PLC控制的無負(fu)壓(ya)穩壓(ya)給水設備系統設計(ji)

無負壓(ya)穩壓(ya)給(gei)水設備(bei)概述

    變頻調速(su)技術(shu)是(shi)一(yi)種(zhong)新型的(de)、成(cheng)熟的(de)交流電機(ji)無級調速(su)驅動技術(shu)，它以其(qi) 優良的(de)控制性被廣泛應(ying)用在速(su)度控制領域。特(te)別(bie)是(shi)在供水行業(ye)中，由于生(sheng)產(chan)安，，全(quan)和供水質量的(de)特(te)殊需要，對恒壓供水壓力有著嚴格要求，變頻調速(su)技術(shu)也得到了更加深入的(de)應(ying)用。

    自(zi)(zi)來水(shui)(shui)(shui)(shui)(shui)(shui)廠(chang)日(ri)產(chan)水(shui)(shui)(shui)(shui)(shui)(shui)量60萬噸(dun)，擔負著市區(qu)及(ji)周邊地(di)區(qu)70%以(yi)上(shang)(shang)的(de)(de)(de)(de)(de)供(gong)(gong)(gong)(gong)水(shui)(shui)(shui)(shui)(shui)(shui)任務(wu)。自(zi)(zi)1999年年底六廠(chang)的(de)(de)(de)(de)(de)三期(qi)工(gong)程投產(chan)后(hou)開始向(xiang)(xiang)縣(xian)供(gong)(gong)(gong)(gong)水(shui)(shui)(shui)(shui)(shui)(shui)，使得我廠(chang)的(de)(de)(de)(de)(de)供(gong)(gong)(gong)(gong)水(shui)(shui)(shui)(shui)(shui)(shui)方(fang)式(shi)從單一的(de)(de)(de)(de)(de)重(zhong)力(li)(li)(li)(li)(li)流(liu)供(gong)(gong)(gong)(gong)水(shui)(shui)(shui)(shui)(shui)(shui)變(bian)(bian)為(wei)重(zhong)力(li)(li)(li)(li)(li)流(liu)和壓(ya)(ya)力(li)(li)(li)(li)(li)流(liu)結合(he)供(gong)(gong)(gong)(gong)水(shui)(shui)(shui)(shui)(shui)(shui)的(de)(de)(de)(de)(de)方(fang)式(shi)。自(zi)(zi)向(xiang)(xiang)縣(xian)供(gong)(gong)(gong)(gong)水(shui)(shui)(shui)(shui)(shui)(shui)以(yi)來，由于考慮到現(xian)階段郫縣(xian)的(de)(de)(de)(de)(de)用(yong)水(shui)(shui)(shui)(shui)(shui)(shui)量較(jiao)(jiao)少，從節約能(neng)(neng)耗(hao)的(de)(de)(de)(de)(de)角度出(chu)發，我廠(chang)使用(yong)一臺(tai)泵同時(shi)向(xiang)(xiang)縣(xian)供(gong)(gong)(gong)(gong)水(shui)(shui)(shui)(shui)(shui)(shui)和提供(gong)(gong)(gong)(gong)我廠(chang)的(de)(de)(de)(de)(de)自(zi)(zi)用(yong)高壓(ya)(ya)水(shui)(shui)(shui)(shui)(shui)(shui)。