铺层结构对碳纤维/环氧层压板火反应特性的影响

利用锥形量热仪,垂直/水平燃烧速度测试仪、极限氧指数测定仪研究了单向、织物两种铺层结构对碳纤维/环氧层压板火反应特性的影响.结果表明,随热辐射强度的增加,不同铺层结构碳纤维/环氧层压板的点燃时间均缩短,质量剩余率降低,热释放速率、产烟速率峰值均增加,达到峰值时间变短,总热释放量和总烟释放量增加;在相同热辐射强度下,相比...     

石墨烯微片对环氧树脂热性能的影响研究

研究石墨烯微片（GNS）对特种环氧树脂（AG-80/JD-919）的热稳定性和燃烧性能的影响。首先采用溶液共混法将GNS 添加到环氧树脂中,并利用热重分析仪（TGA）和锥形量热仪（CCT）分别对阻燃环氧树脂进行热稳定性和阻燃性能的测试分析。结果表明,GNS 添加量为6%时,环氧树脂的残炭量提高了4.6%,同时峰值热释放速率（pHRR）和总热释放量（THR）分别降低了40.63%和15.43%。因此,GNS 能够改善环氧树脂的热稳定性及其阻燃性能,这主要与GNS 在环氧树脂基体热分解过程能够起到物理阻隔作用有关。     

CS/h-BN/APP层层自组装涂层阻燃杨木的研究

为提高杨木的阻燃性能,利用带正电性的壳聚糖/六方氮化硼(CS/h-BN)聚电解质溶液,以及带负电性的聚磷酸铵(APP)溶液,基于层层自组装(LBL)技术,通过两聚电解质溶液之间的静电吸附作用,在木材表面成功制备出具有良好阻燃性能的CS/h-BN/APP薄膜涂层.结果表明:所制备的涂层均匀分布在木材表面,且具有良好的附着力;涂层阻燃木材试件的热释放速率、烟释放速率显著降低,第2放热峰出现时间晚于未处理木材试件,且在燃烧过程中的残余物质量始终高于未处理木材试件,完全燃尽时间则比未处理木材试件多出约100s,阻燃效果随着自组装涂层数的增加而逐渐增强;涂层阻燃木材试件的CO、CO_2气体生成量明显降低,表明阻燃涂层能有效降低木材烟气及毒性气体释放;涂层阻燃木材试件较未处理木材试件更好地保持了木材本身的结构,显示出了良好的抵抗火灾能力.     

家具板材的燃烧性能和环保性能分析

基于现阶段校园家具中常用的人造板材,对其分别进行燃烧性能和环保性能测试,采用引燃时间、单位面积热释放速率峰值、放热总量、产烟总量和甲醛释放量这五个关键性能指标,得出板材综合性能评价结果。结果表明：随着辐射照度的升高,板材阻燃性能会降低;采用浸渍纸贴面措施对板材点燃时间有一定提升,但在热释放速率、放热总量和总产烟量指标上均有不同程度上浮;胶合板和浸渍纸饰面胶合板的热释放速率、产烟总量大,阻燃性能较差。     

阻燃环氧树脂/苯基膦酸铁复合材料燃烧性能研究

以苯基膦酸、硝酸铁为原料,乙醇、乙二醇为溶剂,聚乙烯吡咯烷酮、六亚甲基四胺分别为表面活性剂和配位剂,采用混合溶剂法制备层状化合物苯基膦酸铁（FePP）,并将其添加到环氧树脂中（EP）制备复合材料。热重（TG）结果显示,FePP可以提高EP的热稳定性,同时,EP/4FePP的垂直燃烧测试（UL-94）等级达到V-1,氧指数（LOI）也相应提高。为了进一步改善EP的阻燃性能,将FePP与含磷阻燃剂DOPO协效阻燃EP,测试结果显示EP/3DOPO/1FePP复合材料可以通过UL-94 V-0等级,LOI值高达34.5 %,热释放速率峰值（PHRR）与总热释放速率（THR）与纯EP相比分别降低了28.4%和18.1%,这主要是由于FePP能够在燃烧中降解为含磷和金属的氧化物,促进聚合物快速炭化,并且DOPO可捕捉气相中自由基,抑制链式反应的进行,抑制燃烧,达到气相和凝聚相协效阻燃效果。     

砖木结构古建筑不同风速下火灾蔓延规律研究

为探明砖木结构古建筑火场下火灾蔓延的变化规律,从火灾蔓延特性、热释放速率、温度的变化等方面探究不同风速影响下的火灾蔓延变化情况。选取中国典型砖木结构三原城隍庙为实例,通过古建筑BIM 参数化建模,合理设置火灾场景进行火场模拟分析。结果表明：风速作用下,火焰蔓延过程变化波动较大,呈现一定的周期性,在一定范围内,风速越大,古建筑热释放速率达到峰值的时间越短、一次峰值与二次峰值的时间间隔越短、达到轰燃的时间越早。热浮力的作用将导致火焰向上蔓延至屋面,屋面位置温度最高,上部结构危险更高。     

