油水两相流量测量研究及在三相流量测量中的应用

浙江大学博士学位论文

油水两相流量测量研究及在三相流量测量中的应用

姓名:马龙博申请学位级别:博士专业:控制科学与工程指导教师:张宏建

20061001

摘要摘要多相流广泛存在于石油、化工、冶金等生产过程的各个领域,其参数检测对于资源的合理开发、生产安全及工业过程控制都具有非常重要的意义,目前已成为国内外给予极大关注的前沿学科。由于多相流动是一个非常复杂的过程,致使其参数检测难度较大。流量是多相流中一个非常重要的参数,而且钡4量相当困难。本文对文丘里管测量油水两相流流量进行了研究,建立了基于差压法的两相流流量测量模型,如果与含水率计相结合,可以较好的实现油水两相流的流量测量:同时研究了Coriolis流量计在油水两相流流量测量中的应用,提出了基于SVM韵油水两褶流分相流量预测方法,实现了油水分相质量流量的预测;针对文丘里管和Coriolis测量油水两相流存在的问题,提出了文丘里管和Coriolis流量计相结合的双参数测量方法,并实现了油水两相流的流量测量;最后,在对油水两相流研究的基础上,设计完成了一种气液分离装置,实现了油气水三相流的流量测量。本文的主要工作及创新点如下:1.在考虑油水两相流密度分布不均对流量测量影响并对混合物密度进行修正的基础上,提出并建立了基于文丘里管两端差压和含水率的油水两柑流质量流量测量模型。对建立的流量测量模型,分别采用两种不同管径的文丘里管对油水两相流进行了实验研究。实验结果表明,该模型可以较好的测得混合物的总流量,在整个油水比范围内模型的流量测量误差受含水率变化影响较小。2.采用双U型Coriolis流量计对油水混合物韵总质量流量、分相质量流量和真实密度进行了测量研究。以双U型Coriolis流量计得到的油水混合物的质量流量和密度为基础,提出了基于SVM油水分相质量流量的直接预测方法,避开了直接对滑脱速度、持水率与含水率等之间复杂关系的研究,利用该方法对油水两相流进行了实验研究。实验结果表明,在含水率5%95%范围内,油水总质量流量测量误差在±1.5%以内;油水分相质量流量的测量相对误差在±8%以内。3.通过对文丘里管和Coriolis流量计测量油水两相流各自的优点和存在的问题分析,提出了文丘里管和Coriolis流量计相结合的双参数测量方法。同时,根据文丘里管流量测量需要,提出了基于SVM的油水两相流流型识别方法,给出了特征向量提取方法,并将其用于流型识别,较好的取得了分层流和分散流型识别结果。提出的双参数测量方法与利用SVM识别出的分散流型相结合,较好的实现了油水分散流分相质量流量的测量。4.按照部分分离测量的基本思想,设计了一种基于部分分离原理的气浙江大学博士学位论文液分离装置。在计算方法上,采用本文提出的基于文丘里管的质量流量模型对部分分离后的油水两相流进行了测量。经过对油气水三相流的实验证明,分离装置分离效果良好,气体总体积流量测量的均方根误差小于3%;油水两相总质量流量和分相质量流量的测量均方根误差均小于7.5%。关键词:多相流,流量,文丘里管,差压信号,Coriolis流量计II摘要ABSTRACTMultiphaseflowexistsinvariouskindsoffields,suchaspetroleum,importantchemistryandmetallurgy.AnditsparmneterTaeasurementplaysallroleinrcsourceexploration,productionsafetyandindustrialprocessgreatdealofattentionhasbeenpaid咄othiscontr01.赴afield,which蛔sbecomeflowisaleadingsubjectbothhomeandabroad.Sincemultiphasecomplexprocess,.itisquitedifficulttomeasureitspmameters,ofwhich:flowrateisthe-mostimportant’andprovesratherdifficulttomeasure.nlisthesisdealswithdevelopsaoil—waterflow,ratemeasurementusing儡,vetlt晡anddifferentialapressure-basedtwo-phaseflowmteme刮m北蜘唰畦model,whichdoesofawaterfractionterl证cjob厕ththeusestudiedin;device.Meanwhile,Coriolismeasurementandflowratemeter’isalsoatbeoil-watertwo-phaseflowrateSVM-based-single-phaseflowpredictionmethodisproposed,realizingthepredictionofsingle-ptmse.flowrates.ToovercomethedisadvantagesofbothventuriandCoriofisflow扛屺te培.adoubleparametermeasurcmentmethodisputforward,whichcombinesthemetersandsolvesthetwoproblemofoil-waterflowratemeasurement.Lastforbutnotleast,onthebasisofthestudyoftwo-phaseflow,adevicegastheseparationofandasandrealizestheflowmtemeasurementofthree-phaseliquidisdesignedoil,gasandflowwater.Muchoftheworkdoneandtheinitiativepointsarelistedasfollows:1.Consideringtheasymmetricdistributionofoil-waterwitlaffecttheflowratetwo-phaseflovl‘densitymeasurementandthedensitywillhavetoberevised,a011massflowratemeasurementmodelisdeveloped,,basedpressureofthediametersarethedifferentiaItwoendsofventuriandwaterfraction.Venturiswitlkdifferentflowusingthe‘flowappliedtotheoil-watermeasurementmodel.bywater,fractiontoExperimentsshowthismodel啪measurethetotalflowrateofthemix.wequiteinfluencedratio.wellandthemeasurementerrorofthemodelisonlyalittleextentwithintherangeofoil-waterboth2.m圮massflowratesoftheoil-watermixtla.eandthesinglephaseasdoubleUCoriolisflowobtained,adirectwellastherealdensitya∞studiedwiththeuseofang-'ter.Onthebasisofthell毗qSSflowratesanddensitySVM-basedpredictionmethodandisputforwardforsingle-phasemassflowrotemeasurement,avoidingthestudyofthecomplexrelationshipamongslipvelocity,waterhold-upwaterfraction,etc.Experimentalresultsshowthemassflowm浙江大学博士学位论文ratemeasurementerrorforthetwo。phasemixturecanbekeptwithin±1.5%andforsinglephaseswithin±8%withwaterfractionvaryingfrom5%-?95%.3.ThroughtheanalysisoftheadvantagesandandCoriolisflowdisMvanmgesofbothventurismeters,adoubleparametermeasurementmethodisputforwardwiththecombinationofthemboth.Meanwhile,accordingtotheandneedofventuris,aSVM—basedwater-oilflowpatternidentificationmethodisgiven,usedtoidentifyflowwithwhichcharacteristicvectorsCanbeobtainedpatterns,thusgivinggoodresultsofbothseparatedanddistributedflowpatternidentification.WiththecombinationofthedoubleparametermeasurementevenmethodandtheseparatedflowpatternobtainedthroughSVM,single-phasemassflowratemeasurementoftheoil.waterflowcanbedonebetter.gas-liquidmass4.Basedonthebasicthoughtofpartialseparatemeasurement,atheseparationdeviceisdesigned.Incalculationalflowratemeasurementbasedonmethods,theaforementionedtwo—phasemodelisadoptedtomeasureflow,whichisdifferentialpressure.Itisprovedwitllexperimentsoftheoil-gas-waterofthetotalvolumeflowratethree-phaseflow,theaveragesquarerooterrormeasurelnentofgasislessthan3%andthatvaluesofthemassflowratesofflowbothoil-watertwo-phaseKeywords:Multiphaseandsingephasesarelessthan7.5%.Flow,FlowRate,VenturiTube,DifferentialSignal,CorioilsFlowMeterIV




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