焦炉烟气SDA脱硫与烧结烟气脱硝前混合再热特性研究

发布时间：2018-05-01 21:02

本文选题：SDA旋转喷雾脱硫 + 绝热饱和温差　；参考：《浙江大学》2017年硕士论文

【摘要】：钢铁行业生产过程中排放出大量的大气污染物,对生态环境造成严重危害。焦化和烧结工序是钢铁行业生产流程中的两个主要大气污染源。本文针对焦炉和烧结烟气特性,探讨适宜的烟气净化方案并对焦炉烟气脱硫以及烧结烟气脱硝工艺遇到的关键问题进行研究。本文基于SDA(旋转喷雾脱硫)中试试验台,对低含湿量、高烟温的模拟焦炉烟气进行了脱硫实验,研究高入口烟温、高绝热饱和温差的条件下,Na2C03和Ca(OH)2两种不同脱硫剂的脱硫特性。讨论了化学计量比、脱硫塔入口烟温、绝热饱和温差和脱硫烟气温降对脱硫效率的影响。实验结果表明,随化学计量比增大,Na2CO3脱硫效率增长速率比Ca(OH)2更快;SDA脱硫效率随绝热饱和温差的增大呈指数形式下降;在保持出口烟气温度不变条件下,增大入口烟温有利于提高脱硫效率;此外,增大脱硫烟气温降有利于提高脱硫效率。实验结果表明,Na2CO3更有利于实现焦炉烟气高效脱硫。将SCR脱硝工艺运用于烧结烟气的主要困难在于烧结烟温偏低,达不到SCR催化剂的活性温度窗口。解决的办法是利用热烟气与主烟气进行混合再热来提升主烟气的温度。本文基于烧结烟气混合再热试验台,研究热烟气与空气的混合特性。文章研究单管横向射流和多孔射流两种烟气混合方式下,热烟气在近场区域的速度、温度以及浓度分布特性。实验结果表明,多孔射流方式能够有效的提升烟气混合均匀度,加快烟气的混合进度;多孔射流紊动热混合结果受热烟气的射流穿透力、射流流量分布以及圆柱扰流等因素影响;多孔射流管13×Φ12 mm能够形成最佳的温度场和浓度场分布。
[Abstract]:A large amount of atmospheric pollutants are emitted from the production process of iron and steel industry, which causes serious harm to the ecological environment. The coking and sintering processes are two main air pollution sources in the production process of iron and steel industry. According to the characteristics of coke oven and sintering flue gas, this paper discusses the suitable scheme of flue gas purification and studies the key problems of flue gas desulphurization and denitrification in coke oven. In this paper, the desulfurization experiments of simulated coke oven smoke with low moisture content and high smoke temperature were carried out on the basis of SDA (rotating spray desulphurization) pilot-scale test rig. The desulfurization characteristics of two different desulfurizers, Na2C03 and Ca(OH)2, were studied under the conditions of high inlet smoke temperature and high adiabatic saturation temperature difference. The effects of stoichiometric ratio, inlet flue gas temperature of desulfurizer, adiabatic saturation temperature difference and temperature drop of desulfurization smoke on desulfurization efficiency were discussed. The experimental results show that with the increase of stoichiometric ratio, the increasing rate of desulfurization efficiency of Na2CO3 is faster than that of Ca(OH)2, and the desulfurization efficiency decreases exponentially with the increase of adiabatic saturation temperature. Increasing the inlet flue gas temperature can improve the desulfurization efficiency, in addition, increasing the temperature drop of the flue gas can improve the desulphurization efficiency. The experimental results show that Na _ 2CO _ 3 is more propitious to realize high efficiency desulfurization of coke oven flue gas. The main difficulty of applying SCR denitrification process to sintering flue gas is that the sintering smoke temperature is low and can not reach the active temperature window of SCR catalyst. The solution is to raise the temperature of the main flue gas by mixing the hot flue gas with the main flue gas. In this paper, the mixing characteristics of hot flue gas and air are studied on the basis of sintering flue gas mixing reheat test rig. In this paper, the velocity, temperature and concentration distribution of hot flue gas in the near field are studied under the two mixing modes of single pipe transverse jet and porous jet. The experimental results show that the porous jet method can effectively improve the uniformity of flue gas mixing and accelerate the mixing progress of flue gas, and the jet penetration of heated flue gas caused by turbulent heat mixing of porous jet can be improved. The optimum temperature field and concentration field can be formed in a porous jet tube with 13 脳桅 12mm, which is influenced by jet flow distribution and cylinder turbulence.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X757

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