中英文翻译--频谱分析在转子动平衡中的应用.doc

本科毕业论文（设计）相关中英文翻译资料资料题目：频谱分析在转子动平衡中的应用学生姓名：所在院系：机电学院所学专业：机电技术教育指导老师：APPLICATIONOFFREQUENCYSPECTRUMANALYSISINTHEROTATORMOVINGEQUILIBRIUMABSTRACTTheexperimentalequipmentisdevelopedtosimulatetherotatorvibration.Therunningstateofmachineissimulatedbyusingdifferentrunningconditions.Thevibrationcausedbynon-equilibriummassisanalyzedanddiscussedforfirstorderwithfocusload.Theeffectivemethodisfoundoutbyusingfrequencyspectrumanalysis.INTRODUCTIONIntheconventionalislandofnuclearpowerplant,turbinegeneratorsetisaveryimportantequipmentinwhichthecorethermalenergyistransferredintoelectricenergy.Whentheturbinegeneratorsethasrunforlongtime,theoriginalequilibriumofsystemwouldbeupsetbecauseoftheremnantdeformedofthemetal,abrasionordamagingofthecomponentsetc.Asaresult,thevibrationwillbeincreased.Soitisnecessarytoadjusttheequilibriumatspot.Ontheotherhand,alargeturbinegeneratorsetalsoneedstheworkforadjustingtheequilibriumintheprocessofmanufacture,debugging,installationandoperation.Themovingequilibriumtechniqueatspotisanimportantmeanstoeliminatetheviolentvibrationoftheturbinegeneratorset.Wecouldhaveadefinitelyviewforthevibrationtype,vibrationpowersourceandvibrationpropertybyanalyzingthevibrationoftheturbinegeneratorsetordoingsomespecialexperiment.Whenthevibrationsignalisobtained,thefrequencyspectrumcouldbeusedtoanalysisthevibrationsignalinordertodiagnosequickly.Usingfrequencyspectrumanalysis,theelectricalsignalofvibrationthatisobtainedbythevibrationsensorandhasawidefrequencyrangewillbedecomposedintoseveralmainfrequencycompositions.Differentfrequencycompositionshavedifferentinfluenceontheturbinegeneratorset.Thefrequencyspectrumanalysisisaveryusefulmethodtostudythevibrationofturbinegeneratorset.Thevibrationcausedbyrotatormassnon-equilibriumwithconcentratedloadisdiscussedandanalyzedinthispaper.Andaneffectivemethodtopreventthevibrationispresentedbyusingfrequencyspectrumanalysis.1EXPERIMENTALEQUIPMENTTheexperimentalsystemconsistsofthemotor,shaftcouplingandrotoretc.Itsstructureisverysimple.Therotorisdrivenbythemotordirectly.Itsrotatingspeedcouldbeadjustedinawiderange.Thesystemcouldbeoperatedsmoothlyandreliably.Theratedcurrentofthemotoris2.5A,theoutputpoweris250W.Thefieldexcitationofthemotorisprovidedbythe220VACpowersourcewhichiscommutatedbythespeedregulator,thearmaturecurrentofthemotorisalsoprovidedbythesamepowersource.Itisadjustedbythecompressorgovernor.Throughadjustingtheoutputvoltageofcompressorgovernor,themotorcouldbeofstep-lessspeedregulatedattherange010000r/min,therateofvelocityincreasingcouldbe800r/min.Thelengthoftheexperimentalequipmentis1200mm,thewidthis108mm,themassisabout45kg,thediameteroftheshaftis9.5mm,thelengthoftheshaftis500mmandthemaximumdeflectionislessthan0.0050.015mm.Anypositionalongtheaxialdirectioncouldbeselectedasexperimentalabutmentpoint.Thediameterandmassoftheexperimentalrotatingtableis7619mmand600g,respectively.ThearrangementofexperimentalequipmentisshowninFig.1.Fig.1ThearrangementofexperimentalequipmentTheelectricalvortexsensorsareusedtomeasuretherelativelydisplacementorvibrationforaxistobearingpedestal.Theyareinstalledinthexandydirectionsatthesensorsupport,respectively.Theydonottouchtheshaft,andcouldbeusedtodirectlymeasurethevibrationsignaloftherotationshaft.Theflashingphase-measurerisusedtomeasuretherotatorspeedandthephaseoftheshaft.2THEFREQUENCYSPECTRUMANALYSISOFVIBRATIONSIGNALTherealvibrationofturbinegeneratorsetisthemostofsimpleharmonicperiodicmotion.Itswavetypeisalsomadeofmanysimpleharmonicmotion.Inordertoanalysisthevibration,weshouldstudythewavetype,thefrequencycompositionofthevibration,andtheamplitudes.Frequencycanbeusedasx-axistodescribethevibrationinthefrequency-domain.Themethoddecomposingthevibrationintoitsvariousfrequencycomponentsinfrequencycomponentsinthefrequencydomainiscalledfrequencyspectrumanalysis.Thepurposeoffrequencyspectrumanalysisistodecomposethesignalsintodifferentcompositions.Sothevibrationbecomesthesimpleharmonicmotionincludingdifferentamplitudes,frequenciesandphases.Inthefrequencyspectrumofrotatorvibration,thedifferentfrequencyisoftencorrespondingtothedifferentreason.Ifwecanfindthefrequencycompositionofthevibrationsignal,thereasonofvibrationwillbediscovered.Thereareabout80%accidentscausedbyrotatornon-equilibriuminthevibrationaccidentsofturbinegeneratorsethappenedinthespot,and90%accidentscausedbyrotatormassnon-equilibrium.Intheexperimentsdescribedinthispaperwestudythevibrationcausedbyrotatormassnon-equilibriumbyusingthemethodoffrequencyspectrumanalysisandtheinfluencecoefficientmethodoffindingequilibriumtodeterminethepositionofrotatormassnon-equilibrium.3EXPERIMENTALRESULTSANDANALYSISTheBodediagramshownasFig.2isaboutthehorizontalvibrationcharacteristicsofrotator.Itshowsthatthecriticalvelocityofrotatorisabout2605r/min,themaximumamplitudeofrotatorcorrespondingtothebearingshellis371m,theamplitudeofselectfrequency(AMP-1X)is360m,andthephasedifference(PHA-1X)is-36.ThemarkpositioninFig.3isthemaximumvalueofvibration,andalsoisthepositionwhe