中空玻璃在火灾环境下的破裂行为规律研究

发布时间：2018-05-06 11:27

本文选题：中空玻璃 + 火灾环境　；参考：《中国科学技术大学》2015年硕士论文

【摘要】：普通单层玻璃在建筑中的应用起到了采光、通风和扩大视野的作用,但保温性能较差；双层玻璃的出现有效地解决了保温性能的问题,但易吸收空气中的水蒸气等而结露,影响视野。由两块玻璃板通过铝隔条用密封胶密封制成的中空玻璃,既弥补了单层玻璃隔热差、散热快的缺点,还能将双层玻璃的保暖隔热的优势利用,具有良好的保温隔热以及防结露性能。但是中空玻璃在发生火灾时存在破裂、脱落的危险性,会加速火灾蔓延并威胁人员逃生。因此中空玻璃在火灾环境下的破裂、脱落行为及其耐火性能的研究是建筑火灾安全的重要课题之一。国内外学者已经对中空玻璃在其破裂行为方面进行了研究,并得出在特定实验条件下中空玻璃具有的破裂行为规律和其他定性和定量的结论。但是这些研究中尚未涉及到安装方式对中空玻璃的影响。本文采用了实验的方法从不同安装方式下的中空玻璃热响应和不同空气夹层厚度下的中空玻璃热响应这两个方面重点研究了中空玻璃在火灾场景下的破裂行为规律,并探讨了工程应用中安装方式和中空玻璃厚度的推荐选择。本研究共设计了32组实验,详细分析了中空玻璃向火面中心点处的热通量、火源热释放速率、中空玻璃表面温度分布、向火面和背火面两片玻璃的破裂时间、首次开裂位置、裂纹形态以及玻璃脱落情况等参数。定义玻璃长度为L,中点为零点,则边长区域可表示为[-0.5L,0.5L]。实验结果表明25kW/m2的热通量是使得三种中空玻璃破裂并脱落的最小热通量；向火面玻璃的首次起裂位置都位于玻璃的被遮蔽区域,而且均位于[-0.25L,0.25L]的范围内；四边遮蔽工况下向火面玻璃首次破裂平均时间少于另外两种安装方式,但其向火面玻璃与背火面玻璃的脱落比例低于另外两种安装方式,从而保持了玻璃具备更好的完整性,减少新鲜空气的进入,减慢火势发展,且左右垂直遮蔽的安装方式比上下水平遮蔽更容易脱落；向火面玻璃的破裂和脱落对背火面玻璃的破裂具有较为显著的影响。进一步研究了特定遮蔽方式下三种不同空气夹层厚度的中空玻璃在火灾场景下的热响应,对向火面和背火面玻璃首次开裂时间及脱落面积进行了详细的对比分析。结果表明本文实验条件下,四边遮蔽、上下水平遮蔽和左右垂直遮蔽的安装方式时,12mm、6mm和12mm空气夹层厚度的中空玻璃分别具有比另外两种厚度的中空玻璃更长的耐火时间和更小的脱落比例。
[Abstract]:The application of common monolayer glass in building has played the role of daylighting, ventilation and broadening the field of vision, but the insulation performance is poor. The appearance of double layer glass has effectively solved the problem of insulation performance, but it is easy to absorb water vapor in the air and to form dew. Influence vision. The hollow glass, which is made of two glass panels sealed with sealant through aluminum straps, not only makes up for the shortcomings of poor heat insulation and fast heat dissipation of single layer glass, but also makes use of the advantage of double layer glass to keep warm and heat insulating. It has good thermal insulation and anti-condensation performance. But insulating glass is dangerous to break and fall off in case of fire, which accelerates fire spread and threatens personnel to escape. Therefore, the study of rupture, shedding behavior and fire resistance of insulating glass in fire environment is one of the most important problems in building fire safety. Scholars at home and abroad have studied the fracture behavior of insulating glass and obtained the fracture behavior of insulating glass under certain experimental conditions and other qualitative and quantitative conclusions. However, the effect of installation mode on insulating glass has not been discussed in these studies. In this paper, the thermal response of hollow glass under different installation modes and the thermal response of hollow glass with different thickness of air interlayer are studied by means of experiments. The rupture behavior of hollow glass in fire scene is mainly studied. The recommended selection of installation mode and thickness of insulating glass in engineering application is also discussed. In this study, 32 groups of experiments were designed. The heat flux, the heat release rate of the fire source, the surface temperature distribution of the hollow glass, the rupture time and the first crack position of the glass toward the center of the fire surface and the back surface were analyzed in detail. Crack shape and glass shedding and other parameters. If the length of glass is defined as L and the midpoint is zero, the region of side length can be expressed as [-0.5L]. The experimental results show that the heat flux of 25kW/m2 is the minimum heat flux that causes the three kinds of hollow glass to break and fall off, and the first initiation position of the glass is located in the shaded area of the glass, and all of them are located in the range of [-0.25L ~ 0.25L]. The average time for the first rupture of the flame-facing glass under the four-sided shielding condition is less than that of the other two installation modes, but the ratio of the flare glass to the backfire glass is lower than that of the other two installation modes, so that the glass has better integrity. The installation of vertical shading is easier to fall off than horizontal shielding, and the rupture and shedding of flame-facing glass has a significant effect on the rupture of backfire glass. The thermal response of three kinds of insulating glass with different thickness of air interlayer under the specific shielding mode was studied in the fire scene. The first cracking time and the falling off area of the glass on the fire surface and the back fire surface were compared and analyzed in detail. The results show that under the experimental conditions, the four edges are shaded, The insulating glass with the thickness of 12mm and 6mm and the thickness of 12mm air interlayer has longer fireproof time and smaller ratio of falling off than that of the other two kinds of insulating glass.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ171.727

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