ProvibTech’s Application Note

8/11/2019 ProvibTechs Application Note

1/15

ProvibTechsApplicationNote_PowerGeneration

www.provibtech.com

9/34

Client/Serverarchitectureenablesusertoaccessdataanywhereonintranet/internet

Readilyintegrateswiththirdpartyvibrationmonitorsandprocessmonitorswithminimum

hardwarerequirements

MultipledigitalI/OProtocols,suchasModbusRTU/TCP

Multiplehardwareoutputmodulesreadyforfurtherdatatransferandannunciationinrelays

andcurrenttransmission

24hournotificationthroughonsitealarms,operatorinterfaceandevenSMSmessagingon

GPRSmobile

RemotenotificationwithSMSmessagestoanycellularphonewithmachinerunningstatus

Advancedpostprocessingoftransientdataminimizesdataloss,maximizinganalysiscapability

PCM360DataFlowIntroduction

Inadditiontorunningwellwithtransmitters/monitors ofProvibTechitself,withgreatintegrate

abilityandversatileinterface,PCM360isalsoabletointerfacewithdiversetransmitters/monitors

/sensorsor ModbusTCPServerorOPCserverfromthirdpartywhichtakesgreatconveniencefor

retrofitprojectsandmakestheplantmanagementmoreefficientandeffectivelywithoutspending

muchmoney.

Apartfromthese,PCM360alsocanplayaroleasModbusTCPServerorOPCServerwhichmakes

interfacingwiththirdpartyconditionmonitoringsystemavailable.

Inconclusion,PCM360isveryflexibleandfunctional.Withitsreliability,itnotonlycanacquirethe

datafrom

third

party

but

also

share

its

data

with

third

party.


2/15


www.provibtech.com

10/34

PlotsSupportedByDifferentMeasurementPoints

MeasurementPoint

Device

TypeChannel

TypeDataType

Single

Channel

Dual

Channel

PlotsandLists

bargraph,waveform,spectrum,

bode,polar,cascade,

(dynamic,transient)waterfall,

(dynamic,transient,historical)trend,

statuslist,

alarm

list,

transient

list

Acceleratio

n,Velocity

Dynamic

data,

Transient

data


fullspectrum,shaftXYvibration,

bode,polar,cascade,fullcascade,



statuslist,

alarm

list,

transient

list


bode,polar,cascade,

waveformwithDCcoupling,



statuslist,

alarm

list,

transient

list

DAQ

Card:

6013,

6220,6

250

Vibration[fromProx]

Dynamic

data,

Transient

data



shaftcenterline,

waveformwithDCcoupling,

shaftXYvibrationwithDCcoupling,


3/15


www.provibtech.com

11/34

bode,polar,cascade,fullcascade,



statuslist,alarmlist,transientlist

Position[fr

omProx],

Process

Staticdata

bargraph,statictrend,

statuslist,alarmlist

Modbu

sDAQ

for

Proces

s

Acceleratio

n,Velocity,

Vibration[fromProx],

Position[fr

omProx],

Process

Staticdata




dynamicwaterfall,alarmlist,

(static,

dynamic)

trend,

status

list

Modbu

sDAQ

forDW

Dynamic

data,Static

data



dynamicwaterfall,alarmlist,

(static,dynamic)trend,statuslist

OPC

Client

Acceleratio

n,Velocity,

Vibration[f

romProx],

Position[fr

omProx],

Process

Staticdata




4/15


www.provibtech.com

12/34

Plots

Waveform

plot

(realtimeandhistorical)

Waveform

plotwithDCcoupling


Spectrum

plot(realtimeandhistorical)

Full

spectrumplot(realtimeandhistorical)


5/15


www.provibtech.com

13/34

ShaftXY

vibration


ShaftXY

vibrationwithDCcoupling


Trendplot

(static,dynamic,transient,historical,andrealtime,gap)

Waterfall

plot

(dynamicandtransient)


6/15


www.provibtech.com

14/34

BarGraphshaft

centerlineplot(realtimeandhistorical)

BodeplotCascade

plot

Full

cascadeplotPolarplot


7/15


www.provibtech.com

15/34

Shaftcenterline

mode

shape

Shaft

XY

vibration

mode

shape

Lists

Transientlist

Alarmlist

Statuslist


8/15


www.provibtech.com

25/34

Measurement llustration

Shaft

X,

Y

Vibration

(Radial

Vibration)

ShaftX,YVibrationisforshaftdynamicmotion

whichisgenerallymeasuredinadirection

perpendiculartotheshaftaxis,itisalsocalled

radialvibrationorlateralvibration.Itisindicated

byPKPKwithunitmorMil.5mmor8mm

proximityprobesareoftenusedtoobserveShaftX,

YVibration.ProvibTechsproximityprobe

TM0105(5mm)andTM0180(8mm)willsupply

completesolution.

