The flow field investigations of no load conditions in axial flow fixed-blade turbine

27th IAHR Symposium on Hydraulic Machinery and Systems

Yang, J.^1 ; Gao, L.^2 ; Wang, Z.W.^1 ; Zhou, X.Z.^1 ; Xu, H.X.^3

Department of Thermal Engineering, Tsinghua University, Beijing

100084, China^1

Yuxi Xinhua Water Resource and Hydroelectric Investment Co., Ltd, Zhenghe Road 18th, Luolong District, Luoyang, Henan, China^2

Zhejiang Zhongshui Hydropower Equipment Co., Ltd, Huangpoling 35th, Fuchun River town, Tonglu, Zhejiang, China^3

关键词: Field investigation;    Grid-connected operation;    Guide vane openings;    No-load conditions;    No-load operations;    Pressure pulsation;    Start-up process;    Whole flow passage;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/22/3/032028/pdf
DOI  :  10.1088/1755-1315/22/3/032028

来源: IOP

【 摘 要 】

During the start-up process, the strong instabilities happened at no load operation in a low head axial flow fixed-blade turbine, with strong pressure pulsation and vibration. The rated speed can not reach until guide vane opening to some extent, and stable operation could not be maintained under the rated speed at some head, which had a negative impact on the grid-connected operation of the unit. In order to find the reason of this phenomenon, the unsteady flow field of the whole flow passage at no load conditions was carried out to analyze the detailed fluid field characteristics including the pressure pulsation and force imposed on the runner under three typical heads. The main hydraulic cause of no load conditions instability was described. It is recommended that the power station should try to reduce the no-load running time and go into the high load operation as soon as possible when connected to grid at the rated head. Following the recommendations, the plant operation practice proved the unstable degree of the unit was reduced greatly during start up and connect to the power grid.