Measurement of laminar burning velocities and analysis of flame stabilities for hydrogen-air-diluent premixed mixtures  

作　　者：HU ErJiang HUANG ZuoHua HE JiaJia JIN Chun MIAO HaiYan WANG XiBin 

机构地区：[1]State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China

出　　处：《Chinese Science Bulletin》2009年第5期846-857,共12页

基　　金：Supported by the National Basic Research Program of China (Grant No. 2007CB210006);National Natural Science Foundation of China (Grants Nos. 50636040 and 50521604)

摘　　要：The laminar burning velocities and Markstein lengths of the hydrogen-air-diluent mixtures were meas-ured at different equivalence ratios (0.4―1.5), different diluents (N2, CO2 and 15%CO2+85%N2) and di-lution ratios (0, 0.05, 0.10 and 0.15) by using the outwardly expanding flame. The influences of flame stretch rate on the flame propagation characteristics were analyzed. The results show that both the laminar burning velocities and the Markstein lengths of the hydrogen-air-diluent mixtures decrease with the increase of dilution ratio. The decrease in Markstein lengths means that adding diluents into the hydrogen-air mixtures will decrease the diffusional-thermal instability of the flame front. For a specified dilution ratio, the laminar burning velocities give their maximum values at an equivalence ratio of 1.8. The Markstein lengths increase with the increase of the equivalence ratio monotonously regardless of the diluents. The study shows that CO2 as the diluent has a greater impact on the laminar flame speed and the flame front stability than N2 as the diluent.The laminar burning velocities and Markstein lengths of the hydrogen-air-diluent mixtures were measured at different equivalence ratios （0.4-1.5）, different diluents （N2, CO2 and 15%CO2＋85%N2） and dilution ratios （0, 0.05, 0.10 and 0.15） by using the outwardly expanding flame. The influences of flame stretch rate on the flame propagation characteristics were analyzed. The results show that both the laminar burning velocities and the Markstein lengths of the hydrogen-air-diluent mixtures decrease with the increase of dilution ratio. The decrease in Markstein lengths means that adding diluents into the hydrogen-air mixtures will decrease the diffusional-thermal instability of the flame front. For a specified dilution ratio, the laminar burning velocities give their maximum values at an equivalence ratio of 1.8. The Markstein lengths increase with the increase of the equivalence ratio monotonously regardless of the diluents. The study shows that CO2 as the diluent has a greater impact on the laminar flame speed and the flame front stability than N2 as the diluent.

关 键 词：氢气 空气混合 火焰特性 燃烧速度 稳定性 

分 类 号：O643[理学—物理化学]