【作者】 万嘉瑜；

【导师】 金余其； 池涌；

【作者基本信息】 浙江大学 ， 动力工程及工程热物理， 2010， 硕士

【摘要】 伴随社会的进步和发展,污泥的产生量正在逐年增长,如何实现对污泥无害化、减容化和资源化利用一直是近年城市建设和国家发展中的重要内容。焚烧作为能够较大实现减容化和无害化的技术,目前在污泥处理中逐渐被加以利用。但是,由于污泥热值不高,往往需要在焚烧过程中添加煤等辅助燃料,造成了额外的资源使用。污泥富氧燃烧是一种将污泥处理和富氧燃烧相结合的技术,它不仅能够发挥富氧燃烧的技术优势,同时还能够弥补污泥处理过程中热值不足的问题,具有较强的节能、环保价值。本文以此作为研究背景,选用杭州四堡污水厂污泥作为研究对象,通过理论计算分析、热重实验、水平管式炉试验、流化床燃烧试验和气体燃烧试验研究了氧浓度对污泥燃烧排放特性的影响。通过理论计算定量分析得出,氧浓度的增加可以显著降低送风量、烟气量和排烟热损失,同时还可以提高绝热火焰温度,使工况达到能够维持稳定燃烧的效果。热重实验表明,在一定范围内,随氧浓度的提高,着火温度降低,反应速率加快,综合燃烧性能随着提高。根据实验结果建立了动力学模型,得出氧浓度对反应级数n、活化能E和指前因子A等动力学参数无显著影响,模型与实验结果吻合较好。在此基础上,通过管式炉试验和流化床试验对不同氧浓度下的气体排放特性、灰渣形态和重金属迁移特性进行了研究,得出NOX、SO2、灰渣形态和灰渣中重金属等随氧浓度的变化规律,并对此进行了原因分析。结合上述试验,本文还对气体在不同氧浓度下的燃烧特性进行了分析。最后,综合理论分析和试验研究中的一致性和互补性,本文认为适合污泥试样进行富氧燃烧的理想工况为氧浓度在25%～35%的范围。更多还原

【Abstract】 With the development of the society, the amount of sludge is increasing year by year, and the treatment of sludge is more and more important for the society. Incineration is a good way to dispose sludge. However, because of the low heat value, it always needs to add coal or other fuels to make sludge combust well.Based on the advantage of oxygen-enriched combustion and the low heat of sludge, oxygen-enriched combustion of sludge is a novel technology of energy-saving and environmental protection.This paper chooses sludge from Sibao Sewage Plant of Hangzhou and makes oxygen-enriched combustion tests in the TG apparatus, tube furnace, fluidized bed and Bunsen-Burner to research the combustion and emission characteristics of sludge under different oxygen concentrations.Theoretical calculation results show that the supply gas volume, the flue gas volume and the waste heat loss decreases, the adiabatic flame temperature increases, and the combustion performance is improved when the oxygen concentration increases.The thermogravimetric (TG) analysis shows that the ignition temperature decreases, the reaction rate increases and the overall combustion performance is improved with the increase of oxygen concentration. The computing results from the comprehensive combustion kinetic model are suitable for various oxygen concentrations and agreed well with experimental results. It is also found that the reaction order n, activation energy E and pre-exponential factor A were independent of oxygen concentration.This paper also analyses the effect of oxygen concentration on the release of NOx and SO2, the bottom ash form and heavy metals migration. And then, this paper studies the effect of oxygen concentration on gas combustion characteristics.Based on theoretical analysis and experimental research, the oxygen concentration from 25% to 35% is the ideal region for oxygen-enriched combustion of sludge samples.更多还原