方形管道中二氧化碳抑爆性能实验研究

Experimental study on the explosion suppression characteristics of Carbon Dioxide on methane in visible square pipes

自行搭建研究可视化方形管道内可燃气体爆炸火焰传播规律的实验平台,充入体积分数为3%、6%、9%、12%、15%、18%的二氧化碳,研究其对9.5%甲烷空气预混气体爆炸压力和火焰传播的影响。方形管道实验段长560 mm、宽80 mm。二氧化碳体积分数为3%时爆炸压力达到最大值,为0.163 MPa;二氧化碳体积分数为18%时爆炸压力达到最小值,为0.113 MPa。利用高速摄影/纹影技术对燃烧过程进行分析。结果表明:火焰前锋阵面传播速度随二氧化碳体积分数的上升而降低。火焰传播中期,火焰前锋阵面形成"准平面火焰",火焰传播中后期,火焰前锋阵面形成"郁金香火焰"结构。二氧化碳体积分数上升至6%以后,火焰发生畸变,出现"双重郁金香火焰"及"双重半平面火焰"结构。

The self-made visible square pipe platform was used to study the explosion suppression characteristics of carbon dioxide on methane in the pipeline. 3%, 6%, 12%, 15%, 18%, 20% carbon dioxide was charged into the 9.5% concentration of methane air pre mixed gas and the influence of carbon dioxide on explosion pres sure, speed of flame striker front was analyzed.The length of square pipe was 560 mm and the width was 80 mm. The explosion pressure reaches the maximum value of 0.163 MPa when lhe con centration of carbon dioxide was 3%, and it reached the minimum value of 0.113 MPa when the eoneentration of carbon dioxide was 18%. The combustion process was analyzed by high speed photog raphy/schlieren technology.The results showed that the flame for ward velocity increased with the concentration of carbon dioxide. In the midst of the flame spread, the flame striker formed a ＂quasi planar flame＂ structure and then developed into a ＂tulip flame＂strut ture. After the carbon dioxide concentration rose to 6%, the flame was distorted, and the ＂double tulip flame＂ and ＂double semi-flat flame＂ appeared.