CFD Investigation on the Rotordynamic Characteristics of Shroud Leakage Flow in High Pressure Steam Turbine
CFD Investigation on the Rotordynamic Characteristics of Shroud Leakage Flow in High Pressure Steam Turbine
复制标题
高压汽轮机护罩漏流转子动力特性的CFD研究
DOI：
10.1115/gt2013-94357
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
K. Yamaguchi
中科院分区：
文献类型：
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作者：
N. Nishijima;A. Endo;K. Yamaguchi
为了研究高压蒸汽涡轮机围带迷宫式密封的转子动力学特性，我们进行了计算流体动力学（CFD）研究。由于围带密封通常较短，翅片较少，且周围流场的影响较大，因此，我们构建了四种不同的CFD模型，以研究评估实际蒸汽涡轮机密封力的适当建模方法。这四个模型是由一级定子/转子叶栅和转子护罩上的迷宫式密封组成的完整模型、模拟类似于密封元件实验的条件的导叶模型以及另外两个简化模型。四个模型的刚度系数计算值不一致，分为两组。通过对流场的仔细研究发现，这种差异可以用密封入口处的周向质量流量分布来解释，并且质量流量偏差率是评价涡轮机围带密封力的重要因素。结果还表明，从密封元件实验中获得的转子动力学特性可能与实际涡轮机的转子动力学特性不同，特别是在短密封中。
We conducted a computational fluid dynamics (CFD) study to investigate the rotordynamic characteristics of the shroud labyrinth seal of a high-pressure steam turbine.Four different CFD models were constructed to investigate the appropriate modeling approach for evaluating the seal force of an actual steam turbine because shroud seals are generally short with fewer fins and the effect of surrounding flow field is thought to be large. The four models are a full model consisting of a 1-stage stator/rotor cascade and a labyrinth seal over the rotor shroud, a guide-vane model to simulate the condition similar to seal element experiments, and two other simplified models. The calculated stiffness coefficients of the four models did not agree and fell into two groups. Through careful investigations of flow fields, it was found that the difference could be explained by the circumferential mass flow distribution at the seal inlet and the mass flow bias rate is an important factor in evaluating the seal force of a turbine shroud. The results also indicate that the rotordynamic characteristics obtained from seal element experiments may differ from those of actual turbines, especially in short seals.Copyright © 2013 by ASME