There are concerns on open kitchen fires in small flats of tall residential buildings. Flashover should be avoided in providing fire safety. It is believed that flashover of a compartment fire is a nonlinear physical process. In this article, nonlinear dynamics was used to study flashover in an example open kitchen fire. The mathematical model developed earlier by taking the fire compartment as a thermal system with a hot "smoke and air" layer and a cool air layer was taken as the simulation tool. The two-layer zone model was simplified by taking the smoke layer thickness at a constant value. The compartment fire was then studied with only one variable on the hot smoke layer temperature. The model was programmed in symbolic mathematics software. The single variable on smoke or hot air temperature is then analyzed for system stability. An example open kitchen was selected to illustrate the concept. Control parameters for flashover to occur have been identified for providing fire safety to open kitchens.
{"title":"Study on flashover in an open kitchen fire by nonlinear dynamics","authors":"F. Liang, S. D. Liu, W. Chow","doi":"10.2190/AF.23.2.D","DOIUrl":"https://doi.org/10.2190/AF.23.2.D","url":null,"abstract":"There are concerns on open kitchen fires in small flats of tall residential buildings. Flashover should be avoided in providing fire safety. It is believed that flashover of a compartment fire is a nonlinear physical process. In this article, nonlinear dynamics was used to study flashover in an example open kitchen fire. The mathematical model developed earlier by taking the fire compartment as a thermal system with a hot \"smoke and air\" layer and a cool air layer was taken as the simulation tool. The two-layer zone model was simplified by taking the smoke layer thickness at a constant value. The compartment fire was then studied with only one variable on the hot smoke layer temperature. The model was programmed in symbolic mathematics software. The single variable on smoke or hot air temperature is then analyzed for system stability. An example open kitchen was selected to illustrate the concept. Control parameters for flashover to occur have been identified for providing fire safety to open kitchens.","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"33 1","pages":"157-178"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88649038","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}
In order to study the effects of different wind direction on combustion characteristics of alcohol pool fires, an inclinable wind tunnel was developed for providing venting wind with different directions. The control parameters of the experiments include the tunnel wind velocity, which can be altered from 0 to 3.0 ms –1 , and the tunnel inclination angle, which can be sloped from 0°to 30°while the fuel pan keeping horizontal inside the tunnel. The results show that the mass burning rate increases faster with increasing the slope angle of the wind tunnel when the wind speed is less than 1.5 ms –1 .I n addition, a relationship between the mass burning rate of the pool fire and the wind direction has been determined, that agrees well with the experimental results.
为了研究不同风向对酒精池火灾燃烧特性的影响，设计了可倾斜风洞，提供不同方向的排气风。实验的控制参数包括风洞风速(可在0 ~ 3.0 ms -1范围内变化)和风洞倾角(可在0°~ 30°范围内变化，而燃料盘在风洞内保持水平)。结果表明:当风速小于1.5 ms -1 i时，随着风洞坡角的增大，池火的质量燃烧速率增加较快;此外，还确定了池火质量燃烧速率与风向的关系，与实验结果吻合较好。
{"title":"The effects of wind pressure on mass burning rates of alcohol pool fires in an inclined wind tunnel","authors":"C. Tao, Xishi Wang, Xiaonan Zhang","doi":"10.2190/AF.23.2.B","DOIUrl":"https://doi.org/10.2190/AF.23.2.B","url":null,"abstract":"In order to study the effects of different wind direction on combustion characteristics of alcohol pool fires, an inclinable wind tunnel was developed for providing venting wind with different directions. The control parameters of the experiments include the tunnel wind velocity, which can be altered from 0 to 3.0 ms –1 , and the tunnel inclination angle, which can be sloped from 0°to 30°while the fuel pan keeping horizontal inside the tunnel. The results show that the mass burning rate increases faster with increasing the slope angle of the wind tunnel when the wind speed is less than 1.5 ms –1 .I n addition, a relationship between the mass burning rate of the pool fire and the wind direction has been determined, that agrees well with the experimental results.","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"94 1","pages":"131-141"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80181539","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}
Different acid concentrations were used to synthesize triacetone triperoxid (TATP), which is simple and widely used as an explosive. Each combination was compounded with different thermal hazard characteristics. Methods are needed for the detection and comprehension of thermal decomposition of TATP. Differential scanning calorimetry (DSC) was used to scan the thermal decomposition of TATP, and gas chromatography and mass spectrometer (GC/MS) were employed to exactly affirm the synthesized TATP. In this study, description and analysis of the mechanism of TATP decomposition were provided. Thermokinetics received by Kissinger method and Ozawa method were presented.
