Experimental study on explosion parameters of ethanol aerosol under high-temperature source ignition

• Influence of droplet size and ignition temperature on the explosion characteristics. • LFL of ethanol aerosols for larger SMD is larger than for smaller SMD. • LFL of ethanol aerosols with a mean SMD of 14 μm and 21 μm are 56 g/m 3 and 98 g/m 3 . • LFL of ethanol aerosol has little change within ignition temperature 1273–1473 K. • Vapor-phase concentration in ethanol aerosol is lower than the LFL of the pure gas. Through a series of experiments in a 20 L cylindrical vessel, the explosion characteristics of the ethanol aerosol with Sauter mean diameter (SMD) of 14 μm and 21 μm under high-temperature ignition were analyzed. The impact of transient concentration and droplet size on the explosion characteristics was obtained. The results show that the ethanol aerosol explosion pressure-time history under high-temperature ignition was found to have a “double peak” structure. The latter is greater than the former. The droplet size has an essential effect on the explosion pressure. The smaller the droplet size, the smaller the corresponding concentration when the peak pressure of the explosion reaches the maximum. In the ignition temperature range of 1273–1473 K, the peak pressure of ethanol aerosol (for a mean SMD of 14 μm and 21 μm) decreases with the increase of the ignition temperature, and the lower flammability limit (LFL) has little change with ignition temperature. The former is 56 g/m 3 , and the latter is 98 g/m 3 . The LFL of ethanol aerosol increases as the droplet size increases, and the vapor-phase concentration corresponding to the LFL is lower than the LFL of the pure gaseous phase of ethanol (67.9 g/m 3 ).