智能热式气体质量流量计的研制__传感器系统的研究

密级：学校代码：10075分类号：学号：20091234工学硕士学位论文学位申请人：时慧指导教师：郭增军教授张瑞林教授学位类别：工学硕士学科专业：测试计量技术及仪器授予单位：河北大学答辩日期：二〇一二年六月ClassifiedIndex：CODE：10075U.D.C：NO：20091234ADissertationfortheDegreeofM.EngineeringDevelopmentofIntelligenceThermalGasMassFlowmete——SensorSystemCandidate:ShiHuiSupervisor:Prof.GuoZengjun,ZhangRuilinAcademicDegreeAppliedfor:MasterofEngineeringSpecialty:MeasurementTechnologyandInstrumentationUniversity:HebeiUniversityDateofOralExamination:June，2012摘要I摘要随着人们在燃气计量管理中对计量结算的科学合理性认识的不断提高，传统的容积计量已不能满足要求，传统的流量计容易受天然气的压力和温度的影响，而且不能反映天然气的成份变化（质量变化），另外现有计量仪表对较小的流量计量不出来，对较大的流量又存在饱和等问题，测量不稳定，严重影响了计量的准确性。热式质量流量计可以实现天然气的热值计量，它具有测量范围宽、响应速度快、小流量测量精度高等优点，可以弥补燃气管理部门的损失，具有广阔的应用前景。同时在工业用特种气体测量方面，由于其响应快，小流量测量精度高的特点，适合化工等行业的应用。流量计的传感器系统的性能对流量计的影响至关重要。因此，为了提高传感器的性能，本课题利用微电子技术，采用MEMS工艺制作气体质量流量传感器，深入研究了气体质量流量的传感器系统，设计了采用恒温差法的测量电路。设计加工制作的微型热式质量流量计可以计量天然气的流量和流速，是一种智能型计量仪表。它具有响应速度快、可在较宽的流量比范围内实现精确测量、受环境影响小、体积小、成本低、可批量制备等优点。本项目还参照国家标准中有关流动调整器和流动整直器的相关介绍，设计了一种容易制造的流动调整器。本课题采用Fluent流体仿真技术，通过对管道内流体流动状态进行仿真，并在Labview中进行验证，观察仿真和实验的结果，可以看到设计的流动调整器具有良好的整流效果，并为管道中传感器位置的昀佳放置点提供了依据，昀后制作样机进行试验，对该装置的性能进行验证，并对不确定度进行评定。关键词热式气体质量流量计流量传感器MEMS流体仿真AbstractIIAbstractAlongwiththepeopleunderstandingofcontinuousimprovementinthegasmeteringmanagementofmeteringandbilling,thetraditionalvolumemeasurementcannotmeettherequirements.Thetraditionalflowmeteriseasilyaffectedbygaspressureandtemperatureeffectsanditcannotreflectthenaturalgascompositionchanges.InadditionThesmallflowmeasurementdoesnotcomeout,andexistthesaturationproblemsforlargerflowmeasurement.ThemeasurementinstabilityaffecttheaccuracyofthemeasurementSeriously.Thermalmassflowmetercanmeasurethecalorificvalueofthegas.itcanmeasureatwiderangeandbefastresponseand,especiallyithashighprecisionatthemeasurementofthesmallflow.Whichcancompensateforthelossofgasmanagementsector，andithasbroadapplicationprospects,Atthesametimefortheindustrialuse,itcanbesuitablefortheapplicationofthechemicalindustrybecauseofthefastresponsecharacteristics,lowflowmeasurementandhighaccuracy.Atthesametimefortheindustrialuse,itcanbesuitablefortheapplicationofthechemicalindustrybecauseofthefastresponsecharacteristics,lowflowmeasurementandhighaccuracy.Flowmetersensorsystemperformanceimpactisessentialontheflowmeter,Inordertoimprovethesensorperformance，weuseMEMStechnologytoproducethegasmassflowsensor,In-depthstudyofthegasmassflowsensorsystem,wedesignthemeasurementcircuitofconstanttemperaturedifferencemethod,ThethermalMassFlowmeterwedesignedisanintelligentmeasuringinstrument,whichcanmeasuregasvolumeandflow,Ithastheadvantagesoffastresponse,wideflowrange,smallsize,lowcost,batchpreparation.Theprojectrefertotheintroductionofnationalstandardsinflowregulatorandflowstraightening,Theflowregulatorwedesignediseasytomanufacture.ThistopicusedfluentfluidsimulationtechnologytosimulatefluidflowinthepipelineandvalidatedinLabview,Toobservetheresultsofsimulationandexperimental,wecanseethattheflowregulatorhasgoodrectifiereffectanditcanprovideabasisforthebestplacedofthesensorlocationintheAbstractIIIpipeline,Finallywemadeaprototypetoverifytheperformanceofthedeviceandassesstheuncertainty.KeywordsThermalGasMassFlowmeterflowsensorMEMSFluidsimulation目录IV目录第1章绪论........................................................................................................................11.1引言...........................................................................................................................11.2国内外的研究现状...................................................................................................21.3研究的背景及意义...................................................................................................41.4课题研究内容...........................................................................................................6第2章测量原理与数学模型................................................................................................72.1热式质量流量计概述...............................................................................................72.1.1热式质量流量计的分类................................................................................72.1.2热式质量流量计的特点................................................................................82.1.3热式质量流量计的应用................................................................................92.1.4热式质量流量计的发展趋势........................................................................92.2原理与模型.............................................................................................................102.3本章小结.................................................................................................................11第3章传感器系统的设计与制作......................................................................................123.1传感器探头的设计.................................................................................................123.1.1关于MEMS技术........................................................................................143.1.2探头的制备..................................................................................................1