含油污泥在煤粉锅炉雾化喷燃的研究分析

为了高效低成本处理含油污泥,提出了含油污泥在煤粉锅炉雾化喷燃的工艺。重点介绍了采用雾化喷燃含油污泥的过程,揭示了含水率对于污泥特性影响,探讨了在不同含油污泥与煤混烧比条件下,锅炉效率和污染物排放的变化规律。结果发现污泥含水率越低,炉膛里面的能量损失越小。含水率为90%时,具有较优流动特性。掺烧污泥对燃煤锅炉效率影响较小,在最大污泥掺烧比条件下混合燃烧效率比煤粉单独燃烧时锅炉效率仅减小0.17%。掺烧处理每吨污泥耗煤0.14t。分析表明:处理某大型化工厂的3万t/a污泥的运行费用折合标准煤为4 248t。因此,污掺烧具有较好的环保经济效益。     

210 MW CFB燃烧石煤的可行性研究

为合理、高效综合利用石煤资源发电及灰渣提钒,在210 MW CFB(循环流化床)锅炉上进行石煤实炉试烧试验。结果表明:试验最大掺烧比例为石煤∶无烟煤=78∶22,对应入炉燃料热值在7.96~9.63 MJ/kg。锅炉能连续稳定运行,充分验证了利用CFB锅炉燃烧石煤燃料发电的可行性。试验分析了低热值石煤独有的燃烧特性,为工程项目设计建设提供了准确可靠的试验数据。     

循环流化床锅炉掺烧污泥的炉内燃烧数值模拟

针对不同种类污泥在锅炉内的燃烧分析可知,在循环流化床锅炉掺烧污泥生产以及深度脱硫运行过程中,炉内燃烧数值模拟装置一直是重要的组成部分,炉内燃烧数值模拟装置的正常深度脱硫运行对于循环流化床锅炉掺烧污泥的稳定发展具有重要的意义,因此对炉内燃烧数值模拟装置的深度脱硫运行控制以及深度脱硫技术改造应用是保障炉内燃烧数值模拟装置正常深度脱硫运行的重点。     

300 MW循环流化床锅炉大比例掺烧煤泥试验研究

循环流化床锅炉大比例掺烧煤泥是一种处理煤泥等低品质煤的有效手段。利用一维小室模型对掺混不同比例煤泥的CFB锅炉运行工况进行模拟,研究了掺混煤泥比例对CFB锅炉炉膛内物料平均粒径、颗粒停留时间以及炉膛上部物料浓度的影响,确定了大比例掺烧煤泥条件下的流态优化条件。模拟结果表明,增加煤泥比例可以提高物料循环流率和中间粒径档位(0.1~0.3 mm)颗粒在炉内的停留时间,改善燃料的燃尽率,提高煤泥比例还可以增加炉膛上部的颗粒浓度,有利于提高炉膛上部的传热,降低炉膛温度,便于污染物的控制。根据盘北电厂300 MW循环流化床锅炉机组大比例掺烧煤泥的运行数据,分析了掺烧煤泥比例对床温、排烟温度、底渣与飞灰含碳量的影响。当锅炉负荷为300 MW时,掺烧煤泥后床温明显降低,飞灰含碳量和排烟温度随着掺烧煤泥比例的增加而增大,底渣含碳量则随着掺烧煤泥比例的增加而降低。为了实现大比例掺烧,建议控制矸石的入炉煤粒径,且需要强化尾部吹灰或适当调整尾部受热面。     

电站煤粉锅炉掺烧兰炭试验研究

为考察兰炭在电站煤粉锅炉上的适应性,确定兰炭在煤粉锅炉上的掺烧比例和方式,在充分掌握兰炭燃料特性基础上,在国内首次进行了配中速磨制粉系统的电站煤粉锅炉掺烧兰炭试验。试验结果表明,电站锅炉燃用兰炭具有减轻燃烧器喷口结渣、大幅降低烟气污染物生成量、对低热值煤具有较好替代作用等优势,试验锅炉可以预混掺烧方式实现安全稳定燃用33%比例的兰炭。针对兰炭的强磨损、低燃尽特性对制粉系统以及锅炉安全经济运行可能产生的不利影响,提出了"预混+防磨+燃烧调整"的燃用兰炭原则。     

