瓦斯体积分数对火焰传播规律影响的实验研究

Experimental Investigation About the Influence of Gas Concentration on Flame Propagation

为研究长直管道中体积分数对瓦斯爆炸的影响以及瓦斯爆炸火焰的传播特征,进行了有无障碍物条件下不同体积分数的瓦斯爆炸实验,用高速摄影仪拍摄火焰阵面发展的过程.实验结果表明,火焰在密闭管道中传播经历了多次振荡的过程,这是火焰前方未燃气体在压缩波的作用下形成湍流所致;瓦斯的体积分数对最大火焰速度和火焰最大传播距离有很大的影响;得出了障碍物对火焰的传播有加速作用,接近当量体积分数的瓦斯爆炸火焰传播速度最快,在一定条件下会发生爆燃转爆轰.

In order to investigate the influence of concentration on propagation characteristics in long and straight pipe, experiments gas about explosion and flame gas explosion were performed with and without obstacles in duct, and a high speed camera was used to reveal the process of flame propagation. Results indicate that flame experiences many oscillations in closed pipe, which is caused by the turbulence of unburned gas induced by the compressive wave in front of the flame. Gas concentration greatly influences on the maximum flame velocity and the maximum propagation distance. Obstacles can accelerate flame and flame propagates fastest when gas is close to stoichiometric concentration, and deflagration to detonation transition may occur under certain conditions.