部分进汽条件下汽轮机组振动情况的研究分析

Vibration Analysis of the Steam Turbine Under Partial Admission

针对部分进汽下汽轮机组的振动响应进行建模和仿真计算。首先根据部分进汽试验台建立汽轮机三维有限元模型,按照不同进汽度情况在动叶片上加载利用CFD软件模拟试验工况计算出来的激振力并进行了求解,对考察点加速度序列进行频谱分析,对不同工况下考察点的振动进行对比分析,为减弱实际机组的有害振动提出了预防措施。经过计算发现:机组振动强弱跟所受激振力不平衡程度相关,不平衡程度最高的两相邻通道进汽工况下,机组振动最强,不平衡程度最低的两对角通道进汽和全周进汽工况下,机组振动最弱,同时考察点位置选择对不同工况下机组振动强弱也存在影响。

In this article, a modeling and simulation methods about vibration of the steam turbine under partial admission was proposed, and an effective measure to prevent the harmful turbine vibration was presemted through both the spectrum analysis and the contrast analysis about the steam turbine vibration under different abmission conditions. Firstly, three-dimensional finite element model was established along the steam turbine test-bed. Secondly, the exciting force calculated by CFD software was loaded on the moving blade and. Thirdly, analysing（ spectrum analysis） the test points＇ acceleration by MATLAB. At last, summed up a conclusion： there is a relation between the turbine vibration and the imbalance degree of exciting force, and the of exciting force at two adjacent inlet channel is the highest where the vibration is also the strongest; the imbalance degree of exciting force at two diagonal inlet channel and full scale admission is the lowest, where the vibration is also the weakest. At the same time, if the test points are different, the turbine vibration intensity maybe different.