基于Fluent的氮气定向钻进排渣规律模拟研究

Simulation Study on Slag Discharge Law of Nitrogen Directional Drilling Based on Fluent

以煤矿井下氮气定向钻进孔深、固气比、粒径为变量,研究不同参数下的煤渣运移规律,利用Fluent模拟软件对不同工况煤渣运移轨迹、速度分布、体积分布和排渣效率进行了模拟。结果表明,煤渣在氮气气流作用下,发生复杂的螺旋式运移,轴向速度0.24~2.46 m/s;径向速度-0.377~0.544 m/s。同一时刻不同截面残余煤渣随孔深增加而增多,同一环空截面不同时刻残余煤渣随时间延长而减少。残余煤渣体积分数与孔深之间关联性较小。随着固气比和煤渣粒径增大,排渣效率降低,固气比为1、5、10时前4 s分别排出56%、11%、4%,粒径为0.6、1、2 mm时前6 s分别排出99%、90%、65%。

Taking the hole depth,solid gas ratio,and particle diameter of nitrogen directional drilling in coal mines as variables,the law of coal slag migration under different parameters was studied.The trajectory,velocity distribution,volume distribution,and slag removal efficiency of coal slag migration under different conditions were simulated using Fluent simulation software.The results show that under the action of nitrogen gas flow,coal slag undergoes a complex spiral migration with an axial velocity of 0.24-2.46 m/s;The radial velocity is from-0.377 to 0.544 m/s.At the same time,the residual coal slag at different sections increases with the increase of hole depth,while at different times in the same annulus section,the residual coal slag decreases with the increase of time.The correlation between residual coal slag volume fraction and pore depth is small.With the increase of solid gas ratio and coal slag particle size,the slag removal efficiency decreases.When the solid gas ratio is 1,5,and 10,56%,11%,and 4%are discharged in the first 4 s respectively.When the particle size is 0.6 mm,1 mm,and 2 mm,99%,90%,and 65%are discharged in the first 6 s respectively.