工业锅炉快装式脱硫塔结构设计与优化

发布时间：2018-08-26 18:05

【摘要】：随着生产力的发展,能源消耗的增加,工业锅炉在燃烧煤种时产生的二氧化硫会混杂在烟气中。二氧化硫的生成会引发温室效应、酸化水质和土壤,严重的还会影响动植物的正常生活。为了减少二氧化硫对环境的不利影响,各国开始对脱硫技术展开研究,并逐步推广到大型锅炉的烟气处理系统中。我国95%以上的锅炉为中小型工业锅炉,具有资金和技术力量薄弱的特点,难以承担价格高昂的大型烟气脱硫系统的安装和运行费用。因此,设计一种针对工业锅炉的快装式脱硫塔的意义尤为重大。通过分析目前常用的烟气脱硫工艺,对比各种脱硫工艺的利弊,选出了能够适应现在高排放要求的湿法烟气脱硫技术,并以目前应用最广泛的石灰石湿法烟气脱硫工艺为例,利用双膜理论以及电离方程分析影响该工艺脱硫效率的因素。为了促进气液混合传质过程,引入旋流雾化喷射技术,结合普通喷淋双重吸收的模式,可以在提高吸收效率的同时降低脱硫液气比。控制浆液p H值为5.4左右,浆液中石膏过饱和度在120%至130%时,既能够保证吸收效果,又能提高石膏品质。以广东某75t/h的工业锅炉石灰石湿法烟气脱硫塔设计为例,根据煤质、锅炉容量、烟气、吸收剂等参数,利用硫元素平衡计算吸收系统的吸收剂消耗量、石膏生成量、循环浆液量、氧化风量等设计参数。根据计算出的参数设计出了适用于75t/h锅炉用的吸收塔,并针对吸收系统进行优化。设计吸收塔浆液池直径为5.0m,浆液池设计工作液位为6.1m;吸收区上部设计三层普通喷淋层,相邻两层设计交错夹角为15°;吸收区下部设计两层旋流雾化喷射层,相邻两层设计交错夹角为45°。其中旋流雾化喷射层设计切圆直径为1700mm,切圆高度位于雾化器中心下方200mm至500mm处。通过在某电厂和某工业锅炉脱硫塔改造工程的测试数据中,三层普通喷淋层下方新增一层旋流雾化层可以提高2%至4%的吸收效率,因此设计两层旋流雾化喷射层与三层普通喷淋层的吸收区组合可以满足脱硫效率98.9%的设计要求。采用该吸收塔处理烟气,每年可减少SO2的排放超过200吨,减排经济效益超过30万元。
[Abstract]:With the development of productivity and the increase of energy consumption, sulfur dioxide produced by industrial boilers when burning coal will be mixed in flue gas. The formation of sulfur dioxide triggers Greenhouse Effect, acidification of water and soil, and a serious impact on plant and animal life. In order to reduce the adverse impact of sulfur dioxide on the environment, various countries began to study desulfurization technology, and gradually extended to the flue gas treatment system of large boilers. More than 95% of the boilers in our country are small and medium-sized industrial boilers, which have the characteristics of weak capital and technical strength, so it is difficult to bear the high cost of installation and operation of large-scale flue gas desulfurization system. Therefore, it is of great significance to design a fast-mounted desulfurizer for industrial boilers. By analyzing the commonly used flue gas desulfurization technology and comparing the advantages and disadvantages of various desulphurization processes, the wet flue gas desulfurization technology which can meet the needs of high emission is selected, and the most widely used limestone wet flue gas desulfurization technology is taken as an example. The factors influencing the desulfurization efficiency of the process were analyzed by using the double film theory and the ionization equation. In order to promote the gas-liquid mixed mass transfer process, the swirl atomization and injection technology, combined with the dual absorption mode of common spray, can increase the absorption efficiency and reduce the desulfurization liquid gas ratio at the same time. When the pH value of the slurry is about 5.4 and the supersaturation of gypsum in the slurry is between 120% and 130%, it can not only guarantee the absorption effect but also improve the gypsum quality. Taking the design of limestone wet flue gas desulfurization tower of an industrial boiler in Guangdong province as an example, according to the parameters of coal quality, boiler capacity, flue gas, absorbent and so on, the absorbent consumption and gypsum production amount of absorption system are calculated by using sulfur element balance. Design parameters such as circulating slurry volume, oxidizing air volume, etc. According to the calculated parameters, the absorber suitable for 75t/h boiler is designed, and the absorption system is optimized. The diameter of the slurry pool of the absorption tower is 5.0 m, the working level of the slurry tank is 6.1 m, the upper part of the absorption zone is designed with three layers of common spray layer with a staggered angle of 15 掳between the adjacent two layers, and the lower part of the absorption zone is designed with two layers of swirl atomization spray layer. The intersecting angle of the adjacent two layers is 45 掳. The swirl atomization spray layer is designed to have a tangential diameter of 1 700 mm and the height of the tangent circle lies below the center of the atomizer from 200mm to 500mm. In the test data of the retrofitting project of desulfurization tower of a power plant and an industrial boiler, the absorption efficiency of 2% to 4% can be improved by adding a new layer of swirl atomization layer below the three-layer common spray layer. Therefore, the design of two-layer swirl atomization spray layer and three-layer common spray layer absorption zone combination can meet the design requirements of 98.9% desulphurization efficiency. The SO2 emission can be reduced by more than 200 tons per year and the economic benefit of emission reduction is more than 300000 yuan by using the absorber to treat the flue gas.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TK229

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