汽轮机动叶栅内泄漏流动特性及损失分布  

Flow Characteristics and Loss Distribution of Leakage Flow in Rotor Blade of Steam Turbine

作　　者：曹丽华[1] 王熙 司和勇 李盼[1] CAO Lihua;WANG Xi;SI Heyong;LI Pan(School of Energy and Power Engineering,Northeast Electric Power University,Jilin 132012,Jilin Province,China)

机构地区：[1]东北电力大学能源与动力工程学院

出　　处：《中国电机工程学报》2019年第21期6328-6335,共8页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51576036)~~

摘　　要：针对汽轮机间隙蒸汽泄漏的注入对动叶栅气动性能和损失的影响,以带有叶顶和静叶环汽封的某汽轮机高压级模型为例,分析不同汽封齿顶间隙下汽轮机动叶栅内泄漏蒸汽与主蒸汽的掺混作用、高损失区域体熵增率的变化规律和对轴功率和级效率的影响。结果表明:泄漏蒸汽的影响区域主要集中在叶片的吸力面附近,且泄漏蒸汽流经动叶通道时,其影响范围不断向叶中扩展。高损失区域沿径向集中在上、下叶端附近;沿轴向集中在动叶吸力面中部和叶片前缘处。随蒸汽泄漏量增加,高损区损失量越大,在叶片径向和轴向上的影响范围越大。在齿顶间隙增加时,由叶顶和静叶环漏汽分别导致的动叶栅高损失区的变化趋势相反。汽封齿顶间隙扩大至设计尺寸2倍,级功率下降约1.06%,级效率下降约1.49%。A high pressure stage model of a steam turbine with labyrinth seal was numerically calculated to study the effect of clearance leakage flow on aerodynamic performance of rotor blade and loss distribution. The change of clearance leakage flow mixing with main flow, the generation rate of entropy in high loss area were analyzed. On this basis, the impact of leakage flow on the variation of shaft power and stage efficiency was studied as well. The results show that the clearance leakage flow influences mainly on the suction surface of rotor blade. When the leakage flow passes through the stage, its influence extends to the middle part of the rotor blade. The high loss area is concentrated on the upper and lower ends of the rotor blade along the radial and on the leading edge of rotor blade and the middle part of the suction surface along the axial. The loss is strengthened with the increase of the clearance leakage flow. With the clearance increasing, the change of high loss area caused by blade top clearance leakage flow and stationary blade ring clearance leakage flow is opposite. When the clearance is twice as large as design size, the shaft power comes down about 1.06% and the stage efficiency of declines about 1.49%.

关 键 词：汽轮机 迷宫式汽封 间隙泄漏流 体熵增率 

分 类 号：TM621[电气工程—电力系统及自动化]