炉排式垃圾焚烧炉的结渣特性研究

为了进一步掌握炉排式垃圾焚烧炉的结渣特性和形成机理,选取炉内典型渣块展开研究.通过XRD物相分析、扫描电镜和能谱分析研究炉内结渣特性,并通过化学热力学平衡反应计算与试验结果进行了比较.结果表明,CaO、Al2O3/MgO/ZnO、SiO2等反应生成的钙化合物形成的低熔点共熔物相的存在是灰渣形成的主要原因.渣块内 Si和Ca的分布趋势几乎是完全相同,Fe具有局部富集,Na和K对初始层的形成起主要作用.     

高温纳米陶瓷涂层在垃圾焚烧炉上的应用

为解决垃圾焚烧炉受热面发生的高温酸腐蚀、冲蚀磨损与沾污结渣等共性问题,提出采用喷涂高温纳米陶瓷材料进行防腐、防磨、防结渣处理。阐述了高温纳米陶瓷表面材料的性能指标和技术特点,以及喷涂施工工艺。该涂层在某垃圾焚烧炉中,经8 000 h现场服役后,涂层表面完好,检测结果表明该纳米陶瓷涂层对垃圾焚烧炉受热面具有优异的耐腐、抗磨和防结渣的作用。     

石灰石对流化床焚烧炉结焦结渣的抑制特性研究

研究有机浓缩废液焚烧过程中,石灰石添加剂对流化床焚烧炉结焦结渣的抑制作用.结果表明:加入石灰石添加剂,焚烧炉运行比较稳定、床层流化正常,渣样晶相组成主要为Na6Ca3Si6O18、(Na0.8-Ca0.1)2SiO4、Ca2SiO4等高熔点物相,渣样结构比较疏松;晶粒没有熔融衔接;说明加入石灰石能够很好地抑制焚烧炉的结焦结渣.     

硫铁硫颗粒在炉内运动数值模拟及对结渣的影响

以一台存在结渣的国产300MW机组的1025t/h锅炉为对象,采用数值模拟对其中硫铁矿和煤粉及其飞灰颗粒的运动进行数值计算,通过对两者在炉内的运动和水冷壁附近颗粒浓度的比较,探讨结渣产生的机理和原因,并对与结渣有关的含硫量、FeS2密度、硫铁矿颗粒尺寸分布、缩小切圆直径的影响进行了数值研究。     

循环流化床燃烧生物质的结渣问题研究

在0.2 MW循环流化床上进行实验,以棉杆为燃料,分别采用石英砂和高铝矾土颗粒作为床料,长时间稳定运行.对运行过程中的床料、结渣块取样进行XRF以及SEM分析,分析生物质循环流化床运行中产生结渣的原因.研究结果表明,床料和结渣块中富集了大量的碱金属,并且随着运行时间的延长,富集的含量越来越高.生物质灰中的碱金属和床料中的SiO2反应生成低共熔点的硅酸盐化合物是引起结渣的主要原因.     

硫铁矿在炉内结渣中所起作用的数值研究

以某台有结渣现象的国产300MW机组的1025t／h锅炉为对象,采用数值模拟对其中硫铁矿和煤粉及其飞灰颗粒的运动进行数值计算,通过对两者在炉内的运动和水冷壁附近颗粒浓度的比较,探讨结渣产生的机理和原因,并对与结渣有关的含硫量、FeS2密度、硫铁矿颗粒尺寸分布、缩小切圆直径的影响进行了数值研究。     

TiN对连铸保护渣黏度的影响

采用旋转黏度计并结合XRD分析系统研究了不同碱度条件下,TiN对连铸保护渣黏度的影响。结果表明TiN可以增加连铸保护渣的黏度。TiN加入量〈5％时,对连铸保护渣的黏度影响较小。随着CaO／SiO2的增大,添加10％TIN连铸保护渣的黏度先迅速减小而后有所增大。添加10％TIN,CaO／SiO2为0．3的连铸保护渣中仅存在TiN晶体。CaO／SiO2为1．5的连铸保护渣中出现钙钛矿（CaTiO3）、硅酸二钙（Ca2SiO4）、枪晶石（Ca4Si2O7F2）、霞石（NaAlSiO4）及TiN。     

ZST高温纳米陶瓷涂层技术应用于超超临界煤粉电站锅炉的影响研究

大型电站煤粉锅炉受热面高温区域沾污结渣和高温腐蚀等问题日益突出,影响了锅炉的运行安全与经济性。某1000MW超超临界锅炉应用ZST高温纳米陶瓷涂层技术后,锅炉高温受热面抗沾污结渣和防高温腐蚀能力明显提升,其中锅炉左右墙对应燃烧器区域水冷壁灰渣层厚度减少了50%以上,主力燃烧器喷口外延水冷壁挂渣情况明显减轻,同时屏式过热器和高温过热器底部无挂大渣问题,为安全生产提供了可靠的技术保障。     

