本科畢業(yè)論文（設(shè)計）論文題目:PLC和變頻器在礦區(qū)節(jié)能供水系統(tǒng)中的應(yīng)用學(xué)生姓名：所在院系：機電學(xué)院所學(xué)專業(yè)：機電技術(shù)教育導(dǎo)師姓名：完成時間：I摘要隨著社會經(jīng)濟(jì)的飛速發(fā)展，對礦區(qū)供水的數(shù)量、質(zhì)量、穩(wěn)定性提出了越來越高的要求。我國礦區(qū)尤其是老礦區(qū)供水自動控制系統(tǒng)配置相對落后，機組的控制主要依賴值班人員的手工操作?？刂七^程繁瑣，而且手動控制無法對供水管網(wǎng)的壓力和水位變化及時作出恰當(dāng)?shù)姆磻?yīng)。為了保證供水，機組通常處于超壓狀態(tài)運行，不但效率低、耗電量大，而且礦區(qū)管網(wǎng)長期處于超壓運行狀態(tài)，曝?fù)p也十分嚴(yán)重。本論文結(jié)合我國供水的現(xiàn)狀，設(shè)計了一套基于PLC的變頻調(diào)速恒壓自動控制供水系統(tǒng)。變頻調(diào)速恒壓供水自動控制系統(tǒng)由可編程控制器、變頻器、水泵電機組、壓力傳感器以及控制柜等構(gòu)成。系統(tǒng)采用一臺變頻器拖動4臺電動機的起動、運行與調(diào)速，采用循環(huán)使用的方式運行。在變頻調(diào)速恒壓供水系統(tǒng)中，單臺水泵工況的調(diào)節(jié)是通過變頻器改變電源的頻率f來改變電機的轉(zhuǎn)速n，從而改變水泵性能曲線得以實現(xiàn)的。分析水泵工況的能耗比較圖，可以看出利用變頻調(diào)速實現(xiàn)恒壓供水，當(dāng)轉(zhuǎn)速降低時，流量與轉(zhuǎn)速成正比，功率以轉(zhuǎn)速的三次方下降，與傳統(tǒng)供水方式中用閥門節(jié)流方式相比，在一定程度上可以減少能量損耗，節(jié)能效果明顯。關(guān)鍵詞:PLC,變頻調(diào)速，恒壓供水IITheapplicationofPLCandFrequencychangertominingareaswater-supplyAbstractWiththeprogressdevelopmentofsocialeconomicandtheconstructofminingareacontinuouslyenlarge,increasingofpopulationandstandardoflivingofpeoplecontinuouslyimproved,moreandmoredemandingtoquantity,qualityandstabilityofwatersupplybringforwardinminingarea.Theautomaticdegreeofwaterworksintownismuchlowerthanthecorrespondenceincity.Especiallyinsomeoldwaterworks,theequipmentofautomaticcontrolsystemisdroppedbehind.Thecontrolofunitismainlydependedonmanualoperatingofwatches.Theprocessofcontrolisverycomplicatedandthatmanualcontrolcantmeetthechangeofpressureinthepipesandthewaterlevelofthepurepond.Italsocantacttheproperfeedbackintime.Forthesakeofwatersupply,theelectromotorunitusuallyworksinthestateofovercharge.Notonlyefficiencyofelectromotorislowandelectricityconsumingisbigger,butalsothepressureofpipesisoverloadinlongterm.Onthebasisofanalyzingstatusinquoofthewaterworksinourcountry,thispaperdesignsasuitofconstantpressurewatersupplyautomaticcontrolsystembyusingvariablefrequencyspeed-regulatingtechnologybasedonPLC.ThesystemismadeupofPLC,transducer,unitsofpumpsandelectromotors,pressuresensor,industrialcontrolcomputerandconsole.Thesystemisusedatransducertomakefourelectromotorsstarting,runningandtiming.Totuneupthefrequencyofpowersupplybythetransducerinthesystem,thisadjustingmakethespeedofelectromotorandperformancecurveofpumpchange.Atlast,itmakethestatusofapumpalter.Throughanalyzingthefigureofenergywastingofpump,thequalityinpipesisdirectproportionofthespeedofpumpifthespeedofpumpisreduced.Thepowerofelectromotorfellthecubeofthespeedofpump.Sotheenergywastingofconstantpressurewatersupplybasedonvariablefrequencyspeedregulatingtechnologyisenvidentlessthanthetraditionalmodeisusedthrottletosupplywater.KeyWords:PLC,Frequencychanger,Constantpressurewater-supplyIII目錄1緒論.11.1水泵電機的調(diào)控技術(shù).11.1.1調(diào)速節(jié)能.11.1.2常用的調(diào)速方式.31.2多泵恒壓供水系統(tǒng)中的關(guān)鍵問題和本文的主要研究內(nèi)容.61.2.1多泵恒壓供水的關(guān)鍵問題.61.2.2本文的主要研究內(nèi)容.62變頻調(diào)速恒壓供水系統(tǒng)能耗機析72.1水泵理論及水泵工況點確定的研究.72.1.1水泵的工作參數(shù).72.1.2水泵理論工況點的確定.92.2水泵工況的調(diào)節(jié).102.3變頻調(diào)速恒壓供水系統(tǒng)能耗機理分析.112.3.1水泵工況的調(diào)節(jié)程.112.3.2調(diào)速范圍的確定.133變頻調(diào)速恒壓供水系統(tǒng)的設(shè)計.133.1系統(tǒng)的方案設(shè)計及具體要求.133.1系統(tǒng)的方案設(shè)計及具體要