Influence of the vibro-acoustic sensor position on cavitation detection in a Kaplan turbine

27th IAHR Symposium on Hydraulic Machinery and Systems

Schmidt, H.^1 ; Kirschner, O.^1 ; Riedelbauch, S.^1 ; Necker, J.^2 ; Kopf, E.^2 ; Rieg, M.^2 ; Arantes, G.^2 ; Wessiak, M.^3 ; Mayrhuber, J.^3

Institute of Fluid Mechanics and Hydraulic Machinery, University of Stuttgart, Pfaffenwaldring 10, Stuttgart

70569, Germany^1

Voith Hydro Holding GmbH and Co. KG, Alexanderstrasse 11, Heidenheim

89522, Germany^2

VERBUND Hydro Power AG, Europaplatz 2, Wien

1150, Austria^3

关键词: Cavitation detection;    Cavitation limits;    Experimental investigations;    High frequency acoustics;    Material erosion;    Measured signals;    Operating points;    Prototype kaplan turbines;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/22/5/052006/pdf
DOI  :  10.1088/1755-1315/22/5/052006

来源: IOP

【 摘 要 】

Hydraulic turbines can be operated close to the limits of the operating range to meet the demand of the grid. When operated close to the limits, the risk increases that cavitation phenomena may occur at the runner and / or at the guide vanes of the turbine. Cavitation in a hydraulic turbine can cause material erosion on the runner and other turbine parts and reduce the durability of the machine leading to required outage time and related repair costs. Therefore it is important to get reliable information about the appearance of cavitation during prototype operation. In this experimental investigation the high frequency acoustic emissions and vibrations were measured at 20 operating points with different cavitation behaviour at different positions in a large prototype Kaplan turbine. The main goal was a comparison of the measured signals at different sensor positions to identify the sensitivity of the location for cavitation detection. The measured signals were analysed statistically and specific values were derived. Based on the measured signals, it is possible to confirm the cavitation limit of the examined turbine. The result of the investigation shows that the position of the sensors has a significant influence on the detection of cavitation.