CO/H_2变化对合成气旋流燃烧火焰流动结构的影响

Effect of CO/H_2 Molar Ratio on Flow Structures of Syngas Swirling Flames

利用粒子图像速度场测量技术(PIV)对不同CO/H_2下的合成气旋流燃烧流场进行了实验研究。由所测合成气旋流燃烧火焰的速度场可知:合成气旋流燃烧火焰中,轴向平均速度最大值出现在喷嘴中心轴线处,轴线两侧还会有个小的峰值;随着与喷嘴表面距离的增大,最大轴向平均速度不断减小,轴侧峰值与轴线距离不断增大。对比不同CO/H_2下火焰内部的速度分布可知,CO/H_2是影响合成气旋流火焰流动结构的一个重要参数,随着CO/H_2比的增大:旋流火焰内部的燃料涡与喷嘴表面距离先增大后缓慢降低,与喷嘴轴线距离也是先增大后减小;轴向平均速度最大峰值不断增加,轴侧峰值大小基本不变。

Experiments have been performed to investigate the effect of CO/H2 molar ratio on the flow structures of syngas swirling flames. By PIV technique, the velocity distributions of the syngas swirling flames with different CO/H2 molar ratios were observed. The results show that the maximums of axial mean velocity are at the center of axial sections, and two small peaks of axial mean velocity are on the side of centerline symmetrically. Furthermore, the experiment indicates that CO/H2 molar ratio is an important parameter to the velocity distributions and the structures of vortex in swirling flames. With the increase of CO/H2 molar ratio： the distance between the nozzle and the fuel vortex in flame increases at first, and then reduce slowly; maximum of axial mean velocity adds continuously, but the axial velocity peaks on the side of centerline change little.