IGNITION CHARACTERISTICS OF GAS TURBINE LUBRICATION OILS

Abstract

Ignition of lubricating oil is a highly undesirable event that is a major safety hazard that could also be incredibly costly. The possibility for lubricant ignition is present in numerous mechanical systems and applications. To better understand this possibility, an extensive review of the literature reveals the applications affected by this hazard and methods that have been applied to understand the underlying causes. While some work has been completed in this area, the fundamental chemical kinetics of lubricant ignition remains widely unknown. A shock-tube experiment was hence developed and implemented to collect fundamental ignition delay time (Ï„ign) measurements of lubricants at high temperatures. The shock tube is used to generate high-temperature air, and an automotive injector is used to spray lubricant into the high-temperature air. Combustion of the lubricant is then observed using pressure and chemiluminescence diagnostics. Several key features are observed in the resulting Ï„ign curve from the experiments, and these observations are briefly described and discussed. A second experiment, designed to characterize the propensity of an oil to ignite when touching a hot surface was also developed, called the hot-surface ignition experiment. Initial results from this experiment demonstrate the ability to determine a minimum ignition temperature for an off-the-shelf gas turbine lubrication oil.