Pub Date : 2014-01-01DOI: 10.3801/iafss.fss.11-1430
Xiaodong Xie, Naian Liu, D. Viegas, J. Raposo
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.
{"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":"2 3 1","pages":"1430-1442"},"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}
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.
{"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":"5 1","pages":"46-65"},"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}
Pub Date : 2014-01-01DOI: 10.3801/iafss.fss.11-905
Franz Evegren, M. Rahm, M. Arvidson, T. Hertzberg
Reduced weight makes use of fiber reinforced polymer composite desirable in maritime construction applications. Exterior ship surfaces in combustible materials are although not covered by fire safety regulations and their fire protection is therefore a key issue. This paper reports how SP FIRE 105, a standardized test method for testing reaction to fire properties of facade systems, was adjusted and used to evaluate the potential for fire growth on external combustible ship surfaces; in particular fiber reinforced polymer composite surfaces protected with active or passive measures. The trials show that the test method is highly suitable but that some adjustments could be made to reduce uncertainties; in particular to use a gas burner instead of a heptane pool fire source and to add a strong criterion for when to activate active measures. Further efforts should also be made to develop suitable performance criteria, which were suggested to be based on the produced heat and the gas temperatures at the top of the panel.
减轻重量使得纤维增强聚合物复合材料在海上建筑应用中是理想的。船舶外部表面的可燃材料虽然不受消防安全法规的保护，但其防火是一个关键问题。本文报告了如何调整SP FIRE 105(一种测试立面系统对火灾性能反应的标准化测试方法)并将其用于评估船舶外部可燃物表面的火灾增长潜力;特别是用主动或被动措施保护的纤维增强聚合物复合材料表面。试验表明，该测试方法是非常合适的，但可以进行一些调整，以减少不确定性;特别是使用燃气燃烧器代替庚烷池火源，并为何时启动主动措施增加一个强有力的标准。还应进一步努力制定适当的性能标准，建议以产生的热量和面板顶部的气体温度为基础。
{"title":"Fire testing of external combustible ship surfaces","authors":"Franz Evegren, M. Rahm, M. Arvidson, T. Hertzberg","doi":"10.3801/iafss.fss.11-905","DOIUrl":"https://doi.org/10.3801/iafss.fss.11-905","url":null,"abstract":"Reduced weight makes use of fiber reinforced polymer composite desirable in maritime construction applications. Exterior ship surfaces in combustible materials are although not covered by fire safety regulations and their fire protection is therefore a key issue. This paper reports how SP FIRE 105, a standardized test method for testing reaction to fire properties of facade systems, was adjusted and used to evaluate the potential for fire growth on external combustible ship surfaces; in particular fiber reinforced polymer composite surfaces protected with active or passive measures. The trials show that the test method is highly suitable but that some adjustments could be made to reduce uncertainties; in particular to use a gas burner instead of a heptane pool fire source and to add a strong criterion for when to activate active measures. Further efforts should also be made to develop suitable performance criteria, which were suggested to be based on the produced heat and the gas temperatures at the top of the panel.","PeriodicalId":12145,"journal":{"name":"Fire Safety Science","volume":"1 1","pages":"905-918"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83049601","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}
Pub Date : 2014-01-01DOI: 10.3801/iafss.fss.11-248
Luke D. Robson, D. Torvi, M. Obach, E. Weckman
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.
{"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":"16 1","pages":"248-261"},"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}
Pub Date : 2014-01-01DOI: 10.3801/iafss.fss.11-895
Weizhao Hu, Lei Song, Jian Wang, Y. Hu, Ping Zhang
In order to improve the dispersion and fire retardant property in epoxy resin (EP), graphene oxide (GO) was functionalized via surface modification by a flame retardant which was synthesized by the reaction of methyl dichlorophosphate and 10-(2,5-dihydroxyl-phenyl)-9,10-dihydro-9-oxa-10-phosphaphenan-threne-10-oxide (DOPO-BQ). The property of functionalized GO (FGO) was characterized by fourier transform infrared spectroscopy, H- and P- nuclear magnetic resonance, X-Ray photoelectron spectroscopy and thermogravimetric analysis (TGA). Series different ratios of GO- and FGO- epoxy nanocomposites were obtained by in situ polymerization. The incorporation of FGO enhanced the thermal stability and flame retardancy of epoxy nanocomposites effectively. The thermal properties of the nanocomposites were investigated by TGA test in nitrogen atmosphere, indicating that FGO can improve the char residues. The flame retardancy of the nanocomposites was characterized by cone calorimeter test. The results showed that the incorporation of 2 wt.% FGO into EP decreased the value of peak heat release rate, total heat release, average effective heat of combustion, peak values of the CO release rate and CO2 release rate by 25%, 28%, 29.5%, 27% and 29%, respectively. This work confirms that the FGO is an effective solution for improving the thermal stability and flame retardancy of epoxy resins.
