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该文采用离散单元法(DEM)对水平埋管的鼓泡流化床内颗粒流化过程进行了数值模拟研究。DEM方法通过求解Newton方程来模拟颗粒的运动过程,气相仍采用连续流方法模拟。因此,DEM方法能够获得颗粒尺度量级的详细结果。通过模拟不同埋管布置方式下流化床内密相区颗粒流化过程,研究了埋管布置方式对于鼓泡流化床内的颗粒运动的影响。结果表明:埋管布置方式会改变床层有效流通面积和埋管对颗粒的阻碍作用等,从而影响流化床内的颗粒群和气泡形态。埋管数量越多,颗粒与埋管由于相互作用而消耗的能量越大,平均颗粒速度和颗粒温度值越低。不同的埋管布置方式会导致颗粒混合速率的差异,增加埋管数量会降低颗粒混合程度。
In this paper, the discrete element method (DEM) is used to simulate the fluidization process of particles in a bubbly fluidized bed with a horizontal pipe. The DEM method simulates the motion of the particles by solving the Newton equation, and the gas phase is simulated by the continuous flow method. Therefore, the DEM method can obtain detailed results on the scale of particle size. By simulating the fluidization process of particles in the dense phase zone in different fluidized bed layout, the effect of pipe placement on the particle motion in bubbling fluidized bed was studied. The results show that the arrangement of buried pipes can change the effective flow area of the bed and the obstruction effect of the buried pipe on the particles, thereby influencing the particle groups and bubble shapes in the fluidized bed. The greater the number of buried pipes, the larger the energy consumed by the particles and the pipes due to the interaction, the lower the average particle speed and the particle temperature value. Different tube arrangements lead to differences in particle mixing rates, and increasing the number of tubes reduces particle mixing.