Suppression effect of ultra-fine water mist on methane-coal dust hybrid explosion

Abstract

Methane and coal dust hybrid explosion and its suppression have always been a hot issue. In this study, the suppression effect of ultra-fine water mist on methane coal dust mixed explosion was investigated experimentally and numerically. The pressure of the hybrid explosion was significantly reduced and the pressure rising process was delayed by applying ultra-fine water mist. The results show that the microscopic processes of methane combustion, particle pyrolysis, and particle combustion have a definite time sequence during the explosion. Analysis of the suppression mechanism indicates that the contribution of the fixed carbon combustion to the explosion pressure decreases the most in three sub-processes by 50.8% with the addition of water mist under fuel-lean combustion. Meanwhile, the contribution of the volatile component devolatilization to the explosion pressure decreases the most in three sub-processes by 36.3% and 40.8% with the addition of water mist under stoichiometric combustion and fuel-rich combustion, respectively.