混合垃圾燃烧特性的实验研究

针对我国目前垃圾焚烧以烧原生垃圾为主的特点，以热重分析和流化床燃烧实验台为主要研究手段，对于混合垃圾的燃烧特性展开深入研究并将二者的试验数据进行了对比。认为：混合垃圾在热重分析仪中的燃烧特性可以用单组分物质的叠加来表示，而混合的垃圾在流化床中燃烧时，用简单的单组分叠加来表示不很合理。图3表5参5     

循环流化床中垃圾的运动特性实验研究

以城市固体废弃物中可燃成分的主要代表物 ,塑料、纸张、铝箔片等为例 ,在 1个 2 5 0mm× 2 5 0mm× 2 40 0mm的循环流化床冷态实验台上对于垃圾的运动规律进行实验研究。实验结果表明 :垃圾中这些轻质物料在流化床中的运动很不规则 ,这些轻质物料一般要在床内上下运动多次直至进入旋风分离器 ,因此在床中的停留时间较长。循环流化床中固体颗粒浓度分布呈现明显的环核结构 ,即在中心区域物料浓度偏低 ,而在靠近壁面区域物料浓度较高。当在床内加入少量上述垃圾组分代表物时 ,床层空隙率以及床层压降变化不明显     

城市垃圾典型组分流化床燃烧特性的试验研究

在电加热流化床炉中研究了典型垃圾可着火组分挥发份析出及焦炭燃烧特性，并考察了水份、床温等因素对燃烧的影响，同时还研究了垃圾中高水份组分的焚烧特点。研究表明：聚合物类份的析出可加速焦碳的燃烧；生物质类废弃物焦碳的表观燃烧速率随直径的增大而减小；高水份组分焚烧时间与等效表面积-体积直径成正比。研究结果可为了解垃圾焚烧特性提供基础数据。图11表l参7     

城市固体废弃物的燃烧特性实验研究

通过热分析技术,对城市固体废弃物中几种典型组分进行实验研究,得到了混事垃圾在热重分析仪中的燃烧特性,并对城市固体废弃物的规律开展了有益的探讨。     

糠醛渣在流化床中燃烧特性的试验研究

介绍了糠醛渣生物质燃料的工业分析,临界流化程度,着火温度,与煤掺烧时的烧结特性,灰成分分析以及热天平分析,重点研究了糠醛渣燃烧后灰成分析及热重分析,解释了没有烧结的根本原因在于,糠醛渣燃烧后形成的灰中,钾盐主要以硫酸盐物质存在,熔点较高所致,试验发现,糠醛渣中氯含量较高,燃烧后灰中氯含量很低,说明主要以HCl气体析出,同时糖醛渣中含有呋喃甲醛,当然烧不充分时将会产生多氯二苯并呋喃（PCDFs－二恶英）,提出合理的燃烧温度及停留时间,试验结果为设计流化床糠醛渣锅炉奠定了基础。     

混合垃圾在热重分析仪中的燃烧特性分析

通过热分析技术,对城市固体废弃物中几种典型组分进行实验研究,得到了混合垃圾在热重分析仪中的燃烧特性,并对城市固体废弃物的混烧规律开展了有益的探讨。     

混合垃圾在热重分析仪中的燃烧特性分析

通过热分析技术对城市固体废弃物中几种典型组分进行了实验研究,得到了混合垃圾在热重分析仪中的燃烧特性,同时探讨了城市固体废弃物的混烧规律。     

小型流化床燃烧特性测试装置的初步实验

通过小型流化床燃烧特性测试装置的建立与初步实验研究结果,认为此实验装置设计新颖,功能完善,基本满足燃料燃烧特性研究的需求。并将煤在此实验装置与热重分析仪的实验结果进行类比分析。     

玉米秆在流化床中燃烧特性的初步研究

对玉米秆与弱酸性床料的混合流化特性进行了研究,结果表明,长度为20～50mm玉米秆与一定粒径分布的床料,当质量配比为1%,流化数N=3～6时,能较均匀地混合流化,但N>6后,混合的均匀度有所下降.根据热重试验结果可以看出玉米秆着火温度低,挥发份析出速度快,并容易燃尽.在0.2MWth流化床试验台上研究发现,当N>6时,玉米秆和床料分层严重,密相区温度在820℃以下,当N=3～6时,密相区温度能达到设计要求,说明冷态试验结果能够指导热态运行,玉米秆流化床燃烧时流化风速不能太大.经过24h热态试验后,床料没有出现烧结现象,利用XRF技术分析发现玉米秆灰中碱金属含量较高,高温对流受热面的沾灰可能性较大.     

