High-Speed Video Analysis of Lubricating Oils Undergoing Hot-Surface Ignition

摘要

The ignition of flammable liquids on hot surfaces is a safety concern in industries like automotive, aviation, and power generation. Hot-surface ignition is a function of fluid properties and environmental parameters, chiefly surface temperature. A new hot-plate ignition experiment in the authors' laboratory was used to study the ignition behavior of oil droplets on a plate at 700 °C using a high-speed camera. A stainless-steel block was heated using embedded electrical resistance heaters, and 20.5-μL drops of Mobil DTE 732 oil were dispensed onto the test surface. The experimental apparatus was designed to minimize the negative effects of surface oxidation of the metal plate, droplet movement along the surface, and surface temperature non-uniformities. The resulting surface behavior of the oil droplets undergoing hot-surface ignition was analyzed. Still images from the high-speed video were used to draw fundamental conclusions of hot surface ignition events. These images are used to show the importance of air barriers, that combustible mixtures exist in many places around the hot surface, and that ignition can occur either on or above the surface.