Experimental Study to Enhance Resistance for Boundary Layer Flashback in Swirl Burners Using Microsurfaces
Experimental Study to Enhance Resistance for Boundary Layer Flashback in Swirl Burners Using Microsurfaces
复制标题
利用微表面增强旋流燃烧器边界层回火阻力的实验研究
DOI：
10.1115/gt2017-63367
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
R. Marsh
中科院分区：
文献类型：
--
作者：
Mohammed Al;Fares Hatem;A. Alsaegh;A. Medina;S. Bigot;R. Marsh
火焰回火是预混燃气涡轮机燃烧中的主要不稳定性问题之一，除了显著增加污染物水平之外，还可能对燃烧系统硬件造成相当大的损坏。旋流燃烧已被证明是一种有效的火焰稳定器，在广泛的操作条件下，虽然旋流系统可以容易地在燃料预混条件下的各种类型的回火。不幸的是，在这些系统中，使用用于缓解一种闪回机制的方法将导致另一种闪回机制。因此，本文的重点是改善边界层回火（BLF），同时试图减轻燃烧诱导涡破裂（CIVB）在一个中等旋流燃烧系统。一种受仿生工程启发的新技术已经被开发出来，用于实现这一目标。使用这些生物学设计的形状来成功地稳定流动，可以改善对边界层的控制，从而减少流出阻力，同时抵抗逆燃的随机传播。因此，边界层回火阻力使用这个概念进行了研究，在150千瓦切向旋流燃烧器的数值和实验，以确定使用微表面的旋流与中央空气喷射和不使用的效果。使用了各种技术，包括热线风速仪、LDA测量、LES CFD和RANS CFD。结果表明，采用中心喷射与微表面相结合的方式，可提高系统对边界层回火的抵抗能力，并产生一个新的燃烧稳定性图，其工作区域更宽，从而避免了BLF和CIVB两种回火机制。
Flame flashback has been one of the major instability problems in premixed gas turbine combustion with the potential to cause considerable damage to the combustion system hardware in addition to significant increase in pollutant levels. Swirl combustion has been proven as an effective flame stabilizer over a wide range of operation conditions, although swirling systems can be prone to various types of flashback under fuel premixed conditions. Unfortunately, using methodologies for the mitigation of one flashback mechanism will lead to another one in these systems. Therefore, this paper focuses on improving Boundary Layer Flashback (BLF) while trying to mitigate Combustion Induced Vortex Breakdown (CIVB) in a medium swirl combustion system. A new technique inspired by Biomimetic Engineering has been developed to use micro-surfaces for this aim. The use of these biologically designed shapes for successful flow stabilisation allows improved control of the boundary layer, thus reducing outflow drag while resisting the random propagation of flashback. Therefore, boundary layer flashback resistance using this concept was investigated numerically and experimentally in a 150 kW tangential swirl burner to determine the effects of using a micro-surface in swirling flows with and without central air injection. Various techniques were used, including Hot Wire Anemometry, LDA measurements, LES CFD, and RANS CFD. The results showed enhancement of the system resistance to boundary layer flashback, and a new combustion stability map was generated with a wider operational region when using central injection combined with micro-surfaces, thus avoiding two types of flashback mechanisms, i.e. BLF and CIVB.