IMPROVEMENT OF METHODS FOR DETERMINING THE EFFECT OFELECTRICAL DISCHARGES ON THE DEGRADATION OF TURBINE OILS
Authors:   Odesa Polytechnic National University, Zaitsev Serhii 
Published: March 2024

The article is a publication of scientific and methodical character. Continuous improvement of methods for determining the impact of electric discharges on the degradation of turbine oils to further diagnose the condition of these turbine oils and develop measures to prevent such degradation or reduce its impact on the quality of turbine oils during their operation in oil-filled thermal and mechanical equipment of power plants; ensure, for example, the reliability of hydrogen-cooled turbinegenerators.Improving methods for determining the effect of electric discharges on the degradation of modern mineral or synthetic fire-resistant turbine oils is necessary to diagnose the condition of these turbine oils, for example, in the bearing units of turbine units with continuous circulation systems of turbine oils in the bearing units.An analysis of research and publications has shown that, despite the availability of a large number of studies on the effect of electric discharges on the degradationof mineral electrical insulating oils, improving methods for determining the effect of electric discharges on the degradation of modern mineral or synthetic fire-resistant turbine oils is necessary to diagnose the condition of these turbine oils and develop measures to prevent such degradation or reduce its impact on the quality of turbine oils during their operation.The aim of the study is to improve the reliability of the results of diagnosing the condition of turbine oils by improving methods for determining the effect of electric discharges on the degradation of modern mineral or synthetic fire-resistant turbine oils.The methods used in the work were: a) determining the water content of turbine oils by coulometric titration; b) gas chromatographic determination of the concentrations of dissolved gases C2H6, C2H4, C2H2, CH4, H2, CO, CO2 in turbine oils; colourimetric determination of the content of PH3, H2S, SO2 in gas streams using indicator tubes; determination of the electric test voltage and the "dielectric loss tangent" for turbine oils. The results of improving the methods for determining the effect of electric discharges on the degradation of modern mineral turbine oil "Tp-22 (grade 1)" and synthetic fire-resistant turbine oil "Fyrquel®L" depending on their water content are presented. A schematic diagram of the installation for studying the effect of high-voltage pulsed electric current on the degradation of mineral and synthetic fire-resistant turbine oils was developed.Investigated: the nature of the dependence of the breakdown voltage for these turbine oils on their moisture content in the temperature range t = 20–100 0C; the nature of the dependence of the dielectric loss tangent for turbine oil "Tp-22 (grade 1)" on the content of formic acid at a temperature of t = 20 0C; the effect of pulsed electric voltage on the degradation of these turbine oils depending on their water content and with the formation of dissolved gases C2H6, C2H4, C2H2, CH4, H2, CO, CO2. For the first time, the presence inthe corresponding turbine oils of the process of their degradation under the action of pulsed electric discharges with the formation of gaseous H2S, PH3, SO2 was investigated. The presented materials can be used for the informed selection or design of measuring equipment for further determining the nature of degradation of demulsifying, deactivating, antiwear, and anti-foam additives, combined additives and oxidation and corrosion inhibitors in turbine oils under the influence of a continuously acting alternating electric current and acoustic cavitation in the bearing units of hydro-gen-cooled turbine generators equipped with turbine oil circulation systems, to diagnose the condition of these turbine oils and develop measures to prevent such degradation or reduce its impact on the quality of turbine oils during their operation