Study On Control Technology Of Spontaneous Combustion In Compound Goaf Of Ulan Coal Mine

Most coal mines in China are confronted with potential safety hidden dangers of coal seam spontaneous combustion which will not only affect the normal production of coal mine but also to be serious threat to underground miner’s life safety in the process of mine production.the accident.Especially,the compound Mined-out area with high gas near-distance coal seam mining has special characteristics,such as the large amount of coal residue,the complex structure,the complex gas flow field and the distribution of gas.The gas extraction further aggravate the air leakage in goaf,resulting in more complex gas flow field at the same time,not only makes the natural combustion control difficulty increase but also more difficult to judge the danger area of gas explosion in goaf.This dissertation takes the Ⅱ020803 working face and the Ⅱ020703 working face of Ulan mine as the research object.Firstly,it is combined with the actual situation of the compound Mined-out area,putting forward the theory of the “three zones” stratified multi-point inspection and monitoring of goaf spontaneous combustion.With the help of mine harness monitoring system and manual monitoring it is easy to understand the gas "three zones" distribution law.Secondly,the model of complex goaf flow field is established to know the influence of the horizontal "three zones" and vertical "three zones" distribution in the compound goaf by fluent simulation software.Especially simulating the leakage airflow field in the compound goaf and the influence of high borehole,upper corner buried pipe and ground borehole relief pressure on different gas extraction mode.Finally,according to the spatial distribution characteristics of the "three zones" of spontaneous combustion in the compound goaf,the combination of high and low level combined grouting and fire extinguishing technology is implemented.The practice proves that this set of three-dimensional multi-level monitoring theory of goaf,the actual leakage airflow field simulation in goaf and high and low level joint grouting fire prevention measures are practical and effective,and it also plays a guiding and reference role to other similar mine fire prevention and extinguishing work.