Development of a turbine oil contamination diagnosis method using colorimetric analysis of membrane patches

Abstract

Lubricating oils are used in various machines and devices; however, they degrade during operation because of their usage environment. The causes of lubricating oil contamination are roughly classified into two types: the contamination caused by solid particles and that caused by oil oxidation products. Much research into diagnosing solid particles in lubricating oils has been conducted and many standards have been achieved; however, few diagnosis methods exist for oil oxidation products. Moreover, the oxidation of turbine basis oils has recently become a serious problem in power generation plants. Therefore, an on-site deterioration diagnosis method capable of detecting turbine oil oxidation in its early stages is desirable for proactive maintenance. We have developed a lubricating oil contamination diagnosis method that considers the coloration of contaminated membrane patches. Sample oils for testing the method have been oxidized in a laboratory using a rotary pressure vessel oxidation test apparatus, and the colors of the resulting membrane patches have been determined using the colorimetric patch analyzer. The relation between the colors and the Fourier transform infrared spectroscopy analysis has been investigated. The results verify that the proposed method is capable of an early detection of changes in the oxidation products of turbine oil.