摘要
针对循环流化床上升管内气固两相流动,建立了Eulerian双流体模型,将离散的固体颗粒相看作是连续介质,建立颗粒相和气相的质量守恒、动量守恒及k-ε输运方程等模型,用Fluent软件作计算工具,对流化床上升段内的颗粒速度分布、颗粒浓度分布和床内压力分布等进行了二维数值模拟.计算结果表明:上升段存在固体颗粒浓度中心区域低、近壁面高的环核结构,固体颗粒在横截面上存在由核心区向环形区的内循环运动,在相同气流速度下,沿床高压降随循环物料的增加而变大.数值模拟的结果与Parssinen的实验结果吻合良好,表明所建模型正确,数值计算结果可以有效地应用于预测实际装置性能和指导循环流化床的设计和运行.
The Eulerian two-fluid model is established to simulate the gas-particle turbulent flow in the riser section of a circulating fluidized bed （ CFB ） reactor. The particle flow in the riser is thought as a continuous phase. The model, based on mass equation, momentum equation, k-ε equation and constitutive relations, is coded and solved using Fluent software package to simulate the two-dimensional flow in a riser. The results show that the flow pattern in the riser section of a CFB consists of a core-annular flow regime in which the solid density near the wall region is higher than that at the center of the riser. The solid velocity is high at the center of the riser and solid down-flow at the wall regions. The particles move from the center to the annular zone in the same section and the pressure drop in the riser rises with the increase of circulating mass at the same inlet gas velocity. The computational values agree well Parssinen＇s experimental results. Eulerian models can be used to forecast the performance of a fluidized bed and to guide the operation of the actual device.
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2005年第5期752-756,共5页
Journal of Southeast University：Natural Science Edition
基金
国家自然科学基金资助项目(50176010
90410009)
关键词
循环流化床
两相流
环核流动
计算流体力学
circulating fluidized bed
two phase fluid model
core-annulus fluid
computational fluid-dynamics
