T型分支坑道对油气爆炸传播特性的影响

Effect of T-branch Tunnel on the Transmission Characteristics of Gasoline-air Mixture Explosion

为研究T型分支坑道对油气爆炸传播特性的影响,通过对比实验,测定了相同初始条件下T型分支坑道和直坑道中油气混合物爆炸的火焰传播速度和爆炸波超压值。利用高速摄影仪,记录了火焰传播至T型分支坑道时的火焰阵面变化情况,并对T型分支坑道中油气混合物爆炸的传播情况进行了理论分析。结果表明:T型分支坑道对油气混合物爆炸的影响可以视为面积突扩和障碍物扰动双重作用的影响;火焰经过支坑道时,火焰阵面发生扭曲并产生皱褶,表面积增大导致火焰传播速度增大;T型分支坑道处,大量反射波和绕射波进入波后反应区,加强了气流湍流强度,并推动已燃气体回传,迅速提高了燃烧反应速度和能量释放率,起到了增大火焰传播速度和爆炸波超压值的作用。

In order to explore the effects of T-branch tunnel on the transmission characteristics of gasoline-air mixture explo- sion, the flame velocity and explosion wave overpressure in value of gasoline-air mixture explosion in T-branch tunnel and straight tunnel under the same initial condition are measured through contrast experiments. The changes of the flame front when propagating to the T-branch tunnel are recorded with a high speed camera, and the transmission characteristics of gasoline-air mixture explosion in T-branch tunnel are analyzed in theory. The research results show that the influence of T-branch tunnel on gasoline-air mixture explosion can be regarded as the influence of dual function of the sudden enlargement area and obstacles; when the flame propa- gates to the T-branch tunnel, the flame front creases distorted, and the flame surface area increases significantly, which results in the increase of flame velocity; near the T-branch tunnel, a lot of reflection and diffraction waves to come to the reaction zone so that the airflow turbulence is strengthened, the flame is pushed back, the response speed and energy release rate are rapidly improved, and the combustion rate and the effect of explosion wave overpressure values are also increased.