粉系冷激波灭火弹内壁处压力研究

Study of Pressure on the Inner Wall of Powder Cold Shock-Wave Extinguishing Bomb

为了研究冷激波灭火系统壳体破碎和灭火介质爆炸抛洒初期的运动规律,首先需要了解冷激波灭火弹内壁处的压力峰值情况。根据量纲分析、力学结构及爆炸实验,研究了不同尺寸、不同药量下粉系冷激波灭火弹内壁处压力的变化规律。结果表明:粉系冷激波灭火弹内壁处的压力峰值与装药量和弹体直径有关;内壁处压力波形为矩形,当弹体内径为104mm时,内壁高压持续时间大于100μs,当弹体内径为220mm时,内壁高压持续时间大于200μs;同等弹体直径下,粉系灭火介质的比药量比水系灭火介质的比药量大。由于介质压缩能耗较大,建议采用更细的纳米级粉体或预压缩的粉团作为粉系冷激波灭火弹的灭火介质。

In order to study the shell fragmentation and the early motion of extinguishing medium after explosion in the cold shock-wave extinguishing system, the pressure on the inner wall of the cold shock-wave extinguishing bomb must be firstly understood. The change of pressure has been studied by dimensional analysis, mechanical structure, and explosion experiments. It is found that the pressure is related to the charge weight and bomb diameter, and the pressure waveform measured at the inner wall is rectangular. When the bomb diameter is 104 mm,the duration of high pressure is above 100μs; when the bomb diameter is 220 mm,the duration of high pressure is above 200μs. In addition,the specific central explosive charge of powder is more than that of water under the same dimension of the cold shock-wave extinguishing bomb to reach better effect of the shell crushing. Owing to the higher energy dissipation during compression,the finer powder and pre-compression powder are suggested as extinguishing medium in powder cold shock-wave extinguishing system.