中文摘要：

在定压条件下，基于GRI-Mesh3．0机理（包含53种组分和325个基元反应），采用化学反应动力学模型，研究了在不同初始温度、压力和化学当量比等条件下，氢气掺混比例对天然气／氢气混合气体的自燃着火特性的影响。在仿真分析中，主要着眼于混合气体温度的变化，各主要组分浓度的变化，着火迟延时间的变化，以及火焰传播速度的变化等。研究结果表明：不同初始条件下，随着天然气掺氢比例的增加，混合气体的着火延迟时间明显缩短，火焰传播速度大幅提高，而对火焰温度影响较小。

英文摘要：

Based on GRI-Mech 3. 0 mechanism, using kinetic model, the auto ignition characteristics of nature gas hydrogen air mixture are studied in different initial conditions under constant pressure. This study focuses on the changes of temperature and component concentrations, ignition delay time and flame propagation speed. The results show that under different initial conditions, with the increase of hydrogen fraction in the mixture, the ignition delay time decreases significantly and flame propagation speed increases significantly. On the other hand, Hydrogen fraction has been found of little influence on flame temperature.