Impact of Steam-Dilution on the Flame Shape and Coherent Structures in Swirl-Stabilized Combustors
Impact of Steam-Dilution on the Flame Shape and Coherent Structures in Swirl-Stabilized Combustors
复制标题
蒸汽稀释对旋流稳定燃烧室火焰形状和相干结构的影响
DOI：
10.1080/00102202.2014.890597
复制
发表时间：
2014
影响因子：
1.9
通讯作者：
C. O. Paschereit
中科院分区：
文献类型：
--
作者：
S. Terhaar;K. Oberleithner;C. O. Paschereit
加湿燃气轮机和注汽燃气轮机是降低燃气轮机排放、提高燃气轮机效率和燃料灵活性的有前途的技术。在本研究中，在雷诺数为22,000到32,000的范围内，实验研究了水蒸气稀释对旋流稳定甲烷和氢气燃烧火焰的影响。用高速粒子图像测速仪和OH~*化学发光测量了速度场和火焰位置。采用扩展的定量光片技术来估计温度场。结果表明，随着水蒸气稀释率的增加，火焰位置、速度场和温度场都发生了强烈的变化。特别是，在干燥条件下，V型火焰在宽阔的内回流区内稳定，局部湍流动能较低；当蒸汽含量适中时，火焰变为喇叭状；当蒸汽稀释率很高时，火焰脱离并呈现环状形状。利用适当的正交分解，从粒子图像测速数据中提取相关的相干流动结构。燃烧室入口附近产生的螺旋不稳定性是等温流的主要特征。这种结构在干燥火焰中被完全抑制，而在高度蒸汽稀释的分离火焰中重新出现，其形状和频率与等温情况下相似。在中高稀释率下，喇叭状火焰的流场具有较低频率的螺旋不稳定性，与等温和极湿情况相比，螺旋不稳定位于下游更远的位置。提出了一种概念上的解释，将抑制螺旋不稳定性与所遇到的特定的温度场和火焰形状联系起来。
Humidified gas turbines and steam-injected gas turbines are promising technologies to lower the emissions and increase the efficiency and fuel flexibility of gas turbines. In the current study, the influence of steam-dilution on swirl-stabilized methane and hydrogen-fired flames is experimentally investigated at Reynolds numbers in the range of 22,000 to 32,000. Velocity fields and flame positions were measured using high-speed particle image velocimetry and OH* chemiluminescence. An extension of the quantitative light sheet technique was employed to estimate the temperature fields. The combined results reveal strong changes in the flame position, the velocity field, and the temperature field with increasing rates of steam dilution. In particular, three different flow and flame patterns are encountered: At dry conditions, a V-shaped flame stabilizes in a broad inner recirculation zone with low local turbulent kinetic energy; at moderate steam content, the flame changes into a trumpet-like shape; and at very high rates of steam-dilution, the flame detaches and shows an annular shape. The associated coherent flow structures are extracted from the particle image velocimetry data employing proper orthogonal decomposition. The isothermal flow is dominated by a helical instability arising near the combustor inlet. This structure is completely suppressed for the dry flame and reappears for the heavily steam-diluted detached flame with a similar shape and frequency as for the isothermal case. The flow field of the trumpet-like flame at intermediate to high steam dilution rates features a helical instability of lower frequency that is located further downstream than in the isothermal and very wet case. A conceptional explanation is presented that relates the suppression of the helical instability to the specific encountered temperature fields and flame shapes.
登录
查看更多内容
为什么非均匀密度会抑制进动涡核
影响因子：
1.9
作者：
K. Oberleithner;S. Terhaar;Lothar Rukes;C. Paschereit
通讯作者：
C. Paschereit
在燃烧研究中使用激光光片技术。
DOI：
--
发表时间：
1997
期刊：
影响因子：
--
作者：
P. Voigt;R. Schodl;P. Griebel
通讯作者：
P. Griebel
蒸汽稀释对预混甲烷/氢气火焰中氮氧化物形成的影响
DOI：
--
发表时间：
2013
期刊：
影响因子：
--
作者：
S. Göke;C. Paschereit
通讯作者：
C. Paschereit
影响因子：
4.4
作者：
G. Kuenne;A. Ketelheun;J. Janicka
通讯作者：
G. Kuenne;A. Ketelheun;J. Janicka
干湿条件下出口边界条件对旋流稳定燃烧器反应流场的影响
DOI：
--
发表时间：
2012
期刊：
影响因子：
--
作者：
S. Terhaar;B. Bobusch;C. Paschereit
通讯作者：
C. Paschereit