【作者】 李进龙；

【导师】 胡金榜；

【作者基本信息】 天津大学 ， 化工过程机械， 2004， 硕士

【摘要】 循环流化床烟气脱硫技术是近年来国内外正在研究开发的一种先进的脱硫技术。本文以循环流化床脱硫器为研究对象，对提升管内的速度场分布受装置进口结构形式的影响进行实验分析与数值模拟，为研究循环流化床内气固两相流动的传质、传热过程提供优化结构的依据。设计的实验进口装置采用工业上推广使用的文丘里管。通过实验，测量了气体轴向速度在文丘里扩散段与提升管内径向位置上的分布，运用速度分布不均匀度概念对轴向速度沿径向位置分布特点及其产生原因进行了深入分析与讨论。结果表明：装置的侧向进口结构和回料管的存在严重影响提升管下端气体速度分布均匀性，使得气流在提升管下端产生了不良流动行为，在回料管一侧，甚至出现了旋涡，提升管段的稳定流动区域也有着相应的变化。采用Launder和Spalding提供的模型常数，通过数值模拟分析结果与实验值的比较确认了两方程κ-ε湍流模型对本实验装置的适用性。设计了两种不同于实验装置的进口结构，并运用κ-ε湍流模型对不同进口结构型式气体流动状态进行了数值模拟，获得优化进口结构形式。更多还原

【Abstract】 Flue-gas desulfurization technology with circulating fluidized bed(CFB) has been developed in the world recently. In order to provide the basis on optimal structure of inlet for those who would go in for research on process of mass and heat transfer of gas-solid in CFB, the effects of inlet structure on distribution characteristics of velocity field in riser were studied and numerical simulations were performed in the paper.The inlet structure of venturi-pipe that was extensively utilized in industry was adopted. Distribution of axial velocity across radial position in riser was obtained through experiment. The characteristics of axial velocity distribution were thoroughly discussed with uneven conception. The reasons that the flow phenomena appeared in riser were extensively analyzed. The results showed that the even of velocity profiles in the bottom of riser was badly affected by side inlet duck and circulating feed inlet. As a result, the bad flow behavior in the bottom of riser arised and what is more, in the venturi diffusive section, the eddy, with which the region of steady-flow in riser changed, appeared on the side of circulator.Through comparison of the results of numerical simulation and experiment results, two equation model was validated with constants recommended by Launder and Spalding in the paper. Two different types of inlet structure were designed and numerical simulation of these bodies was made with the help of model. The better inlet type was put forward based on the experiment and numerical simulation.更多还原