高温高压条件下甲醇裂解气-空气-稀释气层流火焰传播速度和马克斯坦长度研究

Experimental Study on Laminar Burning Velocity and Markstein Length of Dissociated Methanol-Air-Diluent Mixtures at Elevated Temperatures and Pressures

利用球型发展火焰研究了不同燃空当量比(0.4～5.0)、初始温度(310K、360K和410K)、初始压力(0.1MPa、0.25MPa和0.5MPa)、稀释气(N2和CO2)和稀释度(0、0.1、0.2、0.3和0.4)条件下甲醇裂解气-空气-稀释气混合气的预混层流燃烧速度和马克斯坦长度。研究结果表明,甲醇裂解气-空气混合气层流燃烧速度在当量比为1.8处达到最大值,并且随初始温度的增加而增加,随初始压力的增加而减小。马克斯坦长度随初始温度的增加而减小,随初始压力的增加而减小。N2和CO2作为稀释气加入混合气降低了混合气层流燃烧速度,较稀混合气时马克斯坦长度随稀释度的增加而减小,化学计量比附近和较浓混合气时马克斯坦长度随稀释度的增加而增加。稀释气CO2对层流燃烧速度和马克斯坦长度的影响高于N2。

Laminar burning velocities and Markstein lengths of dissociated methanol-air-diluent mixtures were measured at different equivalence ratios, initial temperatures and pressures, diluents （N2/CO2） and dilution ratios by using the spherically expanding flame. The influences of these parameters on laminar burning velocity and Markstein length were analyzed. The results show that laminar burning velocities of the dissociated methanol-air mixture are increased with the increase of initial temperature and are decreased with the increase of initial pressure. Peak laminar burning velocity occurs at equivalence ratio of 1.8. Markstein lengths are decreased with the increase of initial temperature and initial pressure. Mixture diluents （N2 and CO2 ） will decrease laminar burning velocities of mixtures. Markstein length increases with the increase of dilution ratio exeept for very lean mixture （ φ less than 0.8）. CO2 dilution has a larger impact on laminar flame speed compared to N2.