气液分配器碎流板结构优化与数值模拟

Structural optimization and numerical simulation of stream breaker structure of gas-liquid distributor

气液分配器是气-液-固三相反应器的重要内构件,其主要作用是充分混合气液两相,将其均匀喷洒到固相床层。目前在石油化工领域被广泛应用的BL型气液分配器存在喷洒角度小等问题。为此,设计了一种利用开孔平面和锥面封闭降液管出口的碎流板结构,并采用计算流体力学方法对比分析了改进前后分配器的流体力学性能。结果表明:原结构中,直接穿过碎流板的中心流量占总流量的99.8%,这部分液体在后续空间很难分散;在原结构上增设锥面,形成封闭式碎流板后,中心流量有效降低,侧边流量明显增大,液相在整个截面分布更加均匀,分配器性能明显提升。在开孔面积不变的条件下,底面和侧锥面的最佳开孔数量均为24,最佳侧锥角为77°。其中,调整侧锥面的结构能更好地增大喷洒量,液相分布也更加均匀。

The gas-liquid distributor is an important internal component of the gas-liquid-solid three-phase reactor,and its main function is to fully mix the gas-liquid two phases and spray them evenly on the solid bed.At present,the BL type gas-liquid distributor,which is widely used in the petrochemical industry,has problems such as small spray angle.For this reason,a broken flow plate structure was designed to seal the outlet of the downcomer by using an open hole plane and a cone surface.The computational fluid dynamics method was used to compare and analyze the fluid dynamics performance of the distributor before and after the improvement.The results show that in the original structure,the central flow directly passing through the broken flow plate accounts for 99.8%of the total flow,and this part of the liquid is difficult to disperse in the subsequent space.After adding a cone surface to the original structure to form a closed flow plate,the central flow rate is effectively reduced,the side flow rate is significantly increased,the liquid phase is more evenly distributed throughout the cross-section and the distributor performance is significantly improved.Under the condition of constant opening area,the best number of openings on the bottom surface and side cone is 24,and the best side cone angle is 77°.Among them,adjusting the structure of the side cone surface can better increase the spray amount,and the liquid phase distribution is more uniform.