摘要
燃气轮机燃烧室出口燃气温度场分布严重不均匀,其中燃气流的高温核心即热斑会加剧燃气透平内部非定常流动和传热的复杂性,引起叶栅的局部过热甚至烧蚀,从而降低透平的可靠性和寿命。研究并揭示热斑迁移机制对于透平叶栅高效冷却技术及非定常气动优化设计方法的发展至关重要。文中综述了燃气透平进口热斑迁移及其影响机制的研究现状及进展,着重介绍了燃烧室特性参数、叶型结构和冷气对热斑迁移的影响规律。有关热斑现象的研究虽然取得一定进展,但尚需要更深入的试验和数值研究,文中指出:目前试验和数值研究中广泛采用的圆形热斑与实际情况差异较大,需要在燃烧室真实出口温度场下实现透平非定常流场和传热的精确测量;关于燃烧室特性参数对热斑迁移影响的研究未考虑湍流强度和旋流等流场特征的影响且缺乏试验数据;叶型结构对热斑迁移影响的研究才刚刚开始,需要对热斑与叶排间的"时序效应"及其对叶栅热负荷和透平整体性能的影响机制开展深入的试验研究;最后,还需要对冷却气流与热斑干涉作用及其引起的透平非定常气热性能的变化进行试验和数值研究,从而为透平的高效冷却和气动传热优化设计奠定理论基础。
The temperature profiles of gas flow at the exit of gas turbine combustor are seriously non-uniform, and the high temperature regions at combustor exit are known as hot streaks. The migration of hot streak intensifies the complexity of the unsteady flow and heat transfer in turbine stage and leads to the excessive heating and even erosion of the blade airfoil, thus reducing the turbine operation reliability and life. The understanding of hot streak migration mechanism is important both to the design of airfoil cooling scheme and the development of turbine aerodynamic design optimization method. Studies on hot streak migration in turbine stage was reviewed, which focused on the effects of combustor characteristic parameters, airfoil geometry and cooling flow on the hot streak migration mechanisms. Although research on the effects of hot streak has made some progress, more detailed and systematic numerical and experimental investigations on following topics are urgently needed. The circle hot streak applied in most of the recent studies cannot reflect the combustor exit real temperature distributions well, and experimental measurements should be conducted to reveal the effects of combustor exit real temperature profiles on turbine unsteady aero-thermal performance. The main flow turbulence intensity and inlet swirl are considered by few researchers when investigating the effects of combustor characteristics on hot streak migration, and the experimental data concerning them are still deficiency. Studies on the airfoil geometry effects are just beginning, and the effects of the hot streak and second stage stator clocking positions on the turbine heat load and overall performance should be deeply understood. Also, experimental and numerical studies should be performed to reveal the unsteady interaction mechanisms between hot streak and air coolant, and the effects of the interaction on the turbine aero-thermal performance, thus providing theoretical foundation for the design of cooling scheme and aero-thermal optimiza
出处
《中国电机工程学报》
EI
CSCD
北大核心
2014年第29期5120-5130,共11页
Proceedings of the CSEE
基金
国家自然科学基金重点项目(51336007)~~
关键词
燃气透平
燃烧室
热斑
非定常迁移
叶栅结构
冷却气流
gas turbine
combustor
hot streak
unsteadymigration
airfoil geometry
cooling air
