【作者】 廖曙江；

【导师】 付祥钊；

【作者基本信息】 重庆大学 ， 供热、供燃气、通风及空调工程， 2002， 博士

【摘要】 火灾发展与蔓延特性是建筑火灾安全科学领域的重要研究课题。本文在大型建筑火灾的分析基础上开展了对大空间建筑内活动火灾荷载的火灾发展及蔓延特性的研究。本研究填补了建筑火灾研究在这个方面的空白。对评估火灾危险性、 “性能化”防火设计、火灾模化等方面都有实用价值。 本文建立了基于预热机制的火焰沿薄型材料表面水平蔓延，贴壁单面向上蔓延和双面向上蔓延的数学模型，以从理论上研究不同放置方式对可燃物火灾危险性的影响。 在专门建立的火蔓延特性试验台上，进行了不同材料的燃烧试验。实验结果表明决定材料火灾危险性的首要条件是材料的放置方式。不同的材料在相同放置方式下均遵循相同的传热学机制。不同的传热机制最终影响了火焰蔓延速度的大小。 在理论模型的基础上，结合大量实验数据，对影响火焰蔓延速度的主要因素进行了多元非线性回归，得到了三种火蔓延方式的火焰蔓延速度的半经验拟合式。该式一方面反映了影响火焰蔓延速度的主要参数是火焰温度、火焰高度、材料与空气的对流换热系数、材料与火焰的对流换热系数和材料物性的影响。另一方面可以预测不同材料在三种火蔓延方式下的火焰蔓延速度。本文对薄型材料在水平和竖直方向放置时的释热率原理进行了研究，结果显示薄型材料释热率决定于材料放置方式，材料外形尺寸，材料类型及燃烧特性，着火点位置和环境状况。同一材料具有不同的释热率变化，不能以单一的指标来评价材料的火灾危险性。通过对某大型商场服装层的活动火灾荷载的实地调查，发现商场内不同楼层之间具有不同的活动火灾载荷的面积分布密度，相同楼层内活动火灾荷载点分布密度也不相同，反映了活动火灾荷载分布的实际状况。统计分析结果表明所有楼层的活动火灾载荷的分布服从二项分布，而不是正态分布。本文建立了大空间建筑内全尺寸服装燃烧试验台和模拟大空间内服装货架火蔓延试验台，以研究以一定方式布置的燃料在货架内和货架间的火蔓延特性。实验结果表明，在这类燃料分布状况下的火蔓延特性表现为扩展型火源。火场边界形状长度和火场面积随时间而变化发展，决定了火灾释热率（HRR）在时间和空间分布上都是变化的函数，火灾HRR不同于稳态火和T2火。在实验结果的基础上，本文建立了大空间建筑内连续分布层状燃料火灾发展的预测模型，以研究这类火灾发展过程的理论计算方法。该模型可以根据一定建筑构造内的活动火灾荷载分布，预测火灾发展过程中的火场参数（如火场边界、面积以及火灾释热率等），为火灾模化提<WP=5>供了新的火源设计类型更多还原

【Abstract】 Fire growth and spreading characteristic has long been recognized an important role in architecture fire safety research. Based on the analyses of fire cases in large space buildings, the fire growth and spreading characteristic of unfixed fire loads in large space building research works have been carried out. The research is a new approach to fire safety engineering. It’s useful to the fire risk evaluation, performance-based design and fire model, and so on. In order to study the influence degree of different placement fashion about the fire risk evaluation of combustible materials in theory, establishing three style of numerical model of horizontal flame spreading, upward flame spreading along the wall and upward flame spreading along both sides. The results of flame spreading test of combustible materials show the placement fashion is the most important factor which determine the risk degree of fire. Under the same placement fashion ,different material obey to the same heat transfer principium. The heat transfer principium will influence the flame spreading velocity at last. Based on the numerical model and testing data, the nonlinear regression summary statistics dependent variable work has been done, and got three style of summary statistics formulas for three style flame spreading fashion. The main influence factors of Uf are Tf, Hf, , and property of material. The formulas can be used to forecast the flame spreading velocity of different materials under some style of flame spreading fashion. According to the research work of heat release rate(HRR) of thin type material under different placement fashion, the HRR is determined by the following main factors, such as the placement fashion, the size of outline, the category and combustion properties , catching fire point position and the environment situation. One kind of material has different HRR at different condition. So ,it’s not reasonable to evaluate the fire risk with the same guideline. The research is useful to extend the research range of fire. Through the investigating of unfixed fire loads of clothes floors in emporium on the spot, the result show there are different area density in different floors, and different portion distributing density in one floor. The distributing condition reflects the real distribution of unfixed fire loads. The statistics result is that the distributing of unfixed fire loads obey the binomial distribution, but not the normal distribution. Through studying the flame spreading characteristic of the fuel which be placed in<WP=7>one rack and in adjacent racks in the full-scale and small-scale testing equipments, the results show the flame spreading characteristic is spreading fire source. The boundary shape and length of fire zone are growth with time, which determine the fire HRR is variational with time and space distribution. The fire HRR is different from the steady fire and T square fire. Through founding the fire spreading model of continuous distributing laminal fuel ,it can be used to forecast the fire parameter when fire spreading in some kind of construction area and provide a new fire design method for fire modeling更多还原