Turbine blade vibration test method and device

Abstract

The invention discloses a steam turbine blade vibration test method and device. The method steps are that firstly, a blade force vibration status is analyzed and a blade excitation force mathematical model is built. Secondly, an excitation force is imposed on the blade by a vibration source. The frequency of the excitation force is regulated until resonance is generated between the blade and the vibration source. Vibration characteristics parameters values of the blade under the excitation force are measured. Thirdly, blade damping characteristics parameters, including modal damping ratio, damper contact stiffness and blade dynamic stress, are worked out according to the vibration characteristics parameters values. The device includes a test bed, a blade clamping mechanism arranged on thetest bed, an excitation generator, a vibration parameter detector and a data processing system. The excitation vibration generator is fixed on the test bed. The excitation vibration head of the excitation vibration generator is fixed with the blade. Corresponding to the blade, the vibration parameter detector transforms the vibration signals of the blade into electric signals, which are input into the data processing system. The invention proves the vibration mechanism of the damping blade. A calculation model of the damping blade is constructed through the test parameters. Experience design is terminated. The blade design is standardized to step into a scientific design orbit.

Description

technical field The invention relates to a steam turbine blade, in particular to a method and a device for testing the vibration characteristics of the blade. Background technique The steam turbine is the key equipment for converting the thermal energy of water vapor into mechanical energy in thermal power plants and nuclear power plants, and the blade is an important part of the steam turbine. During the operation of the steam turbine, the blades are not only subjected to huge centrifugal force, steady-state airflow force, but also unsteady-state airflow force. The working environment is extremely harsh, and blade accidents occur frequently. Vibration fatigue is one of the main reasons for blade accidents. It is the current trend in the design of steam turbine blades to adopt a suitable damping structure to reduce the vibration stress of the blade, thereby improving its safety. When designing a steam turbine blade with a damping structure, the natural frequency and vibrat...

AI Technical Summary

Problems solved by technology

However, the vibration mechanism of the damping blade is still unclear, and the design of the blade lacks theoretical guidance and is still in the empirical design stage.

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