Study On Fire Control Technology Of Water Mist In Goaf

China's coal reserves are large and widely distributed.In the process of coal mining,Coal spontaneous combustion has always been a major problem in mine safety,and also an important factor affecting the healthy and stable development of China's energy industry.The goaf is the most frequent area of coal spontaneous combustion and the most serious consequence.Therefore,the research of efficient and reliable goaf fire prevention technology,rich mine fire prevention technology system,it has important practical significance to improve mine fire prevention ability and targeted management of goaf spontaneous combustion fire.This paper takes Dongrong No.1 mine as the research object,and puts forward water mist prevention and fire extinguishing technology in goaf.This paper expounds and analyzes the prevention and control of coal spontaneous combustion in goaf by using fine water mist from the aspects of atomization method,fire-extinguishing and cooling characteristic and principle of fire prevention,and thought the main principle of fine water mist to prevent coal spontaneous combustion in goaf lie in five aspects:gas phase cooling of the environment,infiltration of residual coal surface,dilution of oxygen concentration in goaf,barrier of radiant heat and dynamics effect.In this paper,the early prediction index of coal spontaneous combustion is study by using the programmed temperature rise experiment,and it is concluded that CO,C2H4 and C2H2 are used as the main index gas of coal seam spontaneous combustion prediction of Dongrong No.1 mine,among them C2H2 is used to predict the stage of vigorous oxidation.While C2H6??(C2H4/C2H6)can be used as auxiliary indicators to judge the spontaneous combustion state of coal,it can not be analyzed and judged separately.Due to?(CO/CO2)?C2H6/CH4 show weak regularity with the change of coal temperature,therefore,it is not suitable to use it as the index of forecast system.Finally,by numerical simulation,the change of temperature field in goaf before and after spraying fine water mist is analyzed,the migration regularity of fine water mist in goaf and the characteristics of preventing coal spontaneous combustion in goaf are summarized,and it is preliminarily comfirm the characteristics of the migration route of fine water mist in goaf appear is consistent with the height of air leakage path.At the same time,it is influenced by the low-temperature airflow and latent heat affected generated by the phase change of fine water mist,the high temperature point in goaf decreases in temperature,and the high temperature area shrinks obviously.Through the field application,the fine water mist fire prevention technology can restrain the coal self-ignition in goaf.Therefore,the technological process is easy application,which can be used as a normal method to prevent and extinguish fire in mining-out area.