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This study focuses on a CFD modelling of biomass-derived syngas co-firing with coal in an older mid-sized PC-fired boiler of type OP-230 with low-emission burners on the front wall. The simulations were performed to determine whether the boiler can be retrofitted for the fulfilment of the prospective environmental protection regulations relating to levels of NO_X emissions. The improvement of the air staging via the dual-fuel technique was based on the indirect co-firing technology. The impact of two arrangements of dedicated syngas nozzles(below and above the existing coal burners), two syngas compositions and two heat replacements(5% and 15%) on the course of thermal processes in a furnace was tested. The reductions in NO_X emissions were predicted relative to the baseline when only coal is combusted. The highest reduction of about 38% was achieved with the syngas nozzles below the existing coal burners and 15% heat replacement. This arrangement of nozzles offers the residence time sufficient to co-fire coal with waste derived syngas. A lower reduction in NO_X emissions was obtained with the nozzles above the burners as the enlargement of local fuel rich zone near syngas injection becomes significant for 15% heat replacement. Results provide for the decreasing impact of methane content along with the increase of syngas heat input. The avoided CO_2 emissions through the syngas indirect co-firing with coal in the boiler are linear function of heat replacements. 相似文献
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A 30 kW bench-scale rig of pulverized anthracite combustion preheated by a circulating fluidized bed(CFB)was developed.The CFB riser has a diameter of 90 mm and a height of 1,500 mm.The down-fired combustion chamber(DFCC)has a diameter of 260 mm and a height of 3,000 mm.Combustion experiments were carried out using pulverized anthracite with 6.74%volatile content.This low volatile coal is difficult to ignite and burn out.Therefore,it requires longer burnout time and higher combustion temperature,which results in larger NOX emis-sions.In the current study,important factors that influence the combustion characteristics and NOX emissions were investigated such as excess air ratio,air ratio in the reducing zone,and fuel residence time in the reducing zone.Pulverized anthracite can be quickly preheated up to 800℃in CFB when the primary air is 24% of theoretical air for combustion,and the temperature profile is uniform in DFCC.The combustion efficiency is 94.2%,which is competitive with other anthracite combustion technologies.When the excess air ratio ranges from 1.26 to 1.67,the coal-N conversion ratio is less than 32%and the NOX emission concentration is less than 371 mg/m 3(@6%O2).When the air ratio in the reducing zone is 0.12,the NOX concentration is 221 mg/m 3(@6%O2),and the coal-N conversion ratio is 21%,which is much lower than that of other boilers. 相似文献
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结焦对锅炉的经济安全运行有较大危害,通过对影响煤粉工业锅炉结焦原因的分析,结合运行实际,总结了锅炉系统完善设计的建议以及实际运行中预防结焦的措施,取得了较好的效果. 相似文献
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文章介绍了28t/h、40t/h燃蔗渣锅炉的设计思路、结构特点、汽水流程特点、冷热风管道系统,锅炉验收成功也标志着江联公司的设计制造技术及IS09001质量管理水平达到了较高的国际水准. 相似文献
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文章详细介绍了一种燃蜂窝型煤锅炉的现状及待改进的问题,针对型煤的燃烧速度慢、出力不足、不易大型化、燃型煤蒸汽锅炉的间歇用汽问题、型煤托盘及水冷炉梁的可靠性、低负荷运行时受热面的积灰及腐蚀、劣质型煤对锅炉运行的影响等问题做了分析并提出了改进措施,并介绍了型煤强化燃烧及蓄热式蒸汽锅炉两项新技术. 相似文献
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针对煤粉锅炉燃烧的稳定特性,从稳燃型煤粉燃烧器,煤粉浓度淡燃烧,二次风对一次风着火的影响以及炉内实际切圆等四个方面提出了稳定煤粉燃烧的措施,并介绍了这些措施在670t/h,420t/h和220t/h锅炉上应用的结果。 相似文献
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600MW亚临界锅炉褐煤燃烧系统设计与运行 总被引:1,自引:0,他引:1
本文通过对华能某电厂600MW亚临界燃煤机组风扇磨高水份褐煤燃烧系统的分析,结合燃烧调整和性能考核试验报告,介绍了燃煤发电机组的超临界风扇磨高水份褐煤燃烧系统设计,为今后的系统设计与运行提供了宝贵的经验。 相似文献
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The pSi-n(Si2)1−x
(ZnS)
x
(0 ≤ x ≤ 0.92) structure, on which thermovoltaic effect is observed, has been obtained by means of liquid-phase epitaxy from tin
solution-melt on plates of p-type technical silicon. This effect is explained by grain boundary defects and influence of ZnS impurities in a thin layer
adjacent to the p-n-junction. 相似文献
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《动力工程学报》2020,(1):8-13
针对某电厂660MW四角切圆燃煤锅炉左右两侧烟温偏差过大以及烟温偏差引起的过热器两侧吸热量偏差较大的问题,在实炉上进行了现场试验,研究单层分离燃尽风(SOFA)两侧角风门开度偏置和多层SOFA两侧角风门开度偏置对过热器两侧吸热量偏差和炉膛出口两侧烟温偏差的影响。结果表明:单独调整E层、D层和C层单层的SOFA两侧角风门开度偏置时,过热器两侧吸热量偏差变化很小,各层炉膛出口两侧烟温偏差的变化规律不一致;同时调整上三层SOFA两侧角风门开度偏置时,过热器两侧吸热量朝着A侧增大、B侧减小的方向变化,炉膛出口两侧烟温偏差随着SOFA两侧角风门开度偏置的增大而增大。 相似文献
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建立了循环流化床锅炉炉膛颗粒燃烧和脱硫反应模型。该模型考虑了炉膛下部为高颗粒浓度的密相区和上部为低颗粒浓度稀相区的特征,模拟计算给出了烟气温度,热流密度和各气体成分(O2,C2O,CO,H2O和S2O)的轴向分布,模拟计算结果的趋势是合理的。 相似文献
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