工業(yè)鍋爐溫度控制系統(tǒng)設計【含CAD圖紙、說明書】
畢 業(yè) 設 計(論 文)外 文 參 考 資 料 及 譯 文譯文題目: Based on the research of PLC temterature control system of boiler 以PLC為基礎的鍋爐溫度控制系統(tǒng)的研究 學生姓名:專業(yè):所在學院:指導教師:職稱:2016年 3 月 6 日BasedontheresearchofPLCtemperaturecontrolsystemofboilerAbstract:fromthedevelopmentconditionofboiler,PLCtypeselection,systemsoftwareandhardwaredesign,communicationupanddownamachine,theconfigurationprogramdesignispresentedinseveralaspects,suchas.BythetemperaturecontrolsystemofPLCdebuggingtheadvantagesofthesimple,lowcost,easytomaintenance,andeasytoexpandtothecorrespondingfieldofindustrialcontrol,goodportabilityisofgreatimportancetotheindustrialdevelopment Keywords:PLC;Thesensor;Temperature;TheautomaticcontroWiththecontinuousdevelopmentofeconomy,theenvironmentproblemincreasinglyprominent.Boilerastheheatingsystemisoneofthemostimportantener combustionofmorethanonethirdoftotalenergyconsumption.Atpresent,thedomesticmostoftheurbanheatingsystemintheoperationoftheboilerequipmentagingbasicrelyonmanualoperation,automationlevelislow,safetyperformanceispoor,thecombustionefficiencyisnothigh,theairpollutionisveryserious.Therefore,theconfigurationofautomatictemperaturecontrolsystemforboilerintodaysincreasinglyseriousenvironmentalpollutionsituationisextremelyimportant.gyconversiondeviceenergyconsumptionishuge,everyyearthenationalboiler1boilertemperaturecontrolbasedonPLCisintroducedThissystemisbasedonPLCboilertemperaturecontrol,throughtheboilerinternalsensorfortemperatureandflowratefeedbacktosystemparameterssuchastemperaturecontrol,theautomaticcontrolofboilertemperatureisrealized.PLCprogrammablecontrollerisakindofcombinedrelaycontrollerandcomputer,throughtheinstaller,centralprocessingunitCPUasthecoreandI/Odevicesconnectedtoitsuseinthefieldofindustrialcontrolcomputerisslightlydifferentwithordinarycomputer,mainlybytheCPU,memorycell,basiccomponentssuchastheI/Ointerfacecircuit,powersupply,plusextension,programmer,externalequipment,etc.PLCprogrammablecontrollercannotonlyreplacetheordinaryrelay,butalsohasAvarietyofextensions,suchasA/Dmodule,etc.Therefore,theuseofPLCforautomaticcontrolofboilerprovidesanewsolution,someadvancedcontrolmethodtotheapplication.UsingPLCprogrammablecontrollerforboilersystem,realizetheautomaticcontrolofthetemperature,ontheonehandcanimprovecombustionefficiency,reducefueluseandemissionsofharmfulgasinfluegas,reducingtheairpollution;PLCcontrolsystem,ontheotherhand,throughavarietyofsensorsinsidetheboilertemperature,pressure,flowandotherrelatedparameters,realizedtheautomaticcontroloftheparameterssuchastemperature.Reducesthemanuallabor,basicallyjustintheengineroomcontrolroomcanfullyunderstandtheoperationoftheboiler,reducethemanpowercost,improvetheleveloftheautomationmanagementsystem.2thetemperaturecontrolsystemdesign2.1thetemperaturecontrolsystemdesignThisdesignbySiemensS7-300programmablecontrollerforthenextbitmachine,twoindustrialcontrolmachineforPC.PCthroughindustrialcontrolsoftwaretorealizeearlywarningfunctionssuchasalarm,underamachineadoptsSiemensS7-300programmablecontroller,realizeautomaticcontrol,suchastemperature,flowrateintheboilercontrollevelandsafetyguaranteed.Systemforthetemperatureoftheobject,andusingPT100typethermalresistancesensorsinsidetheboilerwatertemperature,andthenpassedtoEM235moduletemperaturetransmitter,convertthesignalthroughthePIDarithmetic,adjustedtogetastablePIDparametervalues,thentheinputsignaltothesiliconcontrolledvoltageregulatortocontrolthevoltageoftheheater,achievethepurposeofregulatingtemperature.2.2thetemperaturecontrolsystemhardwaredesign1)thehostsystem.Usingtwosetsofindustrialcontrolcomputerhost,oneofthemasthemaincontrolmachine,anotheroneiscomplementaryhost,makedoubleinsurance.ConfigurationsoftwareWINCCSP26.0usingSiemensindustrialcontrolconfigurationsoftware.2)PLCprogrammablecontroller.SystemsuseSiemensSP-300-PLCprogrammablecontroller.Itsmodularstructure,easytoimplementdistributedconfigurationandhighcostperformance,strongelectromagneticcompatibility,resistancetoshockimpactperformanceisgood,inawiderangeofindustrialcontrolfield,becomeakindofeconomicalandpracticalsolution.VarietyofincreasingperformanceofCPUandrichwithmanyconvenientfeaturesI/Oextensionmodule(includingSMsignalmodule,communicationprocessorCP,IMinterfacemodule,etc.).Theusercanchooseaccordingtoactualapplicationmodule.3)theinstrumentequipment.Inordertoimprovetheanti-interferenceability,typeselectionofinstrumentmeterDDZ-IH45macurrentoutputfor0123,toensurethereliabilityofthesystem.Instrumentinclude:flowtransmitting,pressuretransmitter,temperaturetransmitter,liquidleveltransmitter,microoxygentransmitter,pressuretransmitter,etc.4)thefrequencyconversioncontrolroom.Mainlyincludes:powersupplycontrolcabinet,frequencyconversioncontrolcabinet,boilercirculatingpumpfrequencyconversioncontrolcabinet,controlcabinetisequippedwithvarioustypesofrelaycontactor,relay,etc.,lowvoltageelectricalequipmenttocompletethemotorstartandstop.2.3thetemperaturecontrolsystemsoftwaredesign2.3.1PIDinstructionalgorithmPIDcontrolleraccordingtotheerrorofthesystemparametervalues,calculatedbyproportionalintegralanddifferentialcontrolquantitytocontrol,socalled,PIDcontrolandPIDcontrol.Inthefieldofindustrialcontrol,PIDisstillinwideuse.Threekindsofcontrolvolumehavedifferentcharacteristics,separatelytoexistadvantagesanddisadvantagesareclearly,whenusedwithvariousrestrictionswouldhaveproblems,howtoadjustthePIDparameterofthestability,becomesthecurrentcontrolofthemostimportantstep.2.