切圆喷雾式湿法烟气脱硫塔内过程数值模拟及优化分析

发布时间：2017-12-27 18:42

本文关键词：切圆喷雾式湿法烟气脱硫塔内过程数值模拟及优化分析　出处：《华南理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：实现燃煤电厂的烟气超洁净排放是煤电行业生存和发展的必然趋势。随着国家加大对大气污染物的防治力度,当前的工艺技术已无法满足越来越严格的SO_2排放标准。因此,如何利用现有脱硫装置,在保证系统安全稳定的同时节约改造成本和运行能耗,进一步提高烟气的脱硫效率,成为当今电厂环保产业研究的热点问题。本文从燃烧前、燃烧中和燃烧后脱硫出发,简要概述了几种现用于工业生产中比较成熟的脱硫技术方法,详细介绍了目前燃煤电厂应用最广泛的烟气脱硫技术石灰石-石膏湿法烟气脱硫技术,包括基本原理、设备系统以及脱硫效率的影响因素。在此基础上,提出了一种在脱硫喷淋塔内增设脱硫剂旋流雾化层的脱硫反应方法,并对旋流雾化层的各项参数进行了优化分析。论文以Fluent模拟软件为平台,对某电厂100MW机组湿法烟气脱硫塔建模分析。采用欧拉-拉格朗日多相流模型,使用Simple算法,根据双膜理论,通过相应的用户自定义函数模块将SO_2吸收程序嵌入Fluent软件中,在未加旋流雾化层和开启旋流雾化层两种情况下,对脱硫塔内的烟气流动场、烟气温度场和SO_2浓度场进行了三维数值模拟与分析。同时为了有效地利用旋流雾化层流场再造的功能,文章还从旋流雾化层喷嘴的布置角度、数量以及浆液喷出的速度等相关参数对脱硫效率的影响进行了优化分析。研究结果表明:(1)脱硫塔内烟气流动场和温度场直接影响SO_2浓度场。(2)旋流雾化方法不仅可以增加烟气在脱硫塔内流程,加大气液接触的表面积,而且能够有效防止烟气沿塔壁逃逸,强化气液两相在吸收区的混合。脱硫效率的提高与实际测试结果相吻合。(3)旋流雾化层的直径比d/D选为0.6左右并至少设置8个喷嘴才能形成稳定的螺旋场,有利于提高烟气流动的均匀性。浆液的喷射速度控制在15~20m/s,脱硫喷淋塔的脱硫效率可达到最高。
[Abstract]:The realization of ultra clean emission of flue gas from coal-fired power plants is an inevitable trend for the survival and development of coal and electricity industry. With the efforts of the state to prevent and control air pollutants, the current technology has not been able to meet more and more stringent SO_2 emission standards. Therefore, how to make use of the existing desulfurization devices to ensure the safety and stability of the system while saving the cost and energy consumption and further improving the desulfurization efficiency of flue gas has become a hot issue in the environmental protection industry of power plants. This article from the pre combustion, combustion and after combustion desulfurization of a brief overview of several relatively mature methods for desulfurization technology in industrial production, introduces the technology of flue gas desulfurization limestone coal-fired power plant is currently the most widely used gypsum wet flue gas desulfurization technology, including basic principle, equipment and system factors influencing desulphurization efficiency. On this basis, a desulphurizing method for adding desulfurizer and swirling atomization layer in desulfurization spray tower is put forward, and the parameters of swirling atomization layer are optimized. On the platform of Fluent simulation software, the paper modeling and analyzing the wet flue gas desulfurization tower of a power plant 100MW unit. Using the Euler Lagrange multiphase flow model, using the Simple algorithm, based on the double film theory, through the user-defined function module corresponding SO_2 absorption program is embedded in Fluent software, without atomizing layer and the two layer open the atomizing case of flue gas desulfurization tower flue gas flow field, temperature field and SO_2 concentration the field of numerical simulation and analysis. Meanwhile, in order to effectively utilize the function of regenerating flow field of swirling atomization layer, the influence of the arrangement angle and quantity of swirl atomization nozzle and the speed of slurry ejection on the desulfurization efficiency is also optimized. The results show that: (1) the flue gas flow field and temperature field in the desulphurizing tower directly affect the SO_2 concentration field. (2) swirling atomization method can not only increase the flow of flue gas in the desulfurization tower, increase the surface area of gas-liquid contact, but also effectively prevent flue gas escaping along the tower wall, and enhance the mixing of gas and liquid in the absorption area. The improvement of desulfurization efficiency is consistent with the actual test results. (3) the diameter of the atomization layer is about 0.6 compared with d/D, and at least 8 nozzles can be set up to form a stable spiral field, which is beneficial to improve the uniformity of the flow of flue gas. The injection speed of the slurry is controlled in 15~20m/s, and the desulfurization efficiency of the desulfurization spray tower can be reached to the highest.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X773

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