船舶垃圾辅以煤粉高效焚烧的技术研究

发布时间：2018-04-09 14:55

  本文选题：船舶垃圾　切入点：超细煤粉　出处：《集美大学》2015年硕士论文

【摘要】：阐述船舶垃圾焚烧机理、焚烧主要影响因素,介绍燃烧特性和反应动力学的分析方法与理论,对船舶垃圾各主要可燃组分,如厨余、废纸、竹木、织物、橡胶、塑料、污泥等,进行工业分析、元素分析、热值检测、热分析等,精细化研究船舶垃圾的焚烧热动力学性能。结果表明:不同种类船舶垃圾,燃烧特性差异大,失重阶段主要集中在250℃~600℃,船舶垃圾各可燃组分的表观活化能大多小于100 k J·mol-1,容易实现燃烧反应,适合焚烧处理。船舶垃圾总体具有高水分、高挥发分、低热值、低灰分的物性特点,为助于降低垃圾干燥时间,保证垃圾稳定着火燃烧,有必要为船舶垃圾辅以外部燃料焚烧。探索船舶垃圾辅以超细煤粉实现高效焚烧技术,通过分析煤粉超细化对颗粒粒度分布、孔隙及比表面的影响,讨论超细化前后煤粉的煤质变化,研究超细前后煤粉的燃烧特性及反应动力学。结果表明:煤粉超细化后,煤粉粒度分布更均匀,孔隙容积和比表面积增大;随着煤粉粒径的减小,着火温和燃尽温度下降,且趋势呈线性关系。煤粉超细化对改善福建无烟煤这类极难燃煤种的燃烧特性效果更为显著,以典型的福建龙潭林无烟煤为例,当煤粉平均粒径从53.488μm减小至13.716μm时,其着火温度从673.17℃降低到658.07℃,燃尽温度从802.05℃到773.7℃,表观活化能从191.39 k J·mol-1减小到177.28k J·mol-1,综合燃烧特性指数从4.919×10-8增大到5.705×10-8。探索船舶垃圾辅以混煤粉实现高效焚烧技术,以神木煤粉和不同煤粉粒径的福建无烟煤粉为对象,研究不同混烧比例下的混煤燃烧特性及反应动力学。结果表明:混煤燃烧特性相较于各组分煤发生了明显变化,混煤中高反应性煤的存在可以明显整体改善难燃煤的着火和燃烧情况。当难燃的福建无烟煤混入易燃的神木煤,挥发分初析温度降低了约260℃,着火温度下降了约240℃,燃尽温度降低了约40℃,综合燃烧特性指数上升一个数量级,表观活化能也显著降低。而且,难燃煤种福建无烟煤的粒径越小,对混煤燃烧特性改善的影响贡献越大。综合考虑难燃煤的着火燃烧改善效果、高反应性煤的燃料成本节约,选择难燃煤与优质煤以3:7比例组成的混煤为佳。采用ANSYS CFX数值模拟了船用垃圾焚烧炉以煤粉助燃时的温度场、辐射强度场、浓度场等。模拟发现:当船用焚烧炉用煤粉助燃,其炉膛内部主气相区温度几乎都在1000K~1400 K高温之间,炉内辐射强度也处于较高水平,有利于船舶垃圾中可燃成分的充分燃烧,提高船舶垃圾的焚烧效率,且能够有效预防二恶英类污染物的生成。
[Abstract]:This paper describes the mechanism of MSW incineration, the main influencing factors of MSW incineration, the analysis methods and theories of combustion characteristics and reaction kinetics, and the main combustible components of MSW, such as kitchen waste, waste paper, bamboo, wood, fabric, rubber, plastics, sludge, etc.Industrial analysis, elemental analysis, calorific value detection, thermal analysis and so on are carried out to study the thermal dynamic properties of ship refuse incineration.Marine garbage has the characteristics of high moisture content, high volatile content, low calorific value and low ash content. In order to reduce the drying time of garbage and ensure the steady combustion of garbage, it is necessary to incinerate marine garbage with external fuel.The combustion characteristics and reaction kinetics of pulverized coal before and after superfine were studied.The results show that the particle size distribution is more uniform, the pore volume and specific surface area increase, and the ignition temperature decreases with the decrease of pulverized coal particle size, and the trend is linear.The effect of pulverized coal superfine on improving the combustion characteristics of Fujian anthracite is more remarkable. Taking typical anthracite from Longtan Forest, Fujian Province as an example, when the average particle size of pulverized coal decreases from 53.488 渭 m to 13.716 渭 m, the ignition temperature decreases from 673.17 鈩，

本文编号：1726908