Effect of initial temperature and H2 addition on explosion characteristics of H2-poor/CH4/air mixtures
2020
Li, Ruikang | Luo, Zhenmin | Wang, Tao | Cheng, Fangming | Lin, Haifei | Zhu, Xiaochun
To investigate the temperature dependence of H₂-poor/CH₄/air mixtures explosions, the corresponding explosion characteristics are studied by experimental and numerical methods. The explosion pressure history and flame propagating are obtained using a 20 L spherical tank and a high-speed camera. The heat loss is calculated and the temperature sensitivity and the rate of production are analysed engaged in the GRI-mech 3.0 mechanism. Results showed that the addition of H₂ has the highest improvement in the explosion characteristics of 7 vol% CH₄ mixtures. The effect on the explosion is mainly reflected in the flame speed and explosion time caused by the changes in heat loss. As the initial temperature increase, the most positive and negative reaction on the temperature sensitivity is R38 and R158, respectively. After H₂ addition, the overall sensitivity is reduced and the dominant role of R38 is more prominent. Based on the ROP development, the whole reaction is divided into 4 stages: reaction acceleration, extreme reaction, intermediate species conversion, and reaction termination. Moreover, R38 is the most promoted and dominant reaction for ROP of O₂ and OH. R84 is the most inhibit reaction of H₂ oxidation and has a great influence on the ROP of OH.
显示更多 [+] 显示较少 [-]