合成气低旋流燃烧器设计与流动结构的分析

Design of Low Swirl Syngas Burner and Analysis on the Flow Pattern

设计了一个合成气低旋流燃烧器,采用PIV技术对不同负荷下的冷态流场进行了测量,并比较分析了不同中心射流流速对旋流流场的影响.结果表明:流场中出现中心回流区时的旋流数与中心流速无关,高旋流与低旋流的分界点为S=0.7;流场中的轴向速度、径向速度和湍动能均关于燃烧器中心轴线对称;中心轴线上无量纲轴向速度的分布与中心射流流速(负荷)无关,燃烧器出口下游形成一个发散低速区,有利于稳定充分燃烧;随中心射流速度的增大,径向速度成正比增大,湍动能明显增加.

A syngas burner with low swirling intensity was designed and the cold state flow flields at different loads were measured using PIV technology.The influence of different central jet velocities on swirling flow field was compared and analyzed.Results show that when the central recirculation zone appears,the critical swirl number has nothing to do with the central jet velocity,and the demarcation between high and low swirl flow is S=0.7.The axial velocity,radial velocity and turbulent kinetic energy are all symmetrical about the burner center axis.The dimensionless axial velocity profile along the central axis has nothing to do with the central jet velocity（load）,and downstream the burner outlet there is a low speed area which is helpful to sufficient combustion.With the rise of central jet velocity,the radial velocity increases proportionally,while the turbulent kinetic energy increases significantly.