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.     

Development of Ignition Time and Mass Loss Rate Prediction Models for Rigid Polyurethane Foam with Multi-Step Thermal Degradation Under Various External Heat Flux Conditions

Fire Technology - To predict the ignition time and mass loss rate of rigid polyurethane foam (RPU) under various radiative conditions, numerical models with a multi-step thermal degradation process...     

聚氨酯硬泡外墙隔热保温技术的探讨

目前,聚氨酯硬泡外墙隔热保温技术是一种主要应用的保温技术。本文重点对聚氨酯硬泡外墙隔热保温技术进行了探讨。     

硬泡聚氨酯保温装饰板的开发与性能表征

对硬泡聚氨酯保温装饰板主要组成材料进行了开发和研究。试验结果表明硬泡聚氨酯保温装饰板具有保温性能优异、质量稳定可靠、且易于与墙面进行粘贴的特点。同时,通过实际工程,充分验证了硬泡聚氨酯保温装饰板的工程应用可行性和经济可行性,具有良好的应用前景。     

浅谈喷涂硬泡聚氨酯(PUR)防水保温一体化的施工运用

传统的保温和防水是两个独立体系,当将建筑物屋面保温和防水作为一个系统时,结合绿色环保、发展节能建筑的需要,聚氨酯硬泡体(PUR)施工技术能使墙面防水保温一体化成为可能。     

均摊恒定热流法在土壤温度场影响因素中的应用

结合工程实例,建立相应的物理及数学模型,划分出相应的网格。根据能量守恒定律,流出管壁和流入土壤的能量相等。从土壤侧考虑,把流入土壤的热量进行均分得到恒定热流,以得到的恒定热流作为边界条件。确定7个不同物性土壤,并且确定8个不同观测点,并利用分段的均摊恒定热流法对不同物性下的埋地管道进行长时间的模拟运行,分析埋地换热器在不同物性条件下连续运行的总体土壤温度场分布以及各监测点在不同物性土壤处的温度,总结出不同物性对埋地管道运行影响的结论,为以后更进一步分析打下基础。     

直接喷涂硬质聚氨酯泡沫塑料在屋面隔热防水工程中的应用

介绍直接喷涂硬质聚氨酯泡沫塑料在屋面隔热防水工程中的应用,对建筑节能、防水是一种有益的参考。     

Thermal Analysis and Cone Calorimeter Study of Engineered Wood with an Emphasis on Fire Modelling

Fire Technology - Engineered wood products (EWPs) are a group of materials having a very similar chemical composition but having different and non-uniform thermo-physical properties throughout...     

Validation of Heat Transfer,Thermal Decomposition,and Container Pressurization of Polyurethane Foam Using Mean Value and Latin Hypercube Sampling Approaches

Polymer foam encapsulants provide mechanical, electrical, and thermal isolation in engineered systems. It can be advantageous to surround objects of interest, such as electronics, with foams in a hermetically sealed container in order to protect them from hostile environments or from accidents such as fire. In fire environments, gas pressure from thermal decomposition of foams can cause mechanical failure of sealed systems. In this work, a detailed uncertainty quantification study of polymeric methylene diisocyanate (PMDI)-polyether-polyol based polyurethane foam is presented and compared to experimental results to assess the validity of a 3-D finite element model of the heat transfer and degradation processes. In this series of experiments, 320 kg/m³ PMDI foam in a 0.2 L sealed steel container is heated to 1,073 K at a rate of 150 K/min. The experiment ends when the can breaches due to the buildup of pressure. The temperature at key location is monitored as well as the internal pressure of the can. Both experimental uncertainty and computational uncertainty are examined and compared. The mean value method (MV) and Latin hypercube sampling (LHS) approach are used to propagate the uncertainty through the model. The results of the both the MV method and the LHS approach show that while the model generally can predict the temperature at given locations in the system, it is less successful at predicting the pressure response. Also, these two approaches for propagating uncertainty agree with each other, the importance of each input parameter on the simulation results is also investigated, showing that for the temperature response the conductivity of the steel container and the effective conductivity of the foam, are the most important parameters. For the pressure response, the activation energy, effective conductivity, and specific heat are most important. The comparison to experiments and the identification of the drivers of uncertainty allow for targeted development of the computational model and for definition of the experiments necessary to improve accuracy.     

Metrological Tool for the Characterization of Flame Fronts Based on the Coupling of a Heat Flux Approach with Image Processing Data

The aim of this paper is to present some improvements in the metrology of forest fire flames by coupling image processing and radiative heat flux measurement. A new metrological tool using a visual video camera and a specific multiple thermal sensors is proposed. By means of an appropriate segmentation algorithm and the Direct Linear Transformation, the image processing methodology gives the forward or the backward fire front positions as input data to a radiative heat flux approach. Using a simplified flame model, this technique provides fire front positions versus time, and average values for the flame length, flame depth, flame tilt angle, apparent flame temperature and flame emissivity. The rates of spread, obtained by a linear regression of the determined fire front positions, as well as the thermal and radiative properties of the flame, are compared favorably to those given in the literature.     

