation method for compartment temperatures is derived. The method is applicable to post-flashover ventilation controlled fires. A parameter termed the ultimate compartment fire temperature is defined as the temperature obtained when thermal equilibrium is reached and thick compartment boundaries cannot absorb any more heat from the fire gases. This temperature depends only on the product of the heat of combustion and the combustion efficiency over the specific heat capacity of air. It is, however, independent of the air mass flow rate, and of the fire compartment geometry and the thermal properties of the compartment boundary materials. These parameters on the other hand govern the rate at which the fire temperature is increasing towards the ultimate temperature. It is shown how the fire temperature development as a function of time in some idealized cases may be calculated by a simple analytical closed form formula. The fire temperature developments of two types of compartment boundaries are presented, semi-infinitely thick and thin structures. It is also shown that for the semi-infinite case, the solution resembles the standard ISO 834/EN 1363-1 curve and the parametric fire curves according to Eurocode 1, EN 1991-1-2.","PeriodicalId":12145,"journal":{"name":"Fire Safety Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83371143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the Level of Safety for Performance Based and Prescriptive Structural Fire Design of Steel Structures","authors":"G. D. Sanctis, M. Faber, M. Fontana","doi":"10.3929/ETHZ-A-010194560","DOIUrl":"https://doi.org/10.3929/ETHZ-A-010194560","url":null,"abstract":"The level of safety in structural fire safety is implemented by combining passive and active fire safety measures. Prescriptive and some performance based codes provide requirements to achieve this level of safety without explicitly quantifying it. Here, a reliability based method is used to quantify the level of safety of a design. A generic representation of the building facilitates the application of the methodology on different buildings and to consider the requirements of the codes. Engineering models are used to consider the effect of fire safety measures including the fire brigade intervention under realistic fire conditions. The uncertainties associated with these engineering models are considered through a probabilistic approach. The reliability of the structure is assessed through an advanced Monte Carlo technique called subset simulation. The methodology is applied for retail buildings. The benefits using performance based codes are addressed and compared with the results of prescriptive codes. The methodology can be used for verifying equivalency in fire safety design as well.","PeriodicalId":12145,"journal":{"name":"Fire Safety Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85467758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computer Modeling for Fire and Smoke Dynamics in Enclosures: A Help or a Burden?","authors":"B. Merci","doi":"10.3801/iafss.fss.11-46","DOIUrl":"https://doi.org/10.3801/iafss.fss.11-46","url":null,"abstract":"Fire simulations are of unique value in different respects: for fire safety system design calculations, for improving our understanding (theory and model development and validation) and for fire forecasting. In this paper the effective use of computing power for the further development of fire safety science is discussed, considering only gas phase phenomena in fire and smoke dynamics in enclosures. Arguably, much effort needs to be devoted to multi-phase phenomena (pyrolysis modeling, the effect of water or other suppressants, etc.), but this is not discussed in the paper at hand. A common feature to all types of simulations is that the Required Computing Resources (RCR), determined by the envisaged accuracy and the complexity of the problem to be tackled, must be less than the Available Computing Resources (ACR). Accuracy, reliability and dimensionality of the models used, must therefore be related to the problem tackled. In order to make progress, bench-marking studies, as a joint effort made by modelers and experimentalists, with transparent communication, are argued to be a good approach for systematic progress in the development of, and confidence in, models. Using Computational Fluid Dynamics (CFD) can be very valuable for the development of theory and the study of detailed fluid mechanics phenomena, but several aspects are important to guarantee the quality of the results. Some ideas will be formulated on how to investigate requirements on the computational mesh. Turbulence - chemistry interaction (TCI) and turbulence - radiation interaction (TRI) are also discussed briefly. Yet, it is argued that a major source of uncertainty in computer simulations stems from (and will continue to stem from) the characterization of the ever changing and developing materials (i.e. the fuel), as well as from geometry dependent features (including ventilation and heat transfer). This affects the combustion and soot formation, and therefore the fire and smoke dynamics. Therefore, a user-defined fire will remain indispensible in the foreseeable future when using computer modeling for the sake of design of fire safety systems. Once this fire has been defined, CFD is best suited in regions where detail is required or complex flow patterns establish, while other forms of modeling can be considered in other regions. For real-time and forecasting applications, it is argued that sensor-assisted numerical simulations are very promising and their use is expected to become widespread in the coming decades. With increasing computing power, the use of CFD will become more feasible in this context, but for the time being zone model calculations (perhaps combined