毕业论文PLC变频器在恒压供水上的应用.doc

连云港职业技术学院毕业设计(论文)开题报告学生姓名：学号：所在学院：专业：设计(论文)题目：指导教师：PLC变频器在恒压供水上的应用摘要建设节约型社会合理开发、节约利用和有效保护水资源是一项艰巨任务。根据高校用水时间集中用水量变化较大的特点分析了供水系统存在成本高可靠性低水资源浪费管网系统待完善的问题。提出以利用自来水水压供水与水泵提水相结合的方式并配以变频器、软启动器、PLC、微泄露补偿器、压力传感器、液位传感器等不同功能等传感器根据管网的压力通过变频器控制水泵的转速使水管中的压力始终保持在合适的范围。从而可以解决因楼层太高导致压力不足及小流量时能耗大的问题。另外水泵耗电功率与电机转速的三次方成正比关系所以水泵调速运行的节能效果非常明显平均耗电量较通常供水方式节省近四成。结合使用可编程控制器可实现主泵变频副泵软启动具有短路保护、过流保护功能工作稳定可靠大大延长了电机的使用寿命。关键词：变频调速PLC恒压供水自动控制PLCFREQUENCYCONVERTERINTHEAPPLICATIONOFCONSTANTPRESSUREONTHEWATERABSTRACTBuildingtheconservation-orientedsocietythereasonabledevelopmentsavesandtheeffectiveprotectingwaterresourcesisanarduoustask.Becentralizedaccordingtotheuniversitywaterusedtimethewaterconsumptionchangemajorcharacteristicanalyzedthecampusoriginalwatersupplysystemexistencecosttobehighthereliabilitywaslowthewaterresourceswastethepipenetworksystemtreatedtheconsummationthequestion.ProposedthatdrawswaterthewaywhichusingtherunningwaterhydraulicpressurewatersupplyandthewaterpumpunifiesandmatchesbytheinverterthesoftstarterPLCMicrorevealsthecompensatorthepressuretransmitterthefluidpositionsensorandsoon.accordingtothenetworkmanagementpressurecontrolswaterpump'srotationalspeedthroughtheinvertercausesinwaterpipe'spressuremaintainsatthroughouttheappropriatescopethusmaysolvetheproblemwhichthefloorhighpressureistooinsufficientwhensmallcurrentcapacitytheenergyconsumptionisbig.Moreoverthewaterpumpconsumestheelectricpowerandtheelectricalmachineryrotationalspeedisproportionalthreecubedtherelationsthereforethewaterpumpvelocitymodulationmovement'senergyconservationeffectisobvioustheaveragepowerconsumption