汽轮机扭叶片叶顶间隙泄漏流动的数值分析  

Numerical Analysis of Twisted Blade's Tip Leakage Flow in Steam Turbine

作　　者：杨静[1] 杨松[1] 

机构地区：[1]长春工程学院

出　　处：《化工机械》2016年第5期655-659,664,共6页Chemical Engineering & Machinery

摘　　要：针对某汽轮机中压级扭叶片进行数值研究,分析了不同叶顶间隙下扭叶片顶部的泄漏流动,并着重研究了扭叶片间隙涡的形成、发展和对汽轮机级性能的影响。研究结果表明:叶片的适当扭转,可使径向压力梯度变缓、根部的反动度增加、顶部的反动度减少,在一定程度上控制了泄漏流动的发展。扭叶片叶顶处的泄漏涡在叶栅通道中是以螺旋状向下游发展的,涡核的位置随流动逐渐远离吸力面。当叶顶间隙增大时,泄漏涡强度变大,并且与上通道涡的掺混作用增强,从而导致了更大的流动损失。Twisted blades of an intermediate pressure turbine were investigated numerically and the leakage flow under different tip clearances of twisted blades was analyzed, including the formation and the development of twisted blades passage vortex and its influence on the performance of turbine stage. The results show that, the appropriate twist of blades can slow down the radial pressure gradient and increase the root reaction and decrease the tip reaction as well as control the development of leakage flow to a certain degree; and the leak- age vortexes at twisted blades tip in stage passage can develop toward downstream spirally and the position of vortex core leaves the suction gradually as it flows ; with the increase of the tip clearance, the strength of leak- age vortex can become larger and its mixing effect between the up passage vortexes gets enhanced to result in a greater flow loss.

关 键 词：汽轮机 扭叶片 叶顶间隙 泄漏流 通道涡 

分 类 号：TQ051.21[化学工程]