中心分级燃烧室雾化特性试验研究

Experimental Investigation on Spray Characteristic ofInternally-Staged Combustor

关键词:  中心分级燃烧室  贫油预混预蒸发  雾化  试验

Key words:  Internally-staged combustor  Lean premixed pre-evaporation  Spray  Experiment

摘要:

为了研究中心分级燃烧室雾化特性，设计中心分级燃烧室头部进行雾化特性试验研究。头部预燃级采用贫油直接喷射，主燃级采用预混预蒸发。试验采用了相位多普勒粒子分析仪测量液滴粒径及速度，用10μm以下的小液滴速度近似流场速度。实验结果表明：流场具有中心回流区（PRZ）、唇口回流区、角落回流区（CRZ）、预燃级高速射流区及主燃级高速射流区等结构；流场结构对称且受工况改变影响较小；大液滴集中在中心回流区及角落回流区。中心分级燃烧室不同于其他分级燃烧室，其具有特殊的流场结构及燃油雾化分布规律；在近场流场区域65μm~75μm液滴集中在PRZ区域和CRZ区域；近场区域内Case 4雾化D₃₂是Case 3的60%。

Abstract:

To study the atomization characteristics of the internally-staged combustor, an internally-staged combustor dome was designed. The pilot stage of atomizer adopted lean direct injection, and the main stage used lean premixed pre-evaporation. Four operation conditions were designed for the experiments. Phase Doppler particle analyzer was used to measure droplet size and velocity, and the velocity of droplets below 10μm was represented approximately the flow field velocity. The experimental results show that the flow field has structures such as pilot recirculation zone（PRZ）, lip recirculation zone, corner recirculation zone(CRZ), high-speed jet zone of pilot stage and high-speed jet zone of main stage. The structure of flow field is symmetrical and less affected by the change of working conditions. Large droplets are concentrated in the PRZ and the CRZ. Unlike other staged combustors, the internally-staged combustor has special flow field structure and fuel atomization distribution. In the near-field flow field, 65μm~75μm droplets are concentrated in the PRZ region and CRZ region and Case 4 atomization D₃₂ is 60% of Case 3.