【摘要】 采用计算流体力学-离散单元法(CFD-DEM)和切向撞击能模型(SIEM)来研究气固两相流中高速煤粉颗粒冲击导致的U形弯管冲蚀磨损问题。分析了颗粒粒径、气体流速、固体颗粒形状对其冲蚀磨损特性的影响,并验证粗粒化模型应用于此磨损过程的准确性。结果表明,U形弯头的冲蚀磨损位置主要有3处;磨损率随粒径的增大呈现整体减小的趋势;U形管拱背磨损率随气速的增加而增大,且前2处磨损率峰值位置随气速的增加向入口方向偏移;长椭球对U形管造成的磨损最严重,扁椭球次之,球形最轻;粗粒化CFD-DEM能够基本准确预测U形管冲蚀磨损,且显著降低计算时间。更多还原

【Abstract】 The erosion wear of U-shaped elbow caused by the impact of high speed pulverized coal particles in gas-solid two-phase flow is studied by using computation fluid dynamics-discrete element method(CFD-DEM) and shear impact energy model(SIEM). The effects of particle size, gas flow velocity, particle shape of the U-shaped elbow on the wear are obtained and analyzed. The accuracy of the coarse-grained model applied to the wear process is also verified. The results show that there are three main erosion wear locations of U-shaped elbows. The wear rate shows an overall decreasing trend with the increase of particle size. The wear rate of U-shaped elbow arch back increases with the increase of gas flow velocity, and the peak positions of the first two wear rates shift to the inlet direction with the increase of gas velocity. The wear of the long ellipsoid on the U-shaped elbow is the most serious, followed by the flat ellipsoid, and the spherical one is the lightest. Coarse-grained CFD-DEM can predict the erosion wear of U-shaped tube accurately and significantly reduce the calculation time.更多还原