PleaserefertotheFigure1.1andFigure1.2.Theyareshowingthetypicalwayforprobeinstallation

forRadialVibration.

ApartfromtheinstallationwayofFigure1.1and

Figure1.2,theresanotherinstallationway,please

refertoFigure1.3.ProbeXishorizontally installed

andProbeYisverticallyinstalled.

Sometimes,proximityprobeswillbemounted

insidethemachinebyprobeclamp,andsometimesprobeswillbemountedwithhelpofprobe

holder.ProvibTechsTM0393Xsupplyaverycost

effectivesolutionformountingtheproximityprobes

forthesemachineswhateverfornormalpressureor

highpressurepurpose.Customercanreplacethe

probewithout

opening

the

machine

case

which

takes

greatconvenienceandsavelotsoftimeand

maintenancecost.Adjustablepenetrationdepth

+/13mm(0.512)makestheinstallationveryflexible.

PleaserefertoFigure1.4andFigure1.5for

installationreference.


9/15


www.provibtech.com

26/34

ThrustPosition(AxialPosition)

ThrustPositionistomeasurethemovementofshaftin

theaxialdirectionwithrespecttosomefixedreference.

Typically,thereferenceisthethrustbearingsupport

structureorothercasingmembertowhichthe

displacementprobeismounted.Theprobeisgenerally

toobservethethrustcollardirectlyoraxialshaftsurface.

ThrustPositionisalsocalledAxialPosition,anditis

indicatedbyaveragewithunitmorMil.5mmor8mm

proximityprobes

areoftenusedto

observeThrust

Position.

ProvibTechs

proximity

probe

TM0110(11mm)andTM0180(8mm)willsupplycomplete

solution.

DueThrustPositionisveryimportantforsomeessential

machines,itisstronglyrecommendedtousedualproximity

probestomonitorThrustPositionastheredundancywill

increasethereliabilityofthemonitoring.

Pleaserefer

to

Figure

2.1

and

Figure

2.2.

SeismicVibration(CasingVibration)

SeismicVibrationmeasurestheabsolutevibrationofmachinecaseorstructure.Thismeasurement

doesntrequireotherobjectspositionormovementasareference.Accelerometersandvelocity

sensorsareoftenusedforSeimicVibration.ItisalsocalledCasingVibration.Itwillbeindicatedby

PKorPKPKorRMS.

Theinstallation

direction

could

be

horizontal

or

vertical.

Please

refer

to

Figure

3.1.


10/15


www.provibtech.com

27/34

RotationSpeed

Rotorspeedisimportantmeasurementsduringnormalmachineoperatingconditionsaswellas

duringstartupandcoastdown.Suddenunexpectedchangesinrotorspeedmaybeanindicationof

machineryorprocessmalfunction.

OverSpeed

OverSpeedprotectionsystemismandatoryforcriticalmachinesespeciallylikesteamturbines.Due

therotationspeedforthesteamturbineisthemostimportantfactor,sogenerallyweusetwo

proximityprobesorthreeproximityprobestocomposeasystem.Itcouldbe2outof 2or2outof

3.


11/15


www.provibtech.com

28/34

ReverseRotation

Forboilerfeedpumporsomemachines,ReverseRotationmonitoringisnecessaryasthereverse

flowwillcausethetotalmachineshutdownfinallystopwatersupplying.TypicallyReverseRotation

requirestwoproximityprobestomountonthegearorshaftwithanotch.Pleaserefertobelow

Figure6.1fordetails.