Evaluating Models for Predicting Full-Scale Fire Behaviour of Polyurethane Foam Using Cone Calorimeter Data

Two models that can be used to predict full-scale heat release rates of polyurethane foam slabs were evaluated in this study. Predictions were compared with results of furniture calorimeter tests of 10 cm thick polyurethane foam specimens which were ignited in the centre or on the edge. Furniture calorimeter results indicated that peak heat release rates and fire growth rates were higher during centre ignition tests than edge ignition tests. For both situations, the growth phase of the heat release rate curves measured in the full-scale tests was successfully predicted using t ² design fires; the choice of a specific t ² fire depended on the surface area of the specimen and ignition location. A model originally developed during the European Combustion Behaviour of Upholstered Furniture (CBUF) project was also evaluated using heat release rate data from cone calorimeter tests and flame area burning rates measured using infrared video records of the furniture calorimeter tests. This model was able to successfully predict the initial growth phase of the fires and predictions of peak heat release rates were within 17% of measured values. The model had less success in predicting heat release rates later in the growth phase and during the decay phase of the fires, and did not appear to capture all of the physics of the full-scale tests, in particular foam melting and subsequent liquid pool burning. As the model did show promise, future work is planned to address these shortcomings and to develop improved flame spread models for polyurethane foam.     

The effect of surface coatings on fire growth over composite materials in a corner configuration

Structural composites are vulnerable to fire in two respects: (1) their resin content may ignite and enable the spread of flames over the surface of the structure; (2) the resin may degrade from the heat of a localized fire exposure thus weakening the composite structure. The present study focuses mainly on the first issue, in particular, on the ability of various commercial coatings to prevent flame spread. The second issue is examined briefly by applying thermocouples to the back surface of test specimens. Four commercial coatings have been tested over an unretarded vinyl ester/glass composite. In addition an uncoated phenolic/glass composite and a polyester/glass composite coated with a fire retarded resin were tested. In all cases the configuration was a 3.3 m high corner with a 53 cm square propane gas burner at its base, operated at 250 kW as the fire exposure. The results show that, with the proper choice of coating and coating thickness, fire growth can be suppressed quite effectively. Two of the coatings, applied at a substantial thickness, were reasonably effective at slowing the penetration of heat to the back of the composite panels. The other coatings, much thinner in application, were notably less effective at slowing heat penetration.     

Daylighting design for the Pacific Museum of flight: Energy impacts

The daylighting performance of the Pacific Museum of Flight in Seathle, WA, has been analyzed using the DOE-2.1C building energy simulation program. The main exhibit areas of this museum are enclosed on three sides by glass walls and the 4500-m² roof is completely glazed. Because of the large glass areas, a detailed thermal simulation of the building was carried out during its design phase in order to select glazing parameters that would avoid excessive summer solar heat gain, reduce winter heat loss and, at the same time, provide enough natural light of significantly reduce electric lighting loads. Glazing choices considered included conventional glass, heat mirror, and glass with a low-emissivity coating. On/off, stepped and continuous dimming lighting control systems were analyzed. Daylighting was found to be very effective in reducing annual electric lighting load, peak electrical demand, and the overall annual energy consumption.     

老化对基质沥青阻燃抑烟性能的影响

为探究不同条件老化后沥青阻燃抑烟性能的变化规律,采用旋转薄膜烘箱（RTFOT）对基质沥青进行85 min短期老化、270 min长期老化以及湿热老化。利用氧指数试验（LOI）和锥形量热试验研究老化沥青火灾安全性能,同时结合红外光谱分析技术（FTIR）以及热重-质谱联用技术(TG-MS)分析沥青（BA）成分与气态产物释放特性的变化规律。试验结果表明：基质沥青在经历热氧老化后轻质组分减少,重质组分增加,导致氧指数提升。而湿热老化中由于水蒸气分压力的作用使沥青氧指数略有下降。在热释放方面,热氧老化后沥青燃烧热释放速率峰值下降,峰值对应时间提前,有效燃烧热降低;而湿热老化后热释放速率基本不变。在烟气释放方面,热氧老化后沥青燃烧的炭烟、CO、CO2释放量更低,SO2释放量增加;湿热老化后炭烟、CO、CO2释放量变化不大,而SO2释放量明显增多。     

