熟悉计量系统(LNG)

1GetAcquaintedWithMeasurement

熟悉计量系统2OverviewofMeteringSystem计量系统概述1，MeteringSystemDesignPhilosophyAlltheFiscalMeteringStationsaredesignedfortherangeofgascompositionspecifiedandsizedtoaccommodatethemaximumgasdeliverycapacityofPhase-IandPhase-II.所有贸易计量站的气体组分范围和计量站规模都应满足一期和二期工程的最高输气量Allfiscalmeteringstationsaredesignedandconstructedtofiscal-meteringqualitywithanoverallerroroflessthan±1%onmeteredenergyacrosstheflowranges3Continue全部贸易计量站都是按照贸易计量等级设计和建设，整个流量范围内能量计量的总误差低于±1%。Primarymeasurementisattainedfrommeterrun’sDanielSeniorsonicUSMandS600flowcomputer.FlowcomputerwillsendmeasurementdatatoGMSsystem.FlowconditioningfortheUSMisimprovedbyutilizingapipingconfigurationof5D+profiler+10Dupstreammetertubesand3Ddownstreammetertubes.基本计量值从计量管道的丹尼尔高级超声波气体流量计和S600流量计算机获得。流量计算机将计量数据送往GMS系统。利用5D+断面测量仪+10D上游流量计直管段和3D下游流量计直管段的管道配置对气体超声波流量计的流态进行了改善4ContinueEachofthemeteringstationsarebasedona2x100%capacity（exceptforHKCG),withaprimarydutymeasurementstreamandsecondarystreamforuseasanonlinevalidationcheckmeterandinthecaseofprimaryfailureandinthecaseofprimaryfailure.Acrossoverlinecanlinkthetwostreamstogether(inseries)toenablegasflowthroughboththemeter-runsforverificationpurpose(exceptforterminalmeterstations).每个计量站以2x100%容量为基础，配有主计量通道和备用计量通道(HKCG除外），备用计量通道作,为在线验证校验仪，并在主用通道发生故障时启用。两条通道可以通过跨接管连接起来（串接),使气流同时通过两条计量管道（接收站计量站除外）.5ContinueAnon-lineGasChromatographDanalyser570isinstalledforgascompositionanalyses.一台在线色谱仪Danalyser570用于气体组分分析。On-linehydrogensulphideandtotalsulfuranalyzer;on-linewaterandhydrocarbondewpointanalyzer;on-linemoistureanalyzer,theyareusedforgasqualitymonitoring.(Atterminal)在线硫化氢和总硫分析仪;在线水露点和烃露点分析仪;在线水分分析仪,它们用于气体质量监控.(在接收站）6Atypicalmeteringstation典型计量站RS485或脉冲接收工况流量RS232/RS485色谱的分析数据温度&压力数据标况流量,总能量,天然气组分及管理所需的信息与上位机数字通信,包括所有诊断和报警信息计量系统略图7Atypicaltrunklinemeterstationcomponents典型管线计量站组成DescriptionDetailQuantityTTRosemount3144P2PTRosemount3051S12PressureGaugesLocalindication2TemperatureGaugesLocalindication2USMDanielSeniorsonic2FlowProfilerDaniel2ManualValvesStreaminlet/outlet12PneumaticActuatedValvesStreamoutlet2LimitSwitchesActuatedC/Ovalves6RetractablesampleprobeGCsample18DPLNGOperationinfrastructureandCustomers

运营组织结构和客户FlowSchematiccustomersRealTimeDatabyRS485ShipschedulingCustomersAccountManagementbasedonWebPageGMSLDSStep1NominationStep2InternalCoordinationandSchedulingFlowComputerFiscal

Metering价格GMASfirewallStep6InvoicingInformationFlowandWorkProcedureStep3ConfirmationStep4GasMeasurementanddelivertocustomerStep5PricingFinancialStep7BillingStep8PaymentTankinventoryLinepackPolarisMeteringdata9Volume&EnergyMeasurementThegasvelocity“v”ismeasuredbytheUSMandconvertedtovolumeatlineconditions“V”.气体流速“

v”由超声流量计测得并被转换成在线条件下的体积”V“。Thevaluesofthelinetemperatureandpressureareinputtotheflowcomputer.在线条件下的温度及压力输入到流量计算机An“Online”Chromatographanalyzesthegascomponentsanddownloadsthecompositiontotheflowcomputer.在线色谱仪分析气体组成并下载到流量计算机10ContinueFlowcomputercalculatesvaluesfordensity,grossvolumeandgrossvolumetricheatingvalue(GHV)流量计算机计算密度,在线气体总体积及体积总热值。FlowcomputerconvertsthegrossvolumetocontractedorstandardconditionsvolumeVs.流量计算机转换在线气体体积成合同或者标准条件下的售气条件体积Vs。Flowcomputercalculatesthetotalproductionenergy.Et=(Gj)=VsxEu

