Combustion characteristics of methanol pool fires under the coupling effect of pool size and ambient wind speed

Objective Methanol plays a crucial role in environmental protection and renewable energy development. However, frequent methanol-related accidents have raised safety concerns. Pool fires, common in oxygen-rich open environments, are significantly influenced by factors such as the pool size and ambient wind speed, which significantly affect their combustion characteristics. Methods A methanol pool fire experiment platform was independently designed and constructed to investigate the combustion processes of methanol pool fires across three pool sizes and varying ambient wind speeds. The changes in the combustion rate, flame temperature and ambient temperature of methanol pool fires under the coupling effect of pool size and ambient wind speed were explored to elucidate the underlying influencing mechanisms. Results 1) Under windless conditions, the combustion rate of methanol pool fires increased with pool size, primarily due to the dominance of flame thermal radiation at the current liquid pool size. 2) Under windy conditions, a critical wind speed—positively correlated with pool size—was observed. Below this threshold, the combustion rate increased with wind speed; above it, the rate decreased. This behavior resulted from the interplay between dynamic promotion and thermodynamic inhibition mechanisms. 3) Flame temperature initially rose and then declined as wind speed increased, similar to the influence on the combustion rate. Additionally, when thermal radiation dominated heat transfer, larger pool surfaces received more heat, resulting in higher flame temperatures for larger pools. 4) Ambient wind disrupted the symmetry of the temperature field around the pool, affecting both flame morphology and air convection. Consequently, significant differences emerged in the temperature field distribution surrounding the pool fire. Conclusion Experiments elucidate the combustion characteristics of methanol pool fires under the coupling effect of pool size and ambient wind speed, providing valuable insights for the safe use of methanol.