中心分级燃烧室耦合回流区贫油熄火机理

针对中心分级模型燃烧室开展了常压贫油熄火试验和慢车状态贫油熄火试验,并结合贫油熄火时的主/预燃级耦合回流区流场数值模拟分析了该燃烧室的贫油熄火机理.结果表明:与常规燃烧室的贫油熄火机理不同,中心分级燃烧室的贫油熄火油气比是由预燃级和主燃级共同形成的耦合回流区所决定的.耦合回流区的回流量主要由主燃级回流主导,在该研究的中心分级燃烧室结构下,回流区从主燃级卷吸的气量是预燃级本身气量的4.3倍,导致按预燃级气量计算的熄火当量比达到2~2.5,远高于常规燃烧室头部的熄火当量比0.4~0.5. 

Lean blowout mechanism of coupled recirculation zone in concentric staged combustor

Experiments under atmosphere and idle states were carried out to analyze the mechanism of lean blowout by numerical simulation of coupled recirculation zone formed in main stage and pilot stage.The results show that unlike conventional combustor,the lean blowout fuel-air ratio of concentric staged combustor is determined by coupled recirculation zone formed by pilot and main swirlers.The recirculating flow in the coupled zone is dominated by the main stage in this concentric staged combustor,and air entrainment from the main stage is 4.3 times of that from the pilot stage itself,leading to the lean blowout equivalence ratio of pilot stage up to 2 to 2.5,far higher than that of 0.4 to 0.5 of conventional combustor dome.