采用沉降炉实验系统研究了O2/CO2燃煤气氛下醋酸钙、醋酸调质石灰石和木醋调质石灰石再燃脱硝性能,探索了CO2浓度、温度、再燃比、氧浓度、停留时间、SO2、氨氮比等反应参数对再燃和先进再燃脱硝的影响。结果表明:O2/CO2气氛下,提高CO2浓度有助于有机钙再燃脱硝反应。有机钙再燃和先进再燃脱硝适宜工况参数:温度范围1 223~1 373 K、再燃比为14%~17%、再燃区入口氧浓度为3%左右、停留时间为0.8 s,氨氮比为0.75。典型工况条件下,有机钙基本再燃脱硝效率为62.0%~82.7%,先进再燃脱硝效率88.3%~95.6%。醋酸和木醋调质石灰石再燃和先进再燃脱硝性能略优于醋酸钙。O2/CO2气氛下有机钙再燃在最佳脱硫温度下不能获得最大脱硝效率,先进再燃可以明显改善脱硝性能。最佳反应条件下木醋调质石灰石先进再燃脱硫脱硝效率分别为73.2%和94.8%。

The performance of NO reduction by reburning with calcium acetate (CA), limestone modified by acetic acid (LMAA) and limestone modified by wood vinegar (LMWV) in simulated O2/CO2 coal combustion gas was investigated using a drop tube furnace. The effects of operating parameters on nitric oxide reduction were explored, including CO2 concentration, temperature, reburning fuel fraction, residence time, SO2 and [NH3]/[NO] molar ratio. The results show that the NO reduction efficiency increases with the rise of CO2 concentration in O2/CO2 combustion gas. The optimum operating parameters for basic reburning (BR)/advanced reburning (AR) with organic calcium obtained by the experiments include reburning zone temperature of 1 223~1 373 K, reburning fuel fraction of 14%~17%, O2 concentration of around 3% at reburning zone inlet, residence time of 0.8 second and [NH3]/[NO] molar ratio of 0.75. Under typical experimental conditions, the denitration rates are 62.0%~82.7%and 88.3%~95.6%, respectivel

为了缓解化石能源的不足,开发生物质清洁高效燃烧的利用方式,采用农业废弃物(稻壳、秸秆)和R90煤粉作为再燃燃料在恒温沉降炉上进行再燃脱硝试验。针对燃料种类、化学计量比(stoichiometric ratio)、停留时间、燃料粒度、再燃比等因素对再燃脱硝效率的影响进行了研究。结果表明:农业废弃物(秸秆、稻壳)的再燃脱硝能力明显高于煤粉,其中秸秆再燃脱硝效率最高,稻壳再燃脱硝效率中等,煤粉最低,不同的挥发分含量是造成农业废弃物(秸秆、稻壳)与煤粉再燃脱硝率差别的最主要原因。再燃脱硝率随再燃区化学计量比(SR2)的提高逐渐降低。SR2增加,燃料热解析出的还原组分被氧竞争性地消耗,导致NO还原反应弱化,再燃脱硝率降低。SR2对农业废弃物秸秆和稻壳再燃脱硝率影响明显强于煤粉,再燃比20%工况,SR2从0.8增加到0.9,秸秆再燃脱硝率减少了20.12%,稻壳减少20.07%,煤粉减少了8.38%。燃料粒度的改变将影响颗粒的升温过程,在相同条件下,较细的燃料颗粒能更快速释放出更多的挥发分,可以提供再燃还原NO所需的更多的还原物质,对提高再燃脱硝率是有利的。再燃停留时间增加,在富燃料条件下再燃燃料与NO的反应时间延长,有利于NO消减。采用农业废弃物秸秆、稻壳作为作为再燃燃料,合理的再燃停留时间在600 ms以内,明显低于煤粉。通过调整再燃比可以获得适合的再燃脱硝率,农业废弃物秸秆、稻壳的合理再燃比在15%~20%之间。

