Abstract Water mists are an effective means of suppressing coal fires in enclosed spaces. In the present work, A new type of nitrogen-water mist atomizer was developed. This atomizing device does not need additional power facilities. Only relying on the interaction between nitrogen generated by nitrogen injection equipment in coal mine and water in underground pipelines, it can produce nitrogen with large flow rate, small droplet size, uniform particle size distribution and sufficient mixing, and water vapor liquid two-phase fluid. The structure and working principle of water atomization device were investigated. Numerical simulations and experimentation using the five-hole probe method were used to assess the velocity distributions generated by the atomization device when employing different starter twist numbers CL, and the optimal number was found. With the increase of CL, the gas rotating jet field in the expansion section tends to be more uniform and stable, and the backflow area of the rotating jet appears earlier. At the same time, the tangential velocity conducive to the liquid atomization process also increases significantly. A fire extinguishing experiment in an enclosed space demonstrated that the water mist produced a significant cooling effect and could reduce the combustion temperature effectively.

中文翻译：

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封闭空间氮水雾灭火新技术

摘要 细水雾是抑制密闭空间煤火的有效手段。在目前的工作中，研制了一种新型的氮水雾化器。这种雾化装置不需要额外的动力设施。仅依靠煤矿注氮设备产生的氮气与地下管道中的水相互作用，就可以生产出流量大、液滴尺寸小、粒径分布均匀、混合充分的氮气和水汽液两相流体. 研究了水雾化装置的结构和工作原理。使用五孔探针方法的数值模拟和实验被用来评估当采用不同的起动器扭转数 CL 时雾化装置产生的速度分布，并找到了最佳数量。随着CL的增大，膨胀段气体旋转射流场趋于均匀稳定，旋转射流回流区出现较早。同时，有利于液体雾化过程的切向速度也显着增加。密闭空间灭火实验表明，细水雾冷却效果显着，能有效降低燃烧温度。