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应用欧拉双流体模型对内埋单支换热管的浅层气-固(空气-石英砂颗粒)流化床进行了数值模拟,在换热管周围建立了4个观测点,得出了沿换热管圆周方向流动状况和局部瞬时换热系数的变化。结果显示:在换热管中心水平面的左右两侧壁面处颗粒更新速度较快,并有气泡上升,局部换热系数的变化也较强烈;在管壁下部颗粒运动相对平稳,并有颗粒在此滞留,局部换热系数变化相对较缓;在管壁上部颗粒有堆积,这使得颗粒体积分数在此处变化较小,局部换热系数变化也较为平缓。
Euler bi-fluid model was used to simulate the shallow gas-solid (air-quartz sand particles) fluidized bed with a single heat transfer tube. Four observation points were established around the heat transfer tube. Circulation of heat transfer tubes in the circumferential direction and local transient heat transfer coefficient changes. The results show that the particle renewal speed is faster at the left and right walls of the center of the heat exchange tube, and the bubbles rise and the local heat transfer coefficient changes more strongly. The movement of the particles in the lower part of the tube wall is relatively smooth, The change of local heat transfer coefficient is relatively slow. The accumulation of particles in the upper part of the tube wall makes the change of particle volume fraction smaller and the change of local heat transfer coefficient relatively gentle.