Control Valve Condition Checking by Spectral Analysis

Abstract

The research work considers and analyzes the problem of control valve failure in case of shaft-gear break during normal operation. In order to identify typical deviations and causes of failure of the electrically driven valves, the amplitude-frequency spectra of the current signal taken at one or more phases of the electric motor were analyzed. The method of spectral diagnostics adopted for analysis allows detecting hidden defects of reinforcement not detected in other types of analysis. In order to justify the study, spectral analysis is carried out on control valves installed in the main condensate and feedwater systems of power units WWER-1000 and WWER-1200. As a result of the study, the following relationships were established increase of amplitude speed of electric motor (EM) to -30 dB is a fact of EM operation at increased load, which will lead to wear of thrust-radial bearings; appearance of baseband frequencies in the region of 50 Hz frequency indicates that there are deviations in setting of electric drive torque limiters. The detected defects, in the future, will lead to the failure of the gear shaft and the shutdown of the power unit. The results of the performed work are used to supplement the existing catalog of defects of pipeline valves developed by RI NPE VETI NRNU MEPhI.

Keywords

• диагностика арматуры
• спектральный метод
• аэс
• отклонения в работе
• электроприводная арматура
• регулирующие клапана
• дефект ходовой части
• вал-шестерня
• система основного конденсата
• подача питательной воды