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循环流化床锅炉长期处于低负荷运行时,床温偏低会导致燃烧效率降低、脱硫效率下降、石灰石消耗量增加。以某电厂2×150 MW机组的两台循环流化床锅炉为例,针对机组低负荷运行时床温偏低的现象,寻找合适的改造方法。结果表明:通过调整炉膛出口综合氧量、二次风配风方式、流化风量及床压、炉膛运行负压、入炉煤与石灰石的粒度,机组的低负荷运行参数得到明显改善。调整3个月后,低负荷运行的锅炉平均床温提高了52.1℃,低负荷平均床温能够有效控制在850℃;入炉煤硫分变化不大时,石灰石单耗下降18.9 g/kWh,飞灰、炉渣含碳量下降明显,综合供电煤耗下降3.3 g/kWh。 相似文献
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基于流态重构的循环流化床锅炉节能燃烧技术的应用实践 总被引:1,自引:0,他引:1
针对循环流化床锅炉辅机电耗普遍偏高的问题,先后在燃烧劣质无烟煤的135 MW机组和300MW机组循环流化床锅炉上进行了降低床料存量实现流态重构的燃烧试验,分析了基于流态重构的循环流化床锅炉节能燃烧技术对改善锅炉机组性能的影响.运行实践表明:流态重构后,循环流化床锅炉辅机电耗明显下降,在风机具备变频条件下电耗可降低更多;135 MW机组锅炉运行厂用电率从8.2%降低为6.9%,300MW机组锅炉厂用电率约为4.3%,锅炉主要受热面的磨损明显减轻,飞灰可燃物含量降低3%~5%. 相似文献
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从锅炉运行实际出发,结合高倍率循环流化床锅炉低床压运行的条件,指出了循环流化床锅炉低床压运行的优势和缺点,并提出了开发高倍率、低床压循环流化床锅炉产品的思路. 相似文献
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为满足锅炉岛污染物排放标准的要求,降低锅炉岛系统投资和运行成本,通过控制炉膛温度,减小床料粒径,优化床料质量,增大循环流率,扩充贫氧区,抑制NO、SO_2生成,提高局部CO浓度和CaO的固硫率,对流态重构循环流化床锅炉进行了超低排放优化设计。锅炉的实际运行试验结果表明,所开发的循环流化床锅炉烟气中NO_x、SO_x初始排放浓度小于或接近于锅炉岛超低排放值。 相似文献
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燃烧劣质无烟煤3OO MW循环流化床锅炉节能减排特性的研究 总被引:2,自引:0,他引:2
介绍了龙岩坑口电厂300 MW循环流化床(CFB)锅炉的结构特点、性能测试结果及烟气污染物排放情况,并结合实际运行数据探讨了该300 MW CFB锅炉的节能减排特性.运行实践表明:该300 MW CFB锅炉机组采用清华大学基于流态重构节能型CFB锅炉技术,并结合风机改造,实现了低床压长期稳定满负荷运行,且厂用电率可控制在4.5%左右,节能减排效果显著.同时,以较低的运行成本实现了烟气污染物的达标排放.该炉型的节能减排特性充分体现了大型CFB锅炉机组实现煤洁净燃烧的技术优势. 相似文献
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循环流化床锅炉燃烧优化控制方法,对整台机组进行协调控制的基础上,当机组投入协调控制方式后,以汽机调负荷,锅炉调压力,协调控制系统接受负荷指令;当汽机负荷变化较大时,对流化床锅炉耦合性强的负荷、主汽压、床温、床压等参数进行了解耦,整个系统保持在总的能量平衡的方式下调整,通过改变人炉的给煤量来改变炉膛内的残碳量,残碳量表征床料中未燃尽的燃料,这些燃料将用来快速响应电网负荷指令所需的能量; 相似文献
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介绍某公司75t/h循环流化床锅炉运行、检修中积累的经验。阐述锅炉在运行中床温应控制在880~960℃,防止受热管壁高温腐蚀和磨损;加强一次风量及料层压差控制;防止返料温度超过1000℃。在检修中全面检查和维修,以保证启动时各部位温度上升均匀。 相似文献
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循环流化床锅炉物料外循环异常的原因主要是煤种过多的偏离设计值,以及锅炉受热面的多次改造,导致整个炉膛温度场的改变,降低了物料的流化性,而排渣系统出力不足导致的长期高床压运行,加剧了炉膛的后燃现象,设计的先天不足及缺乏必要的温度监视手段,为外循环回路的低温结焦创造了条件,而针对性的技术改造和运行操作的标准化是解决问题的关键所在。 相似文献
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文章阐述了高低差速床锅炉的技术特点,对在设计运行中所遇到的诸如燃烧、热平衡、磨损、结焦等关键技术问题进行了探讨、对生物燃料在高低差速床锅炉的应用进行了介绍并提出了自己的观点. 相似文献
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在额定蒸发量为410t/h的循环流化床锅炉上进行以烟煤、石油焦混合物为燃料的锅炉热力性能试验,根据ASME锅炉性能规程计算了锅炉热效率,并对温度、汽水流量、气态污染物排放、灰渣含碳量等多个参数进行了测试,整理得到了一些规律性的结果。结果表明,锅炉以烟煤、石油焦为燃料,添加石灰石脱硫,采用尾部飞灰再循环,额定负荷下锅炉热效率可达92.8%;炉内密相区温度分布均匀;床温、分离器入口温度、排烟温度和排渣温度等各温度稳定;主蒸汽流量、给水流量、减温水流量等汽水流量波动小;气态污染物均可控制在较低水平。这对我国循环流化床锅炉燃用煤焦混合物的设计和运行工作有一定借鉴意义。 相似文献
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本文通过对登峰锅炉运行处DZL58-1.6/150/90-AⅡ锅炉两个采暖期的运行研究,通过实验得出了针对该炉型的二次风投入方案,并针对火床充满度对锅炉效率影响作了实验研究,得出了合理的火床长度,提出供热锅炉也必须重视燃料煤的掺混工作。基于炉前煤计量建立了供热量与耗煤量的动态考核系统,从技术和管理两个方面下功夫,使锅炉运行效率达到82%以上。 相似文献
