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1、第44卷第4期浙江大学学报(工学版)Vol.44No.42010年4月JournalofZhejiangUniversity(EngineeringScience)Apr.2010DOI:10.3785/j.issn.10082973X.2010.04.021裤衩型300MW循环流化床炉膛二次风数值模拟郑成航,程乐鸣,骆仲泱,王勤辉,施正伦,岑可法(浙江大学热能工程研究所,能源清洁利用国家重点实验室,浙江杭州310027)摘要:循环流化床锅炉中二次风主要提供燃烧所需氧气并控制NOx生成,但是随着炉膛的大型化发展
2、二次风作用减弱.采用Fluent6.2计算软件数值研究300MW循环流化床锅炉炉膛中二次风速度和风向对炉内颗粒速度和固体浓度的影响,分析炉内不同位置的颗粒速度和浓度的分布以及二次风穿透性规律.模拟结果表明,裤衩型循环流化床内中间的颗粒存在向下流动性,颗粒浓度在Z向截面上呈现不均匀分布,其形状类似是多个环核结构模型的结合.二次风显著提高炉膛上部颗粒浓度,能够优化炉内气体和颗粒流场分布,外侧二次风的穿透性好于内侧二次风的穿透性.模拟结果可以为大型循环流化床锅炉的设计和运行提供理论参考.关键词:循环流化床锅炉;二次风
3、;穿透性中图分类号:TK224文献标志码:A文章编号:10082973X(2010)0420743207Numericalsimulationoftheimpactofsecondaryairforapant2leg300MWcirculationfluidizedbedboilerZHENGCheng2hang,CHENGLe2ming,LUOZhong2yang,WANGQin2hui,SHIZheng2lun,CENKe2fa(InstituteforThermalPowerEngineering,Sta
4、teKeyLaboratoryofCleanEnergyUtilization,ZhejiangUniversity,Hangzhou310027,China)Abstract:SecondaryairplaysveryimportantroleincombustionforoxygensupplementandNOxcontrolinacirculationfluidizedbed(CFB)furnace.Howeverthedistributionofsecondaryairinthefurnacebeco
5、mesworseasthefurnaceisenlarged.Numericalsimulationwasperformedtostudytheimpactsofsecondaryairinthefurnaceofapant2leg300MWCFBboiler.TheflowfieldsofsolidsvelocityandconcentrationwerecomputedatdifferentsecondaryairinjectingvelocityanddirectionusingFluent6.2.The
6、distributionsofsolidsvelocityandconcentrationweregivenandanalyzedatdifferentlocationandcross2sectioninthefur2nace.Thepenetrabilityofsecondaryairwasalsoanalyzed.Thesimulationshowsthatthesolidsflowgoesdowninthemiddleofthefurnace,andthedistributionofsolidsconce
7、ntrationintheZcross2sectionisuneven,whichissimilartoacombinationofseveralcore2annularflows.Thesolidsconcentrationinthetopoffurnaceishigherwiththeone.Thesecondaryaircanoptimizethegasandsolidsflowfieldsinthefur2nace.Thepenetrationofoutboardsecondaryairinjectio
8、nisbetterthanthatoftheinboardone.Thesimu2lationresultscanbereferencedinthedesignandoperationforalargeCFBboiler.Keywords:circulationfluidizedbedboiler;secondaryair;penetrability循环流化床(circulationf