循环流化床锅炉内气固两相流动特性的实验与数值研究

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1、中国石油大学（华东）博士学位论文循环流化床锅炉内气固两相流动特性的实验与数值研究姓名：姬广勤申请学位级别：博士专业：机械设计及理论指导教师：金有海20090301了入口面积比K。、排气管直径比d，、排尘口直径比d，、入口速度矿和温度7-等结构参数和操作条件对气相流场的影响规律，为旋风分离器的结构优化提供了参考依据。最后，在气相流场模拟的基础上，引入颗粒随机轨道模型，计算了颗粒的运动轨迹。结果表明，分离器内颗粒的运动情况非常复杂，并且带有很大的随机性。对于细小颗粒，上行流夹带是影响效率的主要因素，其次是短路流和排尘口返混；对于粒径较大的颗粒，影响效率的主要因素是顶狄

2、环和排气管短路流。以上研究结果对于循环流化床锅炉及旋风分离器的工程应用具有一定的参考价值。关键词：循环流化床锅炉，旋风分离器，气固两相流，流动特性ExperimentalandNumericalStudiesontheGas—SolidTwoPhaseFlowinCFBBoilerJiGuangqin(MechanicalDesignandTheory)DirectedbyProf．JinYouhaiAbstractWater—coal—slurryFluidization—suspensioncombustionboilercombineswater．coal．

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4、esspollutionadvantage．Thegas—solidflowisverytypicalandcomplexintheCFBB．Theresearchonthecharacterofthegas-solidflowisgreatlynecessaryandoneofimportantaspectforthedevelopmentoftheCFBcombustiontechnology．Experimentalmeasurementandnumericalsimulationofthegas-solidflowcharacterinCFBBwerepe

5、rformedonthecoldscalemodelofcommercialstyle，Theresearchresultsshowthattheparticleconcentrationdistributionpresentsacore—annularflowframewherethesolidiSdenserintheannularregionthancoreregionandtheparticleaxialvelocityshowstheinternalcirculationpattemthattheparticlemovementisupwardinthe

6、corezoneanddownintheannuluszone．Inaddition，underdifferentoperatingcondition，particlevolumefractiondistributioniSaffectedprominentlyatthelower．middlezonealongtheaxialdirectionandatthewallareaalongtheradialdirection．Furthermore，theeffectofoperatingconditionontheparticlevelocityreflectst

7、hatthechangingofupwardparticlevelocityatthecoreareaismoreobviousthanatthewallarea．Thegas．solidflowpatternatthewallareaneedsfurtherinvestigation．Theflowcharacterofdifferentsizeparticleisdiverse，andthelargertheparticlesize，themoreparticlevolumefractionatthelowerzoneinthefurnace．Theeffec

8、tofdi