初始压力对合成气爆炸下限的影响研究

Effect of initial pressures on lower explosion limits of syngas

利用8 L圆柱型爆炸罐试验测量不同初始压力下合成气爆炸下限(LEL),通过Chemkin-Pro软件模拟研究初始压力对合成气近下限燃烧的影响效应,并校核Le Chatelier(L-C)计算式、二次多项式、线性及对数函数拟合关系式对加压宽含氢比合成气LEL的适用性。结果表明:合成气LEL随含氢比的升高呈下降趋势,随初始压力的升高近线性下降;加压条件下,H自由基及OH自由基的摩尔分数发生变化,导致H+O_(2)=O+OH等重要支链反应的敏感性系数发生变化,进而使合成气LEL显著降低;与L-C计算式相比,二次多项式对高压下合成气LEL的估算更准确;线性函数关系式可准确计算不同初始压力下的合成气LEL。

The lower explosion limit(LEL)of syngas under different initial pressures was measured by 8 L cylindrical explosion tank.The effect of initial pressure on the near-low limit combustion of syngas was simulated by Chemkin-Pro software,and the applicability of Le Chatelier(L-C)calculation formula,quadratic polynomial,linear and logarithmic function fitting relationship to the LEL of pressurized syngas with wide hydrogen content ratio was checked.The experimental results show that the LEL of syngas decreases with the increase of H_(2) content ratio,and decreases linearly with the increase of initial pressure.Under the high pressure condition,the mole fraction of H radical and OH radical changed,resulting in the change of the sensitivity coefficient of important branched-chain reactions such as H+O_(2)=O+OH,which further reduced the LEL of syngas.Compared with the L-C calculation formula,the quadratic polynomial is more accurate in estimating the LEL of syngas under high pressure.Furthermore,the linear function relationship can accurately calculate the syngas LEL under different initial pressures.