高高原环境下锂离子电池热失控烟气特性

为探究高高原机场低压低氧环境对锂离子电池热失控行为中喷射火焰温度、热释放速率及烟气组分等参数的影响，构建锂离子电池低压试验平台，以4节单体18650型锂离子电池构成电池组，分别模拟高高原机场（50 kPa）、平原机场环境（90 kPa）下锂离子电池热失控试验。结果表明：在50 kPa工况下，池体破损程度、热释放速率及喷射火焰温度均有所下降，喷射火焰峰值温度降低约241.3 ℃。50 kPa工况下产生的热解烟气中C_xH_y、CO等易燃气体浓度更高，最高体积分数分别可达3 134.50×10^-6和0.860%，并且随热释放速率的增加热增加；在90 kPa工况下呈现相反趋势，C_xH_y、CO气体浓度均有所下降，且随热释放速率的增加热降低。90 kPa工况下电池燃爆更为剧烈，作为物质完全燃烧的证明，CO₂气体浓度高于50 kPa工况下试验值，最高体积分数可达1.510 7%。     

轻质GRC配方及应用性能的研究

通过低碱度硫铝酸盐水泥和耐碱玻璃纤维，配合轻质材料（膨胀珍珠岩、聚苯乙烯、膨胀蛭石）研制成轻质GRC材料，对GRC材料的密度、力学性能（抗拉强度、抗弯强度）以及导热性能进行测试分析，发现在合适的抗碱纤维配比，水配比，水灰比，轻质材料配比的情况下，其性能最好，达到密度为0．85g/cm^3，抗弯强度21．5MPa，抗拉强度7．47MPa，导热系数0．358W／m．K。该材料具有轻质、阻燃、隔热、保温、耐用等优越性能。     

水性透明隔热涂料的制备与研究

本文以水性聚氨酯树脂为成膜物,以自制的纳米ATO分散体为功能性填料,经一定的工艺制得透明隔热涂料,将其涂覆在玻璃表面后,能形成一层透明隔热涂膜,在满足采光需求的同时,又表现出较好的隔热效果,在建筑玻璃和汽车玻璃隔热节能领域具有较好的应用前景。     

植酸三聚氰胺盐阻燃环氧树脂研究

利用生物基阻燃剂植酸三聚氰胺盐 (MPA) 阻燃改性环氧树脂并对其性能进行研究。通过红外光谱 (FTIR) 以及X射线光电子能谱 (XPS) 对MPA化学结构进行表征。利用热重分析仪 (TGA)、极限氧指数测试仪 (LOI)、垂直燃烧测试仪 (UL-94) 及锥形量热测试仪 (CC) 研究阻燃环氧树脂的热稳定性及阻燃性能。热重分析结果表明，MPA阻燃剂在800 ℃残炭达到25.6%，引入环氧树脂后可提升材料高温区热稳定性。垂直燃烧测试显示MPA在15%添加量下可赋予环氧树脂UL-94 V-0等级，表明MPA对环氧树脂有较好的阻燃效果。进一步锥形量热结果表明，MPA的加入显著降低了环氧树脂的热释放速率及总热释放，同时表现出优异的抑烟性能。     

干湿混纺地毯燃烧性能研究

为研究火灾初期自动喷水灭火系统作用时对铺地材料燃烧性能的影响,利用火焰传播量热仪,以混纺地毯为例,分别研究了干态、含水率50%、全浸泡3 种状态下水对其燃烧性能的影响。试验结果表明：随着含水率的升高,混纺地毯的引燃时间增长,含水率高的混纺地毯不易被引燃;含水条件下峰值热释放速率比干态条件下大,火灾规模较大,火焰燃烧持续时间内总热值较小;含水条件下,总烟气生成量及组成成分峰值出现时间后移。     

野外组合式软体油罐罐体材料燃烧特性研究

为了研究野外组合式软体油罐在不同辐射强度下的燃烧特性,通过锥形量热仪对软体油罐样本进行燃烧实验,选用25,35,50 kW/m2三种典型的热辐射强度进行研究,得到点燃时间、热释放速率、比消光面积、烟气生成速率、火焰形态等参数的变化规律.结果发现:热辐射强度为50 kW/m2时,点燃时间分别为25,35 kW/m2时的3...     

