液态碳酐相变降温惰化防灭火技术实践

Fire prevention and extinguishing technology of liquid carbonic anhydride phase transition cooling inerting

液体碳酐相变防灭火技术兼顾降温与惰化2种性能,对防控易自燃煤层综放工作面停采撤架期间遗煤自燃灾害具有良好的治理效果。以鄂尔多斯矿区某矿综放工作面为研究对象,在现有防灭火注惰系统技术工艺的基础上,依据液态碳酐气化过程中易结冰的三相点理论,同时结合工作面停采撤架期间防灭火问题的复杂性,设计并施工了井上、下长距离液态碳酐压注系统,重点对采空区内距离停采线100 m、150 m区域进行间断式压注液态碳酐,压注液态碳酐累计398 t。现场应用结果表明,完成液态碳酐压注后,上隅角、工作面2处重点监测区域CO浓度均处于30×10^(-6)以下,回风流处CO浓度处于15×10^(-6)以下,在距离停采线130 m、150 m、170 m这3处测温点的温度均呈现明显的下降趋势,初步达到防灭火工作预期,为工作面的回撤安全提供了技术支撑。

Liquid carbonic anhydride phase transition fire prevention and extinguishing technology takes into account both cooling and inerting performance,which has a good control effect on the prevention and control of the spontaneous combustion of residual coal during the stop-mining and support removal of fully mechanized caving face prone to spontaneous combustion.Taking the fully mechanized caving face of a mine in Ordos mining area as the research object,based on the existing technology of fire prevention and injection inert,in light of the three-phase point theory of liquid carbonic anhydride being easy to freeze in the process of gasification,and combined with the complexity of fire prevention and extinguishing problems during the stop-mining and support-removal period of the working face,the upper and lower long-distance liquid carbonic anhydride pressure injection system was designed and constructed.Intermittent pressure injection of liquid carbonic anhydride was carried out at 100 m and 150 m away from the stop-mining line in the goaf,and the total pressure injection of liquid carbonic anhydride was 398 t.The field application results shows that after the pressure injection of liquid carbonic anhydride,the concentration of CO in the two key monitoring areas in the upper corner and working face was below 30×10^(-6),and the concentration of CO in the return air flow was below 15×10^(-6).The temperatures of three measuring points at 130 m,150 m and 170 m of the mining-stopping line have obvious downward trends,initially reaching the expectation of fire prevention work,and providing technical support for the retracing safety of working face.