大采高综采工作面风流-呼吸带粉尘分布数值模拟

Numerically simulated distribution of the airflow and dust movement in the respiratory zone at the fully mechanized mining face with great mining height

为了研究大采高综采工作面在多工序、多尘源情况下的呼吸带范围粉尘质量浓度分布,运用Fluent软件对井下大采高综采工作面风流分布、粉尘运移、呼吸带高度范围粉尘质量浓度分布进行模拟研究,并结合现场实测对比分析。结果表明,采煤机械设备的影响使得工作面空间体积发生突变,造成采煤机附近局部风速增大,并且在采煤机下风侧附近产生3 m/s的湍流。湍流使得运移到此处的粉尘发生扩散,致使湍流下风侧呼吸带粉尘质量浓度剧烈升高十几倍。根据实测数据与模拟结果对比分析:采煤机下风侧10~20 m是粉尘防治的重要区域;而在采煤机下风侧30 m以后的范围,巷道中心部位呼吸带高度粉尘受风流影响漂浮在空中而不易沉降,导致粉尘质量浓度居高不下,此范围也是重点防尘区域。

The present paper is to examine and define the distributive situation of the dust mass concentration rate in the respiratory zone wherein multiple mining process and multiple dust sources are included. To achieve the purpose,we have simulated the airflow distribution,the dust migration and the dust mass concentration distribution with a great mining height via the CFD software Fluent at the fully mechanized mining face. And,then,the measured data and results of the numerical simulation have been made properly compared and analyzed. And consequently,the trend of the measured results has been proved in nice agreement with the one of the numerical simulated results. And,later,the conclusive idea of given research indicate that the airflow through the working face has been affected by the related mining machinery and other mechanical devices,resulting in the space volume of the fully mechanized mining face where abrupt changes near the shearer have been taking place. And,furthermore,the wind speed near the shearer subsequently increases and the turbulence whose speed of 3 meters per second may arise near the downwind side of the shearer. The dust brought about on the downwind side of the shearer tends to spread by the turbulence,leading to the sharp rise of the dust mass concentration over 10 times. And,such a strong turbulence may in turn strengthen the wind speed after its leeward side,causing the dust floats around the respiratory zone and drift to the downwind side with the airflow. By comparing and analyzing the measured data and the results of the numerical simulation,it can be found that the leeward side of the shearer 10-20 m ought to be a significant area for the dust control. And,meanwhile,at the area where the 30 meters of the leeward side of the shearer should be the center of the roadway wherein the dust is influenced by the airflow and subsides slowly so that the dust mass concentration can be kept up at a high level. Therefore,the range beyond 30 meters of the downwind front of the shearer should also be a crucial area for dust control.