外文翻译PLC在冰蓄冷中央空调系统控制中的应用.docx

外文翻译PLC在冰蓄冷中央空调系统控制中的应用.docx

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外文翻译PLC在冰蓄冷中央空调系统控制中的应用

PLCintheicestoragecentralair-conditioningsystemofcontrol

1Introduction

InPLCin30yearswhichdeveloped,itpassesthroughdevelopsunceasingly,alreadycouldunifysimulatesI/O,thenetworkcorrespondsaswellasusesnewprogrammingstandardlikeIEC61131-3.However,engineersonlymustusedigitalI/OandfewsimulationsI/Onumberaswellassimpleprogrammingskillonpotential80%industrialapplication.

PLChasbeenwidelyusedinallindustrialsectors.Accordingto"TheUnitedStatesmarketinformation"WorldPLCandsoftwaremarketreport,in1995theglobalsoftwarePLCanditseconomiesofscaleofabout5billionUSdollars[5].Aselectronictechnologyandthedevelopmentofcomputertechnology,

Becauseusestraditionalthetooltobepossibletosolve80%industrialapplication,likethisintenselyneedstohavelowcostsimplePLC;ThuspromotedthelowcostminiaturePLCgrowth,ithastheusefultrapezoidallogicalprogrammingdigitalI/O.However,thishasalsocreatedthediscontinuityinthecontroltechnology,ontheonehand80%applicationneedtousethesimplelowcostcontroller,butontheotherhandother20%applicationthenhavesurpassedthefunctionwhichthetraditioncontrolsystemcanprovide.Engineerisdevelopingthese20%applicationtoneedtohavethehighercirculationspeed,theseniorcontrolalgorithm,themoresimulationsfunctionaswellascanwellandtheenterprisenetworkintegration.

In80andthe90's,thesemustdevelop"20%application"engineershadconsideredusesPCintheindustrycontrol.PCprovidesthesoftwarefunctionmaycarryouttheseniortask,providestherichprogrammingandtheuserenvironment,andthePCCOTSpartenablescontrolengineerthetechnologywhichdevelopsunceasinglytouseinotherapplications.Thesetechnologiesincludingfloatingpointprocessor;HighspeedI/Omainline,likePCIandethernet;Fixeddatamemory;softwaredevelopmentkit.MoreoverPCalsocanprovidetheincomparableflexibility,highlyeffectivesoftwareaswellasseniorlowcosthardware.

Icethermalstorageairconditioningisthecentralpowergridcouldberedundant-nighticeelectricityintheformofcoldstorage,inthedaytimepeakhoursofelectricitytoprovideair-conditioningservicesmeltingice.Asmostpartsofourcountryatnightthanduringthedaymuchlowerprice,usingicecoldstoragecentralair-conditioningcangreatlyreduceuseroperatingcosts.

Icestoragecentralair-conditioningsystemconfigurationofequipmentthanconventionalairconditioningsystemtoincreasesome,requireahigherdegreeofautomation,butitautomaticallytomeettherequirementsoftheair-conditionedbuildingsalldayeverydayundertheconditionsoftheenergyhehasexhaustedall,thebiggestlimitstosaveoperatingcosts.

thePLCfunctionsaregreatlyenhanced,withthefollowingcharacteristics:

（1）highreliability.PLCbenefitedfromthehigh-reliabilityhardwareandsoftwareonaseriesofanti-jammingmeasuresandthecycleofitsspecialscanningmethodsofwork.

（2）withrichI/Ointerfacemodule.PLCfordifferentindustrialfieldsignalandthecorrespondingI/Omodulesandindustrialdevicesorequipmentatthesceneofadirectconnection.Inadditiontoimprovingperformance,italsohasavarietyofman-machinedialogueinterfacemodulestotheindustrialcompositionoflocalareanetworks,italsomultiplecommunicationsnetworkinterfacemodule.

（3）modularstructure.Tomeettheneedsofvariousindustrialcontrol,inadditiontoasmallPLCunit,thevastmajorityofPLCaremodularstructure.PLCvariouscomponents,includingtheCPU,powersupply,I/O,etc.ismodularindesignfromtherackandcableswillconnecteachmodule,thesystem'ssizeandfunctioninaccordancewiththeneedsofusersofitsownportfolio.

（4）easytolearnprogramming.MostofthePLCprogrammingrelaycontrolcircuitsimilartotheladderdiagramform,theuser,donothavecomputerexpertise,itiseasytogeneralengineeringandtechnicalpersonnelunderstandandmaster.

（5）Installationissimpleandeasymaintenance.PLCdoesnotrequirespecializedequipmentroominavarietyofindustrialenvironmentscanbedirectlyrun.Variousmodulesarerunandfaultindicationdevices,user-friendlyunderstandingoftheoperationandfindfault.Themodularstructure,soanyfailureofamodule,userscanreplacethemodule,allowingthesystemtorapidlyresumeoperation.

Second,thecharacteristicsandApplicationofindustrialPC

2controlsystem

Thecontrolsystemconsistsofthecrew（FloorControlWorkstation）andPC（centralmanagementworkstation）,withthecrewusingprogrammablelogiccontroller（PLC）withthetouchscreen,PCusingindustrial-gradecomputersandprinters,systemconfigurationnecessaryiftheannexcommunicationsequipmentinterfaces,networkinterfacecards,modemsandsoon,toachievetheparametersofthestoragesystemandintelligentautomaticoperation.

