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节能建筑需要优质保温材料 总被引:1,自引:0,他引:1
易宗文 《保温材料与节能技术》2009,(5):I0001-I0002
专家认为,聚氨酯泡沫燃烧产生毒性气体,不是不可改变的,更不是必然的,这主要取决于聚氨酯泡沫结构,以及采取何种阻燃剂和抑烟剂;通过科学方法,完全可以研制成燃烧产物烟密度小、毒性低的聚氨酯泡沫产品。聚氨酯是一类含有重复氨基甲酸酯链段的高分子化合物。近20年间,聚氨酯的平均增长速度超过了12%, 相似文献
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对模塑聚苯乙烯泡沫板(EPS),挤塑聚苯乙烯泡沫板(XPS)和聚异氰酸酯-聚氨酯泡沫板(PIR-PU)的热分解行为、燃烧行为、燃烧烟气中的主要毒害气体和热裂解产物进行了研究.结果表明:PIR-PU的初始分解温度和最大热分解温度明显低于EPS和XPS,EPS和XPS的热分解行为基本相同,高温下PIR-PU的残炭率高,而EPS和XPS基本不成炭;PIR-PU的热释放速率、总热释放量、生烟速率和总生烟量均明显低于EPS和XPS,但PIR-PU点燃时间比EPS和XPS短;PIR-PU,EPS和XPS的燃烧烟气中均存在CO和HCN等毒害气体,有效剂量分数(FED值)表明PIR-PU的燃烧烟气毒性最大;PIR-PU热裂解产物中的异氰酸酯衍生物、苯胺衍生物和含氯阻燃剂是其燃烧生成HCN和HCl的主要原因,而EPS和XPS热裂解产物中大量的芳香族衍生物是其生烟量较大的一个重要原因. 相似文献
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选择不同添加型阻燃剂,采用一步发泡法制备了软质聚氨酯泡沫(FPUF)。通过氧指数测试、锥形量热仪测试和产烟毒性测试研究其燃烧性能。结果表明:采用质量分数为10%的溴系阻燃剂和10%的MPOP制备的FPUF阻燃效果较好。在辐射照度30kW/m2、样品厚度50mm条件下,溴系阻燃剂和MPOP制备的FPUF的热释放速率峰值降低到284.0、270.8kW/m2。但前者烟气毒性带来的危害更大,当溴系阻燃剂质量分数超过4%时烟气毒性等级达到WX级。 相似文献
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摘 要:以现行燃烧性能分级框架内的小尺度动态管式炉法和中尺度单体燃烧试验为产烟模型,选取典型阻燃和非阻燃材料开展燃烧产烟试验,利用FTIR等气体分析技术实时测量烟气组分数据,借助有效剂量分数(FED)等计算模型进行烟气毒性量化研究。结果表明:根据动态管式炉产烟气体分析计算的FED1值约为单体燃烧试验FED3max值的4~17倍;难燃材料单体燃烧试验获得的FED值较小,通常在0.15以下,而易燃材料的FED值则高达0.65;以小尺度动态管式炉和中尺度单体燃烧试验为产烟模型,应用毒性组分计算模型FED1和FED3,可对材料在火灾无焰燃烧(氧化热解)阶段和通风充足的有焰燃烧阶段的烟气毒性做出具有代表性的有效便捷评价。 相似文献
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吴芸 《消防技术与产品信息》2013,(8):103-106
在分析建筑有机保温材料火灾危险性的基础上,根据有机保温材料燃烧性能试验得到的热释放速率、燃烧热值、烟气释放速率、烟气毒性4个参数指标,建立了基于试验数据的有机保温材料火灾危险综合评价指标层次体系,并利用这4个参数对聚氨酯、橡塑海绵、挤塑板的火灾危险性逐项进行了比较。在此基础上采用AHP法原理对样品的火灾危险性进行了综合评价,结果表明,火灾综合危险性排序为聚氨酯〉橡塑海绵〉挤塑板。 相似文献
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以软质聚氨酯泡沫和聚苯乙烯泡沫颗粒两种典型多孔材料为试验对象,对其孔隙率、孔径分布、表观密度和堆积密度等结构特性参数及表面微观形貌进行了测算和表面扫描电镜(SEM)表征,研究不同热解程度材料结构特性演变与阴燃建立和传播趋势之间的关系。结果表明:软质聚氨酯泡沫结构尺寸更大,整体更为疏松,受热成炭后呈现轮廓清晰的细削骨架,孔隙硕大且畅通,氧气完全自由输运,热量传递更直接,更易建立阴燃、维持传播并实现向明火的转化;相对而言,聚苯乙烯泡沫颗粒孔径较为细小,受热后成炭显著,孔径尺寸减小,空气气流量和氧气容纳量大大减少,不易建立阴燃过程。 相似文献
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Patrick Havey Jeffrey T. Jaquay Maclain M. Holton Nasir Hussain Stephen M. Olenick 《Fire Technology》2018,54(6):1631-1654
Smoke alarms have been shown to develop sonically-deposited regions of acoustically agglomerated soot particles when they sound in smoke-filled air. These sonic depositions can be examined forensically post-fire to determine if the smoke alarm sounded during the incident. However, it is not clear how these sonic depositions are affected by common firefighting and post-fire actions. To determine the effects of post-fire forensic smoke alarm testing and environmental conditions on the persistence of the existing sonic deposition of soot on the horns of a smoke alarm, sixty (60) smoke alarms were subjected to smoke from fires of several different fuel types and common post-fire conditions or actions. Initially, each alarm was exposed to smoke in a small-scale experimental fire to develop sonic deposition around the horn. The fuel types for the fires were smoldering wood, flaming toluene–heptane, smoldering polyurethane foam, flaming polyurethane foam, and a combination of smoldering and flaming polyurethane foam. The alarms were then subjected to four common post-fire actions: pressing the test button, exposure to synthetic canned smoke, exposure to standing water, and exposure to running water. Each detector was visually inspected before and after the post-fire action. Results varied from no soot removed to almost all soot removed depending on the fuel type and post-fire test. An objective evaluation system was used to rank the degree to which soot was removed from the alarm horns: 0 (no soot removed), 1 (some soot removed), and 2 (all soot removed) based on visual inspection. The smoldering wood and smoldering polyurethane foam fires left behind a sticky resin that was essentially unaffected by any of the post-tests. The flaming foam and flaming toluene–heptane fires left powdery soot on the horn which could be easily wiped off. This soot was almost completely washed off by running water (1.067 average degree of removal) while the canned smoke and standing water post-tests removed a significant portion of the soot (0.533 and 1.000 average degrees of removal, respectively), which could lead an investigator to an errant sounding determination. Pressing the test-button appeared to make minimal impact on the amount of soot around the alarms horns regardless of the fuel type (0.067 average degree of removal). 相似文献
