采煤机外喷雾系统数值模拟研究

为提高采煤机外喷雾系统性能,改善工作面作业环境,基于Pro/E与GAMBIT联合建立了采煤工作面模型,选用标准k-ε湍流模型构造采煤机外流场数学模型,并通过FLUENT仿真得到巷道内风流平均速度为1.8 m/s左右,符合《煤矿安全规程》的规定;对采煤机外喷雾系统进行了数值模拟,通过改变喷嘴口径、喷雾压力和扩散角等参数,得到了不同喷雾参数下的雾滴粒径和雾化浓度的变化规律:随着喷雾压力的增大,雾滴粒径减小,喷雾浓度分布更加均匀;小口径喷嘴雾化浓度较高,大口径喷嘴雾化区域浓度均匀、捕集面积大;小雾化扩散角下的雾粒速度相对较大,大扩散角下的雾流浓度分布均匀,但其穿透力差。分析结果为提高采煤机喷雾降尘效率,降低采煤工作面粉尘浓度提供了依据。

Numerical simulation of shearer external spray system

In order to improve the shearer external spray system performance and environment of working face，a model of mechanized coal face was established by the union of Pro/E and GAMBIT，a standard k-ε turbulence flow model was selected to build the external flow field of shearer，the average speed of ventilation in roadway was about 1.8 m/s，it was comply with the provisions of the Safety Standard of Coal Mine.The numerical simulation of shearer external spray situation was established by the software FLUENT，the law of the influence about the effect of parameter variation to spray was obtained through the changes of nozzle caliber，spray pressure and diffusion angle.As the spray pressure increase，the diameter decreases and the spray concentration distribution is more uniform；Small-bore nozzle’s concentration is higher，large-bore nozzle’s concentration is uniform and trapping area is large；the fog particles velocity with small diffusion angle is opposite bigger，the spray concentration distribution with large diffusion angle is more uniform，but its penetration is poor.The result provides foundation for improving the efficiency of shearer spraying dust and reducing the coalface dust concentration.