汽包水位毕业论文---基于PLC工业锅炉汽包水位控制系统的设计

基于PLC工业锅炉汽包水位控制系统的设计TheDesignoftheBoilerDrumWaterLevelControlSystemwithPLCI摘要锅炉是众多工业部门必不可少的重要动力设备。因此，锅炉往往成了不少工厂不可缺少的一部分。因而，对锅炉设备中的自动控制系统进行分析研究是必要的。锅炉水位控制系统是锅炉生产控制系统中最重要的环节。对锅炉生产操作如果不合理，管理不善，处理不当，往往会引起事故。这些事故中的大部分是由于锅炉水位控制不当引起的，可见锅炉汽包水位控制在锅炉设备控制系统中的重要性。锅炉汽包水位是一个非常重要的被控变量。由于锅炉的水位调节过程难以建立数学模型，具有非线形、不稳定性、时滞等特点。传统的锅炉水位三冲量控制系统大都采用PID控制，其控制效果还可以进一步提高。而模糊控制不要求知道被控对象的精确模型，只需要操作人员的经验知识及操作数据，鲁棒性强，非常适合于非线性、滞后系统的控制。关键词:汽包水位；模糊PID；三冲量AbstractTheboilerisnumerousessentialimportantpowerequipmentofindustrialdepartment.So,theboilerhasoftenbecomeanindispensablepartofmanyfactories.Therefore,itisessentialforautomaticcontrolsystemintheboilerequipmenttoresearch.Thewaterlevelcontrolsystemoftheboileristhattheboilerproducesthemostimportantlinkinthecontrolsystem.Iftheproductionoperationoftheboilerisunreasonable,itisimpropertodealwith,andwilloftencausetheaccident.Themajorityintheseaccidentsiscausedbecauseofimproperincontrolthewaterleveloftheboiler.Thatcanseetheimportanceintheequipmentcontrolsystemoftheboilerofcontrolofwaterlevelofsteamdomeoftheboiler.Theauto-controlofthedrumwaterlevelisveryimportant.Thedrumwaterlevelisanimportantvariabletobecontrolled,itishardtogetthemathematicmodelofthewaterlevelwithadjustprocess.Itischaracteristicofnonlinearity,instabilityandtimelag.Thetraditionalcontrolmodeofthree-variableinthedrumwaterlevelmostusePID,theeffectofitcanbeimproved.Thefuzzycontroldoesnotneedprecisemathematicmodelofthecontrolledobject,itonlyneedstheexperienceofoperatorandthedateofoperatingithasgoodrobustnessanditfittocontrolthesystemwithnonlinearityandlag.Keywords:Drumwaterlevel,Fuzzy-PID,Three-variableII目录摘要................................................IABSTRACT...........................................I1.引言.................................................12.工业锅炉的理论基础...................................12.1工业锅炉的控制要求与工艺流程................................................................12.2课题背景及本文研究内容............................................................................22.3锅炉水位控制系统在锅炉生产控制系统中的重要性................................33锅炉汽包水位的基本特性和汽包水位控制系统方案选择.....33.1锅炉汽包水位控制对象的基本特性............................................................33.1.1汽包水位在给水流量扰动下的动态特性................................................43.1.2汽包水位在蒸汽负荷扰动下的动态特性................................................53.1.3燃料量扰动下汽包水位的动态特性........................................................63.2锅炉汽包水位控制系统及控制方案选择....................................................73.2.1单冲量水位控制系统................................................................................73.2.2双冲量水位控制系统................................................................................83.2.3三冲量水位控制系统................................................................................83.2.4三冲量模糊水位控制系统........................................................................93.2.5汽包水位控制系统方案的选择..............................................................104．锅炉汽包水位模糊控制系统的设计.....................114.1主回路模糊控制器的设计..........................................................................114.1.1确定模糊控制器的结构及输入、输出语言变量..................................11III4.1.2确定各变量的隶属度函数和赋值表......................................................114.1.3模糊控制规则的确定..............................................................................144.1.4模糊控制响应表的生成..........................................................................144.2模糊动态前馈控制器的设计......................................................................164.3PID控制的设计..........................................................................................164.3.1PID控制的基本公式................................................................................164.3.2PID的参数设置......................................................................................165.PLC选型及资源分配.................................175.1PLC电气图和I/O分配表..........................................................................175.2PLC选型......................................................................................................185.3传感器选型.................................................................................................185.4特殊模块功能..............................................................................................186.控制系统程序设计....................................186.1编程软件......................................................................................................196.2控制系统流程图..........................................................................................196.2.1控制系统总流程图设计..........................................................................196.2.2模糊控制流程图......................................................................................196.2.3PID控制流程图........................................................................................206.2.4动态前馈流程图......................................................................................206.3系统的程序设计..........................................................................................216.3.1水位控制................................