移动式打磨作业粉尘分布规律及其影响因素

Dust distribution rule and influencing factors in mobile grinding operation

为了探究移动式打磨作业粉尘扩散分布规律及其影响因素,根据气溶胶力学和流体力学原理,在高斯扩散模型基础上建立移动式打磨作业粉尘扩散分布数学模型;利用Python语言设计基于该模型的数据可视化仿真程序,并通过该仿真程序探究粉尘源强、平均粒径、风速及稳定度这4个因素对粉尘质量浓度分布的影响。研究结果表明:在打磨作业阶段,粉尘集中分布在打磨作业点处,粉尘云的位置和质量浓度呈稳定状态;打磨作业结束后,粉尘质量浓度随时间延长而逐渐降低,粉尘云向下游漂移且向四周扩散,其影响半径增大;粉尘质量浓度随源强增强而增大,源强对粉尘质量浓度峰值的位置无影响;粉尘平均粒径越小,粉尘质量浓度越高;风速越大,粉尘质量浓度整体越低,粉尘质量浓度峰值的位置越靠近打磨作业点;当大气稳定度在A^D范围内时,大气稳定度越高,粉尘质量浓度越高,粉尘质量浓度峰值位置有向打磨作业点下风侧移动的趋势;当大气稳定度为F时,粉尘的迁移距离最远。

In order to investigate the distribution and influencing factors of dust diffusion in mobile grinding operations,a dust diffusion model for grinding operations was established based on aerosol mechanics,fluid dynamics theory and Gaussian diffusion model.A simulation program based on the model was implemented in Python.Through the simulation program,the effects of dust source intensity,average diameter,wind speed and stability on distribution of dust mass concentration were investigated.The results show that during the grinding operation,dust is concentrated at the grinding operation point,and the position and mass concentration of dust clouds are stable.After the grinding operation,the dust mass concentration gradually decreases with time,and the dust cloud drifts downstream and goes around.The influenced area of dust cloud is thus enlarged.The dust mass concentration increases with the increase of source intensity,and the magnitude of the source intensity has no influence on the position of the dust mass concentration peak.The dust mass concentration increases with the decrease of the average diameter.The dust mass concentration decreases and the position of the dust mass concentration peak is closer to the grinding operation point as the wind speed increases.In the range of atmospheric stability A to D,the dust mass concentration increases and the peak position of the dust mass concentration moves toward the downwind side of the grinding operation point with the increase of atmospheric stability.The dust migration distance is the longest when the atmospheric stability is F.