锅炉水位控制系统的设计说明书

学号：毕业设计说明书GRADUATEDESIGN设计题目：锅炉水位控制系统的设计学生姓名：专业班级：学院：指导教师：摘要-I-摘要锅炉是多数工业过程中常用的热能动力设备，工业锅炉控制系统是复杂的控制系统。由于设备分散、管理不善或技术原因，使多数锅炉难以处于良好的工况，增加了锅炉的燃料消耗，降低了效率。为确保安全，稳定生产，对锅炉的自动控制十分重要，其中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具有非线性、不稳定性、时滞性等特点，对锅炉汽包水位的控制提出了更高的要求。锅炉汽包水位控制系统的设计方案主要有三种，即单冲量、双冲量、三冲量：前两种方案有系统结构简单，成本低，不能有效的控制“虚假水位”现象等特点；与前两种方案相比，最后一种方案有系统结构复杂，成本高但能抑制“虚假水位”现象，控制效果好等特点。本文在三种汽包水位控制系统方案的基础上较为系统地分析了PID控制、前馈控制和串级控制的基本原理、理论和实现，并且在串级三冲量汽包水位控制系统中做了三种控制算法的MATLAB仿真，最后对以上三种控制算法做了比较。关键词：锅炉汽包水位；虚假液位；PID控制；MATLAB；Abstract-II-AbstractBoileristhermalpowerplantusuallyusedinmostindustrialprocessesandIndustrialboiler’scontrolsystemisacomplexcontrolsystem.Becauseofscatteredequipment,poormanagementortechnicalreason,itisdifficulttoworkingoodconditionforthemajorityofboilersandincreasedtheirfuelconsumptionandreducedtheworkefficiency.Itisveryimportanttocontrolboilerautomaticallyinsafetyandstabilization,andboiler’sdrumwater-levelisanimportantvariabletobecontrolled.Boiler’swateradjustingprocesshasnonlinearity,instabilityanddelaycharacters,soitmakeshigherdemandforboiler’sdrumwater-levelcontrolsystem.Designingmodelsofboilerdrumwater-levelcontrolsystemmainlyincludessingle-impulse,double-impulseandthree-impulse:twoformermodelsofwhichhavethefeaturesofsimplicityandlow-cost,butcannotcontrolfalse-water-level;lastmodelofwhichhasthefeaturesofcomplexityandhigh-costcomparedwiththetwoformermodels,butcancontrolfalse-water-levelandcanreachgoodeffectivecontrol.Theauthoranalysestheprinciple,theoryandrealizationofthealgorithmsofPIDcontrol,feedforwardcontrolandcascadecontrolsystematicallybasedonthemodelofthree-impulseboiler'sdrumwater-levelcontrolsystemand;Thesealgorithmsincascadethree-impulseboiler'sdrumwater-levelcontrolsystemaresimulatedwithSimulink;Finally,above-mentionedthreealgorithmsarecompared.Keywords:boiler'sdrumwater-level;false-water-level;PIDcontrol;MATLAB;第1章绪论-1-目录摘要.............................................................................................................................IABSTRACT.......................................................................................................................II1.1锅炉概述[3]............................................................................................................................21.2目前锅炉控制的研究现状...................................................................................................31.3课题提出及意义....................................................................................................................41.3.1“虚假水位”现象.............................................................................................................51.3.2课题提出的意义及背景....................................................................................................61.4本文的主要工作....................................................................................................6第2章锅炉汽包水位PID控制系统的设计..............................................................82.1锅炉控制系统[4][5][6]..............................................................................................................82.1.1锅炉控制系统结构总图[7].................................................................................................82.1.2锅炉燃烧控制系统............................................................................................................92.1.3锅炉气温控制系统............................................................................................................92.1.4锅炉给水控制系统..........................................................................................................102.1.5辅助控制系统..................................................................................................................10第3章PID控制理论.................................................................................................113.1PID理论概述.......................................................................................................113.2PID控制及其控制算法.......................................................................................113.2.1PID控制概述.....................................................................................................113.2.2PID控制...........................................................................................................123.2.2.1比例（P）控制.............................................................................................123.2.2.2比例微分(PD)控制环节...............................................................................133.2.2.3积分(I)控制.................................................................................................143.2.2.4比例积分(PI)控制.......................................................................................153.2.2.5比例积分微分(PID)控制.............................................................................154.3本章小结...............................................................................................................16第4章锅炉汽包水位特性及其控制........................................................................174.1锅炉汽包水位系统介绍.................................