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C.L. Worrell J.A. Lynch G. Jomaas R.J. Roby L. Streit J.L. Torero 《Fire Technology》2003,39(4):309-346
A series of UL/EN based test fires was conducted in a two room/corridor enclosure to investigate the viability of methods for determining whether a smoke detector sounded under a variety of smoke conditions and to see if this methodology could be applied to a detector with a different horn configuration. The presence of enhanced deposition in the form of a black or orange-brown ring and agglomerates around the central opening of a smoke detector horn was found to be a reliable indicator that the horn sounded when it was exposed to smoke from eight standardized, single-substrate fuel sources including hydrocarbon pool, flaming polyurethane foam, and smoldering polyurethane foam fires. Determinations could generally not be made for detectors exposed to white or gray smoke generated by flaming paper, smoldering paper, flaming wood, smoldering wood, and smoldering cotton wick due to a general lack of visible soot deposition within the detector. Therefore, it is not recommended to use the absence of a black or orange-brown ring of enhanced deposition, in and of itself, as an indicator that the horn did not sound. Nevertheless, this conclusion can be reached when the absence of enhanced deposition is combined with evidence supporting the presence of flaming fuels that produce black, sooty smoke. Test series were conducted using two different smoke detector brands, each having a different horn configuration. Findings suggest that the same type of methodology for determining whether the detector sounded is applicable to both models. Chladni figures were not found on any of the smoke detectors, whether they sounded or not; hence, the absence of a Chladni figure was not an indicator that the detector did not sound. A smoke flow visualization technique was used to determine the mechanism that caused the observed enhanced deposition and agglomerates on horns that sounded during a smoke exposure. Additionally, a smoke box test series showed that the extent of observed soot deposition increased with increasing smoke exposure. 相似文献
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摘 要:以不同密度聚氨酯泡沫为研究对象,采用同步热分析(STA)和气相色谱-质谱联用技术(GC-MS),分析了聚氨酯泡沫塑料热解产物对汽油鉴定干扰性的影响。试验表明,聚氨酯泡沫塑料热解过程可分为两个阶段,80 kg/m3聚氨酯泡沫塑料第一阶段热解初始温度略低,质量损失率略大。聚氨酯泡沫塑料燃烧残留物中可检测到芳香烃、稠环芳烃和茚满类特征组分,但40 kg/m3聚氨酯泡沫塑料燃烧残留物检出的相似特征组分数量明显较多,因此,40 kg/m3聚氨酯泡沫塑料对汽油鉴定的干扰性高于80 mg/m3。 相似文献
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AMNON BAR-ILAN 《消防科学与技术》2006,25(2):176-184
试验主要观察处于阴燃状态的少量聚氨酯泡沫样品的流速、氧气浓度和辐射热通量对气/固界面的影响。因为此试验研究对象是少量聚氨酯汽沫,所以阴燃蔓延以厦转化到有焰燃烧时必须借助于降低热损失并同时增加其氧气浓度。试验中,我们把呈平行六面体的样品竖向放置在风道中。样品的其中三个侧边处在高温状态,第四边暴露在上升气流和辐射中。结果发现,随着气流流速的降低以度氧气浓度的增加,或者增加辐射通量,都会加快其变成有焰燃烧的过程,减少这种变化的延误时间。试验结果表明,炭化部位内部的有焰变化因阴燃作用而出现滞后,这已经通过超声波穿透样品内部得到了证实。笔者这里给出了简化了的分析,证明这种变化可以作为一个气相燃烧程序进行处理。 相似文献
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Thomas Cleary 《Fire Technology》2014,50(3):775-790
A series of 24 full-scale experiments was conducted to examine the effects of alarm type (photoelectric, ionization, and dual sensor), alarm location, fabric type (100% cotton and 100% polyester), polyurethane foam density, ignition scenario, and room configuration, on smoke alarm performance. A two-level, fractional factorial design of eight experimental configurations was developed around the five factors: fabric type, foam density, fire location, ventilation, and ignition scenario. A structure, designed to represent a single-story home or apartment, was constructed inside the Large Fire Laboratory at the National Institute for Standards and Technology for the experiments. The fire source was a chair mockup consisting of a seat and back cushion of a specific cover fabric and foam density, weighing between 5.5 kg and 8.3 kg. It rested on a metal frame and was subjected to a small propane gas flame, or an electric cartridge heater to initiate smoldering. Each experimental configuration was replicated three times. Smoldering fires were allowed to progress until they naturally transitioned to flaming fires except for one test that was terminated early due to time constraints. The smoldering to flaming transition times ranged from (81 to 182) min. Each fire progressed for a time sufficient to produce multiple hazards (smoke, heat, and toxic gases). All alarms tested were purchased from retail