Combustion Instabilities and Control of a Multiswirl Atmospheric Combustor
Combustion Instabilities and Control of a Multiswirl Atmospheric Combustor
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DOI：
10.1115/1.2181595
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发表时间：
2007
影响因子：
1.5
通讯作者：
Tongxun Yi;E. Gutmark
中科院分区：
文献类型：
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作者：
Tongxun Yi;E. Gutmark
对大气压旋流燃烧室的热声不稳定性和贫油熄火进行了实验研究。确定了影响燃烧不稳定性的可能因素。在燃烧空气量小于1.0%的情况下，对旋流剪切层和燃料管线进行单色或连续空气强制，可使压力振荡幅度降低90%~ 98.5%;对火焰进行相移空气强制，可使压力振荡幅度降低78%。当压力脉动衰减时，同时观察到NOx的还原，并且平坦的火焰前缘变为圆锥形。对于LBO，随着当量比的减小，相对强烈的振荡出现从平稳的湍流燃烧，然后是一个更稳定，更安静的状态之前井喷。强烈的热释放振荡的区域重叠的高平均热释放。根据旋流场的不同，LBO的火焰可以是抬升火焰或锚定火焰。LBO极限在更高的空气流速下延伸。在倾卸平面附近具有较低速度区域的倾卸旋流器基本上将LBO限制扩展了42.8%。燃油管路的高频空气压力有助于在LBO附近保持稳定燃烧。
Thermo-acoustic instability and lean blowout (LBO) are investigated experimentally in an atmospheric swirling combustor. Possible factors affecting combustion instability are identified. With less than 1.0% of the combustion air, monochromatic or continuous air forcing of the swirling shear layer and fuel line, can reduce pressure oscillation amplitude by up to 90% to 98.5%; Phase-shift air forcing of the flame can reduce pressure oscillation amplitude by 78%. When pressure pulsations are attenuated, simultaneous reduction of NOx is observed and the flat flame front changes into a conical shape. For LBO, with decreasing equivalence ratio, relatively intense oscillations emerge from smooth turbulent combustions, followed by a more stable and quieter state before blowout. The regions of intense heat release oscillations overlap those of high mean heat release. Depending on the swirling flow field, lifted flame or anchored flame is observed for LBO. LBO limit extends at higher air flow rate. A dump swirler with a lower velocity region near the dump plane substantially extends the LBO limit by 42.8%. High frequency air forcing of the fuel line helps maintaining stable combustion near LBO.