Study Of Temperature Rise Law Of Spontaneous Combustion And Optical Fiber Temperature Measuring Technology In Goaf Of Roof-Cutting Working Face

In order to prevent the occurrence of mine fires,the commonly used beam tube monitoring methods have certain limitations.Through numerical simulation of the dynamic advancement of the working face,combined with on-site optical fiber temperature monitoring methods and beam tube monitoring systems Monitor and report on the oxidation temperature rise situation,so as to judge the high-temperature dangerous position and temperature of the goaf in real time,and provide effective preventive measures for the prevention of spontaneous combustion in the goaf of the mine.In this article,based on the program temperature increase experiment,numerical simulation of dynamic advancing of working face,optical fiber temperature measurement method to study the temperature rise law of the goaf,to provide a reference for the prevention of spontaneous combustion in the goaf of the coal mine.In order to study the law of gas changes during the temperature rise of the goaf,a program temperature increase experiment was carried out on the coal sample of the 12605 working face in Guandi Mine under different air supply.The results showed that during the temperature rise,CO,CO₂and C₂H₆run through the whole In the reaction interval,C₂H₄began to appear at 150?;at70?,the reaction was mainly chemical adsorption,so all kinds of data were kept at a low level.The oxygen concentration was the lowest at 90-130?and the gas flow rate was 80 m L/min.The remaining gas concentration,oxygen consumption rate,CO generation rate,and CO₂generation rate are the highest year-on-year;within 150-230°C,O₂concentration,C₂H₆concentration,CO₂concentration,oxygen consumption rate,CO₂generation rate are positively correlated with gas flow rate,CO concentration,C₂H₄concentration and CO generation rate are inversely related to gas flow.In order to analyze the law of temperature rise in the mined-out area,the distribution of the temperature field and oxidation zone in the mined-out area under different air volume ratios,different propulsion distances and different propulsion speeds in Guandi Mine 12605 working face were simulated.The results were analyzed and compared.The research results show that the distribution of the oxygen field and temperature field in the goaf with the advancement of the working face tends to be stable;with the increase of the air intake side air volume,the oxidation zone range tends to increase,and the temperature area increases,the temperature gradient decreases;when analyzing the gob oxidation zone and temperature field distribution at different propulsion speeds,it is found that with the increase of propulsion speed,the oxidation zone range expands,the high temperature point moves deeper in the gob,the high temperature zone range decreases,the temperature As the temperature decreases,the high temperature area and the high oxygen area gradually diverge,and the coal spontaneous combustion process is gradually inhibited.In the actual fire prevention and control of mined-out areas,the optical fiber temperature measurement technology can solve the problem of high-temperature point positioning in mined-out areas.At the same time,the prevention and control measures should be adjusted according to the length of the mined-out area.The high advancing speed helps reduce the spontaneous combustion of the mined-out area Risk,while controlling the spontaneous combustion of the oxidized coal in the goaf,a certain temperature reduction work should also be carried out in the side area of the remaining lane.