采用激光技术对燃烧器进行校正的试验研究

一些采用切圆燃烧方式的电厂,使用燃烧器测试、调整方法存在不足,在工程上应用不便。文章提出煤粉燃烧新的切圆概念,采用自动激光测量技术,结合燃烧器的实际结构,通过大量锅炉检修的实践,总结出一套实用的燃烧器校正测量技术,对锅炉燃烧器的安装、检修、调试、改造具有重要作用。     

锅炉燃烧切圆反转的数值模拟分析及处理

某发电机组的1 025 t/h锅炉在实际运行中燃烧切圆旋转方向与设计方向相反.通过对燃烧器内的流动过程进行数值模拟分析,并对炉内空气动力场进行动量平衡计算,认为其主要原因是炉膛中心的动量矩与切圆的设计旋转方向相反.对此,经运行调整各次风压,恢复了切圆转向,并将原扭转隔板式WR燃烧器改造为带百叶窗式浓缩器的浓淡风煤粉燃烧器后,锅炉燃烧稳定.     

六角切圆锅炉低氮燃烧器改造前后燃烧特性的数值研究

为了研究褐煤燃烧六角切圆锅炉的燃烧稳定性问题,采用数值模拟技术对六角切圆锅炉低氮燃烧器改造前后的燃烧特性进行了计算,分析了改造前后炉内温度场、CO浓度以及燃尽风对整个炉内温度场的影响,并对燃烧器改造后炉内燃烧过程进行了试验。试验结果表明,低氮燃烧器改造后炉内温度场比改造前有了很大的改善,炉膛整个充满度较好,燃尽风的加入减少了炉膛出口飞灰可燃物,对煤粉的燃尽起了积极地作用,提高了燃烧效率和锅炉效率,但CO浓度有所增大。     

新型直流煤粉燃烧器改造问题探讨

针对安阳电厂新型煤粉燃烧器改造后的效果，从锅炉燃烧效率下降，新型煤粉燃烧器选型，全厂经济效益，切圆燃烧，乏气风影响，节油稳燃等诸多问题进行讨论，并对燃烧器布置和切圆燃烧方式提出一些独特观点和建设性的改进建议。     

无烟煤和劣质烟煤分层燃烧炉内空气动力场研究

介绍在四角切圆锅炉上采取两种不同结构参数的燃烧器对其原燃烧器系统进行改造,实现下两层半燃烧器燃烧无烟煤和上两层半燃烧器燃烧劣质烟煤分层燃烧运行方式,以及改造后的冷态调试和炉内空气动力场试验研究结果。     

420t/h四角切圆燃烧锅炉燃烧器的改造

针对420t/h四角切圆燃烧锅炉运行中主汽温偏高,再热汽温偏低,燃烧工况不佳,煤种适应性较差,易发生结焦与超温,水冷壁管喷燃器区域存在严重的高温腐蚀等问题进行分析,特别是通过对燃烧器燃烧工况的分析,提出了对燃烧器进行改造,采用大小双切圆反切布置,将下层一次风喷嘴改成浓稀相燃烧器,低温再热器更换改造.改造后,锅炉燃烧工况得到改善,锅炉效率提高了1.36%,且不发生一次风喷嘴带火及结焦现象.     

PM浓淡燃烧器在400t／h锅炉上的应用

浓淡燃烧技术即煤粉高浓度燃烧技术，采用该技术能使锅炉煤质在较大范围内变化，提高锅炉调峰能力，降低ＸＯｘ排放量，保护环境，适合我国对现有直流燃烧器四角布置切圆燃烧方式锅炉的改造。文章介绍了浓淡燃烧技术在山东黄岛发电厂４００ｔ／ｈ炉上进行浓淡燃烧技术的改造与应用情况。     

四角布置旋流式燃烧器切圆燃烧方案论证

对直流式燃烧器采用四角切圆布置和旋流式燃烧器的燃烧方式进行了比较,并论证采用四角布置旋流式燃烧器切圆燃烧的可行性。     

2000t/h四墙切圆锅炉炉内空气动力场试验研究

通过模拟燃烧器热态设计工况,对一台660 MW超超临界锅炉PM型四墙布置切圆燃烧器进行了炉内冷态空气动力场试验研究。通过测量某一层燃烧器区域空气速度分布和衰减情况,研究了一次风速,一、二次风动量比和周界风风量等因素对四墙切圆燃烧方式下炉内空气动力场的影响规律。试验结果表明,四墙切圆燃烧器与四角切圆燃烧器有较大差别,冷态实际切圆形成主要取决于假想切圆直径,受一、二次风动量比和周界风量影响较小;降低了燃烧器向火侧火焰刷壁的可能性,更加有利于组织炉内燃烧,从而更好地控制炉膛出口热偏差、火焰中心高度和NOx排放量。     

