动量通量比对轴向分级再燃喷嘴燃烧特性的影响

Effect of Momentum Flux Ratio on Combustion Characteristics of Axial Staged Reburning Nozzle

针对轴向分级再燃喷嘴,运用冷态粒子图像速度分析仪和火焰自发光CH基拍摄等试验研究方法,探究动量通量比变化时,横流与射流掺混、射流火焰以及污染物排放的变化规律。结果表明:动量通量比的变化对横流与射流的掺混和火焰位置影响较大;掺混强度和射流速度共同作用导致CO体积分数随动量通量比的增大呈现先降低后上升的趋势;动量通量比的增大会导致回流强度和射流火焰主要反应区位置发生变化,进而导致NO体积分数呈现增加的趋势;对于特定的再燃喷嘴燃烧,存在恰当的动量通量比,使得燃烧室壁面不受火焰冲刷,且污染物排放维持在较低水平。

Aiming at the axial staged reburning nozzle, the experimental research methods such as particle image velocimetry(PIV) and flame CH photography were used to explore the variation laws of mixing of cross flow and jet, jet flame and pollutant emissions when the momentum flux ratio changed. Results show that changes of the momentum flux ratio have great influences on the mixing and flame position of cross flow and jet. The CO volume fraction decreased first and then increased with the increase of momentum flux ratio due to the combined action of mixing intensity and jet velocity. The increase of momentum flux ratio will lead to the change of recirculation intensity and the position of main reaction zone of jet flame, which will lead to the increase of NO volume fraction. For a specific reburning nozzle, there is an appropriate momentum flux ratio, so that the combustion chamber wall is not scoured by flame and the pollutant emissions remains at a low level.