试样宽度对EPDM卷材竖直火蔓延的影响  

Effects of sample width towards the spread of upward flame over EPDM rubber waterproof sheet

作　　者：许春明[1] 张瑞芳[1] 谢启源[1] 李立明[1] 黄冬梅[1] 张和平[1] 

机构地区：[1]中国科学技术大学火灾科学国家重点实验室,合肥230027

出　　处：《安全与环境学报》2010年第6期150-154,共5页Journal of Safety and Environment

摘　　要：以2．0mm厚三元乙丙橡胶（EPDM）防水卷材为研究对象，在ISO9705全尺寸热释放速率试验台上进行竖直擘面火蔓延试验，研究了不同试样宽度条件下热释放速率、热通量及其与火焰高度的关系。结果表明，热释放速率峰值随着宽度的增加呈非线性变化。当试样宽度小于25cm时，试样火焰高度和怪直火蔓延平均速度随宽度的增加而增大；宽度大于25cm时，横向火蔓延明显，火焰高度和竖直火蔓延平均速度随其增加而减小。25cm可以看作该厚度下的试样临界宽度。由热释放速率与火焰高度关系式Xp／W=aQ＇n得到的7种工况的n值近似为1．08，得出热通量q＇与X／Xf的关系曲线。Previous studies have demonstrated combustion behaviors are affected by sample width. To study the effects of sample width on upward flame spread, full-scale experiments have been carried out in an ISO 9705 standard room. Samples used are 0.2 cm thick EPDM rubber waterproof sheets with fixed height of 120 cm and varied widths of 5 cm, 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, and 40 cm. Parameters associated with fire behaviors, such as heat release rate （HRR）, heat flux and flame height depending on the sheet width （ w ） are measured. Analysis of the data indicates that HRR increases with the width of the sheet. There are two HRR peak values with widths between 5 -20 cm and the first HRR peak value is not obvious when width increases to 25 cm. For w ≥ 30 cm, there＇ s only one peak value remained, Flame height is an important parameter for combustion behaviors which can affect the flame development and radiation properties. The increasing width leads to an increase of flame height and average speed of upward flame spread for w ≤ 25 cm, and to a decrease for w ≥ 25 cm, which may be related to the effects of lateral spread. 25 cm can be taken as the critical width. Previous work has demonstrated a relationship between HRR and flame height per unit width, Xf/W = aQ＇n and the present experimental data show good agreement with this formula. Value 1.08 is taken for the sampies as the power, n. According to the relationship between total heat flux and flame height, we have established a dependence of heat flux on the height normalized by a scale length representing the flame height.

关 键 词：安全工程 EPDM防水卷材 试样宽度 竖直火蔓延 火焰高度 

分 类 号：TK16[动力工程及工程热物理—热能工程] TU576[建筑科学—建筑技术科学]