水蒸汽参数对密封动静特性的影响

Influence of steam parameters on static and dynamic characteristics of labyrinth seal

[目的]为了研究工质参数对透平机械中密封动静特性的影响,[方法]建立梳齿密封三维数值模型,分别以空气和水蒸汽为工质,应用计算流体力学(CFD)方法和旋转坐标系方法分析不同水蒸汽参数对密封泄漏性能和动力特性系数的影响。[结果]结果表明:工质为空气和水蒸汽时,密封的泄漏特性区别很大,其流体激振力与涡动速度分别呈线性和二次非线性的变化关系。当水蒸汽温度增加时,密封动力特性系数的变化将导致系统的稳定性下降。[结论]因此工质参数对透平机械的系统稳定性具有重要意义,在实际应用中需要考虑工质参数对密封动静特性及转子系统的影响。

[Objectives]In order to study the influence of working medium parameters on the static anddynamic characteristics of seals in turbomachinery,[Methods]a three-dimensional model of a labyrinthseal was created, and air and steam were applied in the numerical simulation. The Computational FluidDynamics(CFD) method and a rotating frame were applied to analyze the influence of different steamparameters on the leakage characteristics and dynamic characteristic coefficients.[Results]The resultsshow that great differences in leakage flow rate are apparent under different air and steam conditions, andthe fluid-induced force shows linear and nonlinear variation with the increasing whirl speed. When thesteam temperature increases, the system stability decreases as the dynamic characteristic coefficientschange.[Conclusions]In consequence, working medium parameters are of great significance for turbinestability, and the influence of working medium parameters on the static and dynamic characteristics of sealsshould be given great attention in practical application.