燃煤角管式锅炉烟气脱硫除尘及脱硫液回收工艺设计

发布时间：2018-02-01 22:57

  本文关键词： 角管锅炉 布袋除尘 氨法脱硫 MVR　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：煤炭是我国能源体系中的组成部分,在能源体系中的作用很是重要,但其在燃烧过程中,随烟尘而产生的颗粒物、SO2等污染,是影响空气质量的重要污染源[1],由此引发的环境问题受到我国各级政府及民众的广泛关注。21世纪以来,随着我国工业化的迅猛发展,GDP的快速增长,SO2排放量连年居世界第一位[2],雾霾出现的几率提高,我们正在遭受其不断的伤害。工业燃煤锅炉燃烧烟气中的SO2、颗粒物是导致空气质量恶化、PM2.5超标的主要来源,因此,在实际运行过程中,保证燃煤锅炉的烟气颗粒物、S02的达标排放[3]是提升目前空气质量,预防酸雨、雾霾等大气问题的根本举措。我国燃煤锅炉数量多且分布广泛,由于历史发展的原因,中小型锅炉大量存在,具有难以集中治理的特点。本文以公司35t/h燃煤角管式蒸汽锅炉作为研究对象,对其烟气脱硫除尘工程及脱硫液回收利用问题开展设计。通过比选不同的烟气脱硫除尘工艺,综合分析目前烟气脱硫除尘技术发展的现状,结合公司锅炉烟气排放过程中存在的实际问题,设计并实施一套适合公司发展的、经济可行的燃煤角管式蒸汽锅炉的脱硫除尘设计方案。对吸收SO2后的脱硫液对比了不同的回收方案,选择切实可行的回收利用方案,回收的(NH4)2SO4可外售处理,既减少了废弃物的处理成本,又增加了副产物的经济效益,降低了工程的投资和设备的运行费用。设计方案的实施减少了生产及处理过程中的二次污染,实现了废物的二次利用,变废为宝,取得了一定的经济效益,并达到国家相关烟气排放标准的要求。本方案中角管式蒸汽锅炉使用II类烟煤,发热量多5000kcal/kg,挥发份在20%以下,灰份在30%以上,含硫量≤1.2%[4]。设计方案实施后,经安装调试,烟尘的脱除率可达99.37%,烟尘减少180kg/h,工时按7200h/a,可减少烟尘排放1283.04t/a,对于降低大气PM2.5,消除雾霾给社会造成的困扰,有良好的改善效果;氨法脱硫塔的S02脱除率可达98.29%,S02减少120.56kg/h,工时按7200h/a、锅炉按90%负荷运行计,燃煤5.2t/h,可减少S02排放量约868.03t/a,对作为酸雨控制区大气状况的改善有很好的效果;采用氨法脱硫后的副产(NH4)2SO4溶液,经MVR浓缩、结晶、离心后回收(NH4)2S04产品1853.28t/a,方案实施后减少了废水、废渣的产生,减少环境污染,且取得了部分经济效益,具有良好的示范作用[5]。
[Abstract]:Coal is an integral part of China's energy system and plays an important role in the energy system. However, in the combustion process, particulates such as so _ 2 and so _ 2, which are produced by smoke and dust, are important sources of pollution affecting air quality. [Since the 21st century, the rapid development of China's industrialization has led to the rapid growth of GDP. SO2 emissions ranked first in the world in successive years. [2] the probability of haze is increasing, and we are suffering from its constant harm. Particulate matter in the flue gas of industrial coal-fired boilers is the main source of air quality deterioration and PM2.5 exceeding the standard. Therefore, in the actual operation process, the emission of flue gas particulate matter (S02) from coal-fired boiler is guaranteed to meet the standard of discharge. [3] is a fundamental measure to improve air quality, prevent acid rain, haze and other atmospheric problems. The number of coal-fired boilers in China is large and widely distributed, because of historical development, a large number of small and medium-sized boilers exist. This paper takes 35t / h coal-fired angle-tube steam boiler as the research object. The project of flue gas desulphurization and dust removal and the problem of recovery and utilization of desulphurization liquid were designed. By comparing and selecting different flue gas desulfurization and dust removal technology, the current status of flue gas desulfurization and dust removal technology was comprehensively analyzed. Combined with the actual problems existing in the process of boiler flue gas emission, a set of suitable for the development of the company is designed and implemented. The design scheme of desulfurization and dust removal for coal-fired angle-tube steam boiler is economical and feasible. Different recovery schemes are compared to the desulfurization solution after absorbing SO2, and the feasible recovery scheme is selected. The recovered NH _ 4N _ 2SO _ 4 can be sold out for disposal, which not only reduces the cost of waste treatment, but also increases the economic benefit of by-products. The implementation of the design scheme reduces the secondary pollution in the process of production and treatment, realizes the secondary utilization of waste, turns waste into treasure, and obtains certain economic benefits. And meet the requirements of the relevant national flue gas emission standard. In this scheme, the second type bituminous coal is used in the middle angle tube steam boiler, the calorific value is more than 5 000 kcal / kg, and the volatile content is less than 20%. Ash above 30%, sulphur content 鈮，

本文编号：1483068