锅炉水平烟道烟温差大的原因分析及处理

以珠江电厂 30 0 MW机组锅炉为例 ,分析了锅炉水平烟道温差大的原因是四角切圆燃烧锅炉燃烧器轴线呈切圆布置 ,燃烧过程中烟气在炉膛内旋转上升 ;提出了对上端部风和顶部燃层风进行反切改造的措施。     

煤粉燃烧器计算机辅助设计系统的研究

煤粉燃烧器作为燃烧系统的重要组成部分，直接影响锅炉炉内燃烧工况和燃烧效率，其选型和设计在整个锅炉设计中显得很重要．将计算机辅助设计(CAD)技术引入到煤粉燃烧器的设计中，阐述了燃烧器设计的基本思路，介绍了煤粉燃烧器的CAD过程，最后综合利用Visual basic5．0，AutoCAD，Origin6．1等软件开发了煤粉燃烧器可视化计算机辅助设计系统．利用该系统，使用者只需输入几个参数，系统便能自动完成从设计计算到出图的全过程．     

新型煤粉燃烧器的燃烧机理分析

分析了国内超临界和超超临界锅炉采用的几种新型煤粉燃烧器的燃烧机理。主要特点是采用多级配风技术灵活控制燃烧器出口的煤粉火焰燃烧过程;实现着火初期低氧燃烧和火焰内NOx还原技术;在旋流式燃烧器内采用煤粉浓缩技术和环形齿状稳燃器或直流过渡风,在喷口附近煤粉气流着火初期,加强热烟气回流和维持高温及低氧燃烧,促进挥发分析出过程中的NOx还原,并实现快速着火和低负荷稳定燃烧;在A-PM型直流式燃烧器上采用带扩压管的缩放型小喷口结构,增强稳燃能力和维持高温和低氧燃烧,促进NOx还原,并均衡火焰温度,降低水冷壁的热负荷;设置可调节燃尽风进一步提高炉内脱氮效果和提高燃烧效率等。     

LNB改造后燃烧器烧损及NOx 排放高原因分析

以某电厂为例,一期1、2号锅炉在低氮燃烧器（low-NOx burner,LNB）改造后,燃烧器设备先后出现烧损问题,且1号炉NOx排放较2号炉高约100 mg/m3,危及锅炉运行安全及脱硝设备正常投运。针对上述问题,从改造方案、设备制造及运行方式等方面分析了原因。发现：（1）2号炉改造设计没有考虑煤种变化,采用了常规稳燃措施,同时运行期间周界风开度小,导致燃烧器区域出现局部高温,燃烧器防磨陶瓷脱落引起煤粉堆积,并在一次风室内燃烧导致燃烧器烧损;（2）1号炉燃烧器制造过程中各喷口间空隙未按设计要求封堵,煤粉被负压回流带入燃烧器隔板堆积燃烧,导致燃烧器烧损。同时,喷口间隙未封堵造成燃烧器二次风漏风严重,降低了空气分级效果,导致NOx偏高。在原因分析的基础上,采取了相应改进措施。结果表明,改进措施有效解决了1、2号炉出现的问题,可为其他电厂类似问题的解决提供参考。     

高温空气点火在200 MW机组锅炉中的应用

高温空气点火技术用于煤粉锅炉的稳定燃烧和点火过程,有利于提高锅炉运行的经济性、安全性。文中针对某200 MW机组锅炉的实际要求,按1:1比例建造三级高温空气点火燃烧器实验台,进行数值模拟及实验研究,得到了煤粉浓度、一次风速度等运行参数与着火特性之间的关系。模拟结果与试验结果,趋势相同。将该燃烧器安装到实际锅炉上,进行锅炉的启动点火试验,点火成功,燃烧稳定。研究结果对此燃烧器的改进及进一步应用提供参考。     

