Experimental study on the diffusion and burning characteristics of continuous liquid fuel spillage on sloped ground in open space

Abstract

When liquid fuel spills on sloped ground and an ignition source is nearby, it could lead to a continuous spill fire. To investigate the diffusion and burning characteristics of continuous liquid fuel spillage on sloped ground in open space, a series of experiments were conducted, considering different discharge rates (60–140 ml/min) and ground slopes (2°, 4°, 6°, 8°). Characteristic parameters were measured, including fuel diffusion rate, flame temperature, and burning rate. A model for the diffusion velocity was established. Results indicate that under non-ignited conditions, the diffusion velocity of the liquid fuel gradually decreases with time, eventually converging toward an asymptotic velocity. Under ignited conditions, the burning process of the spill fire in open space could be categorized into three distinct stages. Moreover, compared to our former study on tunnel spill fires, the mass burning rate per unit area of the spill fires in open space is obviously lower than that of spill fires in confined space in the range of experimental conditions in this study. This is mainly because the flame of a spill fire in open space is not constrained by a ceiling, which prevents the formation of a ceiling flame extension phenomenon. In contrast, the tunnel spill fire could form a ceiling flame expansion. This will intensify the radiation heat flux from the flame to the liquid fuel, thereby increasing the mass burning rate per unit area. This work is expected to provide a reference for predicting the diffusion process of a spill fire in open space.

Keywords

• Continuous spilled liquid fuel
• Sloped ground
• Diffusion process
• Spillage width
• Burning rate