Experimental and model study on flame radiation characteristics of ethanol spill fires in tunnel environment

Accidental leakage of liquid fuel frequently results in spill fire accidents, with radiation playing a pivotal role in flame propagation and environmental hazard. Conducted in a scale tunnel, ethanol spill fire experiment utilized five stainless steel rectangular channels, with length of 1 m, widths ranging from 0.1 to 0.3 m, and height of 0.03 m. The study focused on aspects such as flame area, bifurcation and fusion behaviors, flame height, and the distribution of flame heat radiation. Notably, as the channel width increased, the flame area and bifurcation phenomenon decreased, leading to taller flames. Drawing comparisons with the trapezoid flame thermal radiation model, we introduced a weighted multi-point source flame thermal radiation model that takes into account flame shape. In terms of predicting thermal radiation, weighted multi-point source model demonstrates a slightly higher degree of accuracy compared to trapezoid model, providing results closer to experimental values. It not only accurately predicted near-distance radiation from the spill fire but also distant radiation, with an error margin of less than 20%. This work offers crucial insights into the spatial distribution of flame heat radiation in spill fire accidents.