新型煤粉燃烧器--PCSB燃烧器的研制及开发

用火焰传播理论对现有燃烧器在稳燃方面存在的问题进行了分析,根据NOx生成机理对挖掘燃烧器的低NOx潜力进行论证。提出PCSB燃烧器的新构思和设计,PCSB燃烧器是根据煤粉气流分步燃烧原理、火焰传播理论以及强制点火原理研制开发的理念新颖,结构简便的新型煤粉燃烧器,阐述其低NOx原理和稳燃原理,归纳了其性能和特点。结合煤种特性总结PCSB燃烧器的设计原则。PCSB系列燃烧器对各种煤具有很好的适应性,非常适宜我国火电厂切圆燃烧锅炉和墙式燃烧锅炉推广应用。     

Influence of the technique for injection of flue gas and the configuration of the swirl burner throat on combustion of gaseous fuel and formation of nitrogen oxides in the flame

How the points at which the flue gas was injected into the swirl burner and the design of the burner outlet influence the formation and development of the flame in the submerged space, as well as the formation of nitrogen oxides in the combustion products, have been studied. The object under numerical investigation is the flame of the GMVI combined (oil/gas) burner swirl burner fitted with a convergent, biconical, cylindrical, or divergent throat at the burner outlet with individual supply of the air and injection of the gaseous fuel through tubing. The burners of two designs were investigated; they differ by the absence or presence of an inlet for individual injection of the flue gas. A technique for numerical simulation of the flame based on the CFD methods widely used in research of this kind underlies the study. Based on the summarized results of the numerical simulation of the processes that occur in jet flows, the specific features of the aerodynamic pattern of the flame have been established. It is shown that the flame can be conventionally divided into several sections over its length in all investigations. The lengths of each of the sections, as well as the form of the fields of axial velocity, temperatures, concentrations of the fuel, oxygen, and carbon and nitrogen oxides, are different and determined by the design features of the burner, the flow rates of the agent, and the compositions of the latter in the burner ducts as well as the configuration of the burner throat and the temperature of the environment. To what degree the burner throat configuration and the techniques for injection of the flue gas at different ambient temperatures influence the formation of nitrogen oxides has been established. It is shown that the supply of the recirculation of flue gas into the fuel injection zone enables a considerable reduction in the formation of nitrogen oxides in the flame combustion products. It has been established that the locations of the zones of intensive fuel burnout and generation of nitrogen oxides do not coincide over the flame length, and the ambient temperature has a significant impact on the combustion stability at low values and on the concentration of nitrogen oxides in the combustion products at high values.     

荷兰IFRF低NO_x煤粉燃烧技术的试验研究

本文分析介绍了荷兰国际火焰研究基金会近年来关于低ＮＯｘ煤粉燃烧技术的开发设计与试验研究结果．包括燃烧器内部空气动力分级、燃烧器外部空气分级、带富燃烧预燃室的空气分级和燃烧器内部燃料分级等燃烧技术。     

Development of combined low-emissions burner devices for low-power boilers

Low-power water boilers are widely used for autonomous heat supply in various industries. Firetube and water-tube boilers of domestic and foreign manufacturers are widely represented on the Russian market. However, even Russian boilers are supplied with licensed foreign burner devices, which reduce their competitiveness and complicate operating conditions. A task of developing efficient domestic low-emissions burner devices for low-power boilers is quite acute. A characteristic property of ignition and fuel combustion in such boilers is their flowing in constrained conditions due to small dimensions of combustion chambers and flame tubes. These processes differ significantly from those in open combustion chambers of high-duty power boilers, and they have not been sufficiently studied yet. The goals of this paper are studying the processes of ignition and combustion of gaseous and liquid fuels, heat and mass transfer and NO _x emissions in constrained conditions, and the development of a modern combined low-emissions 2.2 MW burner device that provides efficient fuel combustion. A burner device computer model is developed and numerical studies of its operation on different types of fuel in a working load range from 40 to 100% of the nominal are carried out. The main features of ignition and combustion of gaseous and liquid fuels in constrained conditions of the flame tube at nominal and decreased loads are determined, which differ fundamentally from the similar processes in steam boiler furnaces. The influence of the burner devices design and operating conditions on the fuel underburning and NO _x formation is determined. Based on the results of the design studies, a design of the new combined low-emissions burner device is proposed, which has several advantages over the prototype.     

大型锅炉燃烧器技术改造

为了满足电厂燃煤机组调峰的需要和节约电厂燃油，降低发电成本、进一步提高锅炉运行的经济性、适应电网调峰的需求．对某厂1025t／h煤粉锅炉进行了燃烧系统改造。在改造中，将原有的上下采淡燃烧器改为水平浓淡燃烧器。运行结果表明，这一燃烧系统的改造使锅炉取得了很好的稳燃效果及经济性。