為(wei)了滿足六廠(chang)自(zi)(zi)用(yong)水(shui)(shui)(shui)(shui)(shui)(shui)壓(ya)(ya)力(li)(li)(li)(li)(li)，保(bao)證(zheng)廠(chang)內(nei)各個工(gong)藝(yi)環節設備(bei)（如消(xiao)毒(du)環節中的(de)(de)(de)(de)(de)水(shui)(shui)(shui)(shui)(shui)(shui)射器）能(neng)(neng)正常工(gong)作，我廠(chang)自(zi)(zi)用(yong)水(shui)(shui)(shui)(shui)(shui)(shui)壓(ya)(ya)力(li)(li)(li)(li)(li)須較(jiao)(jiao)恒(heng)(heng)定的(de)(de)(de)(de)(de)控制在0.3 Mpa以(yi)上(shang)(shang)，采(cai)用(yong)變(bian)(bian)頻調(diao)速控制是保(bao)證(zheng)壓(ya)(ya)力(li)(li)(li)(li)(li)恒(heng)(heng)定較(jiao)(jiao)為(wei)有(you)效的(de)(de)(de)(de)(de)方(fang)法。根(gen)據我們對縣(xian)城區(qu)供(gong)(gong)(gong)(gong)水(shui)(shui)(shui)(shui)(shui)(shui)量的(de)(de)(de)(de)(de)了解(jie)，發現(xian)縣(xian)全天各時(shi)段用(yong)水(shui)(shui)(shui)(shui)(shui)(shui)量變(bian)(bian)化較(jiao)(jiao)大（見(jian)后(hou)圖5），如果不對供(gong)(gong)(gong)(gong)水(shui)(shui)(shui)(shui)(shui)(shui)量進(jin)行調(diao)節，管網(wang)(wang)壓(ya)(ya)力(li)(li)(li)(li)(li)的(de)(de)(de)(de)(de)波動也(ye)會(hui)很大，容易出(chu)現(xian)管網(wang)(wang)失壓(ya)(ya)或爆管事故。采(cai)用(yong)變(bian)(bian)頻恒(heng)(heng)壓(ya)(ya)供(gong)(gong)(gong)(gong)水(shui)(shui)(shui)(shui)(shui)(shui)控制后(hou)，當縣(xian)用(yong)水(shui)(shui)(shui)(shui)(shui)(shui)量較(jiao)(jiao)小時(shi)，這時(shi)相應管道和泵出(chu)口壓(ya)(ya)力(li)(li)(li)(li)(li)均較(jiao)(jiao)大，變(bian)(bian)頻恒(heng)(heng)壓(ya)(ya)控制方(fang)式(shi)將會(hui)降低泵的(de)(de)(de)(de)(de)頻率，減小泵出(chu)水(shui)(shui)(shui)(shui)(shui)(shui)量，從而降低管網(wang)(wang)壓(ya)(ya)力(li)(li)(li)(li)(li)；反之亦然。這樣，小時(shi)用(yong)水(shui)(shui)(shui)(shui)(shui)(shui)量變(bian)(bian)化較(jiao)(jiao)大也(ye)不會(hui)造成管網(wang)(wang)壓(ya)(ya)力(li)(li)(li)(li)(li)有(you)較(jiao)(jiao)大的(de)(de)(de)(de)(de)波動。經過長(chang)期(qi)運(yun)行實踐，證(zheng)明(ming)了變(bian)(bian)頻調(diao)速手(shou)段實現(xian)恒(heng)(heng)壓(ya)(ya)供(gong)(gong)(gong)(gong)水(shui)(shui)(shui)(shui)(shui)(shui)不僅(jin)保(bao)證(zheng)廠(chang)內(nei)自(zi)(zi)用(yong)高壓(ya)(ya)水(shui)(shui)(shui)(shui)(shui)(shui)壓(ya)(ya)力(li)(li)(li)(li)(li)足夠(gou)且(qie)穩定，而且(qie)保(bao)證(zheng)了縣(xian)供(gong)(gong)(gong)(gong)水(shui)(shui)(shui)(shui)(shui)(shui)的(de)(de)(de)(de)(de)安(an)，，全可靠性(xing)。