{"title":"Thermal Hazard Assessment of Triacetone Triperoxide (TATP) Using Differential Scanning Calorimetry (DSC)","authors":"Nan-Chi Chen, Sheng-Hung Wu, Chih-Hsing Wang, Cheng-Liang Tsai, Yu-Tien Huang, Huei-Ming Shih","doi":"10.2190/AF.23.4.D","DOIUrl":"https://doi.org/10.2190/AF.23.4.D","url":null,"abstract":"Different acid concentrations were used to synthesize triacetone triperoxid (TATP), which is simple and widely used as an explosive. Each combination was compounded with different thermal hazard characteristics. Methods are needed for the detection and comprehension of thermal decomposition of TATP. Differential scanning calorimetry (DSC) was used to scan the thermal decomposition of TATP, and gas chromatography and mass spectrometer (GC/MS) were employed to exactly affirm the synthesized TATP. In this study, description and analysis of the mechanism of TATP decomposition were provided. Thermokinetics received by Kissinger method and Ozawa method were presented.","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"12 1","pages":"423-434"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90096335","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}
Canvas, a potential fire hazard in the buildings, may cause fire by overheating or short-circuit of household appliances. Once ignited, the flame of canvas would quickly spread upward and accelerate the fire development. In this article, upward flame spread over four typical canvas materials was tested in one large space enclosure. Fire thermal parameters such as mass loss rate, surface temperature, and flame spread rate were recorded and analyzed for all upward flame spread experiments. The results show that there is a linear relationship between raw canvases mass and time while a power function relationship between oil canvases mass and time. Surface temperature peak values in the range 400-900°C mainly depend on material characteristics rather than material size. Meanwhile we find that flame spread rate could be expressed as one power function of time. This means if canvas vertical fire is not controlled at fire ignition stage, canvas fire would spread increasingly fast which would cause a big fire hazard.
{"title":"Experimental study of upward flame spread over canvas hung in the air","authors":"Guoqing Zhu, Guowei Zhang, Lili Huang","doi":"10.2190/AF.23.3.G","DOIUrl":"https://doi.org/10.2190/AF.23.3.G","url":null,"abstract":"Canvas, a potential fire hazard in the buildings, may cause fire by overheating or short-circuit of household appliances. Once ignited, the flame of canvas would quickly spread upward and accelerate the fire development. In this article, upward flame spread over four typical canvas materials was tested in one large space enclosure. Fire thermal parameters such as mass loss rate, surface temperature, and flame spread rate were recorded and analyzed for all upward flame spread experiments. The results show that there is a linear relationship between raw canvases mass and time while a power function relationship between oil canvases mass and time. Surface temperature peak values in the range 400-900°C mainly depend on material characteristics rather than material size. Meanwhile we find that flame spread rate could be expressed as one power function of time. This means if canvas vertical fire is not controlled at fire ignition stage, canvas fire would spread increasingly fast which would cause a big fire hazard.","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"46 1","pages":"349-363"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86887378","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 the Thermal Stratification During the Quasi-Steady Region of the Fire Flow Field in a Small-Scale Corridor Model","authors":"Qinkun Xu, Lizhong Yang, Yuanchun Ding","doi":"10.2190/AF.23.4.L","DOIUrl":"https://doi.org/10.2190/AF.23.4.L","url":null,"abstract":"","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"61 1","pages":"551-568"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75120510","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}
Fang Tingyong, Xintao Zheng, Biteng Cao, Han Tingting
Numerous studies have been carried out on the temperature field of steel-concrete composite beams exposed to natural fire. The temperature variation process of indoor air, including heating and cooling phase subjected to natural fire, is simulated by using the fire dynamics software FDS, and the elevated temperature curve of air on the fire source is calculated, which is different from ISO834 standard fire curve. According to the curve, the thermal field of composite beams is analyzed by finite element analysis software ANSYS and the thermal field distribution of composite beams is obtained. The web temperature reaches 718.4°C, which is highest in the cross-section. Also, the influence of the thickness of protection layer on the thermal field under natural fire is investigated. The calculated results show that fire-retardant coating has a significant effect on the thermal field and can effectively improve the fireproof time in fire. The climbing rate of the internal temperature in the composite beams will reduce gradually and the peak temperature will decrease obviously with the increment of the coating thickness.
