Experimental Research on Flame Length when a Fire Source Locates nearby Walls of Corner Configuration and Parallel Configuration

火源位于角构型和平行构型墙体附近时火焰长度的实验研究

• 批准号: 23651170
• 负责人: SUGAWA Osami
• 金额: $ 2.5万
• 依托单位: Tokyo University of Science, Suwa
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Challenging Exploratory Research
• 财政年份: 2011
• 资助国家: 日本
• 起止时间: 2011 至 2012
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-23651170/
• 关键词: 相似則; ツインタワー; 模型実験; 煙突効果; 高層建物; 火炎性状; 火災; 物理モデル

The flame height behavior was studied experimentally with two walls configurations which have setting of a corner having a slit at the deep-corner and a paralleled-walls configuration. These two configurations were adopted to simulate the fire behavior occurred nearby typical twin towers configuration as was occurred in Pusan, Korea, 11th Oct., 2010. Model walls of ceramic boards with 1.8m(H) by 0.9m(W) with 0.02m thick of were used and a square diffusion sand gas burner (LPG) of 0.1m by 0.1m (representative size of D) was also set and used as a model fire source giving 7.5 - 30 kW with the separation (S) between walls to the burner having 0 - 0.5m. In the case of a corner with a slit (0.1m width) at deep corner between two boards, the flame height showed the highest at around the deep corner and which decreased with the increase of separation distance. We found also that the clear flame inclination toward corner and this phenomenon gave the decrease in flame height. The corner configuration gave the convective flow against the fire plume or flame flow as similar as the chimney effect. And no obvious effect on the flame height-elongation when the burner location stood aloof 3 times farther of its size D from the corner. In the case of walls with parallel configuration, the diffusion flame not only expanded horizontally with walls surface but also elongated vertically 1.5 times longer than one in free boundary condition with showing flip-flap snuggling behavior against each wall. The flame height decreased with increase of separation, and no obviouseffect on the flame height-elongation when the burner separated 3 times farther of its size D from walls. It is necessary for fire safety to establish the valid physical model which can estimate the flame height when a fire source locates nearby twin buildings and/or plural buildings.

实验研究了两种壁面构型（深角处有狭缝）和平行壁面构型的火焰高度特性。采用这两种结构来模拟2010年10月11日发生在韩国釜山的典型双塔结构附近的火灾行为。采用1.8m(H) × 0.9m(W)，厚度为0.02m的陶瓷板模型墙，并设置0.1m × 0.1m的方形扩散沙气燃烧器（LPG）（代表性尺寸为D）作为模型火源，功率为7.5 - 30kw，墙与燃烧器之间的距离为0 - 0.5m。当两板之间的深角处有狭缝（宽度为0.1m）时，火焰高度在深角处最高，并随着分离距离的增加而降低。我们还发现，明显的火焰向角落倾斜，这种现象导致火焰高度下降。角落的配置给了对流流动对火羽或火焰流动类似的烟囱效应。当燃烧器位置离角距其尺寸D的3倍时，对火焰高度伸长无明显影响。在平行壁面情况下，扩散火焰不仅在水平方向上随壁面扩展，而且在垂直方向上也比自由边界条件下的扩散火焰长1.5倍，并表现出对各壁面的翻转依偎行为。火焰高度随分离距离的增加而降低，当燃烧器与壁面的分离距离为其尺寸D的3倍时，火焰高度伸长无明显影响。建立有效的火源高度估算模型，对双楼或多楼火源附近的火焰高度进行估算，是保证火灾安全的必要条件。