無負壓穩(wen)壓給(gei)水設(she)備控(kong)制系(xi)統構成

    整(zheng)個恒壓(ya)供水系統(tong)有兩(liang)組變頻(pin)泵，每組均由一臺(tai)變頻(pin)器和一臺(tai)水泵組成(cheng)；系統(tong)以PLC為控(kong)(kong)(kong)制核心，由PLC采集(ji)壓(ya)力信號(hao)和輸(shu)出控(kong)(kong)(kong)制變頻(pin)泵的運行。控(kong)(kong)(kong)制系統(tong)構成(cheng)如圖1所示。

    PLC處理(li)器選用(yong)的(de)(de)(de)(de)(de)是(shi)Allen-Bradley公司(si)的(de)(de)(de)(de)(de)PLC-5型處理(li)器，變(bian)頻(pin)泵(beng)選用(yong)的(de)(de)(de)(de)(de)是(shi)ABB公司(si)的(de)(de)(de)(de)(de)SAMI STAR系(xi)列(lie)的(de)(de)(de)(de)(de)315F 660/690型的(de)(de)(de)(de)(de)變(bian)頻(pin)器和(he)水泵(beng)。系(xi)統由兩只(zhi)量程(cheng)為0~1.0Mpa的(de)(de)(de)(de)(de)壓(ya)(ya)力(li)變(bian)送器分(fen)別(bie)檢(jian)測兩臺水泵(beng)后的(de)(de)(de)(de)(de)輸(shu)水管(guan)道的(de)(de)(de)(de)(de)壓(ya)(ya)力(li)，壓(ya)(ya)力(li)變(bian)送器將檢(jian)測到(dao)的(de)(de)(de)(de)(de)壓(ya)(ya)力(li)信(xin)號(hao)轉換為4~20mA的(de)(de)(de)(de)(de)電流(liu)信(xin)號(hao)，送到(dao)PLC子站的(de)(de)(de)(de)(de)模(mo)(mo)擬(ni)量輸(shu)入模(mo)(mo)板（1771-IFE），通過PLC的(de)(de)(de)(de)(de)PID運算，由模(mo)(mo)擬(ni)量輸(shu)出模(mo)(mo)板（1771-OFE）輸(shu)出4~20mA的(de)(de)(de)(de)(de)電流(liu)控制變(bian)頻(pin)泵(beng)的(de)(de)(de)(de)(de)運行。

無負壓穩壓給水設備控(kong)制原理及(ji)功能實(shi)現

    3.1 PLC控制(zhi)系統簡介(jie)

    我廠(chang)采用Allen-Bradley公司的(de)PLC-5型處理(li)器通(tong)過(guo)DH+通(tong)訊方式構建了全廠(chang)PLC工(gong)(gong)(gong)業(ye)控制(zhi)網絡(luo)，通(tong)過(guo)DH+網絡(luo)上的(de)RSView工(gong)(gong)(gong)作(zuo)站實現(xian)(xian)人(ren)機(ji)對話。RSView工(gong)(gong)(gong)作(zuo)站是(shi)(shi)指運(yun)行(xing)(xing)人(ren)機(ji)圖(tu)(tu)形(xing)界面軟(ruan)件（RSView32）的(de)計算機(ji)工(gong)(gong)(gong)作(zuo)平臺(tai)，該(gai)工(gong)(gong)(gong)作(zuo)站建在中(zhong)(zhong)心控制(zhi)室，是(shi)(shi)實現(xian)(xian)生產現(xian)(xian)場(chang)無人(ren)值(zhi)守和運(yun)行(xing)(xing)集中(zhong)(zhong)管(guan)理(li)的(de)調(diao)度中(zhong)(zhong)心。利用RSView32可以(yi)有效地對控制(zhi)過(guo)程(cheng)進行(xing)(xing)監(jian)視(shi)和控制(zhi)，可以(yi)實現(xian)(xian)圖(tu)(tu)形(xing)化的(de)人(ren)機(ji)對話界面，模擬生產運(yun)行(xing)(xing)的(de)流(liu)程(cheng)，在模擬流(liu)程(cheng)上更(geng)加直觀(guan)地實現(xian)(xian)生產流(liu)程(cheng)的(de)全自動運(yun)行(xing)(xing)監(jian)視(shi)、遠程(cheng)人(ren)工(gong)(gong)(gong)直接干預操作(zuo)（如(ru)PID指令(ling)運(yun)行(xing)(xing)參數(shu)遠程(cheng)設定(ding)）、控制(zhi)環節報警監(jian)視(shi)等功(gong)能。控制(zhi)界面如(ru)圖(tu)(tu)2。

圖(tu)2 變頻恒(heng)壓供水系統(tong)控制圖(tu)形界(jie)面（RSView工(gong)作站）

    3.2 恒壓供水(shui)的控制(zhi)原理(li)

