基于CFD-DEM耦合仿真的抓斗卸料气固两相流场研究

Research on Gas-Solid Two-Phase Flow Field in Grab Discharge Based on CFD-DEM Coupling Simulation

针对抓斗卸料过程中,散体物料的自由下落导致粉尘扩散,对其进行气固两相流场研究,目的是通过空气流场运动速度和轨迹反映出粉尘的运动情况,从而判断粉尘逸出量大小。采用基于CFD-DEM耦合的数值模拟方法,得出了颗粒流场的速度分布和空气流场的运动轨迹及速度分布、不同时刻的气固两相流场相互作用及变化规律,并分析了料斗口平面逸出气流面积、逸出气流质量流量、逸出速度和气流夹角,进一步推导出不同颗粒粒径和气流夹角下的粉尘颗粒悬浮速度。结合仿真数据和推导出的公式,可以分析不同抓斗卸料工况下的粉尘逸出规律,对采取针对性的降尘方法和措施、高效解决粉尘扩散问题具有指导意义。

In order to solve the problem of dust diffusion caused by the free fall of bulk materials in the process of grab discharge, the gas-solid two-phase flow field was studied to reflect the movement of dust through the velocity and trajectory of the air flow field, thereby to judge the amount of dust emission. By using the numerical simulation method based on CFD-DEM coupling, the velocity distribution of particle flow field, the trajectory and velocity distribution of air flow field, as well as the interaction and variation law of gas-solid two-phase flow field at different time were obtained, and the area of liberating airflow, mass flow of liberating airflow, liberating velocity and airflow angle at the plane of grab mouth were analyzed. Furthermore, the suspension velocities of dust particles under different particle sizes and airflow angles were deduced. Combined with the simulated data and derivation formula, the laws of dust liberating under different working conditions of grab discharge can be analyzed, which can provide a guidance for taking targeted dust reduction methods and measures as well as efficiently solving the problem of dust diffusion.