流量计算机计算生产总热值Et

(吉焦)Billing帐单Billing=EtxPrice/Gj11MeasurementCriticalEquipment计量关键设备Therearetwocriticalequipmentsintheprocessofthegasmeasurement:天然气计量中的两样关键设备Ultrasonicmeterandflowcomputer,theyareusedformeasuringflowrateandcalculatingthegasstandardvolumeSCMorSCF.超声波流量计和流量计算机,主要用于测量气体流速和计算气体标准体积立方米或立方英尺.Gaschromatograph,itisusedforanalyzingthegascomponentsandthermalunitenergyBTU/SCMcalculation.气体色普仪,主要用于分析气体组分和气体单位热值计算.12UltrasonicMeterPrinciple

超声波流量计原理

Atypical4-PathHighAccuracyAdvancedTechnologyUSM一种典型的四通道高级超声波流量计.

13USMinstallation超声波流量计的安装14HowanUltrasonicFlowMeterWorks

超声波工作原理Theflowmeterhastwoultrasonictransducers—oneupstreamandtheotherdownstream—facingeachotherinsideatube.

Thetransducerscanbeamultrasonicpulsesfromonetotheotherineitherdirection—withtheflowandagainsttheflow.

Apulsetravelingwiththeflowarrivessoonerthanonetravelingagainsttheflowandthistimedifferenceisrelatedtotheflowspeedinthemeter.

Onceweknowthevelocityofthefluidinsidethemeteroveraknowntimeinterval,itisasimplemattertoconvertthistoafluidvolumemeasurement

流量计有两个超声传感器,一个安装在上游另一个在下游,在计量管内相互面对.两个传感器间可以顺流和逆流发射超声脉冲.顺流超声脉冲要比逆流超声脉冲到达的时间要短,而这个时间差与流量计内的流体流速有关.一旦我们知道一定时间内流量计内的流体流速,我们就可以简单地把它转化为流量体积计量.15HowanUltrasonicFlowMeterWorks

超声波工作原理传输时间.004LFlowXD传输时间.007.00316HowanUltrasonicFlowMeterWorks

超声波工作原理OnepairofUltrasonictransducer

任意一对传感器LFlowXDVC—speedofsound声速;L—lengthofacousticpath声道长度V—averagefluidspeed流体流速;x—distanceofacousticpath声道距离

tdown=

Lc-v(x/L)

(1)tup=

Lc+v(x/L)

(2)17HowanUltrasonicFlowMeterWorks

超声波工作原理c=L2(tdown+tup)tdowntupv=fluidspeed流体速度c=speedofsound声速

tup=timetravelalongwithflow上游传输时间

tdown=timetravelagainstflow下游传输时间v=L2x(tdown-tup)tdowntup218Stateoffluidflow流体流态将流速简化为三个区域ProfileandAreaRepresentation19MultipathUSM多通道超声波流量计Cross-sectional

viewofamultipathUSM有代表性的多通道流量计Multipath多通道流量计ABCDVavg

=S

WnVnn=14Vn=L(t1-t2)2x(t1t2)220Geometryweightfactor几何权重因子Wa=0.1382Wb

=0.3618Wc

=0.3618Wd=0.1382Multipath多通道流量计ChordAChordBChordCChordDGeometryweightfactordependsonhowprobeisinstalled.权重因子仅取决于探头的几何分布情况!21Flowconditioners整流器22Continue续Flowconditioningplatescanbeinstalledtoensurethataconsistentflowprofileisenteringtheultrasonicmeter.ProfilerConsistentflowprofileSwirlflow23Flowrate流量Flowratedependsonvelocityoffluidsandmeterrunsectionarea.流量取决于流体的流速和计量管截面积

