为研究薄叶式气封替换迷宫气封应用于透平级中的可行性,将某一级半高压透平中相应部位的迷宫气封替换为薄叶式气封,采用商业计算软件CFX进行数值模拟,并与采用迷宫气封的原型一级半透平进行对比分析.计算结果表明,简单的气封替换虽然降低气封处的泄漏流量,但没有降低透平级的泄漏损失,而且加强泄漏流动对主流的干扰,将一级半透平中的静叶隔板迷宫气封简单替换为薄叶气封的设计方案是不可行的.为了薄叶气封、平衡孔、轴向间隙的合理匹配,在原型设计方案的基础上,动叶叶顶和静叶隔板处采用薄叶气封,级内轴向间隙设置迷宫气封.采用该薄叶气封应用于透平级的最终方案,薄叶气封和平衡孔达到合理匹配,改善透平级的气动性能,降低泄漏损失,同时为下级透平提供良好的进汽条件.
In order to study the feasibility of the leaf seal replacing the labyrinth seal used in turbine stage,the labyrinth seal of the corresponding parts of one and a half high-pressure turbine stage is replaced by leaf seal,numerical simulation is carried on by using the commercial software CFX,and the result is compared with the original one and a half stage with labyrinth seal.The result shows that,although the simple seal replacement reduces the leakage flow of the seal,but does not reduce the leakage loss of turbine stage,and enhance the interference of the leakage flow to mainstream,the simple design is not feasible.So as to match the leaf seal,the balance hole and the axial gap reasonably,on the basis of the original design,the leaf seal is used as the stator diaphragm seal and the rotor tip seal,and the labyrinth seal is set in the axial gap of the turbine stage.To the final scheme of leaf seal applied to turbine stage,the leaf seal and balance hole achieve reasonable match,and improve the aerodynamic performance,reduce the leakage loss,provide a good inlet condition to the next turbine stage at the same time.