Degradation of Phosphate Ester Hydraulic Fluid in Power Station Turbines Investigated by a Three-Magnet Unilateral Magnet Array

Sensors

Pan Guo¹  Wei He¹ 

[1] State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing 400044, China; E-Mail:

关键词: three-magnet array;    unilateral magnetic resonance;    turbine oils;    power station;    aging accessment;    T_2eff;    long;    T₁;    long;    rejection standard;   

DOI  :  10.3390/s140406797

来源: mdpi

【 摘 要 】

A three-magnet array unilateral NMR sensor with a homogeneous sensitive spot was employed for assessing aging of the turbine oils used in two different power stations. The Carr-Purcell-Meiboom-Gill (CPMG) sequence and Inversion Recovery-prepared CPMG were employed for measuring the ¹H-NMR transverse and longitudinal relaxation times of turbine oils with different service status. Two signal components with different lifetimes were obtained by processing the transverse relaxation curves with a numeric program based on the Inverse Laplace Transformation. The long lifetime components of the transverse relaxation time T_2eff and longitudinal relaxation time T₁ were chosen to monitor the hydraulic fluid aging. The results demonstrate that an increase of the service time of the turbine oils clearly results in a decrease of T_2eff,long and T_1,long. This indicates that the T_2eff,long and T_1,long relaxation times, obtained from the unilateral magnetic resonance measurements, can be applied as indices for degradation of the hydraulic fluid in power station turbines.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.