大口径烟道气体流量测量方法的分析

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1、万方数据AbstractUnderthebackgroundofrapiddevelopmentofglobaleconomy,ontheonehand，itacceleratestheprocessofurbanizationandpeople’Slivingstandardscallbeimproved；ontheotherhand，italsobringsabouttheproblemsofenvironmentalpollution．Hazeweatherevenspreadthroughoutthecountry,whichha

2、saffectedpeople’Shealthanddailylifeseriously．Airpollution，mainlyreferstothedeclineoftheairqualitycausedbyemissionsofdust，wastegas，automobileexhaustemissionsandcoalcombustion，etc．Therefore，establishon—linemonitoringdeviceforthefluegasfloweffectivelyisveryimportant．Firstofa

3、ll，thispaperprovidesflbriefintroductionofthedevelopmentofgasflowmeasurement，especially,largediameterductflowfielddistributionwithrectangularelbowisresearched．Basedoncomputationalfluidmechanics，thethree—dimensionalfluemodelisestablishedinGABMITsoftware，thensimulateit、ⅣimFL

4、UENTtoexploreflowlawoffluidintheflueductandcontrastthesimulationdatawithlaboratorytestdata．Finally,thecorrectionfunctionofaveragevelocityoffluegasisestablishedandfindoutthecompensationcoefficient．Accordingtotheresultsofthenumericalsimulation，theultrasonicflowmeasuringdevi

5、cewithlargediameter,rectangularbendandcomeswithcompensationfunctionisdesigned．ThemaincontrolunitadoptsC8051F120singlechip．Completingtheultrasonictransmitterandreceivercircuit，signalprocessingcircuitandthemall—machineinterfacecircuitsoftwareandhardwaredesign．Thenconvertthe

6、calculationresultsintothestandard4-20mAcurrentsignaloutputbyD／Aconversioncircuit．UsingRS232serialcommunicationinterfacetoaccomplishthepurposeofauto·controlofultrasonictestingprocess，datacollectionandstorage．Finally,adoptingcross—correlationalgorithmtoprocesstheultrasonics

7、ignal，whichensuregettingeffectivesignaldetectioninstrongnoisejammingenvironment，inordertoimprovethesignaltonoiseratio．Keywords：Largediameterflue；Ultrasonic；FLUENT；Flowcompensation；Timedifferencemethod；Cross—correlation万方数据目录第一章绪论⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯一11．1引言⋯⋯⋯⋯⋯⋯⋯⋯

8、⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯．11．2研究背景及意义⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯．11．3气体流量检测的研究现状与国内外发展趋势⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯．21．4本