单凹腔驻涡燃烧室值班油气匹配研究

Matching of Fuel and Air in Pilot Stage of Single-Cavity Trapped Vortex Combustor

关键词:  单凹腔驻涡燃烧室  油气关系  凹腔当量比  油气比  燃烧效率

Key words:  Single-cavity trapped vortex combustion  Fuel-air organization,Cavity equivalent ratio,Fuel air ratio,Combustion efficiency

摘要:

为开展单凹腔驻涡燃烧室值班油气匹配思路研究，采用试验研究方法，在燃烧室进口压力、温度以及马赫数分别为0.101MPa，487K，0.25，燃料为航空煤油的条件下开展试验。试验中主要研究了4种不同总油气比0.0093，0.0124，0.0155，0.0186，以及对应相同总油气比下不同凹腔油气匹配思路，即通过更改凹腔进气结构，在总油气比一定的情况下，调节凹腔当量比Φ_ca。研究结果表明：凹腔内的油气匹配对燃烧效率影响显著。当总油气比<0.0155时，不同凹腔当量比的燃烧效率均随总油气比增大而提高；总油气比>0.0155后，不同凹腔当量比的燃烧效率随油气比的变化规律有所差异，当凹腔富油时，燃烧效率降低；当凹腔由贫转富时，燃烧效率缓慢上升；进一步研究发现，凹腔当量比<1.4时，不同当量比的燃烧效率随总油气比增大均有所增长，在凹腔当量比>1.4后，效率有下降的趋势。因此，在总油气比相同，仅凹腔供油的工作状态，凹腔局部富油时的燃烧效率高于当量比为1时的燃烧效率。凹腔当量比1.4为仅凹腔供油燃烧的最佳当量比。

Abstract:

In order to explore the matching of fuel and air in the pilot stage based on single-cavity trapped vortex combustor， the experimental was carried out under 0.101MPa， the inlet temperature being 487K， and the inlet Mach number being 0.25. The fuel was aviation kerosene. In the experiment， four different total fuel-air-ratio （FAR） divided in 0.0093， 0.0124， 0.0155， 0.0186 were studied， and the air and fuel organization modes of different cavities corresponding to the same FAR were studied. The cavity equivalent ratio Φ_ca was adjusted by changing the cavity fore-inlet structure with a certain FAR. The results show that the relationship between air and fuel in the cavity has a significant effect on the combustion efficiency. The combustion efficiency of different Φ_ca increases with the increase of FAR， when the FAR is less than the 0.0155. After the FAR is more than 0.0155， the combustion efficiency of different cavity Φ_ca varies with the FAR. When the Φ_ca is relatively rich， the combustion efficiency is reduced， and when the Φ_ca is lean， the combustion efficiency is slow up. Further research found that when the Φ_ca is less than 1.4， the combustion efficiency of different Φ_ca increases with the increase of the FAR， while the Φ_ca is greater than 1.4， the efficiency decreases. The combustion efficiency of Φ_ca more than 1 is higher than that of Φ_ca=1，when the FAR is same and kerosene is only supplied in cavity. The optimum Φ_ca of combustion is obtained when the local equivalent ratio in the cavity is 1.4.