In order to develop clean and efficient utilization technologies of biomass to supplement insufficient fossil energy, the reduction of NO was studied in a drop tube furnace (DTF) using rice husk, straw, and pulverized coal as reburning fuels. The impacts of fuel type, stoichiometric ratio (SR), reburning reaction temperature, residence time in the reburning-zone, the ratio of fuel particle size and reburning fuel on NO removal efficiency were analyzed in this study. The results indicated that NO reduction efficiency of biomass fuels such as rice husk, straw and sawdust of pine were higher than that of pulverized coal. The NO removal efficiency of straw and sawdust of pine was the highest, but the efficiency of the pulverized coal was the lowest among these three fuels. The composition of volatile components in different fuels had major impacts on the efficiency. NO removal efficiency was decreased with SR increasing in reburning zone. As SR was increased, reducing components released d

从系统NOx还原效果,主燃区、再燃区和燃烬区内NOx的降解几方面对煤粉再燃在燃煤四角炉和一维试验台上的试验结果进行对照分析,给出了适合燃煤四角炉再燃评价的NOx还原率计算公式。通过比较认为,一维煤粉再燃试验结果与四角炉试验基本相符,但是,四角炉可以让工作人员更全面地了解锅炉烟气行程内NOx的降解情况。四角炉试验与一维试验的结果相互补充,为实际生产应用提供了有益的参考。

NOx reduction effect from the system, the main combustion zone, reburn zone and burnout zone NOx degradation of several aspects of the coal reburning test results in the four corners of the furnace and fired a one-dimensional test rig were compared, given suitable coal-fired furnace reburn corners evaluate NOx reduction rate calculation formula. By comparison believes that a one-dimensional coal reburning test result is basically consistent with the four corners of the furnace test, however, the four corners of the furnace can allow staff more comprehensive understanding of the boiler flue gas NOx degradation of the trip. Corners furnace test and one-dimensional test results complement each other to provide a useful reference for practical application.

燃煤的汞排放控制技术是个十分重要的环保课题。采用生物质炭作为再燃燃料，并掺混一定比例的尿素或者消石灰，在某锅炉主燃烧器上方喷入炉膛，研究生物质炭再燃技术对燃煤脱汞的影响。试验结果表明：掺混不同物料的生物质炭进行再燃时，能够抑制煤燃烧时汞向烟气中的迁徙能力，促使烟气中的元素态汞(Hg0)向氧化态汞(Hg2+)或颗粒态汞(HgP)转化，有效降低了尾部烟气中总汞含量，提高了除尘器内飞灰和炉渣中的汞含量；试验还发现掺混消石灰的生物质炭对元素态汞的氧化促进作用更强，降低烟气总汞含量的作用更明显。

Controlling technology of mercury emissions for a coal-fired boiler is an important issue for environmental protection. The biomass charcoal reburning technology was researched on the coal-fired mercury removal, and biomass charcoal was sprayed into the top of furnace from a certain distance and mixed with a certain proportion of urea or slaked lime. The experimental results show that: by reburning the biomass charcoal blended with different materials,the migration ability of the mercury in the flue gas with coal combustion can be suppressed, prompting the conversion of elemental mercury (Hg0) in the flue gas to oxidation state mercury (Hg2+) or particulate mercury (HgP), so as to reduce the total content of mercury in the flue gas and to improve the content of mercury in the fly ash and slag. The experiments also discovery that the biomass charcoal blended with slaked lime has a much stronger oxidation promoting effect to the elemental mercury, and the reduction of the total

论述了循环流化床锅炉的主要特点及运行原理，对该锅炉在运行过程中常见的水冷壁爆管、省煤器泄露及爆管、尾部烟道灰分再燃等现象进行了描述，并进行了原因分析，研究了各问题的防治措施，对循环流化床锅炉的推广应用具有重要意义。

This paper discussed the main characteristics and operation principle of circulating fluidized bed boiler,described the common water wall tube explosion,economizer leakage and tube explosion,tail flue ash reburning and other images in boiler running process,and made causes analysis,researched the prevention and control measures of all kinds of problems,had important significance for the popularization and applica-tion of circulating fluidized bed boiler.