棉秆在流化床中的燃烧特性

介绍了棉秆的物理、化学特性,30～50 mm棉秆和床料混合物的临界流化速度,以及棉秆热解、燃烧的热重试验结果,重点研究棉秆流化床燃烧时的温度分布,并利用ICP技术对灰组成进行了分析,得出棉秆流化床燃烧时碱金属的析出特性.分析表明,棉秆着火温度低,挥发分析出速度快,部分碱金属流化床燃烧时以挥发态析出,其中钾元素析出比例最大,飞灰中碱金属成分含量较高,对高温对流受热面的沾灰可能性很大.     

污泥在流化床中的焚烧特性研究

本文研究了高水分、低热值的污泥在流化床中的结团特性、着火特性。考察了床温、污泥水分、辅助燃料、给料粒径、流化风速对污泥结团的影响，比较了多种不同污泥的结团情况，并运用中间相理论对污泥结团机理作了初步分析。试验结果对于污泥流化床焚烧的基础理论和应用研究都有着重要意义。     

Hydrogen-rich syngas produced from co-gasification of municipal solid waste and wheat straw in an oxygen-enriched air fluidized bed

The gasification characteristics of solid waste and wheat straw were investigated in an oxygen-rich atmosphere by using a laboratory-scale continuous fluidized bed reactor in the range of oxidation equivalent (ER) of 0.2~0.5 and reaction temperature of 600 °C~900 °C. Gasification of biomass and waste is an economical method for hydrogen production. When air is used as a carrier gas to gasify municipal solid waste, increasing the oxygen concentration can effectively increase the hydrogen concentration of the syngas. The product distribution of gasification reaction under different mixing ratios and reaction parameters was obtained. As is shown in the results, first, when the ER is between 0.2 and 0.5, if ER decreases by 0.1, the hydrogen concentration of gas production will increase by about 30%; second, if the oxygen concentration increases by 5%, the hydrogen concentration of gas production will increase by about 14%, and the calorific value of gas production will increase by about 14–18%; third, after adding wheat straw in a ratio of 1:1, due to the reduction of plastics, the overall yield of syngas decreased, but the yield of hydrogen increased, and the concentration of hydrogen in syngas increased by 6.4%.     

Combustion of isolated bubbles in an elevated-temperature fluidized bed

Combustion of isolated bubbles was investigated with a laboratory-scale fluidized-bed reactor. Two different combinations of oxygen and argon were employed as the fluidizing gas. Single bubbles of methane were injected into an incipiently fluidized bed maintained at elevated temperatures. Gas composition inside the bubbles was measured using a suction probe connected to an on-line mass spectrometer, and the temperature of the bubbles was monitored using a fast-response thermocouple. The effects of bed particle type, particle size, bubble size, bed temperature, and oxygen concentration in the emulsion phase were examined for bed temperatures between 923 and 1203 K. A theoretical model of homogeneous combustion within the bubble phase was developed for comparison to the experimental results. The model accounted for the heat and mass transfer between bubble and emulsion phases, but only considered combustion within the bubble. The results indicated that small bubble size and high oxygen concentrations in the emulsion phase enhanced bubble-phase combustion. The bed temperature also proved to be an important parameter, with higher temperatures promoting bubble combustion, but unlike some other investigations, no critical ignition temperatures were observed in either experiments or model results. The fluidized bed's particle size and particle composition influence the heat and mass-transfer coefficients, and therefore the bubble-phase combustion, but these have a smaller influence than bed temperature and bubble size. Model results for bubble-phase gas composition and temperature compared favorably with the experimental measurements.     