1000MW塔式锅炉燃烧结渣定量评价的数值研究

以某1 000MW塔式锅炉为研究对象,模拟了炉内煤粉燃烧过程,获得了炉内速度场和温度场,梳理汇总了包含碰撞壁面的颗粒质量、壁面结渣概率和结渣增长率等参数的结渣评价模型,基于炉内的燃烧数值模拟结果,给出了炉内煤粉颗粒燃烧后碰撞壁面的质量、壁面结渣概率和结渣增长率,对塔式锅炉进行了较为细致的结渣评价。结果表明:该塔式锅炉结渣概率较大区域主要分布在燃烧器区域及其下游和分离燃尽风(SOFA)的下游区域;壁面的结渣增长率在10-12 m/s的量级范围;相比于额定工况,该塔式锅炉70%负荷工况下可能结渣的区域缩小,结渣增长率也降低。     

生物质与煤掺烧对锅炉结渣特性影响的实验研究

采用CAF digital imaging灰熔点测试仪和飞利浦分析仪器分别对稻草、木屑、谷壳等常见的生物质灰及其与煤掺烧后灰的熔融特性和灰成分进行了检测,通过软化温度DT,灰分的酸碱比(B/A)、硅铝比(SiO2/Al2O3)、硅比(G)、铁钙比(Fe2O3/CaO)等判别指数对单一生物质与煤掺烧的结渣特性进行了研究和分析.结果表明:稻草和谷壳与煤粉掺烧,灰熔点降低,引起结渣.但是掺烧木屑则不会出现灰熔点降低而导致结渣的问题.     

Innovative experimental study for slagging diagnosis based on vibration signal of the superheater tube panels in coal-fired boilers

Slagging on the exchanger surfaces in boiler in power plants is still a serious issue that reduces thermodynamic efficiency and threatens the operation of the generation unit. In this paper, an innovative slagging diagnosis method based on the analysis of vibration signal of the exchanger tube panels is proposed to monitor the slagging condition. We build a scaled-down tube panel according to the actual structure of the superheater panel in laboratory to study the relationship between vibration signal and varied slagging conditions and air speed. Root Mean Square (RMS) in time domain and wavelet packet decomposition in frequency domain are employed to extract the features from vibration signals and predict the slagging condition without shut-down in the future. It is found that RMS value of the tube panel signals decreases with the increase of slagging weight, especially at a low air speed. Relative signal energy in a certain frequency band will experience significant change after tube panel slagged. In order to verify the experimental result on the feature changes of the tube panel vibration signals with varied slagging conditions, we successfully demonstrate our laboratory result via analysis of vibration signals of a superheater tube panel in Banshan Power Generation (Hangzhou). It indicates that the vibration signals of tube segment between the header and furnace wall of the superheater panel can be collected and used for slagging diagnosis in a running pulverized coal boiler. Our study is promising for prediction of slagging and furtherly reduce the risk induced by slagging of exchanger panel in the boiler.     

浅谈二段式垃圾焚烧炉燃烧自动控制技术

讨论了生活垃圾焚烧炉燃烧自动控制技术的原理,并以二段式垃圾焚烧炉自动化控制的实例流程说明它的技术应用。通过合理的参数控制,生活垃圾焚烧炉燃烧自动控制能达到成本控制的要求与绿色环保的要求。然而在该自动控制技术的应用中可以看到它的流程依然需要大量的人工干涉,人们需要生活垃圾焚烧炉燃烧自动控制技术向更加智能化方面发展。     

A critical review of ash slagging mechanisms and viscosity measurement for low-rank coal and bio-slags

Gasification or combustion of coal and biomass is the most important form of power generation today. However, the use of coal/biomass at high temperatures has an inherent problem related to the ash generated. The formation of ash leads to a problematic phenomenon called slagging. Slagging is the accumulation of molten ash on the walls of the furnace, gasifier, or boiler and is detrimental as it reduces the heat transfer rate, and the combustion/gasification rate of unburnt carbon, causes mechanical failure, high-temperature corrosion and on occasions, superheater explosions. To improve the gasifier/combustor facility, it is very important to understand the key ash properties, slag characteristics, viscosity and critical viscosity temperature. This paper reviews the content, compositions, and melting characteristics of ashes in differently ranked coal and biomass, and discusses the formation mechanism, characteristics, and structure of slag. In particular, this paper focuses on low-rank coal and biomass that have been receiving increased attention recently. Besides, it reviews the available methodologies and formulae for slag viscosity measurement/prediction and summarizes the current limitations and potential applications. Moreover, it discusses the slagging behavior of different ranks of coal and biomass by examining the applicability of the current viscosity measurement methods to these fuels, and the viscosity prediction models and factors that affect the slag viscosity. This review shows that the existing viscosity models and slagging indices can only satisfactorily predict the viscosity and slagging propensity of high-rank coals but cannot predict the slagging propensity and slag viscosity of low-rank coal, and especially biomass ashes, even if they are limited to a particular composition only. Thus, there is a critical need for the development of an index, or a model or even a measurement method, which can predict/measure the slagging propensity and slag viscosity correctly for all low-rank coal and biomass ashes.     

