Study on the Influence of Water Mist on Methane Explosion Characteristic Parameters in Variable-volume Space

Abstract

A transparent and variable volume pipe was used to investigate the influence of water mist on different development stages of methane explosion flame. A sliding device was installed to enable the adjustment of the pipe space volume during the experiments. The results demonstrate that water mist has varying effects on different flame development stages, leading to changes in flame development structure and mechanisms. When water mist is sprayed before the flame passes through the nozzle, it will cause a turbulent transformation of the flame, accelerate the flame propagation speed, and increase overpressure in the combustion zone. Specifically, when water mist acts on the tip of a finger flame, it promotes the explosion with a significant increase in overpressure and flame velocity, resulting in the maximum overpressure that is 90.48% higher compared to the without water mist condition. When the flame front has already passed through the nozzle and the water mist is sprayed, the water mist will significantly improve the efficiency of flame quenching and reduce the maximum overpressure in the unburned area. Compared with the absence of water mist, the overpressure in the unburned zone decreases by 21.91% and the flame extinction time decreases by 28.07%.