EFFECT OF HEATING INTERVAL AND CONTAMINATION WITH WATER ON STEAM TURBINE LUBRICANT VISCOSITY

Abstract

Several factors affect lubricant viscosity that make its value undesirable and out of the working range. This study includes the effect of two factors, heating interval and contamination with water, on kinematic viscosity at atmospheric pressure for steam turbine lubricating oil. The  experimental program take into account increasing the temperature of the lubricant oil (ISO32) by heating to specified temperature and time interval. Also the lubricant has been contaminated with a particular water contents. The values of these factors are chosen to represent the inspected real working conditions of steam turbine lubricant at south Baghdad thermal power plant. Experimental heating intervals are (20, 40, 60, 80 and 100) hours. Heating temperature is (60)◦C. Water contamination of oil expressed as a percentage are 0.3%, 0.6%, 0.9%, 1.2% and 1.5%.

           The results show that oil kinematic viscosity decreases as heating interval increased by (4.7, 12, 19.6, 27.1, 34.2)%. Also the oil kinematic viscosity decreases as contamination with water increases by (1.1, 2.3, 3.6, 4.9, 6.9) % respectively and as an average for the above heating intervals. The decrease in kinematic viscosity due to heating approximately reaches unrecommended level at 40 hours as experimental heating interval, while the decrease in kinematic viscosity of oil due to contamination with water reaches unrecommended level when water content in oil exceeds 1.5%.