Underthecrewatthesceneandtouch-screensystemscancontrol,parametersettingsanddata.PCremotemanagementandprint,itcontainsthecrewandallofthefeaturestouchscreen.Followingthesystemasawholecrewofindustrialprogrammablelogiccontrollerasthecore,toachieveautomaticcontrol.Controlequipmentanddevicesincluding:

detectionsensorcomponents,electricvalves,converter,etc..

Underthe2.1-Systems（Regionalworkstations）

2.1.1TP21touchscreen

TP27usedasacolortouch-screenoperatorpanel,completelyreplaceconventionalbutton,lightsdevice,thecontrolcabinetinterviewedmoretidy.Moreover,TP27touchscreenatthesceneshowedthatthestatecanberealized,systemsettings,modeselection,parametersetting,faultrecording,recordload,time-of-day,real-timedata,loadcurveandreportingstatistics,andotherfunctions,Chineseintuitiveandfriendlyuserinterface.

2.1.2SIEMENSPLC

SIMATICS7-300SeriesPLCappliedtoallwalksoflife,allkindsofoccasionsinthedetection,monitoringandcontrolautomation,itspowerfulfeaturestobothoperateindependently,orlinkedtoanetworkabletoachievecomplexcontrolfunctions.

Theproductfeaturesphotoelectricisolation,andhighelectromagneticcompatibility;highindustrialapplicability,allowingtheambienttemperatureof60℃;hasastronganti-jammingandanti-vibrationandimpactresistance,intheharshenvironmentoftheworkhasbeenwidelyapplications.

IalsomeansfreedomofcommunicationsS7-300PLC,averyuniquefeatures,itmakesS7-300PLCwithanycommunicationprotocolcanopenotherequipment,communicationscontroller,orPLCS7-300canbedefinedbytheusersthemselvescommunicationsprotocols（forexampleASCIIprotocol）,baudrateof1.5Mbit/s（adjustable）.Thusthescopeofthecommunicationscanbegreatlyincreased,thecontrolsystemconfigurationmoreflexibleandconvenient.Anyserialinterfacewithperipherals,suchas:

printerorbarcodereaders,thedrive,amodem（Modem）,theupperPCcanbeconnectedtothemachine.Userscanprogramtodevelopcommunicationprotocoltoexchangedata（suchas:

ASCIIcharactercode）,RS232interfacewiththeequipmentavailablePC/PPIfreecablelinkingcommunicationscommunication.

ChipandChipHolders

lntegratedCircuisareusuallycalledIcsorchips.Thayarecomplexcircuits,whichhavebennetchedontotinychipsofsemiconductor（silicon）.Thechipispackagedinaplasticholderwithpinsspacedona0.1（2.54mm）grid,whichwillfittheholesonstipboard.Veryfinewiresinisdethepackagelinkthechiptothepins.

1）Pinnumbers

Thepinsarenumberedanti-clockwisearoundtheIC（chip）startingnearthenotchordot.Itshowsthenumberingfor8-pinand14-pinIcs,buttheprincipleisthesameforallsizes.

2）Chipholders（DILsockets）

ICs（chip）areeasilydamagededbyheatwhensolderingandtheirshortpinscannotbeprotectedwithaheatsink.Insteadweuseachipholder,strictlycalledaDILsocket（DIL=DualIn-Line）,whichcanbesafelysolderedontothecircuitboard.Thechipispushedintotheholderwhenallsoldingiscomplete.

Chipholdersareonlyneddedwhensoldingsotheyarenotusedonbreaboards.

Commerciallyproducedcircuitboardsoftenhavechipssoldereddirectlytotheboardwithoutachipholder,usuallythisisdonebyamachinewhichisabletoworkveryquickly.Pleasedonnotattemptodothisyourselfbecauseyouarelikelytodestorythechipanditwillbedifferenttoremovewithoutdamagebyde-soldering.

3）Removingachipfromitsholder

4）Ifyouneedtoremoveachipitcanbegentlyprizedoutoftheholderwithasmallflat-bladescrewdriver.Carefullyleverupeachendbyinsertingthescrewdriverbladebetweenthechipanditsholderandgentlytwistingthescrewdrive.Takecaretostatreliftingatbothendsbeforeyouattempttoremovethechip,otherwiseyouwillbendandpossiblybreakthepins.

5）BipolarIntegratedCircuitsMOSIntegratedCircuits

Historically,bipolarIntegratedCircuitsusedtobemuchmorepopularthanMOSIntegratedCircuits,particularlyforsmall-sacelogicCircuits.Thereweretwomajorreasonsforthis:

first,bipolar-junctiontransistorsoriginallycouldbemanufacturedmorereliablythanMOStransistors,andsecond,theywerefaster,AsthereliabitityofMOStransistorsimproved,andasintegratedCircuitsbecamemorecomplex,whichmadethelowerpowerandsmallsizeofMOSlogicmoreimportant,thepopularityofBJTlogicdecreased,however,BJTtechnologyisstillpopularforthehighestfrequencylogiccircuits.

WhenthePCoffline,underthecontrolofthenextcrew,theentiresystemcanoperatenormally.

PCSystem2.2（centralmanagementworkstation）

PC2.2.1

PCthatisbyc