    SAMI STAR變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)具(ju)有(you)REMOTE和(he)LOCAL兩種操作(zuo)方式(shi)(shi)。LOCAL操作(zuo)方式(shi)(shi)下(xia)(xia)，通(tong)(tong)(tong)過LOCAL START/STOP開(kai)關啟停(ting)(ting)變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)，通(tong)(tong)(tong)過f REF LOCAL INPUT0 輸(shu)(shu)(shu)(shu)入(ru)端口的(de)電(dian)(dian)位(wei)開(kai)關人工(gong)調節(jie)(jie)(jie)變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)工(gong)作(zuo)頻(pin)(pin)(pin)(pin)(pin)率(lv)(lv)；通(tong)(tong)(tong)過LOCAL/REMOTE輸(shu)(shu)(shu)(shu)入(ru)點可(ke)以將變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)切(qie)換到(dao)(dao)REMOTE操作(zuo)方式(shi)(shi)下(xia)(xia)，在(zai)REMOTE方式(shi)(shi)下(xia)(xia)，通(tong)(tong)(tong)過REMOTE START/STOP輸(shu)(shu)(shu)(shu)入(ru)點進(jin)(jin)行(xing)(xing)PLC遠(yuan)程啟停(ting)(ting)變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)，通(tong)(tong)(tong)過f REF REMOTE INPUT0端口輸(shu)(shu)(shu)(shu)入(ru)頻(pin)(pin)(pin)(pin)(pin)率(lv)(lv)控(kong)制(zhi)(zhi)信(xin)號(hao)(hao)(hao)（百分(fen)比(bi)）控(kong)制(zhi)(zhi)變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)工(gong)作(zuo)頻(pin)(pin)(pin)(pin)(pin)率(lv)(lv)。根據供水量情況，我們把(ba)變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)的(de)工(gong)作(zuo)頻(pin)(pin)(pin)(pin)(pin)率(lv)(lv)上限設(she)(she)定(ding)為(wei)(wei)水泵基頻(pin)(pin)(pin)(pin)(pin)，即頻(pin)(pin)(pin)(pin)(pin)率(lv)(lv)變(bian)化范圍(wei)(wei)控(kong)制(zhi)(zhi)在(zai)0~50Hz，在(zai)此范圍(wei)(wei)內水泵運(yun)(yun)行(xing)(xing)頻(pin)(pin)(pin)(pin)(pin)率(lv)(lv)和(he)定(ding)子相(xiang)(xiang)壓(ya)(ya)成正比(bi)（及與變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)輸(shu)(shu)(shu)(shu)入(ru)頻(pin)(pin)(pin)(pin)(pin)率(lv)(lv)成正比(bi)），這使(shi)(shi)得(de)變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)輸(shu)(shu)(shu)(shu)入(ru)、水泵運(yun)(yun)行(xing)(xing)頻(pin)(pin)(pin)(pin)(pin)率(lv)(lv)和(he)泵的(de)輸(shu)(shu)(shu)(shu)出(chu)壓(ya)(ya)力(li)成較(jiao)好的(de)線(xian)形(xing)關系，可(ke)得(de)到(dao)(dao)較(jiao)好的(de)控(kong)制(zhi)(zhi)效果(guo)。