{"title":"Nonlinear analysis of temperature field of steel-concrete composite beams subjected to natural fire","authors":"Fang Tingyong, Xintao Zheng, Biteng Cao, Han Tingting","doi":"10.2190/AF.23.4.A","DOIUrl":"https://doi.org/10.2190/AF.23.4.A","url":null,"abstract":"Numerous studies have been carried out on the temperature field of steel-concrete composite beams exposed to natural fire. The temperature variation process of indoor air, including heating and cooling phase subjected to natural fire, is simulated by using the fire dynamics software FDS, and the elevated temperature curve of air on the fire source is calculated, which is different from ISO834 standard fire curve. According to the curve, the thermal field of composite beams is analyzed by finite element analysis software ANSYS and the thermal field distribution of composite beams is obtained. The web temperature reaches 718.4°C, which is highest in the cross-section. Also, the influence of the thickness of protection layer on the thermal field under natural fire is investigated. The calculated results show that fire-retardant coating has a significant effect on the thermal field and can effectively improve the fireproof time in fire. The climbing rate of the internal temperature in the composite beams will reduce gradually and the peak temperature will decrease obviously with the increment of the coating thickness.","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"121 1","pages":"381-393"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75128604","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":"Smoke Density in a Sealed Compartment","authors":"Qiang Li, Shouxiang Lu, Jiaqing Zhang, B. Chen","doi":"10.2190/AF.23.1.A","DOIUrl":"https://doi.org/10.2190/AF.23.1.A","url":null,"abstract":"","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"16 1","pages":"1-14"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75380903","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":"Comparative Study of Evacuation Efficiency Using Stairs and Elevators in High-Rise Buildings","authors":"Zhu Kong-jin, Y. Lizhong, Zhan Xin, Ding Yuanchun","doi":"10.2190/AF.23.1.G","DOIUrl":"https://doi.org/10.2190/AF.23.1.G","url":null,"abstract":"","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"24 1","pages":"105-113"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73679747","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":"A Numerical Study on the Influence of Smoke Vent Height on Mechanical Smoke Exhaust Efficiency for Platform Fire in a Subway Station","authors":"N. Meng, L. Hu, Lizhong Yang","doi":"10.2190/AF.23.4.J","DOIUrl":"https://doi.org/10.2190/AF.23.4.J","url":null,"abstract":"","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"15 1","pages":"517-527"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78413532","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}
This article is concerned with the problem of modeling and simulation of occupant evacuation process in public buildings under emergent conditions. First, the six floors' building models with two types of staircases respectively are constructed by Pathfinder. Based on this obtained model, 2, 10, 20, 30, 50, and 100 occupants respectively on each floor are adopted to do the simulation. RESULTS show evacuation time almost is a monotonically increasing linear function to the number of occupants when the number of occupants on each floor is more than a limitation, and staircase of bifurcated type can evacuate the occupants more effectively than double-flight staircase. Second, another situation, which includes some obstacle on the stair, is considered, and the results also show evacuation time is a monotonically increasing function to the number of occupants when there is an obstacle on the stair, and the anti-obstacle performance of the double-flight staircase is better than that of the staircase of bifurcated type.
{"title":"Occupant evacuation process study of public buildings based on computer modeling and simulation","authors":"Yuanchun Ding, Lizhong Yang","doi":"10.2190/AF.23.3.H","DOIUrl":"https://doi.org/10.2190/AF.23.3.H","url":null,"abstract":"This article is concerned with the problem of modeling and simulation of occupant evacuation process in public buildings under emergent conditions. First, the six floors' building models with two types of staircases respectively are constructed by Pathfinder. Based on this obtained model, 2, 10, 20, 30, 50, and 100 occupants respectively on each floor are adopted to do the simulation. RESULTS show evacuation time almost is a monotonically increasing linear function to the number of occupants when the number of occupants on each floor is more than a limitation, and staircase of bifurcated type can evacuate the occupants more effectively than double-flight staircase. Second, another situation, which includes some obstacle on the stair, is considered, and the results also show evacuation time is a monotonically increasing function to the number of occupants when there is an obstacle on the stair, and the anti-obstacle performance of the double-flight staircase is better than that of the staircase of bifurcated type.","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"144 1","pages":"365-380"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77477197","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}
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