基于PLC的太阳能热水器自动控制系统设计

基于PLC的太阳能热水器自动控制系统设计DesignofSolarWaterHeaterAutomaticControlSystemBasedonPLC学院：电气工程学院专业班级：自动化1005班学号：100302516学生姓名：魏天野指导教师：白山（教授级高工）2014年6月密级：公开密级：公开密级：公开密级：公开密级：公开I摘要现在，城市居民绝大部分都使用了太阳能热水器，农村也有相当一部分人使用。太阳能热水器在技术上比较成熟、造价比较低廉，同时由于给人民提供绝对安全的热水而受到人们的欢迎，且具有节能、环保、安全、便利、长久等优点，所以它的应用会越来越广。因此，研究和开发先进的太阳能热水器控制系统变得越来越重要。本设计阐述了可编程控制器（PLC）在太阳能热水器控制系统中的应用,重点研究了系统的硬件构成及软件的设计过程。指出了PLC设计的关键是能满足基本的控制功能,并考虑维护的方便性、系统可扩展性等。本设计利用西门子S7-200PLC，进行了太阳能热水器自动控制系统的I/O分配和PLC选型，编写了PLC程序梯形图和接线图，实现了自动上水排水、自动循环、自动加热、PID闭环控制恒温出水、手动与自动模式切换等功能。并在此基础上，利用S7-200的仿真软件对系统进行了仿真，利用WinCCFlexible软件组态了人机界面，使用MPI通信协议实现了PLC与触摸屏的通信连接。把可编程控制器PLC作为太阳能热水器的控制系统，增加了系统的方便性与可靠性，减少了其它元器件的使用。它使系统接线简单，检修维护方便快捷，增进了系统的先进性。论文分为四章：第一章介绍了太阳能热水器发展背景及设计意义；第二章介绍了太阳能热水器的工作原理；第三章介绍了硬件选型及系统流程；第四章介绍了系统程序的编写、系统的仿真、人机界面（WinCCFlexible）组态过程。关键词：太阳能热水器；PLC；自动控制系统IIAbstractNow,vastmajorityofurbanresidentsusesolarwaterheaters,sodoaconsiderablenumberofruralpeople.Solarwaterheatersaretechnicallymoremature,relativelylowcost.Meanwhile,sinceitprovideabsolutesecuritytothepeopleofhotandpeoplearewelcome,andithassomeadvantagesofenergysaving,environmentalprotection,safety,convenience,long,etc.Soitwillbewidelyapplied.Therefore,theresearchanddevelopmentofcontrollingsystemofadvancedsolarwaterheaterarebecomingincreasinglyimportant.ThisdesignexpoundstheapplicationofPLCinsolarwaterheaterautomaticcontrollingsystem,especiallythedesigningprocessofhardwareandsoftwareofthesystem.Furthermore,theprojectshowsthatthekeyofPLCdesigningistosatisfythebasiccontrollingfunction,consideringtheconvenienceofmaintenanceandscalability.Inthisdesign,theaddressofI/OisresignedandthesuitablePLCischosen.Theelectricalprinciplediagramandtheinterconnectiondiagramaredrawn,accordingtotherequirement.Automaticwaterdrainage,automaticcycle,automaticheating,PIDloopcontroltemperaturewater,manualandautomaticmodeswitchingfunctionhavebeenrealized.Andonthisbasis,thesystemwassimulatedusingthesimulationsoftwareforS7-200,producedaman-machineinterfacebyusingWinCCFlexiblesoftware.Asthecontrollingsystemofsolarwaterheater,PLCgreatlyreducesthenumberofothercomponents.Moreover,ithasthefeaturesuchassimpleinterconnection,rapidandeasyfaultdetectingandmaintenance,andadvancementofthesystem.Thepaperisdividedintofourchapters:thefirstchapterdescribesthebackgroundofthedevelopmentanddesignofsolarwaterheaterssignificance;Secondchapterdescribestheworkingprincipleofsolarwaterheaters;Thirdchapterdescribesthehardwareselectionandsystemprocesses;Thefourthchapterdescribestheproceduresforthepreparationofthesystem,systemsimulation,HMI(WinCCFlexible)configurationprocess.Keywords:Solarwaterheater;PLC;AutomaticcontrolsystemI目录摘要.....................................................................................................................................IAbstract.....................................................................................................................................II第1章绪论..............................................................................................................................11.1课题研究的背景..........................................................................................................11.2国内外研究现状简述..................................................................................................21.3太阳能热水器市场分析..............................................................................................31.4本设计特点及主要内容..............................................................................................5第2章太阳能热水器的组成及工作原理..............................................................................62.1太阳能热水器的基本结构..........................................................................................62.2太阳能热水器的工作原理..........................................................................................82.3本设计要实现的功能................................................................................................10第3章太阳能热水器硬件的选型及设计............................................................................113.1PLC的工作原理........................................................................................................113.2硬件设备的选型........................................................................................................133.2.1PLC的选型.....................................................................................................133.2.2其他硬件的选型.............................................................................................153.3太阳能热水器的整体设计........................................................................................183.3.1PID闭环控制.................................................................................................183.3.2PLC与外部设备连接方案.............................................................................203.3.3水工艺流程设计.............................................................................................22第4章系统软件框架的构建与系统仿真............................................................................234.1系统的I/O口地址及相关的软元件功能设置......................................