基于CFD的采空区三维流场分析及注氮参数优化研究

Analysis of 3D flow field in goaf based on CFD and optimization study on nitrogen injection parameters

注氮是煤矿采空区发生自然发火征兆时常用的抑制措施,因其效果显著、安全可靠等特点被广泛应用于采空区灭火实践。注氮位置选取、注氮量的多少等直接影响注氮的效果及成本;采用数值模拟及现场实测相结合的方法,对注氮防灭火参数进行优化。以试验工作面为原型建立仿真物理模型,通过现场实测数据验证模型的有效性。在开展数值模拟试验的过程中,通过研究不同注氮位置、不同注氮流量等对采空区“三带”的影响,找到最优注氮参数,并进行了现场实测验证。研究结果表明,注氮口在进风侧距离工作面50 m处、注氮流量1 000 m~3/h时,注氮效果良好且成本最低。

Nitrogen injection is a commonly used suppression measure when natural fire signs occur in goaf of coal mines.Due to its significant effect,safety and reliability,it is widely used in the practice of extinguishing fires in goaf.The selection of location and amount of nitrogen injection during the nitrogen injection process directly affect the effectiveness and cost of nitrogen injection.A combination of numerical simulation and on-site measurement was used to optimize the nitrogen injection fire prevention and extinguishing parameters.By establishing a simulation physical model based on the experimental working face,the effectiveness of the model was verified through on-site measurement data,and numerical simulation experiments were carried out to study the effects of different nitrogen injection locations and flow rates on the"three zones"of goaf and find the optimal nitrogen injection parameters,the results were verified through on-site application and actual testing,and verify them through measurement.The research results indicated that when the nitrogen injection port was 50 m away from the working face on the inlet side and the nitrogen injection flow rate was 1000 m 3/h,the nitrogen injection effect was good and the cost was the lowest.