【摘要】 多床耦合装置可实现不同的化学反应过程和温度匹配,为了理解多床的调节特性和稳定运行范围,采用数值模拟对提升管耦合双流化床的气固流动行为进行了研究。固体循环流率通过上下2个L阀充气进行控制,并且上L阀和下L阀充气量匹配才能保证装置的稳定运行。模拟了多组操作工况,发现稳定运行范围内上L阀和下L阀充气量呈线性匹配关系,固体循环流率也与L阀充气量线性相关,最高达到了564 kg/(m~2·s)。当下L阀充气增大到一定值时,气体会沿下立管上升产生明显气泡,而随着上L阀充气量的提高,上立管中的物料堆积高度明显下降。对各部件压降分析表明,在不同工况条件时下L阀、提升管、上斜管的压降变化较大,而其余部件的压降变化较小。更多还原

【Abstract】 Multi-bed apparatus can realize reaction process with matching temperature in different reactors. To understand the control behavior and the stable operating conditions of multiple beds, the numerical simulation was employed to study the gas-solid flow behavior in the full-loop apparatus of a riser coupled with two fluidized beds. The solids circulation rate was controlled by the aeration of lower and upper L-valves, and the aeration rate of upper L-valve should match lower L-valve to maintain stable operation. Through the simulation of various operating conditions, the matching linear relationships among upper L-valve aeration, solids circulation rate, and lower L-valve aeration within stable range were obtained, and the maximum solids circulation rate reached 564 kg/(m~2·s). When the aeration of the lower L-valve is too big, there are obvious bubbles in the lower standpipe. With the increase of the upper L-valve aeration, the level of the particles accumulation in the upper standpipe decreases significantly. Under various conditions, the pressure drops of the lower L-valve, the riser, and the upper inclined pipe change greatly, while the pressure drops of other parts change little.更多还原