《传感器与检测基础》容积式流量计.pptx

传感器与检测基础FundamentalsofSensorsandDetection

FlowMeasurement流量测量05

Slide3信息与控制工程学院POsitiveDisplacementFlowmeter容积式Positivedisplacementmeters(sometimesreferredtoasdirectvolumetrictotalisers（加法器）)alloperateonthegeneralprinciplewheredefinedvolumesofthemediumareseparatedfromtheflowstreamandmovedfromtheinlettotheoutletindiscretepackages.Totalisingthenumberofpackagesprovidesthetotalvolumepassedandthetotalvolumepassedinagiventimeprovidestheflowrate,forexample,litres/min.Becausetheypassaknownquantity,theyareidealforcertainfluidbatch,blendingandcustodytransferapplications.Theygiveveryaccurateinformationandaregenerallyusedforproductionandaccountingpurposes.1.概述1.概述2.椭圆齿轮流量计3.腰轮流量计4.刮板流量计5.双转子流量计6.湿式气体流量计经测量元件将流体连续地分割成固定体积的单元流体，根据测量元件的动作次数得到总量。V0—固定体积；N—测量元件的转数；k—与流量计结构有关的系数。

Slide4信息与控制工程学院POsitiveDisplacementFlowmeter容积式1.概述PositivedisplacementflowmetershavebeenthetraditionalchoiceforresidentialandcommercialnaturalgasflowandwaterflowmeasurementintheUnitedStates(asimpleapplicationofcustodytransferflowmeasurement,wherethefluidbeingmeasuredisacommodityboughtandsold).Arotarygasflowmeterisshowninthefollowingphotograph.Notetheodometer-stylenumericaldisplayontheleft-handendofthemeter,totalizinggasusageovertime:

Slide5信息与控制工程学院POsitiveDisplacementFlowmeter容积式2.椭圆齿轮流量计（Ovalgearmeters）Ovalgearflowmeterscomprisetwoidenticalprecisionmoulded（铸造）ovalrotorswhichmesh(啮合)togetherbymeansofgearteetharoundthegearperimeter.TherotorsrotateonstationaryshaftswhicharefixedwithinthemeasuringchamberConstructionoftheovalgearmeter(courtesyEmerson)

Slide6信息与控制工程学院POsitiveDisplacementFlowmeter容积式2.椭圆齿轮流量计（Ovalgearmeters）(a)Wheninthepositionshownin(a),GearAreceivestorquefromthepressuredifferencewhilethenettorque（力矩）onGearBiszero.A-主动轮，B-从动轮；(b)GearAdrive