TURBINE BLADE THICKNESS ESTIMATING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a turbine blade thickness estimating method for estimating a thickness of a turbine blade of a steam turbine to be eroded. SOLUTION: While measuring an AE signal occurring by collision of particles flowing in liquid with a blade, particle diameter of a particle is obtained from a correlation between strength of the AE signal and a particle diameter. A spectral ratio R is acquired which is a ratio between an integration value S1 of components of low frequency ranges A1, B1 in a frequency spectrum of the AE signal and an integration value S2 of components of high frequency ranges A2, B2. The thickness is estimated from the correlation of the particle diameter of a particle, the thickness and the spectral ratio. The integration value S1 of the low frequency range component is an integration value preferably chosen from the whole A1 or a part B1 of the frequency range between 100 kHz and 400 kHz. The integration value S2 of the high frequency range component is an integration value preferably chosen from the whole A2 or a part B2 of the frequency range between 450 kHz and 600 kHz. COPYRIGHT: (C)2005,JPO&NCIPI