SAMI STAR變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)對(dui)用戶開(kai)放的(de)I/0接口位(wei)于TERMINAL BLOCK CARD上，主要使(shi)(shi)用的(de)有(you)：X11-1（REMOTE START/STOP）；X11-4（LOCAL/REMOTE）；X11-13/14（f REF REMOTE INPUT0、4~20mA信(xin)號(hao)(hao)(hao)輸(shu)(shu)(shu)(shu)入(ru)）；X11-15/16（輸(shu)(shu)(shu)(shu)出(chu)4~20mA變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)運(yun)(yun)行(xing)(xing)頻(pin)(pin)(pin)(pin)(pin)率(lv)(lv)信(xin)號(hao)(hao)(hao)）；X11-17/18（輸(shu)(shu)(shu)(shu)出(chu)4~20mA變(bian)頻(pin)(pin)(pin)(pin)(pin)泵運(yun)(yun)行(xing)(xing)電(dian)(dian)流信(xin)號(hao)(hao)(hao)）。變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)由(you)(you)(you)PLC遠(yuan)程控(kong)制(zhi)(zhi)時(shi)，啟動是(shi)由(you)(you)(you)PLC向X11-4輸(shu)(shu)(shu)(shu)出(chu)信(xin)號(hao)(hao)(hao)，使(shi)(shi)變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)切(qie)換到(dao)(dao)外部(bu)設(she)(she)備(bei)控(kong)制(zhi)(zhi)方式(shi)(shi)（REMOTE方式(shi)(shi)），再向X11-1輸(shu)(shu)(shu)(shu)出(chu)信(xin)號(hao)(hao)(hao)，啟動變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)。在(zai)恒壓(ya)(ya)調節(jie)(jie)(jie)時(shi)，PLC處理器(qi)(qi)(qi)(qi)把(ba)檢測到(dao)(dao)的(de)壓(ya)(ya)力(li)信(xin)號(hao)(hao)(hao)作(zuo)為(wei)(wei)反(fan)饋值，與PID運(yun)(yun)算的(de)壓(ya)(ya)力(li)設(she)(she)定(ding)值（由(you)(you)(you)調度人員(yuan)根據情況在(zai)REView上設(she)(she)定(ding)）進(jin)(jin)行(xing)(xing)比(bi)較(jiao)，再經過PID運(yun)(yun)算得(de)到(dao)(dao)調節(jie)(jie)(jie)后的(de)修正值，通(tong)(tong)(tong)過模擬量輸(shu)(shu)(shu)(shu)出(chu)模板（1771-OFE）輸(shu)(shu)(shu)(shu)出(chu)到(dao)(dao)X11-13/14，作(zuo)為(wei)(wei)REMOTE方式(shi)(shi)下(xia)(xia)變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)的(de)頻(pin)(pin)(pin)(pin)(pin)率(lv)(lv)控(kong)制(zhi)(zhi)信(xin)號(hao)(hao)(hao)，由(you)(you)(you)于該信(xin)號(hao)(hao)(hao)是(shi)相(xiang)(xiang)對(dui)變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)工(gong)作(zuo)頻(pin)(pin)(pin)(pin)(pin)率(lv)(lv)上限的(de)百分(fen)比(bi)，所以變(bian)頻(pin)(pin)(pin)(pin)(pin)器(qi)(qi)(qi)(qi)將輸(shu)(shu)(shu)(shu)入(ru)信(xin)號(hao)(hao)(hao)進(jin)(jin)行(xing)(xing)內部(bu)運(yun)(yun)算后轉(zhuan)為(wei)(wei)真實工(gong)作(zuo)頻(pin)(pin)(pin)(pin)(pin)率(lv)(lv)。

