【摘要】 实现氢气和空气在氢燃气轮机燃烧室喷嘴管外均匀掺混可以在避免回火的同时实现低NO_x燃烧。为了在喷嘴出口到燃烧之前尽量实现均匀的掺混，通过数值模拟方法计算分析了微混喷嘴出口的流动特性以及燃空来流相互作用对氢气和空气混合的影响，研究了燃空动量比、燃料微孔间隙比、射流高度及混合长度对微混喷嘴冷态燃空掺混的影响。结果表明：掺混效果直接受标准射流深度、邻射流扰动及扩散段旋涡结构的影响。燃空动量比R_m为1.19～1.77时，所达到的标准射流深度可以实现较均匀掺混；间隙比为0.54时，邻射流相互作用会增大射流中心的氢气浓度下降梯度；增加射流高度和混合长度均能降低混合不均匀度；近壁旋涡对的完整发展有利于改善掺混。更多还原

【Abstract】 Realizing the uniform mixing of hydrogen and air outside the tube of the hydrogen gas turbine can avoid flashback and achieve low NO_x emission. In order to achieve as uniform mixing as possible from the nozzle outlet to combustion, the flow characteristics of the micro-mix nozzle outlet and the influence of the interaction between the fuel-air inflow on the mixing of hydrogen and air were calculated and analyzed by numerical simulation, and the effects of the fuel-air momentum ratio, fuel hole gap ratio, jet height and mixing length on the cold mixing of the micro-mix nozzle were investigated respectively. Results show that the mixing effect is directly impacted by the standard jet depth, the neighboring jet disturbance and the vortex structure of the diffusion section. The suitable standard jet depth is achieved with a momentum ratio R_m in the range of 1.19-1.77, which can lead to more uniform mixing. When the fuel hole gap ratio is 0.54, the interaction of adjacent jets causes a larger gradient in the decrease of the hydrogen concentration in the center of the jet. Increasing the jet height and mixing length can reduce the mixing inhomogeneity, and the development of near-wall vortex pair integrity is beneficial to the mixing improvement.更多还原