Experiment Research For The Prevention And Control Of Mine Goaf Fire Using Gas-liquid Two Phase Flow

Coal mine fire is one of the five major coal mine disasters, which seriously affects the safety production of coal mine. Most of the current management technology of goaf fire can not get better effect in both aspects of prevention and control effect and economic benefit. Therefore, it is urgent to put forward a kind of economical and effective fire-fighting technology. Nitrogen gas fire prevention and extinguishing technology is a kind of inert gas fire prevention and extinguishing technology,in the prevention and control work of coal spontaneous combustion due to its good control effect, low cost, friendly to people and environment safety and other characteristics, nitrogen has been widely used. Water mist fire extinguishing technology is a new type of fire extinguishing technology, which can achieve the purpose of control, suppress and extinguish fire in the multiple effection of cooling, suffocation, cutting off thermal radiation, wetting,etc, has the dual function and advantages of water spray and gas extinguishing,and compared with the traditional fire extinguishing technology, it has the advantages of good fire extinguishing effect, low water consumption, no pollution, the nozzle is not easy to jam,etc.The technology of goaf spontaneous combustion fire prevention and control under the coupled action of two-phase flow of nitrogen and water mist was proposed in this paper.With the efficient function of inerting and suppressing explosion of nitrogen,this technology would take the nitrogen with pressure as gas source, made it interact with water, produced water mist, covered and cooled high temperature coal and rock in three-dimensional of the fire zone, with the comprehensive utilization of advantages of nitrogen and water mist in fire prevention and control of goaf fire,realized effective fire prevention and control of goaf fire.The theoretical of fire control and provention technology by nitrogen and fire extinguishing techonlogy by water mist was analyzed in detail,the nitrogen-water mist generation system was designed,the Implementation plan of controlling and extinguishing fire in goaf by gas liquid two phase flow technology,the pororus media model and equations of two phase flow dynamics of goaf were established.The experiment model of gas liquid two phase flow was established in the laboratory,the gas liquid two phase flow fire extinguishing experament of goas was studied,then the experimental results were summarized and analyzed.The results of nitrogen-water mist two-phase flow technology of fire prevention and extinguishing experiment showed that,the nitrogen-water mist generating system generated good uniformity droplets of gas-liquid two-phase flow water mist;The nitrogen and water mist from the two-phase flow atomization nozzle could transport and diffuse to the whole area of the mine goaf, and nitrogen had a good effect on the atomization and carrying of water;Nitrogen water mist could quickly reduce the burning of coal, reduce the temperature of the goaf, reduce the amount of CO, CO2, H2, reduce the oxygen consumption and CH4 emission, and had a better effect in extinguishing fire.