汽轮机叶顶汽封间隙内的流动形态分析  

Analysis of Flow Pattern in Rotor Tip Seal Clearance of Steam Turbine

作　　者：曹丽华[1] 李盼[1] 司和勇 胡鹏飞[1] CAO Li-Hua;LI Pan SI;He-Yong;HU Peng-Fei(School of Energy and Power Engineering,Northeast Dianli University,Jilin 1320121,China)

机构地区：[1]东北电力大学能源与动力工程学院

出　　处：《工程热物理学报》2020年第2期299-306,共8页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.51576036)

摘　　要：采用k-ωSST紊流模型和三维RANS方程求解方法,数值研究了平齿汽封、高低齿汽封、侧齿汽封和阻旋齿汽封四种叶顶汽封腔室内部的泄漏流动特性和涡系相互作用规律,旨在揭示叶顶汽封结构变化对泄漏涡动的影响。研究结果表明:叶顶汽封腔室泄漏流体的周向速度是影响旋涡耗散的一个重要因素。高低齿及侧齿的汽封结构依靠增强旋涡之间的相互作用来降低泄漏流体的周向速度,而阻旋齿的汽封结构具备更好的周向阻隔作用,可使旋涡在腔室内的耗散更加充分。在汽封出口,阻旋齿汽封的掺混损失最小,泄漏总损失较高低齿及侧齿汽封分别下降了3.55%和0.59%.In order to reveal the effect of tip seal structure on the leakage vortex,the characteristics of leakage flow and the interaction law of leakage vortexes in the cavities of four kinds of tip seal structures including comb-type seal,stepped labyrinth seal,lateral tooth seal and swirl-brake tooth seal are numerically researched by using the Reynolds-Averaged Navier-Stokes equations and k-ωSST turbulent model.The results show that the circumferential velocity of leakage flow is one of the important factors which can affect the dissipation of vortexes in the tip seal cavities.The circumferential velocity of leakage flow is reduced by enhancing vortex interactions in the cavity of stepped labyrinth seal and lateral tooth seal,but the leakage vortexes in the cavity of swirl-brake tooth seal is dissipated more fully due to its better circumferential barrier.In the outlet of seal,the mixing loss of swirl-brake tooth seal is the least,and the total leakage loss is 3.55%and 0.59%lower than that of stepped labyrinth seal and lateral tooth seal,respectively.

关 键 词：叶顶间隙 阻旋齿汽封 掺混损失 数值模拟 

分 类 号：TK263[动力工程及工程热物理—动力机械及工程]