首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到9条相似文献,搜索用时 15 毫秒
1.
Estimation of the time available for escape (ASET) in the event of a fire is a principal component in fire hazard or risk assessment. Valid data on the yields of toxic smoke components from bench‐scale apparatus is essential to accurate ASET calculations. This paper presents a methodology for obtaining pre‐flashover and post‐flashover toxicant yields from room‐scale fire tests. The data are to be used for comparison with bench‐scale data for the same combustibles: a sofa, bookcases, and electric power cable. Each was burned in a room with a long adjacent corridor. The yields of CO2, CO, HCl, HCN, and soot were determined. Other toxicants (NO2, formaldehyde, and acrolein), whose concentrations were below the detection limits, were of limited importance relative to the detected toxicants. The uncertainty values were comparable to those estimated for calculations used to determine ASET and were sufficiently small to determine whether a bench‐scale apparatus is producing results that are similar to the real‐scale results here. The use of Fourier transform infrared spectroscopy was useful for obtaining toxicant concentration data; however, its operation and interpretation are not routine. The losses of CO, HCN, and HCl along the corridor were dependent on the combustible. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

2.
The development of fire‐safety measures for high‐speed passenger trains has been focused on preventing fire initiation or delaying fire growth and spread through small‐scale tests of the materials used in trains. However, new fire‐safety approaches for trains consider a systemic approach. This approach considers numerous global factors that influence fire dynamics, such as the influence of vehicle design, selection of materials, and active and passive protection systems installed. In the present paper, the results of small‐scale and full‐scale tests carried out on the new generation of high‐speed trains operating in Spain are presented. This rolling stock is classified as category B according to the Technical Specification for Interoperability and Operation Category 3 according to EN 45545–1. The results confirmed good fire behaviour using both approaches (small and full‐scale tests). Additionally, several analyses have been performed, including an analysis of the quality of materials used for making different components of the passenger compartment and the influence of ignition source position on fire development. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

3.
The hazards for passengers during vehicle fires result from the increasing temperature and the emitted smoke gases. A fire was set on a car to investigate the development of temperature and of gaseous fire products in the passenger compartment. The study was based on a full‐scale test with a reconstructed scene of a serious car fire. The aim of this work was to identify the conditions for self‐rescuing of passengers during a car fire. A dummy, equipped with several thermocouples, was placed on the driver's seat. Also, the smoke gases were continuously collected through a removable probe sensor corresponding to the nose of the dummy in the passenger compartment and analyzed using Fourier transform infrared spectroscopy. Additionally, several car components were investigated in the smoke density chamber (smoke emission and smoke gas composition). It was found that the toxic gases already reached hazardous levels by 5 min, while the temperatures at the dummy were at that time less than 80 °C. The toxicity of smoke gases was assessed using the fractional effective dose concept. The various experimentally parameters (temperature and smoke gas composition) were implemented into numerical simulations with fire dynamics simulator. Both the experimental data and the numerical simulations are presented and discussed. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

4.
About 80% of all fire fatalities in Germany occur because of fires in homes. It has been known for some time that modern materials (synonym for materials consisting mostly of synthetic polymers) tend to burn differently from older materials (synonym for materials consisting mostly of fibrous cellulosic substances) and it has been acknowledged that the amount of combustible plastics in homes has increased significantly over the last decades. To investigate the influence of modern furniture and ventilation conditions of fires in homes, a series of four large‐scale tests in two living rooms (LRs) with adjacent rooms (ARs) was performed by BAM and the Frankfurt fire service. Two LRs, one with older furniture and one with modern furniture, were tested twice each. Each test started with the ignition of a paper cushion on an upholstered chair. The influence of modern materials on the fire development was investigated, as well as the influence of the ventilation on the fire development. In all settings, an upholstered chair was the first burning item. Results of the test series show that fires in rooms with modern furniture develop faster than fires in rooms with older furniture. This is true for temperature development in the rooms as well as for smoke production.  相似文献   

