industry steam turbine under partial admission condition

ZHOU Li-ming1，SHI Pei-li2，CHU Peng1，LI Hong-fu1，SUI Yong-feng1，3

（1. Industrial Turbine Academy Turbomechanical Institute，Hangzhou Steam Turbine Co.，Ltd.，Hangzhou 310022，

China； 2. School of Aeronautics and Astronautics，Zhejiang University，Hangzhou 310058，China；

3. College of Mechanical Engineering，Zhejiang University of Technology，Hangzhou 310014，China）

Abstract：In order to solve the problems of the efficiency and safety of the control stage in a steam turbine. Based on RANS with the application of structural hexahedron mesh and finite volume method，the flow field of the control stage in a steam turbine was calculated. Pressure contour and velocity contour were performed to analysis the flow field of the control stage under different conditions. Torque of the blade rotating one circle were performed. Amplitude-frequency map of the torque was obtained according to the FFT analysis. The results indicate that the flow field is nonuniform under partial admission condition. The maximum torque of the blade is 2.2 times larger

than that in the flow area under four valves open condition，while under three valves open condition the maximum torque of the blade in the blocked area is 1.8 times larger. It can help to check the safety of the blade. Spectrum analysis indicates that the typical low frequency of the exciting force is caused by the rotating speed of the blade. The efficiency of the control stage under three valves open condition is 7% lower than that under four valves open。

Key words：steam turbine；control stage；numerical simulation；nonuniform；safety