桦甸油页岩的流化床燃烧特性

根据实验室研究结果和理论计算,介绍了桦甸油页岩的物理、化学特性以及桦甸油页岩在流化床内的着火、燃烧和燃烬等技术特征,为更大规模利用桦甸油页岩提供了基础。     

Evaluation of municipal wastes as secondary fuels through co-combustion with woody biomass in a fluidized bed reactor

Co-combustion of two municipal waste materials (food waste and bio-solids) with an agricultural residue was carried out in a fluid bed unit, for investigating the thermal exploitation of these wastes for energy production. The reactivity of the fuels was studied by thermogravimetric analysis, while temperature profiles, gaseous emissions and combustion efficiency were determined under different operating conditions of the fluid bed reactor. By blending municipal solid waste or sewage sludge with olive stone burnout was improved, nevertheless even at high percentages of these wastes in the mixture combustion efficiency was very good, ranging between 98.5 and 99.5%. A reduction in excess air from 50 to 30%, or an increase in fuel feeding, resulted in higher SO₂ and NO_x emissions. SO₂ levels from olive stone/municipal solid waste blends were negligible, while those of NO_x exceeded emission guidelines. To meet legislation without any extra measures, generally the share of municipal solid waste in the mixture should be up to 10%, reactor loading for all mixtures below 0.72 kg/h and excess air over 40%.     

造纸污泥流化床燃烧特性及燃烧过程数学模型

对造纸污泥在流化床中燃烧时的失重、粒径和密度变化、水分蒸发和挥发分的析出等过程进行了试验研究,提出了一种适用于高水分的多孔介质污泥并综合考虑传热传质过程的水分蒸发和挥发分析出数学模型,通过求解能量方程和组分守恒方程,用数学方法描述并预测了造纸污泥在流化床内的水分蒸发和挥发分析出过程,并将理论结果与试验结果进行对比,二者吻合较好。     

城市垃圾典型组分燃烧特性研究

本文首先分析了垃圾燃烧存在的问题,再介绍垃圾燃烧特性的热重分析原理和燃烧特性参数的确定方法.对十种工况的垃圾燃烧进行分析,通过试验得出各组分的TGA和DTGA曲线及其燃烧特征参数.经研究发现混合组分垃圾的燃烧过程具有分步性,其活化能低于单组分垃圾,比单一组分垃圾更易燃烧;混合垃圾的燃烧特性并没有发生显著变化,可以近似用...     

燃烧高水分低热值燃料的内旋流流化床燃烧技术研究

内旋流型流化床炉利用非均匀布风产生高温气－固两相旋流，使燃料在炉内运动、相互碰撞、干燥、破碎、燃烧，并可通过改变布风控制燃料加热与挥发份析出速率、燃烧温度与热负荷，适合多种高水分劣质煤及城市垃圾的洁净燃烧，是一种高效低污染流化床燃烧技术。本文研究该型燃烧器床内空气运动、燃烧、传热及排放规律，发展新型清洁燃烧技术。     

运行工况对基础燃料均质压燃燃烧过程影响的试验研究

在一台经改装的单缸直喷式柴油机上进行了不同辛烷值基础燃料下发动机转速对均质压燃（HCCI）燃烧特性、工况范围和排放特性影响的试验研究。研究结果表明：发动机转速升高,不同辛烷值燃料着火燃烧时刻推迟,以曲轴转角计算的燃烧持续期延长,高辛烷值燃料的缸内最大爆发压力和缸内温度降低;在中间转速,HCCI实现的最高平均指示压力最大,高转速工况,最高平均指示压力降低;对于低辛烷值燃料,转速对燃烧效率影响不大,转速升高,指示热效率增大;对于高辛烷值燃料,转速升高燃烧效率降低,指示热效率在中间转速最高,高转速降低。排放测试表明,转速升高使得HCCI运转的HC和CO排放都升高,NOx排放则逐渐降低。     

水冷布风板传热特性试验研究

在一床截面积为0.664×0.656m2的热态试验台上,对流化床锅炉床下点火过程中水冷布风板的传热特性进行试验研究。得到密相区温度、风室烟温和风室烟速与布风板传热系数之间的关系曲线。试验还表明,在点火过程中,水冷布风板主要吸收来自热烟气的热量。