3.2characteristicsofPIDcontrolalgorithm1)theproportion(P)control.Proportional(P)controlisoneofthemostsimplecontrolmethod,thecontrolleroutputtotheinputerrorsignalisproportionaltotherelationship.Controllerwillhappenifskewed,adjustthecontroloutput,theaccusedtoreducetheamountofdeviationinthedirectionofchange.DeviationreducespeeddeterminedbyproportionalcoefficientKp,Kpthefaster,thegreaterthedeviationdecrease.Butthiswillcauseoscillation,especiallyinthehysteresislinkislarger,theproportionalcoefficientKpreducethepossibilityofoscillationwillbereduced,butatthesametimecanalsoleadtoslowadjustment.Proportionalcontrolweaknessiscanteliminatethesteady-stateerror,integralcontrolmustbeavailabletoassist.2)theintegral(I)control.Theoutputofthecontrollerintheintegralcontrolisproportionaltotheinputoftheerrorsignalintegralrelationship.Afterenteringthesteadystate,ifexiststeady-stateerrorcontrolsystem,inordertoeliminatethesteady-stateerrorofthesystem,theintegralitemmustbeadded.Astimeincreases,theintegraltermwillalsoincrease,soeventherelativelysmallerrorintegralitemwillalsobeincreasedwiththeincreaseoftime,itwillfurtherreducethesteadystate,theexistenceoferrortozero.Sotheproportionalintegral(PI)controllercanmakethesystementerthesteady-statenosteady-stateerror.3)differential(D)control.Underdifferentialcontrol,thecontrolleroutputdifferentialincreases,theinputerrorsignaldifferentialwillalsoincrease.Theautomaticcontrolsystemforerrorcontrol,therewillbeotherunnecessaryproblemssuchasmovementswillmoreseriousinstability.Thatistosay,inthecontrolleronlyintroducedratioisoftennotenough.Proportionalactionisonlymagnifiederroramplitude,butjoindifferentialitemtoavoidlargeerrors.Becauseitcanpredictthedirectionoftheerrorchange,butthedifferentialcontrolcanenlargethehighfrequencynoise,lowersignal-to-noiseratiointhesystem,resultinginadeclineintheabilityofthesystemsuppressinterference.Thatistosay,differentialcontrolcanteliminatetheresidual.2.3.3PIDparametersettingPIDparameterssettingismainlytoadjustP,Pi,Pt.Tochangethesystemcharacteristicandcausingthesystemtoachievesatisfactionindex.2.3.4PIDalgorithmprogramimplementationIntheSP-300-PIDfunctionisaccomplishedbyPIDinstructionfunctionblock,byregularlyperformPIDfunctionblock.AccordingtothePIDoperationrule,accordingtoagivenatthetime,proportionalintegraldifferentialdata,calculatethecontrolquantity.3thePIDprogramdesignSiemensPLCcontrolprogramistousetheprogrammingsoftwareS7V5.3.Firstinputanalogsignals,theboilerscurrentvoltagebynumericaldisplay.Secondwatchboilerthecurrenttemperatureisnormal,alarmindicatorlampwhethercannormaluse.Initiator,observationafterthestartposition,initializethePIDparameters,closetheprogram,zeroanalog,continuetostopboilerheatingbutstillshowsthetemperature.Settemperature,theinterruptprogram,adjustPIDparameter,outputPIDarithmeticasaresult,theoutputanalogsignals. 