某MW级燃机变几何动力涡轮动/静叶栅与排气道的流动分析  

Analysis of the Flow Inside the Variable Geometrical Power Turbine Stator/rotor Cascade and Exhaust Gas Duct of a MW Class Gas Turbine

作　　者：侯建飞[1] 顾春伟[1] 刘红[1] 

机构地区：[1]清华大学热能工程系,北京100084

出　　处：《热能动力工程》2012年第6期643-648,733,共6页Journal of Engineering for Thermal Energy and Power

基　　金：国家高技术研究发展计划(863)基金资助项目(2008AA050502)

摘　　要：某MW级燃机末端的变几何动力涡轮动/静叶栅与非对称排气道之间的流场会相互作用,使用商用CFD软件CFX研究了不同导叶安装角下、二者之间的耦合流场。在导叶设计安装角下的流场分析表明:排气道的非周向对称性主要影响动力透平的动叶流场,导致动叶不同叶片载荷出现周向差异,同时动叶出口气流角分布也会出现强烈的周向不均匀性。导叶旋转7°后,导叶进口正冲角增大导致吸力面大范围分离;动叶进口呈现负攻角,压力面的分离程度增大;同时排气道内旋涡程度加剧,这导致了导叶安装角改变后动力涡轮的效率和功率出现明显下降。The flow field of the variable geometrical power turbine stator/rotor cascade at the end of a MW class gas turbine may interact with that of the unsymmetrical exhaust gas duct.By using the commercial CFD software CFX,the authors have studied the coupled flow field between them at various installation angles of the stator blades.An analysis of the flow field at the installation angle of the stator blades under the design operating condition shows that the circumferential asymmetry of the exhaust gas duct will mainly affect the flow field of the rotating blades of the power turbine,leading to a difference of the load between any two rotating blades in the circumferential direction.In the meantime,the distribution of the gas flow angle at the outlet of the rotating blades may also assume an intense non-uniformity along the circumferential direction.After the stator blades have been rotated by 7 degrees,an increase of the positive attack angle at the inlet of the stator blades may result in a separation in a large area of the suction surface of the stator blades.Therefore,the rotating blades have a negative attack angle at the inlet,increasing the separation area of the pressure surface.At the same time,the vorticity of the vortices in the exhaust gas duct will be intensified,leading to a marked drop of the efficiency and power output of the power turbine after the installation angle of the stator blades has been changed.

关 键 词：MW级燃气轮机 变几何涡轮 非对称排气道 数值模拟 

分 类 号：TK472[动力工程及工程热物理—动力机械及工程]