露天矿铲装作业点压风射流驱雾数值模拟研究

Study on numerical simulation of fog dispersal by compressed air jet at shovel loading operation point in Open-pit Mine

基于露天矿开放空间流场特征提出采用人工干扰作业点流场的驱雾技术,考虑铲装作业点浓雾形成过程、射流扰动特点及雾与流场的相互作用,建立合理的数学模型,对射流驱雾流场特点进行数值模拟研究。模拟研究发现:相同的强浓雾涌出时间,铲装点位置采用压风射流驱雾技术明显比不采用时雾浓度低;随着强浓雾的持续涌出,压风射流对雾浓度的影响先增大后减小,快速射流与雾颗粒发生动量交换,压风射流干扰区域雾颗粒运移速度增大;射流携带雾颗粒沿着压风射流方向运移,电铲前方水平方向上射流场携带雾粒向电铲的两侧发生运移,靠近煤壁气流沿垂直方向上升,从而明显降低了电铲前方的雾场浓度,提高电铲司机作业视线。

Based on the characteristics of the flow field in the open space of open-pit mine,the fog dispersal technology of flow field of artificial interference operation point is proposed,The formation process of fog,the characteristics of jet disturbance and the interaction between fog and flow field are considered.The formation process of fog,the characteristics of jet disturbance and the interaction between fog and flow field are considered,building a reasonable mathematical model,the characteristics of jet spray flow field are simulated.As a result,the same strong fog gushing time,the fog concentration that the same shovel loading operation point is lower when using pressurized air jet fog dispersal technology.With the continuous outflow of strong dense fog,the influence of pressure air jet on fog concentration increases first and then decreases.The momentum exchange between the fast jet and the fog particles,and the velocity of the fog particles which the pressure air jet passes is large.The jet carries fog particles along the direction of the pressure air jet.In the horizontal direction in front of the electric shovel,fog particles carried by the jet field migrated to both sides of the electric shovel.The air flow rises vertically near the coal wall.Thus the fog field concentration in front of the shovel is obviously reduced and the sight line of the shovel driver is improved.