Experimental Study On Nitrogen-Inhibited Water Mist To Suppress Coal Combustion

Coal spontaneous combustion is the main cause of mine fires and has always threatened the safety of coal mine production.In order to effectively suppress coal combustion,this paper proposes a high-efficiency fire extinguishing technology of nitrogen-inhibited fine water mist.Through temperature-programmed and gas chromatography combined experiments and thermogravimetric experiments,the temperature-increasing oxidation of coal by nitrogen,different inhibitors and fine water mist was studied.The impact of the process.The results show that high concentration of nitrogen can increase the characteristic temperature of coal combustion,slow down the oxidation heat of coal,and reduce the generation of CO and CO₂.When the mass ratio of magnesium chloride to sodium dihydrogen phosphate is 3:2,it has the strongest inhibitory effect on the entire coal temperature oxidation process.When the fine water mist acts on the burning coal body,the temperature in the system decreases rapidly,and its inhibitory effect on coal combustion is significantly stronger than that of water spray.In this paper,the self-designed nitrogen-resistance fine water mist generating device is used to study the fine water mist atomization characteristics under different working conditions.The results show that under a certain water pressure,the fine water mist particle size decreases rapidly with the increase of air pressure small.Under the same air pressure conditions,the fine water mist particle size increases with increasing water pressure.Under the conditions of the same water pressure and air pressure,the particle size of the fine water mist containing the inhibitor is slightly larger than that of the pure water fine water.The best working condition of the nitrogen-resistance fine water mist generating device:the air pressure is 0.5?1.0MPa,The water pressure is 0.4?0.8MPa.In this paper,by building an experimental platform for suppressing coal combustion in goaf by nitrogen-restrained fine water mist flow,the fire extinguishing effect of nitrogen-restrained fine water mist is studied.The results show that nitrogen-fine water mist can effectively suppress coal combustion.Reduce the generation of CO,CO₂,H₂ and CH₄,adding inhibitors in the fine water mist can shorten the fire extinguishing time,improve the effect of suppressing coal combustion,and can also reduce the content of CO,CO₂,H₂and CH₄ after fire extinguishing,greater To a certain extent,it reduces the possibility of reignition of leftover coal.