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This paper presents results from an experimental study performed on a 13 kWth commercial domestic boiler using pellets as fuel. Four different types of pellets were used and, for each one, the boiler was tested as a function of its capacity and the fan regulation affecting excess air. Measurements were performed for boiler heat load, pellets consumption rate, flue-gas temperature and composition. Mass balances allowed the calculation of the flue-gas flow rate and associated heat losses. Losses from incomplete combustion have also been quantified. Under boiler steady-state conditions the flue-gas O2 concentration changes with boiler load and ventilation due to the regulation scheme of the boiler. Flue-gas CO shows a minimum for values of O2 in the flue-gases of about 13%. NOx emissions are independent of excess air for low values of nitrogen in the fuel whereas, for larger values, NOx emissions increase with the O2 present in the combustion products. The fractional conversion of the pellets nitrogen into NOx is in line with literature data. The boiler start-up was characterised by the temperature evolution inside and above the bed showing the propagation of combustion in the bed during about 10 min. During boiler start-up, a maximum in CO emissions was observed which is associated with the maximum combustion intensity, as typified by the flue-gas O2 concentration and temperature, regardless the pellets type. 相似文献
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This work concerns the first stage of combustion in a small, air-staged, wood-chip boiler because comprehensive experimental data on the release of wood-volatiles during thermal conversion of solid biomass on grates are necessary to provide reliable data for the validation and optimization of fuel bed models and gas phase combustion models. Despite this importance, data especially from small-scale boilers are rare. This work provides detailed information about the spatial distribution of gaseous species, water and tar above the fuel bed of a commercial boiler with a nominal heat output of 40 kW. Furthermore, the influence of the primary air ratio and the wood-chip moisture on the fuel gas composition and the quantity of fine particulate matter emissions were investigated. Fuel gas volume fractions were: 16.6% CO, 3.6% H2, 1.8% CH4, 6.3% CO2, 0.2% O2, 28.3% H2O, 43.2% N2 for wood-chips with a fuel water content of 12% and a primary air ratio of 0.25. The corresponding tar content and the lower calorific value amounted to 78 g m−3 at standard temperature and pressure (STP) and 5.14 MJ kg−1, respectively. The locally different concentration of species and temperature above the fuel layer resulted from the fuel bed movement. Strong gradients in species fraction were detected in direction of the fuel flow while species fraction gradients perpendicular to fuel bed movement were marginal. Particulate matter emissions of the investigated boiler were 7 mg m−3 (at STP and O2 volume fraction of 13% in the dry exhaust gas) with aforementioned testing conditions. 相似文献