{"title":"Covalent functionalization of graphene oxide with flame retardant and its effect on thermal stability and flame retardancy of epoxy composites","authors":"Weizhao Hu, Lei Song, Jian Wang, Y. Hu, Ping Zhang","doi":"10.3801/iafss.fss.11-895","DOIUrl":"https://doi.org/10.3801/iafss.fss.11-895","url":null,"abstract":"In order to improve the dispersion and fire retardant property in epoxy resin (EP), graphene oxide (GO) was functionalized via surface modification by a flame retardant which was synthesized by the reaction of methyl dichlorophosphate and 10-(2,5-dihydroxyl-phenyl)-9,10-dihydro-9-oxa-10-phosphaphenan-threne-10-oxide (DOPO-BQ). The property of functionalized GO (FGO) was characterized by fourier transform infrared spectroscopy, H- and P- nuclear magnetic resonance, X-Ray photoelectron spectroscopy and thermogravimetric analysis (TGA). Series different ratios of GO- and FGO- epoxy nanocomposites were obtained by in situ polymerization. The incorporation of FGO enhanced the thermal stability and flame retardancy of epoxy nanocomposites effectively. The thermal properties of the nanocomposites were investigated by TGA test in nitrogen atmosphere, indicating that FGO can improve the char residues. The flame retardancy of the nanocomposites was characterized by cone calorimeter test. The results showed that the incorporation of 2 wt.% FGO into EP decreased the value of peak heat release rate, total heat release, average effective heat of combustion, peak values of the CO release rate and CO2 release rate by 25%, 28%, 29.5%, 27% and 29%, respectively. This work confirms that the FGO is an effective solution for improving the thermal stability and flame retardancy of epoxy resins.","PeriodicalId":12145,"journal":{"name":"Fire Safety Science","volume":"170 1","pages":"895-904"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80668363","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}
Pub Date : 2014-01-01DOI: 10.3801/iafss.fss.11-874
X. Shan, S. Lo, Q. Tai, Z. Gui, Yuan Hu, S. Jiang
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.
{"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":"22 1","pages":"874-882"},"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}
Pub Date : 2014-01-01DOI: 10.3801/iafss.fss.11-666
Yu Wang, Qingsong Wang, G. Shao, Haodong Chen, Yanfei Su, Jinhua Sun, Linghui He, J. Wen, R. Zong, K. Liew
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.
{"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":"42 1","pages":"666-676"},"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}
Pub Date : 2014-01-01DOI: 10.3801/IAFSS.FSS.11-289
U. Wickström, Alexandra Byström
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.
{"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":"39 1","pages":"289-301"},"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}
Pub Date : 2014-01-01DOI: 10.3929/ETHZ-A-010194560
G. D. Sanctis, M. Faber, M. Fontana
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.
{"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":"4 1","pages":"996-1009"},"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}
Pub Date : 2014-01-01DOI: 10.3801/iafss.fss.11-432
N. Johansson, P. Hees
The mass flow of air through an opening in a well-mixed compartment fire can be calculated with a simple expression. Similar simple models are lacking for the stratified pre-flashover case. Usually an advanced computer model is required to calculate the mass flow through an opening in a pre-flashover compartment fire. However, two equations for the opening mass flow through an opening are presented and validated in this paper. The presented equations are predominantly valid for temperatures above 200°C and predictions with the equations are shown to be within 10% of results from computer simulations and experimental measurements. The equations can also be combined with existing plume models in order to give an estimate of the hot layer height in a compartment fire with a predefined heat release rate. (Less)
{"title":"A Simplified Relation Between Hot Layer Height and Opening Mass Flow","authors":"N. Johansson, P. Hees","doi":"10.3801/iafss.fss.11-432","DOIUrl":"https://doi.org/10.3801/iafss.fss.11-432","url":null,"abstract":"The mass flow of air through an opening in a well-mixed compartment fire can be calculated with a simple expression. Similar simple models are lacking for the stratified pre-flashover case. Usually an advanced computer model is required to calculate the mass flow through an opening in a pre-flashover compartment fire. However, two equations for the opening mass flow through an opening are presented and validated in this paper. The presented equations are predominantly valid for temperatures above 200°C and predictions with the equations are shown to be within 10% of results from computer simulations and experimental measurements. The equations can also be combined with existing plume models in order to give an estimate of the hot layer height in a compartment fire with a predefined heat release rate. (Less)","PeriodicalId":12145,"journal":{"name":"Fire Safety Science","volume":"6 1","pages":"432-443"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74394350","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：