Research On The Evolution Law Of Mine Belt Fire And The Prevention And Extinguishing Technology Of Fine Water Mist

Mine belt fires are highly sudden,have many secondary disasters,and are difficult to rescue.The smoke generated after the fire carries a lot of heat and toxic gases,which can easily damage underground operating facilities and even cause secondary accidents such as gas and dust explosions,resulting in serious economic losses and casualties.Research on the law of smoke spread in mine belt fire and water mist fire extinguishing technology is conducive to timely control and prevention of fire development,and reduce economic losses and casualties.In this paper,the method of combining theoretical analysis and numerical simulation is used to study the evolution law of mine belt fire and the fire extinguishing effect of water mist under different system parameters.Firstly,from the two aspects of mine fire evolution characteristics and water mist fire extinguishing mechanism,the research results of domestic and foreign scholars on the development law of belt fire and water mist fire extinguishing technology are summarized,which lays the theoretical foundation for the following fire dynamics simulation and result analysis.Secondly,the roadway model of the 378 working face of Anyuan Coal Mine was established by using the fire dynamics simulation software FDS.By changing the wind speed and the power of the fire source,the evolution law of smoke flow and temperature field in the roadway during the catastrophe period under 8 working conditions was discussed.The effects of wind speed and fire source power on the temperature,CO concentration and visibility in the roadway were obtained.Then,a water mist fire-fighting technology suitable for belt fires was proposed.By changing the droplet size,spray flow and nozzle density,12 different fire scenarios were set up,and the fire-extinguishing effects of different water mist characteristic parameters were studied.The change of fire extinguishing time,temperature and oxygen concentration under different working conditions was compared and analyzed,and the best fire extinguishing parameters were obtained.That is,when the droplet size is 100 μm,the nozzle flow rate is 8 L/min,and the nozzle spacing is 1 m,the heat absorption and cooling effect of the fine water mist is the most significant and the fire extinguishing time is the shortest,which can quickly and effectively extinguish the fire.Finally,by comparing the changes of temperature,CO concentration and visibility before and after the application of the water mist,the fire extinguishing effect of the water mist was verified,and the effectiveness of the water mist in extinguishing the mine belt fire was proved.Through the research of this paper,the evolution law of mine belt fire and the best parameters of water mist fire extinguishing system can be mastered,which can provide reference for effective control and prevention of the occurrence and development of fire and parameter setting of underground water mist fire extinguishing system.