with CFD in regions where more detail is required) seem better suited to that purpose.","PeriodicalId":12145,"journal":{"name":"Fire Safety Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81445503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Thickness and Ignition Location on Flame Spread Rates in Furniture Calorimeter Tests of Polyurethane Foam","authors":"Luke D. Robson, D. Torvi, M. Obach, E. Weckman","doi":"10.3801/iafss.fss.11-248","DOIUrl":"https://doi.org/10.3801/iafss.fss.11-248","url":null,"abstract":"Furniture calorimeter tests of polyurethane foam specimens were conducted to determine the effects of ignition location and specimen thickness on measured flame spread rates. These measurements were made using a new procedure that measured flame areas using infrared video records. Furniture calorimeter tests were conducted using specimens with thicknesses ranging between 2.5 cm and 10 cm, which were ignited in either the centre or on one edge. Flame spread rates increased with foam thickness, and flame spread rates in centre ignition tests were quicker than in edge ignition tests. These flame spread measurements will be used in a model, along with heat release rate data from cone calorimeter tests of the same foam, in order to predict heat release rates in furniture calorimeter tests of polyurethane foam slabs.","PeriodicalId":12145,"journal":{"name":"Fire Safety Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82394874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of Fire Scenarios for Car Parking Buildings using Risk Analysis","authors":"M. Tohir, M. Spearpoint","doi":"10.3801/iafss.fss.11-944","DOIUrl":"https://doi.org/10.3801/iafss.fss.11-944","url":null,"abstract":"This paper describes a relatively simple probability quantitative risk analysis model to determine appropriate fire scenarios for car parking buildings. The approach introduces a dimensionless measurement defined as fire risk level by multiplying probability by consequence. For the development of fire scenarios for car parking buildings, the key variables for the fire risk analysis are identified as vehicle parking distribution probability and how vehicles then form clusters of neighbours, vehicle classification, vehicle fire involvement probability, and the severity of vehicle fires. The selection of clusters of neighbouring vehicles and whether all vehicles in the cluster catch fire has the probability to affect the fire risk level. An example analysis is performed where a simple two-row, 100 space parking model with a 75 % vehicle occupancy and 0.90 tendency factor weighting is used to obtain the vehicle distribution probability combined with various data sourced from the literature. It is found from the example analysis that fire risk level is largely driven by the vehicle fire involvement probability such that a single vehicle fire presents the worst case scenario in terms of fire risk.","PeriodicalId":12145,"journal":{"name":"Fire Safety Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90401115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Research on Upslope Fire and Jump Fire","authors":"Xiaodong Xie, Naian Liu, D. Viegas, J. Raposo","doi":"10.3801/iafss.fss.11-1430","DOIUrl":"https://doi.org/10.3801/iafss.fss.11-1430","url":null,"abstract":"This paper presents an elementary analysis on the difference and similarity between upslope fire and jump fire, by a series of experiments performed in laboratory. The rate of spread (ROS), fire line angle (separation angle of the two fire lines), angular velocity of fire line, flame residence time and nondimensional radiant heat transfer for the two kinds of phenomena are investigated. For upslope fire, it is found that ROS remains almost steady for line ignition, while it increases with time for point ignition. For upslope fires with line ignition, the fire line angle decreases with time from the initial 180 o to a steady small value, while for point ignition, the initially generated fire line angle remains steady. The angular velocity of fire line does not depend on slope angle in an upslope fire with line ignition. For jump fire, the ROS first increases sharply and then decreases gradually, and it depends on slope angle more significantly than the initial fire line angle. The fire line angle increases with time, and the angular velocity of fire line varies with slope angle. For upslope fires with line ignition, the flame residence time increases with slope angle, while it remains almost constant for upslope tests with point ignition. For jump fire, under one specific initial fire line angle, the overall mean residence time increases with increasing slope angle. Nondimensional heat radiation for fuel preheating is calculated which effectively explains the ROS development in upslope fire with line ignition and jump fire.","PeriodicalId":12145,"journal":{"name":"Fire Safety Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90419872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Nickel-containing Ligand on Thermal Stability and Combustible Property of Poly(lactic acid)","authors":"X. Shan, S. Lo, Q. Tai, Z. Gui, Yuan Hu, S. Jiang","doi":"10.3801/iafss.fss.11-874","DOIUrl":"https://doi.org/10.3801/iafss.fss.11-874","url":null,"abstract":"Nickel-containing ligand (L.) decorated with molybdenum and 1h-pyrazole template was prepared by the hydrothermal method. Then it was added in poly(lactic acid) (PLA) matrix. One goal of this work was to investigate the effect of L. on thermal stability and combustible property of PLA matrix. The structure and property of L. were characterized by fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). The thermal properties of composites were tested by TGA, differential scanning calorimetry (DSC) and real time fourier transform