应用循环流化床锅炉掺烧城市污泥的技术探索

循环流化床锅炉掺烧城市污泥技术的运用,可以大大降低城市污泥对环境的影响。其污泥掺烧的可行性技术方案包含湿污泥直接入炉掺烧及湿污泥干化后掺烧两种。文章对这两种技术进行了对比分析,并针对某电厂使用的型号为SG-240/9.8-M257,上海锅炉厂生产的240t/h高压循环流化床锅炉,分析了湿污泥直接入炉掺烧系统的工艺流程,并根据掺烧污泥后的运行数据,分别分析了污泥掺烧对燃烧以及对氮氧化合物（NOx）排放等的影响。文章可以为同类型循环流化床锅炉掺烧城市污泥技术的运用提供有益的参考。     

循环流化床锅炉掺烧煤泥发电技术及其应用

煤泥掺烧发电是煤泥综合利用的最重要方式;循环流化床锅炉燃烧技术与高压管道输送技术成功解决了工业化燃用煤泥过程面临的难题。通过分析CFB机组煤泥掺烧关键环节,及其掺烧煤泥对机组运行工况的影响,并且对比了多台机组煤泥掺烧前后的经济性差异,证实CFB机组掺烧煤泥技术可行,经济效益好。     

污泥连续深度脱水与无害化处理实验

利用连续污泥深度脱水机开展了污泥连续深度脱水实验和锅炉掺烧实验,研究了污泥含水率的变化情况及在循环流化床锅炉中的燃烧情况。结果表明,连续污泥深度脱水机可将污泥含水率从90%降至60%,放置后可进一步降至54%;污泥按照原煤质量5%的比例进行掺混,能够在锅炉内稳定燃烧,实现了污泥无害化处理。     

小颗粒油页岩及半焦CFB锅炉燃烧适应性研究

油页岩经低温干馏可以得到页岩油,因生产工艺限制,干馏炉无法使用粒径12 mm以下的油页岩,同时会产生大量副产品(页岩半焦)。为提高副产品的利用能力,实现资源利用最大化。通过在1 MW_(th)CFB燃烧试验台对小颗粒页岩及页岩半焦进行试烧试验,研究小颗粒页岩及页岩半焦的理化特性、着火特性、燃尽特性、结焦特性。试验结果表明,控制床温在720~850℃内,由油页岩小颗粒和半焦掺混而成的设计燃料在试验台采用CFB方式能够稳定燃烧,试验各工况灰渣含碳量均低于1.81%,试验燃料较易燃尽。CFB锅炉适合油页岩小颗粒与半焦掺烧利用,且燃烧效率高,燃烧稳定性较好。     

煤与污泥混燃及污染物逸出特性

污泥与煤以一定比例掺烧,有望提高其综合燃烧性,促进污泥的减量化、无害化处理处置及资源化利用。前人对污泥与煤的燃烧及掺烧特性进行了大量的研究,但对燃料中N、S的赋存形态及其对污染物释放的影响,以及污染物在掺烧交互作用中的减排机制尚不清楚。利用热重傅里叶红外联用技术研究了市政污泥与徐州烟煤掺烧综合燃烧性能、交互作用及动力学特性,重点讨论了燃料中N、S赋存形态以及热转化规律。结果表明：污泥与煤掺烧在300～750℃存在显著交互作用,并有利于提高其燃烧性能,随着污泥比例增加,混合样着火温度和燃尽温度逐渐降低。动力学结果表明,掺烧活化能介于两单样之间,掺烧少量污泥的反应机理与煤接近。污泥中N主要以吡咯氮(90.58%)和季氮(9.42%)形式存在,其分解导致大量NH₃及HCN释放;而烟煤中主要以吡咯氮(N-5)的形式存在,其分解主要以NO和HCN逸出;污泥与煤掺烧过程中氮化物排放强度均低于两单样。污泥中S主要为砜硫和非芳香硫类有机硫化合物,其在400℃前分解并释放大量SO₂。而烟煤中S元素主要以硫酸盐(66.24%)、硫铁矿(21.97%)和噻吩硫(1...     