流温法热分配系统研制及应用

目前,我国北方分户热计量节能改造迫在眉睫.流温系数热分配法是一种新型的熟计量方法,详细论述了该方法的工作原理、基本结构、创新点及实现方式.试点工程测试结果表明,这种将热量表计量关键要素--流量、温度引入热分配技术中而形成的计量方法构成的系统具有安装简便、运行稳定、计量合理、查询方便、性价比高等特点,适用于多种供暖系统的新建建筑热计量和既有建筑供热计量改造.     

楼板刚、弹性计算假定对梁式转换高层建筑地震作用效应的影响

论述了楼板刚弹性计算假定对梁式转换结构地震反应的影响。提出楼层地震剪力在抗侧力构件中的分配除按楼盖的刚性、柔性和弹性三种情况考虑以外,还存在另一种分配方式,即转换层上邻近楼层框支剪力墙分配的地震剪力受转换层下部结构落地剪力墙设置的间距和楼板面内变形的影响。建议进行复杂高层建筑结构内力与位移计算时,楼板宜按弹性考虑。     

现喷硬泡聚氨酯防水保温一体化屋面系统在既有建筑节能改造中的应用

现喷硬泡聚氨酯防水保温一体化屋面系统在既有建筑节能改造工程中应用,不破坏原屋面结构,现喷80 mm厚硬泡聚氨酯、上覆3~5 mm厚聚合物砂浆保护层;该屋面系统具有防水保温、隔音、节能、环保、质轻、使用寿命长、适应温度范围广、耐化学腐蚀、施工快速方便等优点。     

某商业综合体空调冷热源方案论证分析

根据潍坊市某商业综合体项目工程实际情况,列出了各建筑的几种冷热源方案,并从经济性、技术性和使用效果等方面加以比较。通过对各方案的初投资、运行费用等的经济性分析,可以看出,电制冷机组+市政热网方案为最优选择,对冷负荷较大的大商业部分,水蓄冷空调方案更为合适。     

浅谈现喷聚氨酯硬泡体屋面防水保温复合层的施工

对一些房屋屋面工程防水保温的材料、施工及防水保温效果进行了总结。文中介绍的整体式聚氨酯泡沫屋面防水保温材料集防水与保温于一身,减少了施工工序,消除了保温层施工对防水层的破坏,增强了防水保温效果,是一种新型高科技的屋面防水保温材料。本文主要介绍了应用该材料在施工过程中的一些施工工艺、施工方法及相应的质量技术保障措施。     

格子体堵塞对气流分布和传热的影响

根据相似原理，通过物理模型研究了格子体堵塞部位，堵塞率同格子体内气流分布之间的关系。研究表明：中部或底部发生堵塞时，格子体内气流分布的变化规律是相同的，即开始是随着堵塞率的增加，气流分布趋于均匀、堵塞到一定程度后，气流颁均匀怀随着堵塞率的增大而主 ；中部堵塞气流分布变化经底部堵进要快一些；堵塞后，蓄热室的阻力损失变大，但是变化趋势缓慢，传热分析表明；轻微的堵会改善格子体内气流分布，提高格子砖利用率     

双塔柔性连体结构地震响应等效试验电路设计与实现

针对一非对称阻尼耗能双塔连体结构,建立了对应的动力分析模型和振动方程,推导出该结构体系的传递函数矩阵,并对所获得的传递函数进行基于动力特性相同原则的等效降阶处理,得到该结构体系在‘THBCC-1型信号与自动控制试验台’上进行试验分析的等效电路图。分别采用试验电路模拟和数值仿真两种方法对该连体结构进行天然地震荷载EL-Centro1940波作用下的地震响应研究,研究结果表明:等效模拟试验电路模型和原系统具有较好的相似性,两种分析方法所获得地震响应的结果非常的接近,说明了本文所提方法分析连体结构地震响应的有效性。     

泡沫混凝土研究及应用新进展

介绍泡沫混凝土的原料组成、生产工艺特性以及国内外应用情况,并针对应用中出现的问题提出改进措施.     

纳米氧化铝对水性聚氨酯硬度和耐磨性能的影响

纳米氧化铝改善了水性聚氨酯膜的硬度和耐磨性能,涂膜硬度随纳米氧化铝添加量的增加而增加,涂膜的耐磨性在纳米氧化铝添加量约为3%时达到最佳。透射电镜图表明,纳米氧化铝与聚氨酯胶束相容性良好。     

通断时间面积法热计量装置设计及应用探讨

本文介绍了通断时间面积法热计量装置的控制原理,叙述了设计过程中系统型式选择、水力平衡、散热器温控阀、通断控制器阀门、过滤器、室温控制器设置等问题,探讨了应用过程中发现的问题并提出了解决办法。只有该装置应进一步完善,才能发挥预想的计量节能作用。