螺旋微通道对掺氢甲烷爆轰传播的影响

Effect of spiral microchannel on detonation propagation of hydrogen-doped methane

为探究复杂结构管路中CH4/H2二元燃料混合体系爆轰传播特性,研究了在连续弯管(螺旋结构)扰动作用下,CH4/H2-O_(2)混合物的爆轰失效与重新起爆特征行为,利用光电探测技术和烟迹技术获取了不同氢气比例与初始压力下的火焰传播速度与胞格结构变化规律。实验结果表明,螺旋结构对爆轰波的传播存在抑制作用,爆轰火焰通过螺旋管前后的传播过程可以分为加速、减速、重起爆三个阶段。H2的添加可以有效提高预混气的爆轰敏感性,降低火焰通过螺旋管的速度亏损,当掺氢比超过50%时,减速阶段的速度亏损大幅减小。初始压力的增大同样可以降低火焰的速度亏损,当初压从50 kPa增加到200 kPa,速度亏损减少了40.5%。螺旋管的存在使得重起爆的起爆能量减小,爆轰胞格尺寸增大。

To explore the detonation propagation characteristics of CH4/H2 binary fuel mixture system in complex structure pipeline,this paper studies the detonation failure and re-initiation characteristic behavior of CH4/H2-O2 mixture under the disturbance of continuous elbow(spiral structure).The variation of flame velocity and cell structure is measured by using photoelectric detection technology and smoke trace technology by varying the hydrogen ratio and initial pressure.The experimental results show that the spiral structure has an inhibitory effect on the propagation of detonation waves.The propagation process of detonation flame before and after passing through the spiral tube can be divided into three stages:acceleration,deceleration,and re-initiation.The addition of H2 can effectively improve the detonation sensitivity of the premixed gas and reduce the velocity loss of the flame through the spiral tube.When the hydrogen ratio exceeds 50%,the change of velocity loss is less affected by the hydrogen ratio.The increase of initial pressure can also reduce the velocity loss of the flame.As the initial pressure increases from 50 kPa to 200 kPa,the velocity deficit decreases by 40.5%.The existence of the spiral tube reduces the initiation energy of re-initiation and increases the detonation cell size.