文档介绍：湖南大学
硕士学位论文
新型湿法除尘脱硫斜板塔的数值模拟
姓名:李思民
申请学位级别:硕士
专业:环境科学
指导教师:李彩亭
20070425
硕士学位论文
摘要
我国现阶段的大气污染物主要以总悬浮颗粒物、二氧化硫为主,环境保护
工作者对如何减少和控制大气污染进行了大量的研究。李彩亭教授在总结前人的
基础上自主开发设计了两种新型湿法除尘除有害气体的斜板塔:矩形斜板塔和伞
罩形斜板塔。该系列装置不仅除尘效率高,而且能有效地去除有毒有害气体,体
积小,结构简单,维护方便,运行费用低,具有广泛的应用前景。为了观察塔内
流场分布规律,运用 CFD(计算流体力学)软件,对两种新型塔内气液两相流动
进行了数值模拟。
在气体单相流方面,采用标准 k-ε湍流模型进行描述,运用 SIMPLE 算法对
湍流方程进行离散,模拟了矩形塔和斜板塔在空塔气速为 2-4m/s 下的塔内流场,
结果发现:气体的湍流度显著增加,斜板除尘塔能有效延长气体的塔内停留时间;
在塔体的进口区域会出现烟气冲壁的现象;采用中心出口的圆柱型塔可以有效地
避免气体“死区”的产生。
在气液两相流动方面,建立了以颗粒动力学理论为基础的双流体模型,模型
中考虑了气液两相耦合,修正了气液两相流动中的湍流动能 k 和湍流动能耗散率
ε输运方程的源项,对实验装置进行了瞬态和稳态的数值模拟。模拟当中,液滴
的壁面模型采用壁面液膜模型。结果表明:喷淋液体对气场有一定的整流作用,
在喷嘴处可以观察到气体卷吸的现象;增大进口气速,可增大液滴在塔内的充满
度,但同时会出现液滴夹带的现象。
最后,在空塔气速为 2- 内,液气比为 -1L/m3 工况下对塔内的压
力损失进行实验验证,相对误差小于 %,实验值与模拟值吻合较好。
该模拟为塔体的进一步优化设计提供了依据。

关键词:斜板塔;数值模拟;气液两相流;标准 k-ε湍流模型;颗粒轨
道模型;壁面液膜模型

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新型湿法除尘脱硫斜板塔的数值模拟
Abstract
The total suspended particulate(TSP) and sulfur dioxide are still the primary air
pollutant of China in present period, and environment protection operators have done
a lot of study to reduce and control the air pollutant. On the basis of systematically
summarizing predecessors' work, Professor Li Caiting designed the new two types of
towers for wet dedusting and hazardous gas removal, which were the tower with
rectangle sloping plates and the tower with umbrella sloping plates. With the high
efficiency of dust removing, simple pact configuration , and low operating
cost, the equipments has wide application in the future. In order to observe the
distribution laws of the towers’ flowfield, the gas-liquid two-phase flow in the two
new types of towers was numerically simulated by using of CFD (computational fluid
dynamics) software.
The gas-phase simulation described with standard k-ε turbulence model was
adopted SIMPLE algorithm. In this paper, the gas flow for different models was
simulated with the gas velocity of tower from 2 to 4m/s. The re