半球条栅型障碍物对可燃气云爆燃压力波的影响

为考察障碍物对爆燃压力波的影响，进行了可燃气云内、外分别设置障碍物的爆燃实验.浓度为13.3%乙炔-空气可燃气云爆燃压力由量程为-10~35 kPa的动态压力变送器感受，压力信号转变为电流信号传送给16通道DT12L数据采集卡，由125 Ω的标准取样电阻转化为0.5~2.5 V的电压信号输出，经过数据处理得到测点爆燃压力.实验结果表明:障碍物层数越多，爆燃压力越强；障碍物设置在气云边缘和气云外部障碍物附近的爆炸超压增大，但小于内部障碍物对爆炸威力的增大趋势，且障碍物后爆炸超压随测点距离的变化趋势是一致的. 对于该气云爆燃实验， 无障碍物时，爆炸等级能达到2.5级；当气云受半径为300 mm的障碍物约束时，爆炸等级能达到6级.可见障碍物对爆燃压力波的影响是显著的.

Effect of semi-spherical shaped grate obstruction on pressure wave of flammable vapor cloud deflagration

A series of flammable gas cloud deflagration experiments built in and built out obstruction were carried out in order to study the effects of obstruction on deflagration pressure wave. Deflagrating over pressure of flammable gas cloud composed of acetylene/air of a fuel concentration 13.3% was acquired by pressure sensor， whose measure scope is -10~35 kPa. Electrical flow signal transformed from pressure signal was sent to DT12L data acquiring card， which possesses 16 channels. Electrical pressure signal between 0.5~2.5V was put out by means of 125 Ω standard sample resistance. Thus deflagrating over pressure was achieved. The results of experiment show that the more obstruction is， the stronger deflagrating pressure is. If obstruction is situated at the edge of gas cloud or outside of gas cloud， over pressure in the vicinity of obstruction increased， but is smaller than that of experiment when obstruction is built in gas cloud. The change trend among them of blast pressure behind obstruction is consistent. For this test， explosion power can reach to 2.5 if there isn’t obstruction. Nevertheless it can reach to 6. It is concluded that the effect of obstruction to over pressure is prominent.