流量=流速*截面积Flowrate=velocityxmeterrunsectionarea24USMCommunication超声波流量计通讯SerialModbusRS-485(2-wire)toflowcomputer.(flowvelocitydata&basicdiagnosticdata)串行ModbusRS-485(两线）联流量计算机（传输流速及基本诊断数据）CUIcommunicationport用户界面CUI通讯口25USMMonitoring超声波流量计监测Gain增益值Signalquality信号质量SNR信－嘈比Velocityprofile流速特性Speedofsound声速KeypointofnewversionAGA9isConditionBaseMonitoring新版AGA9要点是在线监测超声波26FlowcomputerFlobossS600流量计算机27FlowcomputerFlobossS600流量计算机TheFloBossS600isamicroprocessorbasedflowcomputer,utilizedtocarryoutmeterstreammonitoringandcalculationfunctions.该型流量计算机基于微处理器，用于执行计量监控及计算50MHz,i80486DX2processor28Flowcomputerfunction流量计算机作用PP&TTCompensationcomputation压力及温度补偿计算convertstherawoperatingdataintostandardvolume(AGA81994)将原始数据转换为标准体积ReceivedatafromGCandenergyflowcomputation.(ISO6976:1995)接受来自色谱仪的数据计算能量流量。TransferdatatoSCADA&GMS传递数据到SCADA及GMS29MajorComponents主要构件MainBoard–CPUTCP/IPEthernetcommunications(MODBUSProtocol)andprovides5SerialCommunicationsPortsTCP/IP以太网通信能力（MODBUS协议），并提供5个串行通信端口IndividualRS232/485serialcommunicationwithgaschromatographforGasCompositionData与气相色谱仪的RS-232/485串行通信，用于获

取气体组分数据30Continue续IndividualRS485serialcommunicationwithultrasonicflowmeterforFlowandBasicDiagnosticsdata与超声波流量计的RS-485串行通信，用于获取流量和基本诊断数据RS485serialcommunicationlinkforfurtherconnectiontoSCADA与SCADA连接的RS-485串行通信链路。Input/OutputBoardCPUboardtalkstoI/Oboardbyaddress.CPU板按地址与输入/输出板通信31Continue续S600OPERATORINTERFACEOperationoftheS600isthroughanoperatorinterfacecomprisinganLCDdisplayandkeypadS600通过操作员接口操作，操作员接口由LCD显示屏和键盘构成Keypad;Display;DisplayMatrix;ViewParameter

ReturntoMainMenu;ChangeValue;ChangeMode;Clear;ScientificNotation;Alarm;Print;DefaultDisplay;ProgramFunctionKeys;SecurityCode;32FlowcomputersecurityThesecuritysystemallowsupto50uniqueusers.安全系统最多支持50个不同用户Eachuserisallocatedtwoindividualpasswords;oneisnumericforaccesstotheS600andtheotherisalphanumericforaccesstotheConfig600suiteofprogramsortheWebServer.每个用户分配有两个密码；一个为数字密码，用于使用S600，另一个为字母数字型密码，用于使用Config600程序套件或网络服务器。Eachuserisallocatedasecuritylevelbetween0(highest)and9(lowest).每个用户还分配有一个在0（最高）到9（最低）之间的安全级别33Continue续TheS600flowcomputerwillgenerateanalarmandswitchovertolastgoodvalueunderthefollowingconditions:S600流量计算机会在下列条件下产生报警，并切换到最后一次正常值：Incasetheun-normalizedtotalfromtheGCcontrollergoesbeyondthespecifiedlimits如果气相色谱仪控制器提供的未标准化的累积量值超过规定限值。IncasethereisafaultsignalfromtheGC(e.g.,carriergaslowpressureetc.)如果气相色谱仪有故障信号（例如，载气压力过低等）IncaseoffailureofcommunicationwithGC.如果与气相色谱仪的通信发生故障。34Flowcomputeroperationmode流量计算机操作模式ModeOfOperation操作模式Measuredvalue:测量值Keypadvalue:键盘键入值Kaypad-Fvalue键盘键入与自动值MaintenanceMode维修模式35GCdatatoflowcomputer进入流量计算机的数据ThefollowingdatawillbereadfromtheGCcontroller:如下数据将会从色谱仪控制器读取Nitrogen(N2)氮气(N2)CarbonDioxide(CO2)二氧化碳(CO2)Methane(C1)甲烷(C1)Ethane(C2)乙烷(C2)Propane(C3)丙烷(C3)i-Butane(iC4)异丁烷(iC4)n-Butane(nC4)正丁烷(nC4)i-Pentane(iC5)异戊烷(iC5)n-Pentane(nC5)正戊烷(nC5)Hexane(C6+)己烷(C6+)36Flowcomputercomputation流量计算机计算ConvertUSMmeasuredgasvelocityVeltoon-lineconditionflowrate.

