石膏旋流器空气柱内三维速度场的数值模拟

石膏旋流器是火电厂石灰石-石膏湿法烟气脱硫系统中的重要设备,在运行过程中会出现空气柱现象,致使能耗增大、流场不稳定、分离效率降低。为了解空气柱内气体流场特性,采用Fluent软件,应用流体体积模型（VOF）,对单一入口石膏旋流器内空气柱产生、发展到稳定的整个过程进行了数值模拟。研究结果表明：空气柱内为螺旋流动;由两端出口进入的空气在相遇后还需经过一定时间的发展才能达到稳定的状态;气相的轴向速度随时间有明显的变化,切向速度变化幅度较小,径向速度比轴向及切向速度小一个数量级。进行石膏旋流器结构优化时应考虑设计对称入口结构和空气柱内空气运动方向不同。

Numerical Simulation of 3-D Velocity Field in Air Core of Gypsum Cyclones

Gypsum cyclones are important equipments in wet limestone-gypsum flue gas desulfurization(WFGD) system in power plants. The air core phenomenon in gypsum cyclone operation may cause waste of energy, unsteady flow conditions, separation efficiency decrease and so on. The three-dimensional velocity field in the air core is simulated with volume of fluid(VOF) model in Fluent to study the characteristics of the flow field. The simulation results indicate that there is a spiral flow in the air core and a certain period of time is needed for the air entered from the two outlets developing into a steady air core. The velocity of the air changes with time obviously in axial but less in tangential direction. Also, the radial velocity is one magnitude order lower than the axial and tangential velocity.