【正文】
.. . . ..摘 要建設(shè)節(jié)約型社會,合理開發(fā)、節(jié)約利用和有效保護水資源是一項艱巨任務(wù)。根據(jù)高校用水時間集中,用水量變化較大的特點,分析了校園原供水系統(tǒng)存在成本高,可靠性低,水資源浪費,管網(wǎng)系統(tǒng)待完善的問題。提出以利用自來水水壓供水與水泵提水相結(jié)合的方式,并配以變頻器、軟啟動器、PLC、微泄露補償器、壓力傳感器、液位傳感器等不同功能等傳感器,根據(jù)管網(wǎng)的壓力,通過變頻器控制水泵的轉(zhuǎn)速,使水管中的壓力始終保持在合適的范圍。從而可以解決因樓層太高導(dǎo)致壓力不足及小流量時能耗大的問題。另外水泵耗電功率與電機轉(zhuǎn)速的三次方成正比關(guān)系,所以水泵調(diào)速運行的節(jié)能效果非常明顯,平均耗電量較通常供水方式節(jié)省近四成。結(jié)合使用可編程控制器,可實現(xiàn)主泵變頻,副泵軟啟動,具有短路保護、過流保護功能,工作穩(wěn)定可靠,大大延長了電機的使用壽命。關(guān)鍵詞:恒壓供水,PLC,變頻調(diào)速ABSTRACTBuilding the conservationoriented society, the reasonable development, saves and the effective protecting water resources is an arduous task. Be centralized according to the university water used time, the water consumption change major characteristic, analyzed the campus original water supply system existence cost to be high, the reliability was low, the water resources waste, the pipe network system treated the consummation the question. Proposed that draws water the way which using the running water hydraulic pressure water supply and the water pump unifies, and matches by the inverter, the soft starter, PLC, Micro reveals the pensator, the pressure transmitter, the fluid position sensor and so on. according to the network management pressure, controls water pump39。s rotational speed through the inverter, causes in water pipe39。s pressure maintains at throughout the appropriate scope, thus may solve the problem which the floor high pressure is too insufficient when small current capacity the energy consumption is big. Moreover the water pump consumes the electric power and the electrical machinery rotational speed is proportional three cubed the relations, therefore the water pump velocity modulation movement39。s energy conservation effect is obvious, the average power consumption usual water supply way saves 40%.The union uses the programmable controller, may realize the main pump frequency conversion, the auxiliary pump soft start, has the short circuit protection, the overflow protection function stably, the work reliable, lengthened electrical machinery39。s service life greatly.Key words: Constant pressurewatersupply。 PLC。 Variable velocity Variable frequency.目 錄摘要.........................................................................................1ABSTRACT...................................................................................1目錄.........................................................................................3緒論.........................................................................................4變頻恒壓供水系統(tǒng)構(gòu)成及工作原理.................................................9相關(guān)器件的選型及接線...............................................................14PLC控制及編程.........................................................................20MCGS組態(tài)軟件..........................................................................28總結(jié).......................................................................................37致謝.......................................................................................38參考文獻...................................................................................391緒 論隨著變頻技術(shù)的發(fā)展和人們對生活飲用水品質(zhì)要求的不斷提高,變頻恒壓供水系統(tǒng)以其環(huán)保、節(jié)能和高品質(zhì)的供水質(zhì)量等特點,廣泛應(yīng)用于多層住宅小區(qū)及高層建筑的生活、消防供水中。變頻恒壓供水的調(diào)速系統(tǒng)可以實現(xiàn)水泵電機無級調(diào)速,依據(jù)用水量的變化自動調(diào)節(jié)系統(tǒng)的運行參數(shù),在用水量發(fā)生變化時保持水壓恒定以滿足用水要求,是當今最先進、合理的節(jié)能型供水系統(tǒng)。在實際應(yīng)用中如何充分利用專用變頻器內(nèi)置的各種功能,對合理設(shè)計變頻恒壓供水設(shè)備、降低成本、保證產(chǎn)品質(zhì)量等有著重要意義。變頻恒壓供水方式與過去的水塔或高位水箱以及氣壓供水方式相比,不論是設(shè)備的投資,運行的經(jīng)濟性,還是系統(tǒng)的穩(wěn)定性、可靠性、自動化程度等方面都具有無法比擬的優(yōu)勢,而且具有顯著的節(jié)能效果。目前變頻恒壓供水系統(tǒng)正向著高可靠性、全數(shù)字化微機控制、多品種系列化的方向發(fā)展。追求高度智能化、系列化、標準化,是未來供水設(shè)備適應(yīng)城鎮(zhèn)建設(shè)中成片開發(fā)、智能樓宇、網(wǎng)絡(luò)供水調(diào)度和整體規(guī)劃要求的必然趨勢。變頻恒壓供水系統(tǒng)能適用生活水、工業(yè)用水以及消防用水等多種場合的供水要求,該系統(tǒng)具有以下特點:⑴供水系統(tǒng)的控制對象是用戶管網(wǎng)的水壓,它是一個過程控制量,同其他一些過程控制量(如:溫度、流量、濃度等)一樣,對控制作用的響應(yīng)具有滯后性。同時用于水泵轉(zhuǎn)速控制的變頻器也存在一定的滯后效應(yīng)。⑵用戶管網(wǎng)中因為有管阻、水錘等因素的影響,同時又由于水泵自身的一些固有特性,使水泵轉(zhuǎn)速的變化與管網(wǎng)壓力的變化成正比,因此變頻調(diào)速恒壓供水系統(tǒng)是一個線性系統(tǒng)。⑶變頻調(diào)速恒壓供水系統(tǒng)要具有廣泛的通用性,面向各種各樣的供水系統(tǒng),而不同的供水系統(tǒng)管網(wǎng)結(jié)構(gòu)、用水量和揚程等方面存在著較大的差異,因此其控制對象的模型具有很強的多變性。⑷在變頻調(diào)速恒壓供水系統(tǒng)中,由于有定量泵的加入控制,而定量泵的控制(包括定量泉的停止和運行)是時時發(fā)生的,同時定量泵的運行狀態(tài)直接影響供水系統(tǒng)的模型參數(shù),使其不確定性地發(fā)生變化,因此可以認為,變頻調(diào)速恒壓