ZeroSpeed

Whenthesteamturbineormachineisunderturningstate,therotationspeedshouldnotbevery

slow.Ifitrotatesslowerthanitshouldbe,thenitwilltrip.ZeroSpeedissimilarlikespeed

monitoring,butSpeedmonitoringistotripwhenitrotatetoofastthanitshouldbe,andZeroSpeed

monitoringistotripwhenitrotatetooslowthanitshouldbe.


12/15


www.provibtech.com

29/34

PhaseReference

PhaseReferenceisatransducerthatproducesavoltagepulseforeachturnoftheshaft.Thissignal

isusedprimarilytomeasureshaftrotativespeedandservesasareferenceformeasuringvibration

phaselag

angle.

Typically

proximity

probe,

magnetic

pickup,

optical

pickup

are

used

for

measuring

PhaseReference.

PleaserefertobelowFigure7.1fordetails.

Differential

Expansion

DifferentialExpansionistomeasuretheaxialpositionoftherotorwithrespecttothemachine

casingatsomedistancefromthethrustbearing.DifferentialExpansionisusuallymeasuredwhen

machinestartupandshutdownasthemachinehasabigthermalexpansionduringthatperiod.

Themeasurementistypicallymadewithaproximityprobetransducermountedtothemachine

casingandobservinganaxialoftherotor.

Theproximityprobecouldbemountedbytwoways.Oneisbynormalshaftdirection,pleaserefer

tobelowFigure9.1.


13/15


www.provibtech.com

30/34

Anotherwayismountedbyrampshaftdirection.PleaserefertobelowFigure9.2.

CaseExpansion

CaseExpansionistomeasureaxialpositionofthemachinecaserelativetoafixedreference,usually

thefoundation.Changesincasingaxialpositionaretheresultofthermalexpansionandcontraction

ofthecasingduringstartupandshutdown.ItisgenerallymeasuredbyLVDT(LinearVariable

DifferentialTransformer).

PleaserefertobelowFigure10.1forCaseExpansion.


14/15


www.provibtech.com

31/34

Eccentricity

Eccentricityisveryimportantformonitoringturbinerotorbow.PT2060/10PROXproximitymodule

canprovidesophisticatedonlineeccentricitymonitoring.Themonitorissuitableforvirtuallyall

typesof

rotating

machinery

in

terms

of

eccentricity.

The

PT2060/10

PROX

proximity

module

will

be

continuously measureandmonitoringinuptotwochannelspermodule.

Eccentricitymeasurementsindicatethedeviationoftherotorphysicalcenterandthetheoretical

center.Thedifferencehastobesmallenoughtoallowmachinestartupwithoutcausingdamage.

ThePT2060/10PROXproximitymoduleprovidespeaktopeakeccentricitymeasurement,which

measurethedifferencebetweenthepositiveandthenegativeextremesoftherotorbow.Italsohas

onemorechannelthatoutputthepositionoftherotor.

Operatorsuseeccentricitymeasurementstodeterminewhenacombinationofslowrollandheating

havereduced

the

rotor

eccentricity

to

the

point

wheretheturbinecansafelybebroughtupto

speedwithoutdamagefromexcessivevibrationor

rotortostatorcontact.

EccentricityisthemeasurementofRotorBowat

rotorslowrollwhichmaybecausedbyanyora

combinationof

Fixedmechanicalbow

Temporarythermal

bow

Gravitybow


15/15


www.provibtech.com

32/34

ValvePosition

ValvePositionistomeasurethepositionoftheprocessinlet

valvesonamachine,usuallyexpressedasapercentageof

thevalve

opening;

zero

percent

is

fully

closed,

100

percent

is

fullyopen.

PleaseseebelowFigure12.1forValvePosition.

Temperature

Temperaturemonitoringisalsoanimportantparameterto

monitorthemachinehealthstatus.Whensomethingwrong

insidethemachine,itwillcausemorefrictionwhichwillcausetemperaturegettinghigher.Typically

welluseRTD/TCsensortoacquiretheprocesssignalandtransfertotransmitters/monitors, finally

transfertoconditionmonitoringsystem.

FlowRate,Pressureandotherprocessvariables

Alltheseparametersareliketemperatureastheyareprocessvariables,andthesearetocontrol

somethingorfeedbackthehealthstatusofthemachine.Typicallywellusedifferentkindsof

sensorsto

get

the

process

signals

and

finally

transfer

to

condition

monitoring

system.

Documents

ProvibTech’s Application Note