Experimental And Numerical Simulation Research On Suppressing Gas Explosion By Water Mist

The gradually increased gas explosion accidents in underground coal mines of china are seriously threatening the lives of mining workers, restraining the development of mining production and bringing about heavy burden to coal enterprises. The gas explosion is so frequent, but there is not any technique which can completely stop the gas explosion whether it has all three explosion elements. So it is important signification to find the bester explosion control material and technology.The original 20L Similar spherical explosion suppression test apparatus was transformed and water mist nozzle was included,and then it conduct experiments by using the original and modified apparatus respectively.This paper analysis the properties of water mist explosion suppression based on the mechanism of coal gas explosion and mechanism of explosion suppression of water mist on the foundation of physical properties and chemical properties of water mist by using Eddy- Dissipation- Concept-Model that elementary reaction can be conducted into CHEMKIN in the Fluent software,and do numerical simulation combined with the three conservation equations of fluid mechanics,the turbulence equations,the ideal gas state equation and the physicochemical properties of CHEMKIN,cooperated the result of coal gas explosion numerical simulation and experiments,the conclusion shows that,contrast the maximum blast pressure and the accessional velocity of blast pressure,the bias are below 20% except individual value,they are basically tallies,contrast the blast pressure curves changed with time of numerical simulation and experiments, we get the conclusion that the reason that the pressure curve dropped after the maximum value is due to the wall surface heat-transfer and pressure relief. analysis the three stages of explosion: the initial stage, the propagation stage and the decrease stage by numerical simulation , and analysis the relation of molar concentration of different components with chemical reaction rate in the elementary reaction. Contrast the results of water mist explosion suppression numerical simulation and experiments we can find obvious deviations between them, therefore give the correction suggestion to the numerical simulation model. Analysis the numerical simulation of water mist explosion suppression from pressure and temperature we can find there is a certain weakening effect , especially to the first step of chain reaction with a reduction of 50%.