中文摘要低料位操作下气固挡板流化床的压力脉动特性摘要：在一套有机玻璃流化床冷模实验装置上，以CRP-1催化裂解催化剂颗粒为内部固体介质，以常温空气作为流化介质，通过对气速的不断调节，初始装料高度（H）为450mm的操作条件下，内构件安装在静床高度上方的操作模式，分析床层内的压力脉动特性。结果表明：单构件床内平均压力随表观气速的增大将出现三个阶段：0.04≤Ug≤0.48m/s，平均压力随表观气速的增大缓慢增大；0.48≤Ug≤0.83m/s，平均压力随之快速增大；0.83≤Ug≤1.14m/s，平均压力随之几乎不变。随着轴向高度的增大，压力逐渐下降。随着床层高度的升高，压力脉动标准偏差整体呈下降趋势。在床层底端随着床层升高压力脉动标准偏差逐渐下降，在床层的中部，压力脉动标准偏差随床层高度变化不大，0.6m的床层以上，随着床层增高，压力脉动标准偏差迅速下降。随着床层高度的增大，该比值先增大后减小。当气速在0.04m/s≤Ug≤0.44m/s范围内时单构件流化床中的气固两相处于湍动流态化阶段。当0.44m/s≤Ug≤0.83m/s时，流化床内气固两相处于鼓泡-节涌过渡流态化，压力脉动功率谱密度曲线表现为单主频，并且主频密度值远大于其他频率所对应的密度值。当单构件床中气固两相处于鼓泡流态化阶段（Ug≥0.83m/s）时，主频功率与相邻频率的功率差别较鼓泡-节涌过渡流态化而言较小。毕业设计（论文）外文摘要TitlePressurepulsationcharacteristicsofgas-solidbafflefluidizedbedunderlowleveloperationAbstractInaplexiglassfluidizedbedLengMoexperimentdevice,catalyticcrackingcatalystswithCRP-1forinternalsolidmedium,withnormaltemperatureairasstreamingmedia,byconstantlyadjustthegasvelocity,theinitialloadingheight(H)conditionsfortheoperationofthe450mm,innercomponentinstallationoftheoperatingmodeonthetopofthestaticbedheight,pressurepulsationcharacteristicsanalysisofbed.Theresultsshowthat:theaveragepressureinthesingle-memberbedwillappearthreestageswiththeincreaseoftheapparentgasvelocity:0.04≤Ug≤0.48m/s,andtheaveragepressurewillslowlyincreasewiththeincreaseoftheapparentgasvelocity;0.48≤Ug≤0.83m/s,theaveragepressureincreasesrapidly;When0.83≤Ug≤1.14m/s,theaveragepressureisalmostconstant.Astheaxialheightincreases,thepressuredecreasesgradually.Asthebedheightincreases,thepressurepulsationstandarddeviationdecreasesasawhole.Atthebottomofthebed,thepressurepulsationstandarddeviationdecreasesgraduallyasthebedincreases.Inthemiddleofthebed,thepressurepulsationstandarddeviationchangeslittlewiththeheightofthebed.Abovethe0.6mbed,thepressurepulsationstandarddeviationdecreasesrapidlyasthebedincreases.Withtheincreaseofbedheight,theratiofirstincreasesandthendecreases.Whenthegasvelocityiswithintherangeof0.04m/s≤Ug≤0.44m/s,thegas-solidphaseinthefluidizedbedisinthephaseofturbulentfluidization.When0.44m/s≤Ug≤0.83m/s,thegas-solidtwophasesinthefluidizedbedareintransitionfluidizationfrombubblingtothrottling,andthepressurepulsationpowerspectrumdensitycurveshowsasingledominantfrequency,andthedominantfrequencydensityvalueismuchhigherthanthedensityvaluecorrespondingtootherfrequencies.Whenthegas-solidtwophasesinasingle-memberbedareinthebubblingfluidizationstage(Ug≥0.83m/s),thepowerdifferencebetweenthemainfrequencyandtheadjacentfrequencyissmallerthanthatbetweenthebubble-nodaltransientfluidization.Keywords:gas-solidtwo-phaseflow;flowcharacteristics;pressurepulsation;powerspectraldensities(PSD)目录1绪论.....................................................................................................................................-1-1.1研究背景.......................................................................
VIP
