二次风对CFB锅炉NO_x排放的影响.docxVIP

文章编号：1005-6548（2014）06-0542-06中图分类号：TM621文献标志码：B学科分类号：47040DOI:10.13357/ki.jep.002412二次风对CFB锅炉NOx排放的影响吴剑恒1，2，何宏舟1，俞金树2（1.集美大学福建省能源清洁利用与开发重点实验室，福建厦门361021；2.福建省石狮热电有限责任公司，福建石狮362700）TheInfluenceonNOxEmissionofSecondary-airinCFBBoilerWUJian-heng1,2，HEHong-zhou1，YUJin-shu2（1.CleaningCombustionandEnergyUtilizationResearchCenterofFujianProvince,JimeiUniversity,Xiamen361021,China；2.FujianShishiHeatPowerCogenerationCo.，Ltd.,Shishi362700,China）好效果；（2）随着二次风率β的增加，NOx排放浓度明显下降，降低速率逐渐减小；保持二次风率β在40%～50%之间，NOx排放浓度较低；（3）随着上二次风率k的增加，NOx排放浓度呈现先明显下降再逐渐减小至平缓最后略微上升的趋势，表明燃烧福建无烟煤的中温分离CFB锅炉存在有一个最佳的上二次风率k，使NOx排放浓度最小；根据本试验结果，在过量空气系数λ=1.2、二次风率β=45%的情况下，最佳的上二次风率k在55%～65%之间。ABSTRACT：Industrialthermalexperimentswerecarriedoutonthecirculatingfluidizedbedboilerusingmediumtempera-tureseparation,inordertoaccuratelygraspandevaluatetheef-fectofsecondaryaironNOxemissionconcentrationfromtheearlylaunched75t/hcirculatingfluidizedbedboilerburningfu-jiananthracite.Theresultsshowthat,theNOxemissionconcen-trationincreasesobviouslywiththeincreaseofexcessaircoeffi-cient,usedasλ,While,theincreasingtrendbecomesslowdown.Whenkeepingtheairexcesscoefficientoftheexitofe-conomizerbetween1.15and1.25,goodeffectofthecontrolofflyashcarboncontentandNOxemissioncanbeobtained.Withtheincreaseofsecondaryairratio,usedasβ,NOxemissioncon-centrationdecreasesobviously,therategraduallyreducing.TheNOxemissionconcentrationislowerasthesecondaryairofbe-tween40%and50%.Withtheincreaseofuppersecondaryairratio,usedask,theNOxemissionconcentrationfirstlydecreasessignificantlyandthenreducesslightlytoaflat,atlastithasgen-tleupwardtrend,whichmeansthatthereisanoptimaluppersecondaryairratioforthecirculatingfluidizedbedboilerusingmediumtemperatureseparationandburningfujiananthracitetominimizetheNOxemissionconcentration.Inthecaseoftheex-cessaircoefficientof1.2andthesecondaryairratioof45%,thebestuppersecondaryairratioisbetween55%and65%.关键词：CFB锅炉；二次风；福建无烟煤；NO排放浓度；x二次风率；中温分离0引言低温流化燃烧、分级分段送风、物料反复循环是CFB锅炉的重要特点[1]，也是CFB锅炉能够高效低污染洁净燃烧的基础。为此，许多学者对二次风进行研究。LU[2]