燃料分配策略对低排放燃烧室的燃烧组织具有重要影响,为探究低工况条件下,预燃级燃料分级比对中心分级燃烧室性能的影响规律,保持0.017恒定油气比条件,对5种不同燃料分配模式的单头部中心分级燃烧开展数值模拟研究,分析了不同预燃级燃料分级比对燃烧流场流动特性、温度分布特性、燃料空间分布与火焰结构,以及排放特性的影响,评估了燃烧室综合性能。研究结果表明：在低工况条件下,预燃级燃料分级比变化对燃烧流场结构与速度分布影响并不显著。降低预燃级燃料的分配占比,燃烧室内部高温区面积先减后增,高温区边界与预燃级喷嘴的间距缩短；预燃级火焰锋面沿燃烧室轴向朝旋流器偏移,主燃级火焰锋面位置与张角基本不变。当预燃级燃料分级比由1减至0.2,燃烧室燃烧效率由99.87%降至99.71%,CO排放量由68.12ppm增至190.32ppm,OTDF先减后增且在预燃级燃料分级比为0.6时取得最小值21.75%。

The fuel distribution strategy significantly influences the combustion organization of low-emission combustors. To explore the effect of pilot fuel-staging ratio on the performance of centrally staged combustors under low-power operating conditions, numerical simulations are conducted in a single-sector centrally staged combustor using five different fuel distribution schemes, under 0.017 constant fuel-air ratio. The effects of various pilot fuel-staging ratios on the combustion flow field characteristics, temperature distribution, fuel spatial distribution, flame structure, and emission characteristics are analyzed. Furthermore, the comprehensive performance of the combustor is evaluated. The research results indicate that variations in the pilot fuel-staging ratio have no significant impact on the combustion flow field structure and velocity distribution under the low-power operation. Reducing the proportion of pilot fuel distribution causes the high-temperature zone inside combustor to initially enlarge and then shrink, while the distance between high-temperature zone boundary and pilot nozzle simultaneously shortens. Concurrently, the pilot flame front shifts toward the swirler along combustor axis, with the front position and opening angle of primary flame remain essentially unchanged. The fuel-staging ratio decreases from 1 to 0.2, resulting in a reduction in combustor combustion efficiency from 99.87% to 99.71% and an increase in CO emissions from 68.12 ppm to 190.32 ppm. The OTDF initially decreases and then increases, reaching a minimum value of 21.75% at a pilot fuel-staging ratio of 0.6.

V231.2

国家科技重大专项（J2019-III-0012-0055)