大尺度障碍物与泄爆面对天然气内爆炸的协同作用规律研究

为阐释民用建筑内部大尺度物品与门窗等泄爆面对天然气爆炸灾害的协同作用机制，基于典型厨房空间布局及内部物品特征，借助计算流体动力学技术研究了不同泄爆面开启压力和不同大尺度障碍物体积阻塞率条件下天然气内爆炸火焰速度、爆炸超压的分布规律。研究结果表明:大尺度障碍物与泄爆面对室内天然气爆炸过程具有显著的协同作用，共同促进火焰速度与爆炸超压的显著增长，并缩短峰值超压到达时间；大尺度障碍物的存在虽然显著降低了室内天然气的体积，但从增加房间内湍流源和相对长径比的角度进一步促进了泄爆效应；大尺度障碍物与泄爆面协同作用下，室内火焰速度呈现明显的阶段性特征，并在泄爆面附近发生波动。研究结论可为民用建筑物内气体爆炸事故调查分析和灾害评估提供科学依据。

Research on synergetic effect of large scale obstacles and explosion vents on indoor explosion of natural gas

In order to illustrate the synergetic effect mechanism of large scale obstacles and explosion vents like door and window on the indoor explosion of natural gas in the civil buildings, based on the spatial layout and objects characteristics in typical kitchen, the distribution laws of flame speed and explosion overpressure for the indoor explosion of natural gas under different opening pressures of explosion vents and different volume blockage ratios of large scale obstacles were studied by using the computational fluid dynamics (CFD) technology. The results showed that the large scale obstacles and explosion vents had significant synergetic effect on the indoor explosion process of natural gas, which promoted the significant increase of flame speed and explosion overpressure together, and shortened the arrival time of peak overpressure. Although the presence of large scale obstacles significantly reduced the volume of natural gas in the room, the explosion venting effect was further enhanced from the viewpoint of increasing the source of turbulence in the room and the relative aspect ratio. Under the synergetic effect of large scale obstacles and explosion vents, the indoor flame speed presented the obvious stage characteristics and fluctuated near the explosion vents. The results can provide scientific basis for the accident investigation, hazard assessment and mitigation of gas explosion in the civil buildings.