Plasma assisted combustor dynamics control
Plasma assisted combustor dynamics control
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DOI：
10.1016/j.proci.2014.08.025
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发表时间：
2015-04
期刊：
影响因子：
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通讯作者：
Wookyung Kim;J. Snyder;J. Cohen
中科院分区：
文献类型：
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作者：
Wookyung Kim;J. Snyder;J. Cohen
当前研究的主要目的是证明和解释实施等离子体放电以改善燃烧室动力学和火焰稳定性的有效性。具体而言，纳秒脉冲等离子体放电（NSPD）被施加到预混甲烷/空气转储燃烧室的动态燃烧不稳定性的缓解与最小的NOx惩罚。结果，在NSPD存在的情况下观察到高达25 dB的噪声降低。高速图像表明，NSPD重新定位火焰稳定点从外部回流区的中心区。由于NSPD的高度非平衡温度特性，在放电存在下排放的增量增加是最小的，通常约为0.5EINOX，而燃烧效率的增加可能是显著的，并且在约10%的量级上。提出了一种以等离子体功率为激励源，测量压力振荡幅度的新型控制算法。该算法不需要压力振荡相位的知识/测量，并且因此避免了与对流和致动器相位延迟相关联的挑战。NSPD对旋流稳定火焰的影响也进行了研究，旋流数从0到0.33。结果表明，由于初生火焰动力学的固有降低，NSPD对动力学降低的相对效果随着旋流的增加而降低。在目前的工作中的所有观察表明，火焰的形状起着核心作用，在确定等离子体的有效性的程度，任何嘈杂的，外回流区稳定的火焰将显着改善这种实施的NSPD。还讨论了具有更广泛可操作性的先进燃烧室概念的潜在影响。
The primary purpose of the current research is to demonstrate and interpret the effectiveness of implementing a plasma discharge to improve combustor dynamics and flame stability. Specifically, a nano-second pulsed plasma discharge (NSPD) was applied to a premixed methane/air dump combustor for mitigation of dynamic combustion instabilities with a minimal NOXpenalty. As a result, up to ∼25 dB noise reduction was observed in the presence of the NSPD. High speed imaging suggests that the NSPD relocated the flame stabilization point from the outer recirculation zone to the center zone. Due to the highly non-equilibrium temperature characteristic of the NSPD, the incremental increase of emissions in the presence of the discharge was minimal, typically around 0.5 EINOX, while the increase of combustion efficiency could be significant and on the order of ∼10%. A new control algorithm that measured pressure oscillation amplitude, and actuated with plasma power was developed. This algorithm does not require knowledge/measurement of pressure oscillation phase, and therefore, avoids challenges associated with convective and actuator phase delays. The impact of NSPD on swirl-stabilized flames was also investigated for swirl numbers from 0 to 0.33. It is shown that the relative effect of NSPD for dynamics reduction decreases with increasing swirl due to the inherent decrease in nascent flame dynamics. All observations in the current work suggest that the flame shape plays a central role in determining the degree of plasma effectiveness and that any noisy, outer recirculation zone stabilized flames will be significantly improved by this implementation of NSPD. Potential impacts for advanced combustor concepts with wider operability are also discussed.