内蒙乌海煤矸石循环流化床燃烧试验研究

针对设计煤、校核煤及石灰石在1MWth循环流化床燃烧(CFBC)试验台上的燃烧试验研究结果进行分析总结。取得了内蒙乌海煤矸石采用CFB燃烧方式时的大量重要的技术数据,可为京煤集团有限责任公司的CFB锅炉设计和锅炉岛系统设计提供基础数据和设计依据。     

Designing of primary air nozzles for large-scale CFB boilers in a combined numerical-experimental approach

The article presents a numerical-experimental approach for designing the primary air nozzles working with a large-scale Circulating Fluidized Bed (CFB) boiler. An analysis of the criteria that must be satisfied by CFB air grids has been made and it has been demonstrated that the existing correlations which are used in designing air grids are not possible to be utilized for determining the optimal nozzle design. On the example of a prototype nozzle design, based on the proposed design algorithm, the results of both numerical simulations and laboratory tests, whose aim was to determine the optimal geometry of a nozzle operating with a 235 MW_e asymmetric-design CFB boiler, are presented.     

水冷异型分离循环流化床燃烧技术

根据物料平衡理论分析了循环流化床锅炉分离器的选取原则,对各种分离器锅炉运行结果的测试认为分离器性能是影响燃烧效率的一个重要原因,但不能解决燃烧效率的全部问题,对循环流化床燃烧技术发展历史的回顾,认为冷却式分离 中国循环环床的发展方向。低成本的方形分离器在７５ｔ／ｈ等级的成功研制和运行的良好性能为该炉型的大型化提供了依据,目前在国家有关部门的支持下,１３０ｔ／ｈ和２２０ｔ／ｈ的设计工作已经基本完成４     

Flow structure and combustion characteristic of 65 t/h oil shale-fired circulating fluidized bed riser—2: Dilute phase

In this paper, a 65 t/h oil shale-fired circulating fluidized bed (CFB) boiler was put into commercial operation in Huadian of China in 1996 and industrial hot experiment was done for studying the flow structure and combustion characteristic of CFB dilute phase regime. Flow structure and solid flux of dilute phase regime were investigated along both vertical direction and horizontal direction under different boiler loads. Particle-size distribution and carbon content of oil shale combustion residues were obtained. Experimental investigation shows that SO₂ concentration decreases with increasing the furnace height, and NO_X emission can be reduced by adopting staged combustion technology, low-temperature combustion and circulating combustion. Experimental results are valuable for adjusting the 65 t/h boiler and designing large-scale oil shale-fired CFB boiler. At the same time, the experiment lays a foundation for modeling the flow structure, combustion, heat transfer and abrasion of oil shale-fired CFB dilute phase regime.     

Regulating characteristics of loop seal in a 65 t/h oil shale-fired circulating fluidized bed boiler

In this paper, an industrial cold experiment was conducted for studying regulating characteristics of a loop seal in a 65 t/h oil shale-fired circulating fluidized bed (CFB) boiler. The starting characteristic of the loop seal, and the effect of the supplying air and the fluidizing air in the loop seal were investigated. Compared with other regulating modes, the combined regulating mode of keeping the fluidizing air rate constant and regulating the supplying air rate can make the loop seal obtain better regulating quality, and offer more reliable guarantee for steady operation of the CFB boiler as well. In order to prevent circulating material depositing and slagging at the bottom of the loop seal, it was suggested that the fluidizing air rate and the supplying air rate is 2-3 and 1.2-1.5 times of the minimum fluidizing velocity of circulating material, respectively. These experimental results may be used as a reference for regulating the loop seal of the 65 t/h CFB boiler in hot condition and designing a new loop seal.     

