基于采空区流场的遗煤自燃危险区域判定及复合惰化技术研究

采空区遗煤自燃火灾是影响煤炭生产安全的主要灾害之一。基于Fluent数值模拟技术,构建采空区三维物理模型,模拟研究了采空区流场立体分布规律,并以O2体积分数为判别指标划分了采空区遗煤自燃危险区域;通过分析采空区遗煤空间分布规律及不同惰性气体的惰化特性,提出了综放工作面采空区复合惰化技术,即高位压注CO2和低位压注N2,并与单一气体惰化技术进行了对比研究。结果表明:复合惰化技术相较于单一气体惰化技术有着更好的防灭火效果;在工程应用中,各监测点CO体积分数在短时间内均降低到2.4×10^-5以下,压注惰气期间防灭火效果良好。

Research on dangerous area determination of spontaneous combustion of residual coal and compound inerting technology based on flow field in goaf

Spontaneous combustion of residual coal in goaf is one of the main accidents affecting coal production safety.Based on Fluent numerical simulation technology,a three-dimensional physical model of goaf was built,the three-dimensional distribution law of the flow field in goaf was simulated and studied,and the dangerous areas of the spontaneous combustion of residual coal in goaf were divided by the O2 volume fraction as the discriminant index;by analyzing the spatial distribution of residual coal in goaf and inert gas characteristics of different inert gases,the compound inerting technology in fully mechanized working face in goaf was put forward,namely high pressure injection of CO2 and low pressure injection of N2,and it was compared with the single gas inerting technology.The results show that the compound inerting technology has better fire prevention and extinguishing effect than the single gas inerting technology;in engineering application,the CO volume fraction at each monitoring point is reduced to less than2.4×10^-5 in a short time,and the fire prevention and extinguishing effect is good during injection of inert gas.