富油燃烧/快速淬熄/贫油燃烧 (RQL) 燃烧室燃烧中间组分及火焰结构特征研究

Research on Characteristics of Combustion Intermediate Components and Flame Structure in Rich-Burn/Quick-Quench/Lean-Burn （RQL） Combustor

关键词:  燃烧室  主燃孔结构  自发辐射  燃烧中间组分  火焰结构

Key words:  Combustor  Primary holes structure  Spontaneous emission  Combustion intermediate components  Flame structure

摘要:

为了研究主燃孔结构对RQL燃烧室燃烧中间组分及火焰结构特征的影响，在常温、常压及总油气比为0.032的状态下，保持掺混孔结构、主燃孔轴向位置和总面积不变，利用CH基和OH基自发辐射成像技术对采用三种不同结构主燃孔的RQL燃烧室燃烧中间组分进行试验研究。研究结果表明:在燃烧室工作状态不变的条件下，主燃孔结构的改变不会影响火焰的初始扩张角度。OH和CH反应了不同的油气比区域，且OH的起始边界和截止边界较CH滞后约4～8mm。同时结合两者的分布特征、面积及其标准差可以从宏观上反应出燃烧室的油气比变化历程、气流快速混合效果及化学反应剧烈程度。采用三种主燃孔结构均实现了富油-淬熄-贫油的燃烧过程，但主燃孔结构及单孔射流动量对燃烧室内气流混合和油气分布具有很大的影响。主燃孔采用交错排列及增大部分单孔射流动量，能有效地促进燃烧室内气流的快速混合，并在快速混合的同时伴随着强烈的化学反应过程。采用主燃孔相对排列时，减小单孔面积同时增加孔数虽然略微提高了气流的混合效果，但会造成全局化学反应强度的降低。

Abstract:

In order to study the effects of primary holes structure on the combustion intermediate components and flame structure characteristics of rich-burn/quick-quench/lean-burn (RQL) combustor， the experiment investigation has been undertaken into a RQL combustor at three different structures of primary holes by using spontaneous emission imaging of CH and OH. The experiment was carried out under atmospheric pressure and temperature and the ratio of total fuel/air to 0.032 conditions，keeping the structural parameters of dilution hole，axial position and total area of primary holes consistent. The results show that the diffusion angle of flame would not change with the different structures of primary holes under the same operating conditions. The OH and CH reflect different regions of fuel/air ratio，the initial and end boundary of OH lag about 4～8mm compared with CH. The changing process of fuel/air ratio，mixing effect and intensity of chemical reaction can be reflected from macroscopic by combining their distribution characteristics，area and standard deviation. The combustion process of rich-quenching-lean were achieved by using three primary holes structure. However，the primary holes structure and a single jet momentum have a great influence on air mixing and distribution of fuel/air. The rapid mixing of airflow and process of chemical reaction were enhanced by using the structure of primary holes staggered and increasing the momentum of part single hole. When the primary holes is arranged symmetrically，the mixing effect of airflow was improved slightly by reducing the area of single hole and increasing the number of holes at the same time. But it could cause a decrease in the intensity of global chemical reaction.