4theconfigurationmoduledesign1)Configurationsoftwaredesign.SelecttheconfigurationdesignofthissystemsoftwareisSiemensWINCCconfigurationsoftware,WINCCisapowerful,hastheverygoodopensoftware.Allkindsofcomplextask,WINCCcanhandle.WINCCbelongstoman-machineinterfaceconfigurationtool,itsbiggestcharacteristicistosystemintegrationonthebasisoftheconfiguration.Aslongasthepresetofvarioussoftwaremodulesforsimpleconfiguration,youcaneasilyimplementeachfunctionofmonitoringlayer,shortensthetimeofsystemintegrationtoimprovetheworkingefficiency.WINCCconfigurationsoftwarewithMicrosoftsystemasaplatform,providepowerfuleditingfunctions,anditselfcontainsrichgraphicsresources,convenientdesignallkindsofindustrialusedfigure,andeasytoedit,atthesametimewiththecomputersversatility,reducingtheworkload.Userscandesignandeditingfunction,makefulluseoftheopensexualfunction.BecausebelongtoSiemens,whenusingWINCCconfigurationsoftwarecaneasilytocreateS7-300PLCinthesystemvariables,editandmodify,greatlyconvenientfortheuser.2)pleasecommunicationupanddown.ConnectthePLCandthecomputerconnection,afterthecompletionofthesetupcommunicationinsoftware.3)thesystemdebugging.Againandagain,afterthecompletionofupanddownamachineconnectionadjustPIDtemperaturecontrolparameters,inordertogettheoptimalPIDparametervalues.Oscillationphenomenonoccurringinasystem,byaddingdifferentialadjustment,multipleoptimalPIDparametersresultingfromthedebug.以PLC為基礎的鍋爐溫度控制系統(tǒng)的研究摘要:從鍋爐的發(fā)展情況,PLC選型,系統(tǒng)軟硬件設計,上下位機通信,組態(tài)程序開發(fā)設計等幾個方面進行介紹。通過PLC實現(xiàn)的溫度控制系統(tǒng)具有調(diào)試簡單、成本低、易維修等優(yōu)勢,并且容易拓展到相應的工業(yè)控制領域,較好的可移植性對產(chǎn)業(yè)發(fā)展具有重要的意義。關鍵詞:PLC;傳感器;溫度;自動控制 隨著經(jīng)濟的不斷發(fā)展,環(huán)境問題日益突出。鍋爐作為加熱系統(tǒng)中最重要的能源消耗裝置能源消耗巨大,每年全國鍋爐燃燒消耗的能源占總產(chǎn)量1/3以上。目前,國內(nèi)大部分城市采暖系統(tǒng)中運行的鍋爐設備老化,基本依靠手工操作,自動化水平低,安全性能差,燃燒效率不高,空氣污染十分嚴重。因此,為鍋爐配置自動溫度控制系統(tǒng)在當今日益嚴重的環(huán)境污染下就顯得極為重要。1介紹基于PLC的鍋爐溫度控制這個系統(tǒng)是基于PLC的鍋爐溫度控制,通過對鍋爐內(nèi)部傳感器溫度、流量等參數(shù)的反饋來對系統(tǒng)溫度進行控制,實現(xiàn)鍋爐溫度的自動控制。PLC可編程控制器是一種將繼電器控制器和計算機組合起來,通過安裝程序,CPU中央處理單元為核心與I/O設備相連接,使用在工控領域的計算機其構成與普通計算機略有不同,主要是由CPU、存儲單元、I/O接口電路、電源等基礎部分,外加擴展部分、編程器、外部設備等方面組成。PLC可編程控制器既能替代普通的繼電器,又具有多種擴展功能,如A/D模塊等。因此,PLC的運用為鍋爐的自動控制提供了新的解決辦法,使一些先進的控制方法得以應用。使用PLC可編程控制器對鍋爐系統(tǒng)進行改造,實現(xiàn)溫度的自動控制,一方面可以提高燃燒效率,減少燃料使用和煙氣中有害氣體的排放量,減少空氣污染;另一方面,PLC控制系統(tǒng)通過各種傳感器檢測鍋爐內(nèi)溫度、壓力、流量等相關參數(shù),實現(xiàn)了對溫度等參數(shù)的自動控制。減少了手工勞動,基本上只要在機房控制室內(nèi)就可以全面了解鍋爐的運行,降低了人力成本、提高了自動化管理系統(tǒng)的水平。2溫度控制系統(tǒng)設計2.1溫度控制系統(tǒng)設計該設計采用西門子S7-300可編程控制器為下位機,上位機為兩臺工業(yè)控制機。上位機通過工控軟件來實現(xiàn)報警功能,下位機采用西門子S7-300可編程控制器,實現(xiàn)鍋爐內(nèi)溫度、流量等自動控制,保證鍋爐控制水平及安全性。