Turbine Lubricant Oxidation: Testing, Experience, and Prediction

Early in the 1970s failure of conventional turbine lubricating oil in modern heavy-duty gas turbines fostered the development of high-temperature mineral oils, the search for appropriate more severe oxidation tests, and efforts to relate the experience to tests and analysis. In parallel with this lubricant effort, bearing and bearing seal developments were undertaken.

The oxidation testing results have evolved into characteristic curves. Operating experience can be related to the heat source temperature. On the basis of the oil characteristic curves and the exposure temperatures, life predictions are made.

In general, the characteristic curves and the operating experience show that the rate of the reaction doubles for every 10°C increase in temperature.