Temperatureandpressurecorrectedvolumetricflowrateofthegasthroughthespool.(m3/hour)流经计量管道经过压力温度校正的体积流量Measuredvelocityflowratewithinthespool(m/s)；计量管道内测得的流速Calibratedinternaldiameterofthespoolbody校正过的计量管内径37Continue续Correctionfactorfortheeffectsofpressureonthespool；计量管压力影响校正系数Correctionfactorfortheeffectsoftemperatureonthespool；计量管温度影响校正系数MeterFactorcorrectionbasedonflowrate基于流速的计量校正系数VelocitycorrectionforReynoldsnumber.(OnlyrequiredonJuniorSonicmeters).ForSeniorsonicmeters,asinthisproject,CFact=1.雷诺数速度校正系数（仅限低级超声流量计），对高级超声流量计，象DPLNG项目，CFact=1。Where：38Continue续Where：39Standardvolumeflowrate&Energyflowrate标准体积流量及能量流Which：

m：Densityatthemeter(kg/m3)在线密度

std：StandardDensity(kg/Sm3)

标准状态密度Both

m&

stdiscalculatedbasedonAGA81994Which：GHViscalculatedbasedonISO69761995andcompositionisfromGC40Gross/StandardVolumeTotalIncrement(m3)

在线及标准体积总增量41Energytotalincrement能量总增量42GascompressibilityZand

calculation压缩系数Z及密度

计算

AGA8compressibilityfactor

andrealtimedensity

calculation.AGA8压缩系数Z及实时在线密度

计算。

Detailcharacterizationmethod,气体全组分输入方法Grosscharacterizationmethod,总额特征输入方法43ISO6976ISO6976-1995:ComponentCalorificvaluesat20°Cand101.325Kpa.组分热值在20°C和101.325KpaTable5CalorificvalueMJ/m3(Hj)表5热值MJ/m3Table2Summationfactor(bj)求和因子44PressureandTemperatureTransmitter压力温度变送器PressureandTemperatureTransmittersFunction:压力和温度变送器的功用Livepressureandtemperaturewillbeusedforcompensatingthemetertubediameterduetopressureandtemperatureaffection.在线的压力和温度将会用于补偿计量管由于压力和温度影响而变化的管径.LivepressureandtemperaturewillbealsousedforconvertingtheUltrasonicmeteron-lineflowtostandardconditionflow.(AGA8)在线的压力和温度也将会用于转换超声波在线流量至标准条件下的流量.(AGA8号报告)45PressureTransmitterprinciple压力变送器原理SensorA/DconvertermicroprocessorD/Aconverter4-20mAFlowComputer46Continue续A/D,microprocessor,D/ASensor,capacitor47TerminalpressuretransmitterModelHoneywellSTG974Accuracy:•Accuracy=+/-0.0375%•Stability=+/-0.01%peryear•Reliability=470yearsMTBF•精度=+/-0.0375%•稳定性=每年+/-0.01%•可靠性=平均故障间隔时间为470年48TerminaltemperaturetransmitterModelHoneywellSTT25HAccuracy:•Accuracy=+/-0.0375%•Stability=+/-0.01%peryear•Reliability=470yearsMTBF•精度=+/-0.0375%•稳定性=每年+/-0.01%•可靠性=平均故障间隔时间为470年49Truncklineoff-takestationpressuretransmitter管线分输站压力变送器ModelRosemount3051S1Accuracy：•Accuracy=0.065%ofspan•Stability=0.125%over5years•Reliability=3.50E-04(AverageProbabilityofFailureonDemand)•精度=量程的0.065%•稳定性=5年为0.125%•可靠性=3.50E-04(随机平均故障概率)50Truncklineoff-takestationtemperaturetransmitter管线分输站温度变送器ModelRosemount3144PAccuracy:•Accuracy=0.02%ofspan•Stability=0.1%over2years•Reliability=2.89E-04(AverageProbabilityofFailureonDemand)•精度=量程的0.02%•稳定性=2年为0.1%•可靠性=2.89E-04(随机平均故障概率)51SystemUncertaintyCalculationUncertaintyofMeasurementcanbedefinedasthediscrepancybetweenameasuredquantityandthetruevalueofthatquantity.计量的不确定性可定义为测定量和该量的实际值之间的差异。TheinternationalstandardISO5168–1978givesspecificguidelinesfortheevaluationofuncertaintyinflowmeasurement.国际标准ISO5168-1978给出了评估流量计量不确定性的特定指导原则。52Example53Howuncertaintycalculated怎样计算不确定度Therealexampleshowhowtheuncertaintyiscalculated真实的例子表明不确定度是怎样计算出来的。CALCULATIONOFUNCERTAINTY(BASEDONISO5168-1978)54Meteringsystemreliabilityandavailability计量系统可靠性及可用性Availabilityisdefinedastheprobabilitythatthesystemisoperatingproperlywhenitisrequestedforuse可用性定义为系统在使用时能够正确运转的概率。Qualitative:Adescriptiveassessmentismadeoftheconsequencestoavailabilityofparticulardevicefailure。定性：针对特定设备故障对可用性的影响进行说明性评估55Continue续Quantitative:Ananalyticalassessmentismadeapplyingreliabilityfiguresforindividualdevicesinordertoquantify“SystemAvailability.定量：利用各设备的可靠性数据进行分析评估，以量化“系统可用性”。Thesestationshaveanoverallfiscalmeteringsystemavailabilityof99.9567315%withredundant2x100%streams(refertotherelevantsystemFDSforfurtherdetails).这些计量站的贸易计量系统（配有2x100%通道）的总可用性为99.9567315%(关于详细信息，参见相关系统的FDS)56GasMeasurementControl计量控制Engineeringdesigncontrol;工程设计控制Internationalindustryrecognizablestandard;国际通用工业标准Contractspecification;合同说明Dailyoperation.每天例行操作Guaranteegasmeasurementaccuracy57EngineeringDesignControlMetertubedownstreamandupstreamminimumlengthrequirements,(AGA9);计量管上下游长度最低要求。Metertubeupstreamvalveinstallationrequirements,(AGA9);计量管上游阀门安装要求Meterruninstallationrequirements,(AGA9);计量管安装要求。Instrumentsinstallationrequirements,etc.(AGA9).计量仪表安装要求等

