玻璃窗泄爆下室内燃气爆炸荷载规律试验研究

建立了一套野外试验系统,设计了19组试验工况,分别研究了室内燃气浓度、泄爆窗玻璃破坏强度及面积对室内燃气爆炸荷载的影响,得到了玻璃窗泄爆条件下室内燃气爆炸的荷载特性和变化规律。试验研究结果表明：甲烷浓度在7.5%~10.5%时,室内燃气爆炸产生两个压力峰值,并引起声振不稳定燃烧,形成远大于第一个压力峰值的第二压力峰值;甲烷浓度较高时,声振现象不容易出现,只产生一个压力峰值,其大小仅与泄爆口封闭物有关;当甲烷气体浓度为9.5%时,燃气爆炸反应最剧烈,第一个压力峰值和声振压力峰值均为最大;提高泄爆窗玻璃破坏强度,会导致爆炸荷载的第一个压力峰值增大;增加泄爆窗面积,会使第一个压力峰值略微降低,但第二个的声振压力峰值则会大幅降低。研究结果有利于了解玻璃窗泄爆条件下室内燃气爆炸荷载规律和作用机理,并对进一步研究燃气爆炸荷载下结构的动力响应和破坏形态具有实际意义。

Experimental Investigation on Indoor Gas Blast Loading with Vent Glass Window

A gas blast experiment system is established in this paper. The regularity and characteristics of gas blast loading is investigated by 19 tests with respect to gas concentration, vent glass failure strength and vent area. The analysis results show that when the gas concentration of methane is 7.5%~10.5%, there are two pressure peaks produced by indoor methane gas explosion, the combustion is acoustically unstable, and the second peak is larger than the first one. When the gas concentration of methane is larger than 10.5%, there is no acoustic phenomenon with only one pressure peak, and the peak is mainly affected by the cover of the vent window. When the gas concentration of methane reaches 9.5%, the internal gas blast pressure is the maximum because of vigorous reaction. Increasing vent glass failure pressure gives rise to the first pressure peak, and increasing vent area results in the slight drop of the first pressure and the drastically decrease of the second peak. The results may be helpful for knowing the regularity and characteristics of internal gas blast loading and investigating the response and failure patterns of structure under gas blast loading.