outlets and activated at their preset levels. Photoelectric, ionization, and dual photoelectric/ionization alarms were co-located at multiple locations to facilitate comparisons of each alarm type, and different designs of the same type of alarm. For smoke alarms in the room of fire origin, it was observed that each of the five factors had an effect on the measured alarm times that was primarily a result of fire growth rate (fabric type, foam density, and ignition scenario), or smoke dilution and transport (fire location and ventilation). The photoelectric alarm responded quicker on average than ionization alarm in two of four smoldering fire configurations, responding before the ionization alarm in all 6 trials, while the ionization alarm responded before the photoelectric alarm in two of three trials for the other two configurations. The ionization alarm responded quicker on average than photoelectric alarm in all four flaming fire configurations, and responded before the photoelectric alarm in all 12 flaming fire trials. One dual alarm had the fastest average alarm time for all four smoldering fire configurations, and responded first in 11 of the 12 trials. It also yielded faster average alarm times than the other dual alarm in seven of eight configurations, and was the first dual alarm to respond in 22 out of 23 trials where dual alarms were present. 相似文献
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Gordon E. Hartzell 《Fire Safety Journal》1987,12(3):179-182
Evaluating the toxic hazard of fire gases has been an area of recent interest. Units of measure for toxic hazard based on the concept of dose are presented. The role of carbon monoxide and hydrogen cyanide as principal toxicants in combustion products is reviewed. The importance of the time-related aspects of smoke transport and exposure to the toxicants is discussed. 相似文献
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A significant element in the cost of a new building is devoted to fire safety. Energy efficiency drives the replacement of traditional building materials with lightweight insulation materials, which, if flammable can contribute to the fire load. Most fire deaths arise from inhalation of toxic gases. The fire toxicity of six insulation materials (glass wool, stone wool, expanded polystyrene foam, phenolic foam, polyurethane foam and polyisocyanurate foam) was investigated under a range of fire conditions. Two of the materials, stone wool and glass wool failed to ignite and gave consistently low yields of all of the toxic products. The toxicities of the effluents, showing the contribution of individual toxic components, are compared using the fractional effective dose (FED) model and LC50 (the mass required per unit volume to generate a lethal atmosphere under specified conditions). For polyisocyanurate and polyurethane foam this shows a significant contribution from hydrogen cyanide resulting in doubling of the overall toxicity, as the fire condition changes from well-ventilated to under-ventilated. These materials showed an order of increasing fire toxicity, from stone wool (least toxic), glass wool, polystyrene, phenolic, polyurethane to polyisocyanurate foam (most toxic). 相似文献
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The primary goal of this research is to provide recommendations for the eventual development of more effective and efficient fire sensors to be installed in space vehicles and habitats. An entirely new ground-based testing facility that generated fire signatures was developed to perform the combustion and pyrolysis experiments of eight different practical spacecraft materials. The flaming and smoldering of polymers approved by the National Aeronautics and Space Administration (NASA) generate three types of residues: condensables, light gases, and particulates. The residues were characterized by gas chromatography (GC), Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM). The analysis was interpreted as a function of oxygen concentration, temperature, and flow direction. Key findings are that the combustion of some materials such as Kevlar and cotton can only be identified by light gases, while the combustion of other materials, such as silicone and melamine, is best detected using a particulate-specific sensor. The implications during a fire event, its suppression, astronaut health in post-event cleanup as well as material recommendations are briefly discussed. 相似文献