Development and testing of PCM doped cool colored coatings to mitigate urban heat island and cool buildings

In this study the performance of organic PCMs used as latent heat storage materials, when incorporated in coatings for buildings and urban fabric, is investigated. Thirty six coatings of six colors containing different quantities of PCMs in different melting points were produced. Accordingly, infrared reflective (cool) and common coatings with the same binder system and of the same color were prepared for a comparative thermal evaluation. The samples were divided in six groups of different color and eight samples each: three PCM coatings of different melting temperatures (18 °C, 24 °C, 28 °C) each one of two different PCM concentrations (20% w/w, 30% w/w), an infrared reflective and a common coating of matching color. Surface temperature of the samples was recorded at a 24 h basis during August 2008. The results demonstrate that all PCM coatings present lower surface temperatures than infrared reflective and common coatings. Analysis of the daily temperature differences showed that peak temperature differences occur between PCM and common or cool coatings from 7 am to 10 am. Investigating the temperature gradient revealed that for this time period the values for PCM coatings are lower compared to infrared reflective and common. From 10 am to 12 pm, temperature gradients for all coatings have similar values. Thus coatings containing PCMs store heat in a latent form maintaining constant surface temperatures and discharge with time delay. PCM doped cool colored coatings have the potential to enhance thermal inertia and achieve important energy savings in buildings maintaining a thermally comfortable indoor environment, while fighting urban heat island when applied on external surfaces.     

Flame Heights and Heat Transfer in Façade System Ventilation Cavities

The design of buildings using multilayer constructions poses a challenge for fire safety and needs to be understood. Narrow air gaps and cavities are common in many constructions, e.g. ventilated façade systems. In these construction systems flames can enter the cavities and fire can spread on the interior surfaces of the cavities. An experimental program was performed to investigate the influence of the cavity width on the flame heights, the fire driven upward flow and the incident heat fluxes to the inner surfaces of the cavity. The experimental setup consisted of two parallel facing non-combustible plates (0.8 × 1.8 m) and a propane gas burner placed at one of the inner surfaces. The cavity width between the plates ranged from 0.02 m to 0.1 m and the burner heat release rate was varied from 16.5 kW to 40.4 kW per m of the burner length. At least three repeated tests were performed for each scenario. In addition, tests with a single plate were performed. The flame heights did not significantly change for Q′/W < 300 kW/m² (where Q′ is the heat release rate per unit length of the burner and W is the cavity width). For higher Q′/W ratios flame extensions up to 2.2 times were observed. When the distance between the plates was reduced or the heat release rate was increased, the incident heat fluxes to the inner surface increased along the entire height of the test setup. The results can be used for analysing methodologies for predicting heat transfer and fire spread in narrow air cavities.     

Structural performance of laminated and unlaminated tempered glass under monotonic transverse loading

A total of thirty six bending tests have been conducted on 1220 × 460 mm sheets of glass, 9.5-, 12.7- and 15.9-mm thick, using slow-rate monotonic loading. Twenty four specimens were laminated on one side using either one or two 0.36-mm thick polyester transparent laminates. The study showed that lamination has significantly changed the failure mode of glass from a catastrophic failure, where fragments of glass shatter in different directions, to one which is still brittle yet safer, as the fractured glass remains fully intact. The average gains in flexural strength, stiffness and strain energy, as a result of lamination, were 20%, 10% and 34%, respectively, while the maximum gains in flexural strength, stiffness and strain energy were 36%, 33% and 52%, respectively. Because of the scatter of data, no specific correlation between the gains and reinforcement ratio (expressed as the ratio of laminate-to-glass thickness) could be established. The load–deflection behaviour of both laminated and unlaminated glass was linear up to failure. No rupture or delamination of the laminates were observed     

多孔金属板燃气灶燃烧性能数值模拟

应用FLUENT软件对影响多孔金属板燃气灶燃烧性能的多个参数进行了控制变量的数值模拟,对各参数进行归一化处理与敏感性分析,探讨各参数对灶具燃烧性能的影响。简化模拟计算,取多孔金属板上的一个单火孔的一半作为数值模拟对象并划分网格进行模拟。得出以下结论:火焰中心位置随板面表面发射率的增大而上升,表面发射率的增大使氮氧化物体积分数峰值出现下降,降幅约7.9%。表面发射率的增大在维持火焰温度基本不变且氮氧化物排放降低的情况下,提升了火焰位置,因此为提升灶具热效率,应将主要优化方向集中在通过表面处理以提高板面的表面发射率。灶具热负荷和火孔内直径的增加对上板面温度的提升有明显的促进作用,当热负荷从3.1 kW增加至3.9 kW时,火焰中心温度增幅为5.3%,同时氮氧化物排放量随之增大。内直径对上板面温度的提升作用在其值大于1.10 mm后开始显现,内直径的增加会明显提高氮氧化物的排放。因此在适当考虑烟气中氮氧化物排放的范围内,可提高灶具的热负荷和火孔内直径。在灶具热负荷较小时,孔隙率不可过大,但随着热负荷的增加,孔隙率可适当增大。鉴于板面厚度增加会明显增加达到稳态所需的时间,因此不宜采用过厚板面,以3.00~4.00 mm为宜。