infrared (RTIR). Combustible properties were researched by microscale combustion calorimetry (MCC). The volatilized products after the sample pyrolysis were also discussed. The thermal stability and combustible property analyses indicated that L. had positive effect in PLA matrix. Dynamic mechanical analysis (DMA) was used to measure the mechanical strength of PLA composites.","PeriodicalId":12145,"journal":{"name":"Fire Safety Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86478778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Utilization of the Haddon Matrix to Organize Factors of Survived Accidental Residential Fires: Frequencies for Human, Agent, and Environment-related Variables","authors":"Lin Xiong, M. Ball, D. Bruck","doi":"10.3801/iafss.fss.11-1049","DOIUrl":"https://doi.org/10.3801/iafss.fss.11-1049","url":null,"abstract":"Drawing upon interviews of 183 people who have survived accidental residential fires, this study adopted the basic concepts (human, agent, environment) of the Haddon Matrix to organize factors associated with survived accidental residential fires where there was no fire death or serious injury with extended hospitalization involved. Human activities during a fire were also identified, including how people first alerted to the presence of a fire and how they attempted to extinguish a fire. Electrical failure and unattended cooking were found to be the leading causes of survived fires. Kitchens and bedrooms were reported as the main rooms of fire origin. The study revealed four important new findings. These new findings are: 1) people’s knowledge of fire safety and awareness of unsafe fire behaviours was extremely limited; 2) an overwhelming majority of hosts had previous fire experiences at the time of the survey; 3) risk factors that are documented elsewhere to be highly related to fire fatalities were found not to be closely related to survived fires, such as alcohol, drugs, smoking, and being asleep; and 4) the majority of hosts took proactive actions when facing a fire, such as calling fire brigade, attempting to extinguish a fire, and trying to alert others. The Haddon Matrix was found to be a useful tool for organizing a wide range of relevant accidental residential fire variables, with the current paper presenting important new information about the frequencies of such variables where no fire death or serious injury has occurred.","PeriodicalId":12145,"journal":{"name":"Fire Safety Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75928216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Study on Thermal Breakage of Four-Point Fixed Glass Façade","authors":"Yu Wang, Qingsong Wang, G. Shao, Haodong Chen, Yanfei Su, Jinhua Sun, Linghui He, J. Wen, R. Zong, K. Liew","doi":"10.3801/iafss.fss.11-666","DOIUrl":"https://doi.org/10.3801/iafss.fss.11-666","url":null,"abstract":"As the weakest part of building facades, glass panels can easily break in fires and change the compartment fire dynamics by creating new openings for air to enter. A series of full scale tests were conducted to investigate the thermal breakage and fallout of four-point fixed glass facades, in which glass panes of 1200 × 1200 × 6 (mm 3 ) were placed at 35, 45, 50 and 70 (cm) away from n-heptane pool fires on a 500 × 500 (mm 2 ) square pan. Both float and toughened glasses were investigated. The glass surface temperature, gas temperature at the centre of the exposed side and heat release rate were measured and analyzed. The cracking patterns and glass fallout processes were recorded by digital camera. It is found that all the cracks initiated from the fixed point and their intersections formed islands to cause glass pieces fallout when the exposed side reached around 200-300 °C for the float glasses tested. The fallout fractions suggest that once the first crack is initiated, the point-supported glass panes are much more easily to fallout than edge covered glasses. The toughened glass panes were found to be softened by the fire and bent, but they did not crack even when the fire directly impinged on them.","PeriodicalId":12145,"journal":{"name":"Fire Safety Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89811719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Application Method of Free Burn HRR Data to Room Fire Scenarios","authors":"Yusuke Shintani, T. Nagaoka, Y. Deguchi, Kazuyo Harada","doi":"10.3801/iafss.fss.11-276","DOIUrl":"https://doi.org/10.3801/iafss.fss.11-276","url":null,"abstract":"An application method of free burn heat release rate (HRR) data for a single seater sofa to predict the burning behavior in a compartment is proposed. A single seater sofa was burnt in an open environment to measure the HRR using a furniture calorimeter. The time-HRR curve was fitted with a model of burning of a cubic polyurethane block developed earlier. The model included the flame spread over horizontal, downward and lateral directions. The flame spread rates were increased if the block received radiative heat from external heat sources other than from the flame. The thermal radiation feedback from the flame, smoke layer, and heated wall surfaces was coupled with the burning model. Using the coupled model, the burning and spread rate of several sofas and a table in a small compartment was calculated and compared with experimental results. The model could reproduce the trend for the increase in HRR qualitatively. However, the time to spread to an adjacent object was not in good agreement. If the time to spread was given input to the model, other parameters such as compartment temperature and so on could be calculated with reasonable agreement.","PeriodicalId":12145,"journal":{"name":"Fire Safety Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78597429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}