58MeteringSystemOperatingControlAstandardprogramtoverifytheflowcomputercalculation;一标准程序核实流量计算机Testequipmentsperiodicallyverifiedandre-certificated.测试设备周期送检。Periodicmeterstationinspectionandcalibration;计量站周期检查及校正Dailyflowcomputerreports.流量计算机每天报告Companyinternalandexternalaudit.公司内外审计GCautomaticcalibration.GC自动校正Meteringsystemannualverificationandrecertification.计量系统年度核实及证书59InternationalIndustryRecognizableStandardStandard

DescriptionApplicationAGA8(1994)

Compressibilityfactorsofnaturalgasandotherrelatedhydrocarbongases,densityandstandarddensityCompressibility,StandardDensityetc.AGA9(1998)

MeasurementofnaturalgasbyMulti-pathUltrasonicMetersUSMcalculation,installationetc.AGA10(1998)SpeedofsoundinnaturalgasandotherrelatedhydrocarbongasesSpeedofsoundISO6976-1995Naturalgascalculationsofcalorificvalues,relativedensityandwobbeindexfromcompositionGasparametercalculationfromcompositionalanalysisISO5168-1978

Measurementoffluidflow–Estimationofuncertaintyofaflow-ratemeasurementFlow-ratemeasurementuncertaintycalculationISO10715-1997

NaturalgassamplingguidelinesManualgassamplingprocedureASTMD1945-96

STMforanalysisofnaturalgasbyGasChromatographyprocessGCandlaboratoryGCanalysisstandard60Continue续ASTMD1142-1995

StandardTestMethodforWaterVaporContentofGaseousFuelsbyMeasurementofDew-PointTemperatureWaterdewpointanalysisASTMF25-2004

StandardTestMethodforSizingandCountingAirborneParticulateContaminationinCleanRoomsandOtherDust-ControlledAreasDesignedforElectronicandSimilarApplicationsParticulatesTestJJG198-NewversionCompulsoryinspectionandcalibrationregulationforvelocitytypeofmeterCalibrationofUSM61