5.
The literature on rigid polyurethane foam has been reviewed with an emphasis on the gaseous products generated under various thermal decomposition conditions and the toxicity of those products. This review is limited to publications in English through 1984. Carbon monoxide (CO) and hydrogen cyanide (HCN) were the predominant toxicants found among more than a hundred other gaseous products. The generation of CO and HCN was found to increase with increasing combustion products from various rigid polyurethane foams. Lethality, incapacitation, physiological and biochemical parameters were employ as biological end points. In general, the combustion products generated from rigid polyurethane foam in the flaming mode appear from to be more toxic than those produced in the non-flaming mode. The LC50 values for 30-min exposures ranged from 10 to 17 mg l?1 in the flaming mode and were greater then 34 mg l?1 in the non-flaming mode. With the exception of one case, in which a reactive type phosphorus containing fire retardant was used, the addition of fire retardants to rigid polyurethane foams does not appear to generate unusual toxic combustion products.  相似文献   

6.
The recently approved EU Construction Products Regulation (CPR) applies to cables as construction products. The difficulty of predicting the fire performance of cables with respect to propagation of flame and contribution to fire hazards is well known. The new standard EN 50399 describes a full‐scale test method for the classification of vertically mounted bunched cables according to CPR. Consideration of the material, time, and thus cost requires an alternative bench‐scale fire test, which finds strong demand for screening and development purposes. The development of such a bench‐scale fire test to assess the fire performance of multiple vertically mounted cables is described. A practical module for the cone calorimeter is proposed, simulating the fire scenario of the EN 50399 on the bench scale. The efficacy of this module in predicting full‐scale CPR test results is shown for a set of 20 different optical cables. Key properties such as peak heat release rate (PHRR), fire growth rate (FIGRA), and flame spread are linked to each other by factors of around 5. In a case study, the bench‐scale test designed was used to investigate the influence of the main components on the fire behaviour of a complex optical cable. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

7.
8.
Ammonium, iron, manganese and hydrogen sulfide are a serious problem for water reservoirs all over the world. The aim of this work was the design, construction and operation of a full‐scale trickling filter for the simultaneous removal of the above pollutants. The long‐term removal efficiency and the effect of environmental and operating conditions on filter performance were studied. Start‐up time of the filter was minimized using as inoculum backwash water from an existing pilot‐scale plant, while natural advection was adequate to provide sufficient aeration. Redox potential variation throughout the filter depth enhanced simultaneous removal of the pollutants. Under steady operating conditions the filter presented perfect performance, while under pollutant concentration and/or hydraulic loading shocks the filter retained high removal efficiency. Seasonal or daily temperature variations did not affect filter performance since raw water temperature was constant at 20 °C. The proposed system exhibited high pollutant removal rates for all hydraulic and pollutant loadings tested, under various environmental conditions. The simplicity of the installation and the minimal operating cost provide an effective solution to a serious environmental and social problem. Copyright © 2010 Society of Chemical Industry  相似文献   

9.
Herein, we describe a reduced‐scale test (“Cube” test), measuring the fire performance of specimens including a fire barrier (FB) and a flammable core material, which acts as the main fuel load. The specimen is intended to reproduce a cross‐section of a composite product where heat/mass transfer occurs primarily in a direction perpendicular to the FB. The Cube test procedure and benefits are discussed in this work by adopting residential upholstery furniture as an exemplary study. One flexible polyurethane foam, one polypropylene cover fabric, and 10 commercially available FBs were selected. They were used to compare the fire performance of FBs, measured in terms of peak of heat release rate, in the ASTM E1474‐14 standard test and the newly developed Cube test. Edge effects severely affected the performance of FBs in the ASTM E1474‐14 standard test but not in the Cube test. Furthermore, appropriate test conditions were determined in the Cube test to measure the so‐called “wetting point,” that is, the time and value of heat release rate measured when flammable liquid products were first observed on the bottom of the specimen. The relevance of the “wetting point” in terms of full‐scale fire performance and failure mechanism of FBs is discussed.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号