基于PLC的称重给煤机控制系统设计毕业论文

基于PLC的称重给煤机控制系统设计I中文摘要随着火电厂规模和单机容量的扩大，给煤机在整个选煤系统中的作用越来越大，目前300MW及以上的大机组的锅炉一般采用直吹式制粉系统，即一台磨煤机配备若干台给煤机，磨煤机的煤粉直接进入锅炉燃烧器燃烧。这样锅炉的給煤量就完全由给煤机决定，给煤机的控制性能就显得尤为重要。给煤机给煤量过多会加大皮带电机负荷，增加皮带磨损程度，增加设备故障发生几率，影响生产效率；给煤机给煤量过少又会降低生产效率，影响效益。称重式给煤机是一种可均匀、连续、定量地给煤到磨煤机中的设备，并且可以在给煤过程中对煤连续称重,同时根据燃烧系统需求的煤量信号，随时调节给煤量。因此称重给煤机广泛适用于电力、冶金等各行业的工业锅炉的连续给煤。可编程控制器PLC因具有高可靠性、易集中控制的优点，使其在工业控制中得到广泛应用。本设计用S7-200PLC和MCGS监控软件实现称重式给煤机监控系统的设计、调试等。通过上位机的监控画面，我们便可以对现场的机器运行状况一目了然。本文重点介绍了可编程控制器在给煤机称重监控系统中的应用。分析了目前给煤机在电厂中的重要地位，根据给煤机控制系统的现有状况，详细阐述了改造后系统的工作原理及方式、控制系统的组成、PLC应用领域、发展方向以及如何设计梯形图在本文中都一一进行了介绍。并且经过模拟试验，证明了改造后系统运行达到了经济高效稳定的预定要求。因此用PLC及上位机监控实现对给煤机的控制是现代化火电厂的需要。关键词称重式给煤机，可编程序控制器，上位机，监控系统沈阳工程学院毕业设计（论文）IIAbstractWiththescaleofthepowerplantandsinglecapacityexpansion,toploughinthewholeselectiontheroleofcoalsystemismoreandmorebig,Ofthe300MWandabovetheboilergenerallyUSESthestraightblowingpulverizingsystem,namelyamillisequippedwiththenumberofcoalfeeder,millcoaldirectlyintotheboilercombustionburner.Sothecoalboileriscompletelytothecoaltodecision,sotothecontrolperformancemeasurementcoalareparticularlyimportant.thecoaltogivetoomuchcanincreasetheamountofcoalbeltmotorload,increasebeltworndegree,increaseequipmentfailurerisk,affectstheproductionefficiency;Togivecoalstokerhadmeasuredandwillreducetheproductionefficiencyless,affectbenefits.Coalisakindofweighcanbeevenly,continuousandquantitativelytocoaltothemillequipment,andcanbeintheprocessofcoaltocoalforweighing,andaccordingtothedemandofthecoalcombustionsystemofsignal,adjustatanytimetocoalquantity.Toplowhassetupconvenient,environmentalprotection,andotherverymuch,widelyusedinelectricpower,metallurgyindustriesoftheindustrialboilercontinuouslytocoal.PLCprogrammablecontrollerwithhighreliability,easyfortheadvantagesofcentralizedcontrol,sothatintheindustrycontrolhavebeenwidelyused.ThisdesignwithS7-200PLCandMCGSsoftwarerealizationweighingtypemonitoringtoploughthedesignofmonitoringandcontrolsystem,commissioning,etc.Byusingcomputermonitorscreen,thenwecanthemachinerunningsituationofthebeclearataglance.Thispaperintroducesaprogrammablecontrollerinweighingsystem.Analysisofthecurrentcoalfeederinpowerplantinanimportantposition,accordingtothecoalfeedercontrolsystempresentsituation,elaboratedthetransformationsystem'sprincipleofworkandthestyle,thecompositionofthecontrolsystem,PLCapplicationdevelopmentdirection,andhowtodesigntheladderdiagraminthispaperoneoneareintroduced.Andthroughthesimulationtest,provedafterthetransformationoftheoperatingsystemtoachievetheeconomicefficientstabilityrequirements.SowithPLCandPCmonitortothecontrolofthecoaltorealizethemodernizationconstructionofcoal-firedpowerplantsisneeded.KeyWordsWeighingtypecoalfeeder,programmablecontroller,PC,monitoringsystem基于PLC的入仓煤计量控制系统设计I目录中文摘要..........................................................................................................................................IAbstract..........................................................................................................................................II1引言.........................................................................................................................................-1-1.1选题意义........................................................................................................................-1-1.2称重式给煤机国内外现状及发展趋势........................................................................-1-2称重给煤机软件简介.............................................................................................................-3-2.1PLC概述........................................................................................................................-3-2.2S7-200PLC性能简介...................................................................................................-5-2.3MCGS软件概述............................................................................................................-6-2.4变频器概述....................................................................................................................-7-3称重给煤机控制系统硬件设计.............................................................................................-9-3.1称重式给煤机简介........................................................................................................-9-3.2称重给煤机的计量原理图..........................................................................................-12-4称重给煤机控制系统软件设计...........................................................................................-13-4.1称重给煤给煤机控制系统I/O表...............................................................................-13-4.2称重给煤机控制系统梯形图.......................................................................................-13-4.3梯形图工作过程分析...................................................................................................-13-4.4称重给煤机组态设计...................................................................................................-21-总结...........................................................................................................................