系統(tǒng)為對象的溫度,使用PT100型熱電阻傳感器檢測鍋爐內(nèi)部水溫,然后傳遞給EM235模塊溫度變送器,經(jīng)過PID的運算轉(zhuǎn)換信號,調(diào)節(jié)后得到穩(wěn)定的PID參數(shù)值,然后輸入信號給可控硅電壓調(diào)節(jié)器,以控制加熱器的電壓,達到調(diào)節(jié)溫度的目的。2.2溫度控制系統(tǒng)硬件設計1)主機系統(tǒng)。使用兩套工業(yè)控制計算機控制主機,其中一個作為主控制機,另一個作為輔主機,構成雙保險。采用西門子工業(yè)控制組態(tài)軟件WINCCSP26.0。2)PLC可編程控制器。系統(tǒng)選用西門子的SP-300PLC的可編程控制器。它的模塊化結(jié)構,便于實現(xiàn)分布式的配置以及高性價比、強大的電磁兼容性、耐沖擊沖擊性能好,使其在廣泛的工業(yè)控制領域中,成為一種經(jīng)濟實用的解決方案。多種性能遞增的CPU和豐富的且?guī)в性S多方便功能I/O擴展模塊(包括信號模塊SM、通信處理器CP、IM接口模塊等)。用戶可以根據(jù)實際應用選擇模塊。3)儀表設備。為了提高抗干擾能力,儀器儀表DDZ-IH選型電流輸出為012345mA電流,保證系統(tǒng)的可靠性。儀表主要包括:流量變送、器壓力變送器、溫度變送器、液位變送器、含氧量變送器、微壓變送器等。4)變頻控制室。主要包括:電源控制柜、鍋爐變頻控制柜、循環(huán)泵變頻控制柜、控制柜內(nèi)配有各類斷電器接觸器、繼電器等,低壓電器設備,完成電機的啟動、停止。2.3溫度控制系統(tǒng)軟件設計2.3.1PID指令算法PID控制器根據(jù)系統(tǒng)參數(shù)的誤差值,通過比例積分、微分計算出控制量來進行控制,故稱為PID控制,或者PID調(diào)節(jié)。在工業(yè)控制領域中,PID現(xiàn)在還在廣泛使用。三種控制量具有不同的特點,分別存在明顯的優(yōu)點與缺點,一起使用時又會有各種約束限制的問題,如何調(diào)節(jié)出穩(wěn)定的PID參數(shù),就成為電流控制中最為重要的步驟。2.3.2PID控制算法的特點1)比例(P)控制。比例(P)控制是最簡單的一種控制方法,控制器輸出與輸入的誤差信號成正比關系。若產(chǎn)生偏差,控制器就發(fā)生作用調(diào)節(jié)控制輸出,使被控量向減小偏差的方向變化。偏差減小的速度由比例系數(shù)Kp來決定,Kp越大偏差減小的越快。但這樣會引起振蕩,特別是在遲滯環(huán)節(jié)比較大的時候,比例系數(shù)Kp減小振蕩發(fā)生的可能性就會減小,但同時也會導致調(diào)節(jié)速度變慢。比例控制的缺點是不能消除穩(wěn)態(tài)誤差,必須要有積分控制來輔助。2)積分(I)控制。在積分控制中控制器的輸出與輸入誤差信號的積分成正比關系。進入穩(wěn)態(tài)后,如果控制系統(tǒng)存在穩(wěn)態(tài)誤差,為了消除系統(tǒng)中存在的穩(wěn)態(tài)誤差,必須加入積分項。隨著時間增大,積分項也會增大,因此即便誤差比較小積分項也會隨著時間的增加而加大,它的存在會進一步減少穩(wěn)態(tài),誤差直至為零。所以比例積分(PI)控制器可以使系統(tǒng)進入穩(wěn)態(tài)后無穩(wěn)態(tài)誤差。3)微分(D)控制。在微分控制下,控制器輸出的微分增加了,輸入誤差信號的微分同時也會增加。而自動控制系統(tǒng)在對于誤差的控制來說,會出現(xiàn)別的不必要的問題比如波動更嚴重的會失穩(wěn)。這就是說,在控制器中僅引入“比例”項往往是不夠的。比例項的作用僅是放大誤差的幅值,但是加入的微分項卻能夠避免較大的誤差出現(xiàn)。因為它可以預測誤差變化的方向,但是微分控制會放大高頻噪聲,降低系統(tǒng)的信噪比,導致系統(tǒng)抑制干擾的能力下降。也就是說微分控制不能消除余差。2.3.3PID參數(shù)設置PID參數(shù)的設置主要是為了調(diào)節(jié)P,Pi,Pt。改變系統(tǒng)的特典,使得系統(tǒng)達到滿意指數(shù)。2.3.4PID算法程序?qū)崿F(xiàn)在SP-300中PID功能是通過PID指令功能來實現(xiàn)的,通過定期執(zhí)行PID功能塊。根據(jù)PID運算規(guī)律,根據(jù)當時的給定,比例-積分-微分數(shù)據(jù),計算控制量。3PID方案設計PLC控制程序是采用西門子編程軟件S7V5.3。首先輸入的模擬信號,通過數(shù)值顯示鍋爐的電流電壓。其次觀看鍋爐目前溫度是否正常,報警指示燈是否能正常使用。啟動程序,觀察起始位置,初始化PID參數(shù),關閉程序,清零模擬量,停止鍋爐繼續(xù)供熱但仍顯示溫度。設定溫度值,中斷程序,調(diào)節(jié)PID參數(shù),輸出PID運算結(jié)果,輸出模擬信號。4組態(tài)模塊設計1)組態(tài)軟件設計。本系統(tǒng)的組態(tài)設計軟件部分選擇的是西門子WINCC組態(tài)軟件,WINCC是一個功能強大,具有很好的開源的軟件。各種復雜的任務,WINCC都可以處理好。WINCC屬于人機界面的配置工具,其最大的特點是能夠以組態(tài)方式進行系統(tǒng)集成。只要對各種軟件模塊進行簡單配置預設,就可以方便地實現(xiàn)監(jiān)控層的各項功能,縮短系統(tǒng)集成時間,提高了工作效率。WINCC組態(tài)軟件以微軟系統(tǒng)作為平臺,提供了強大的編輯功能,而且本身含有豐富的圖形資源,方便設計各種工業(yè)用圖,而且方便編輯,同時因為與計算機的通用性,減少了工作量。用戶可以自行設計編輯函數(shù),充分利用了開放性功能。因為都屬于西門子公司,使用WINCC組態(tài)軟件可以輕松對S7-300PLC系統(tǒng)中的變量進行創(chuàng)建,編輯和修改,大大方便了用戶。2)上下機位通信。鏈接PLC與計算機,在軟件上建立通信。3)系統(tǒng)調(diào)試。上下位機連接完成后,一次又一次調(diào)整溫度控制PID參數(shù),以獲得最佳的PID參數(shù)值。系統(tǒng)中出現(xiàn)震蕩現(xiàn)象,通過加入微分調(diào)整,多次調(diào)試后得到最好的PID參數(shù)。
收藏