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1、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。根据生活小区用水时间集中,用水量变化较大的特点,分析了小区原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、PLC、压力传感器、液位传感器等不同功能的传感器,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
2、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,具有短路保护、过流保护功能,工作稳定可靠,较大的延长了电机的使用寿命。关键词:恒压变频供水变频器PLC自动控制34ABSTRACTBuildingtheconservation-orientedsociety,thereasonabledevelopment,savesandtheeffectiveprotectingwaterresourcesisanarduoustask.Accordingtothecharacteris
3、ticofthetimetofocusonwaterofthedomesticandvariationinwaterconsumption,itanalyzesthattherearequestionsthathighlycost,lowreliability,thewater-resourceswaste,andtheconsummateof thepipenetworksystemoftheoldwater-supplysystemintheresidentialarea.Soweproposedthat
4、wecouldmakeuseofthewayof combininghydraulicpressurewatersupplyoftherunningwaterwith thewaterpump,andaccompaniedbythetransducer,PLC,thepressuresensor,thefluidpositionsensorandsoon.Accordingtothepressureofthenetworkmanagement,itcouldmaintainthepressureofthepi
5、peinappropriaterangethroughcontrollingrotationalspeedofthewaterpumpthroughtheinvertercommands.Thuswemaysolvetheproblemthattheinsufficientpressurecausedbythehighfloorandthehighenergyconsumptionwhenthecurrentissmall.Moreover theelectricpowerconsumptionofthewa
6、terpumpandtherotationalspeedoftheelectricalmachinery isproportionalthreecubedtherelations,thereforetheenergyconservationeffectof thewaterpumpvelocitymodulationmovementisobvious,theaveragepowerconsumptionusualwatersupplywaysaves40%.Combinedwiththeprogrammabl
7、econtroller,wemayrealizethemainpumpfrequencyconversionwhichhastheshortcircuitprotection,theoverflowprotectionfunctionstablyandtheworkreliable,thusweextendelectricalmachinery'sservicelifegreatly.Keywords:Constantpressurefrequencyconversionwatersupply,thetran
8、sducer,PLC,automaticcontrol34目录目录1第1章绪论31.1恒压供水问题的提出31.2本课题产生的背景和意义41.3变频恒压供水现况41.3.1国内外恒压供水现况41.3.2变频恒压供水系统应用范围5第2章变频恒压供水系统的硬件设备62.1变频器62.1.1变频器的基本原理62.1.2变频器结构电路图72.1.3变频器的配线82.2其他低压电器的选择122.3文本显示器12