外加磁场对乙炔气体爆炸反应影响研究

为探究磁场对气体爆炸反应的影响，实验研究了磁场强度对C₂H₂爆炸特征的影响规律，结果表明：磁场能抑制C₂H₂爆炸压力和升压速率，磁场强度越大，抑制效果越明显；沿火焰传播方向，磁场对C₂H₂爆炸火焰传播速度呈现先促进后抑制的效果，整体表现为抑制作用。磁场强度较低时，爆炸火焰平均传播速度降低了38.94%，磁场强度较高时，爆炸火焰平均传播速度降低了49.62%。利用Chemkin-Pro软件模拟了C₂H₂爆炸基元反应过程，理论推导了磁场影响C₂H₂爆炸的反应机理，磁场改变了C₂H₂爆炸反应路径，是造成爆炸特征参数下降的主要原因。由于不同种类自由基的摩尔质量和磁化强度不同，在磁场中，洛伦兹力和梯度磁场力对小分子量自由基比对大分子量自由基的作用力更大。磁场改变了自由基的运动轨迹，由于同种小分子量自由基的聚集和器壁效应的产生，减小了关键自由基之间的碰撞几率，降低了基元反应的速率，导致爆炸强度下降。

Effect of external magnetic field on explosion reaction of acetylene gas

To study the effects of magnetic fields on the gas explosion, considering equivalent acetylene premixed combustible gas as the research object, the effects of different magnetic field intensities on acetylene explosion characteristics were studied experimentally. The explosion pressure and flame propagation velocity were measured simultaneously by transient pressure sensors and a detonation velocity instrument, respectively. The results show that the magnetic fields reduce the explosion pressure and the pressure rise rate of acetylene. With increasing magnetic field intensity, the suppression effect is more significant. Along the direction of flame propagation, the magnetic fields first promote and then suppress the explosion flame propagation velocity of acetylene, and the inhibition effect is stronger than the promotion effect. In these experimental conditions, the average propagation velocity of the explosion flame decreased by 38.94% under lower magnetic fields intensity, and at higher magnetic fields intensity, it decreased by 49.62%. To further study the impact mechanism of magnetic fields on premixed combustible gas explosion, the acetylene explosion free radicals reaction process was simulated numerically by Chemkin-Pro software. The chain reactions, rate of products, and sensitivity are analyzed. And the key radical and reaction paths of acetylene explosion are obtained. Combined with the force analysis of magnetic fields on free radicals, it is deduced that magnetic fields change the reaction paths of acetylene to produce carbon dioxide and water, which is the main internal reason for the decrease in explosion parameters. The different free radicals have different molar masses and magnetization. Lorentz force and gradient magnetic field force have stronger effects on small molecular weight free radicals than on large molecular weight free radicals. The calculation shows that the magnetic fields change the trajectory of the free radicals, cause the aggregation of free radicals with the same small molecular weight, and produce a wall effect, which reduces collisions between key free radicals and the rate of elementary reactions, resulting in a decrease of explosion intensity.