600MW超临界CFB锅炉耐火材料应用探索

根据四川白马电厂600 MW超临界循环流化床锅炉运行情况,结合循环流化床锅炉循环系统中炉膛、回料器、外置床、灰控阀等重要设备工况特点,分析了各部位耐火材料作用行为和特性要求。运行6年的实践证明:大型循环流化床CFB锅炉设备合理选择耐火材料,可有效解决金属受热面磨损造成爆管,克服金属材料高温变形、耐磨性能差、不耐高温等问题,保证了机组安全稳定运行。大型循环流化床CFB锅炉对耐火材料的性能提出了更高要求,有待进一步分析和研究耐火材料在超临界CFB锅炉中的应用,提高机组耐磨性能和运行稳定性。     

Firing of coal and biomass and their mixtures in 50 kW and 12 MW circulating fluidized beds - Phenomenon study and comparison of scales

The combustion dynamics of coal, wood chips and their mixture is investigated. Load change capability and the effect of the individual control variables, for example the mixture ratio of different fuels, on pilot-scale CFB boiler dynamics were also studied.Disturbances in fuel feeding cause fluctuations in the flue gas concentrations. Changes in the heating value are possible due to varying moisture content of the fuel. Both these disturbances affect the instantaneous firing rate in a boiler. Also the characteristics of the fuels have to be taken into consideration when designing boiler control systems. When co-firing two fuels with clearly distinct combustion characteristics, direct assumptions based on each fuel’s characteristics cannot be made about combustion behaviour of their mixture.Combustion experiments with coal and wood chips and their co-firing were carried out in a pilot-scale CFB reactor (VTT) and a large-scale CFB boiler (Chalmers). A comparison of the combustion in the two different size reactors, provides information about scaling. The combustion responses due to changes in the fuel feeding of the two circulating fluidized beds are analyzed by a dynamic model.     

Pilot Development of Polygeneration Process of Circulating Fluidized Bed Combustion combined with Coal Pyrolysis

A pilot polygeneration process of a 75 t h^–1 circulating fluidized bed (CFB) boiler combined with a moving bed coal pyrolyzer was developed based on laboratory‐scale experimental results. The process operation showed good consistency and integration between boiler and pyrolyzer. Some critical operating parameters such as hot ash split flow from the CFB boiler to the pyrolyzer, mixing of hot ash and coal particles, control of pyrolysis temperature and solid inventory in the pyrolyzer, and pyrolysis gas clean‐up were investigated. Yields of 6.0 wt‐% tar and 8.0 wt‐% gas with a heating value of about 26 MJ m^–3 at 600 °C were obtained. Particulate content in tar was restrained less than 4.0 wt‐% by using a granular filter of the moving bed. Operation results showed that this pilot polygeneration process was successfully scaled up.     

循环流化床锅炉SO_2超低排放技术研究

针对循环流化床锅炉污染物生成量较低的特点,分析了锅炉SO_2生成量的影响因素,不同脱硫工艺的优缺点,结合试验研究结果和工程应用实例提出了循环流化床锅炉实现SO_2超低排放的技术。结果表明:循环流化床锅炉SO_2生成量取决于煤的硫分中可燃硫所占比例、煤灰中CaO等碱金属氧化物含量和锅炉运行参数,运行参数中床温影响最大;通过优化锅炉运行参数降低SO_2生成量,炉内干法高效脱硫和烟气脱硫相结合的深度脱硫技术可以实现SO_2超低排放的目标,并具有更高的调节灵活性和运行可靠性;烟气脱硫工艺的选取上,CFB-FGD半干法脱硫工艺相对于石灰石-石膏湿法脱硫工艺更具有经济优势。     

循环流化床锅炉临界流化风量确定及影响因素

循环流化床锅炉的临界流化风量是锅炉设计、运行的重要参数,结合YG240—3．82／450型循环流化床锅炉临界流化风量的测试,笔者提出了临界流化风量的测试方法,同时对影响循环流化床锅炉临界流化风量参数的重要因素进行了讨论。