Abstract The effect of the vertical position of horizontal projections on the thermal and flow characteristics of Externally Venting Flames (EVF) was investigated by using a ¼ scale compartment-facade experimental setup to perform five fire tests. A constant 144 kW fire power level was used in all fire tests; the fire source was a methane-fed porous burner, located at the geometrical centre of the compartment. A broad variety of measuring sensors was employed to determine the thermal and flow characteristics of the developing EVF. A parametric study was performed, aiming to evaluate the impact of the horizontal projection's “height above lintel” and “depth” on the EVF characteristics; two “height above lintel” and two “depth” values were investigated. Using an in-house developed image processing software tool, flame intermittency contour plots were produced, allowing the determination of EVF height, horizontal projection and width values. The EVF external dimensions were compared to the respective values predicted by correlations proposed in Eurocode (EN 1991-1-2); large discrepancies were found, especially for EVF projection and width. The Eurocode predictions for the EVF width and, occasionally, the EVF height, were found to yield markedly non-conservative values, thus rendering them inappropriate for fire engineering design purposes.

中文翻译：

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水平投影垂直位置对外泄火焰特性的影响

摘要 通过使用 1/4 比例隔室立面实验装置进行五次火灾测试，研究了水平投影的垂直位置对外部排放火焰 (EVF) 的热和流动特性的影响。所有火灾测试都使用恒定的 144 kW 火力水平；火源是一个甲烷供给的多孔燃烧器，位于隔间的几何中心。使用多种测量传感器来确定正在开发的 EVF 的热和流量特性。进行了参数研究，旨在评估水平投影的“门楣上方高度”和“深度”对 EVF 特性的影响；研究了两个“门楣上方的高度”和两个“深度”值。使用内部开发的图像处理软件工具，生成火焰间歇性等高线图，允许确定 EVF 高度、水平投影和宽度值。EVF 外部尺寸与欧洲规范 (EN 1991-1-2) 中提出的相关性预测的相应值进行了比较；发现了很大的差异，尤其是 EVF 投影和宽度。欧洲规范对 EVF 宽度和偶尔的 EVF 高度的预测被发现产生明显的非保守值，从而使它们不适用于消防工程设计目的。