Reasons for water presence in turbine oil

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An increase in moisture content in turbine oil during operation is inevitable; moisture enters the bearing box mainly through leaks in the turbine shaft seals, or it may result from leaks in equipment such as coolers. Additionally, due to changes in system temperature, water vapor from the air can enter the oil; of course, moisture is also introduced when new oil is added. Water in turbine oil exists in two forms: dissolved and free state. Excessive water content in turbine oil has two main effects on turbine equipment: first, it affects the lubrication properties and accelerates wear of the units; second, it leads to the formation of acidic substances in the oil, which causes corrosion of various components. The corrosion products act as abrasives within the system, further increasing wear on the units and posing a threat to the safe operation of the system. There are many ways through which mechanical impurities can enter the oil system, and this is somewhat unavoidable. In new systems, strict flushing of the pipelines helps to meet the requirements regarding oil particle size, but over time, mechanical impurities accumulate again. If the water content in the oil system is too high, the aforementioned corrosion products increase rapidly, leading to the breakdown of the oil film and accelerated wear of the machinery; the resulting rise in bearing temperature has extremely serious consequences. Sludge is a product of aging that occurs when oil is exposed to high water levels over a long period of time, and it tends to form especially when new oil is added or antioxidants and rust inhibitors are incorporated. Sludge also affects the lubrication of the engine units, and sometimes it can cause blockages in the oil circuits as well as clogs in the filters. In summary, removing excessive moisture and particles from turbine oil is key to improving its quality and ensuring the safe and long-term operation of the equipment.