应用计算机控制系统预防危险废物回转窑焚烧结渣的研究

危险废物回转窑焚烧处置工艺具有诸多优点,但是当危险废物焚烧产生的灰渣熔融温度较低时,窑内的高温气氛会将灰渣颗粒熔融成液相,导致回转窑的结渣。灰渣的熔融实验结果证明,灰渣的熔融温度比较低,变形温度仅有1000℃左右。化学组分对灰渣熔融温度的影响研究表明,SiO2、Al2O3、CaO和CaSO4都对灰渣的熔融温度起到了升高的作用。采用计算机控制系统对整个系统进行监测、控制和管理,控制回转窑的温度在略低于灰渣熔融温度的水平运行,或者对危险废物在焚烧前进行合理的预混配伍,都能起到较好的预防回转窑结渣的作用。     

城市垃圾焚烧炉的结构与炉衬用耐火材料

根据近年来世界各工业发达国家在城市垃圾处理方面进行的大量科学研究和技术开发工作所取得的成功经验，系统地介绍了目前用于处理城市垃圾和各种工业废弃物的焚烧炉和无焚烧残留物熔融炉的类型与其结构以及相应的炉衬用耐火材料。     

Investigation on ash deposition characteristics during Zhundong coal combustion

The reserves of Zhundong (ZD) coal in China are huge. However, the high content of Na and Ca induces serious slagging and fouling problems. In this study, the ZD coal was burned in a DTF (drop tube furnace), and the ashes collected at different gas temperature with non-cooling probe were analyzed to obtain the ash particle properties and their combination mode. The results showed that Na, Ca and Fe are the main elements leading to slagging when the gas temperature is about 1000 °C during ZD coal combustion, but their mechanisms are quite different. Some sodium silicates and aluminosilicates and calcium sulfate keep molten state in the ashes collected at 1000 °C. These molten ash particles may impact and adhere on the bare tube surface, and then solidified quickly. With the growth of slag thickness, the depositing surface temperature is increased. The molten ash particles might form a layer of molten film, which could capture the other high fusion temperature particles. The Fe₂O₃ sphere were captured by the formed molten slag and then they blended together to form a new molten slag with lower melting temperature.     

新型高温蓄热燃烧垃圾焚烧炉的创新设计

文章提出了一种以节能环保为目的并且适合中国垃圾处理的新型高温蓄热燃烧式垃圾焚烧炉[1-2],介绍了此种焚烧炉的工作原理及结构特点[3],最后通过热态测试结果证实了采用此种高温蓄热燃烧技术焚烧处理垃圾的有效性.     

开发生活垃圾焚烧炉势在必行

我国城市生活垃圾日益增多，目前广泛采用裸露班或填埋处理方法，暴露弊端甚多，堆肥处理的局限性也大，采用焚烧方法，开发焚烧炉处理生活垃圾已是势在和行。文中介绍了搞温热解，分段燃尽的自燃式垃圾连续焚烧炉是目前值得推广应用的一种新炉型。     

浅议我国垃圾焚烧发电的现状及发展趋势

垃圾处理和资源化利用已经成为成熟的产业,从全球特别是发达国家和地区的发展趋势来看,垃圾焚烧发电技术正在向大型化、高效化、清洁化方向发展.近年来我国垃圾焚烧发电产业得到了较快发展,政策法规日益健全,技术发展迅速,已投产的项目运行收益稳定,发展空间日益增大.焚烧炉是垃圾发电的核心,在国外,由于垃圾分类严格,因此以炉排炉为主:而在我国炉排炉、流化床焚烧炉两者并举,其余方式也有少量应用.烟气处理是垃圾发电系统的关键,它决定了垃圾发电的环境友好性和公众认可度,典型的烟气处理宜采用半干法加布袋除尘工艺.我国垃圾焚烧目前还存在一些问题,如世界各国普遍关注的二恶英的控制;出于垃圾分类不到位导致垃圾成分复杂,水分含量高,成分复杂的垃圾产生的污染物也更复杂,而含水量高易导致燃烧不充分及热量损失,进而导致更多污染和能量浪费.在工艺技术先进、设备仪器到位、运行管理严格等前提下,垃圾焚烧发电可以实现稳定运行、达标排效.我国垃圾发电产业刚刚起步,建议在示范运行的基础上严格监管、稳步推进,同时要做好规划选址和垃圾分类工作.     

生活垃圾焚烧炉的选型与设计

简述了我国生活垃圾焚烧炉的发展现状,对已有各种焚烧炉的技术现状进行了比较,以往复炉排工和链板炉排式焚烧炉为代表就炉型结构,设计计算、焚烧炉必须达到的各项指标进行了论述。