    為了使三期變頻恒壓供水自(zi)動控(kong)制系(xi)統與全廠自動控制(zhi)(zhi)網(wang)絡(luo)有(you)機(ji)地結合起(qi)來，全面實現(xian)對(dui)恒(heng)壓供水系統的運(yun)行情況(kuang)和(he)設備運(yun)行進行監(jian)視和(he)遠程(cheng)控制(zhi)(zhi)，更(geng)加 可靠地實現(xian)恒(heng)壓供水，我們使用PLC進行PID運(yun)算(suan)和(he)監(jian)控。PID閉環(huan)反饋控制(zhi)(zhi)原理如圖3：

    PLC的(de)(de)PID運(yun)(yun)算(suan)(suan)調(diao)節(jie)通過該型處(chu)(chu)理器(qi)專用(yong)(yong)(yong)PID指(zhi)(zhi)令(ling)(ling)完成，通過設(she)(she)置各參數即(ji)可由(you)PLC完成PID運(yun)(yun)算(suan)(suan)調(diao)節(jie)。PID程(cheng)序段流(liu)程(cheng)如圖4。PID指(zhi)(zhi)令(ling)(ling) 須以相同(tong)的(de)(de)時(shi)(shi)間間隔周期性地執行，可采(cai)(cai)用(yong)(yong)(yong)計時(shi)(shi)器(qi)，定(ding)(ding)(ding)(ding)(ding)時(shi)(shi)中斷或實時(shi)(shi)采(cai)(cai)樣的(de)(de)等方法，此(ci)處(chu)(chu)選用(yong)(yong)(yong)了(le)定(ding)(ding)(ding)(ding)(ding)時(shi)(shi)方法；PV是(shi)PID指(zhi)(zhi)令(ling)(ling)采(cai)(cai)樣的(de)(de)壓(ya)力控(kong)(kong)(kong)制(zhi)反(fan)饋(kui)值(zhi)，SP是(shi)PID指(zhi)(zhi)令(ling)(ling)的(de)(de)壓(ya)力控(kong)(kong)(kong)制(zhi)設(she)(she)定(ding)(ding)(ding)(ding)(ding)值(zhi)，KP為PID的(de)(de)比例增(zeng)(zeng)益(yi)，KI為PID的(de)(de)積分增(zeng)(zeng)益(yi)，KD為PID的(de)(de)微(wei)分增(zeng)(zeng)益(yi)，這五個控(kong)(kong)(kong)制(zhi)參數作為主要的(de)(de)PID參數參與控(kong)(kong)(kong)制(zhi)，確定(ding)(ding)(ding)(ding)(ding)PID參數時(shi)(shi)要兼顧系統靈敏性和穩定(ding)(ding)(ding)(ding)(ding)性，由(you)于(yu)我們恒壓(ya)控(kong)(kong)(kong)制(zhi)要求和設(she)(she)備的(de)(de)性能(neng)條件，參數設(she)(she)定(ding)(ding)(ding)(ding)(ding)更(geng)強調(diao)穩定(ding)(ding)(ding)(ding)(ding)性（及KI），由(you)于(yu)微(wei)分環(huan)節(jie)有放大(da)噪聲的(de)(de)特點，我們將(jiang)KD盡量設(she)(she)置得較(jiao)小(xiao)；SWM為PID指(zhi)(zhi)令(ling)(ling)轉為手(shou)(shou)動直(zhi)接調(diao)頻的(de)(de)開關，SO設(she)(she)定(ding)(ding)(ding)(ding)(ding)為PID指(zhi)(zhi)令(ling)(ling)的(de)(de)在手(shou)(shou)動控(kong)(kong)(kong)制(zhi)輸(shu)(shu)(shu)出(chu)(chu)方式時(shi)(shi)的(de)(de)輸(shu)(shu)(shu)出(chu)(chu)值(zhi)，當變頻器(qi)從PID自控(kong)(kong)(kong)調(diao)節(jie)轉為手(shou)(shou)動直(zhi)接調(diao)頻時(shi)(shi)，SO替(ti)代PID運(yun)(yun)算(suan)(suan)結(jie)果作為轉換(huan)時(shi)(shi)的(de)(de)輸(shu)(shu)(shu)出(chu)(chu)值(zhi)，將(jiang)SO設(she)(she)定(ding)(ding)(ding)(ding)(ding)為控(kong)(kong)(kong)制(zhi)值(zhi)就可實現無(wu)縫轉換(huan)，減小(xiao)變頻器(qi)運(yun)(yun)行頻率的(de)(de)震蕩(dang)。DB為PID指(zhi)(zhi)令(ling)(ling)的(de)(de)死區設(she)(she)定(ding)(ding)(ding)(ding)(ding)值(zhi)，輸(shu)(shu)(shu)出(chu)(chu)超出(chu)(chu)死區時(shi)(shi)PID指(zhi)(zhi)令(ling)(ling)通過自動運(yun)(yun)算(suan)(suan)限制(zhi)輸(shu)(shu)(shu)出(chu)(chu)超出(chu)(chu)限定(ding)(ding)(ding)(ding)(ding)范圍。

    3.3 相關(guan)控制功能實現(xian)

    為(wei)(wei)了防(fang)止運(yun)行(xing)時由于壓(ya)(ya)(ya)力(li)(li)變送器(qi)不可預(yu)見(jian)的故障造成PLC的PID運(yun)算調節(jie)失實，從而造成管(guan)網(wang)壓(ya)(ya)(ya)力(li)(li)失恒引發失壓(ya)(ya)(ya)或(huo)爆管(guan)的嚴(yan)重事故。我們分別在(zai)1#和(he)2#變頻(pin)(pin)泵后輸(shu)水管(guan)上(shang)(shang)(shang)安(an)裝壓(ya)(ya)(ya)力(li)(li)變送器(qi)，可以同時測到出廠輸(shu)水管(guan)線上(shang)(shang)(shang)的壓(ya)(ya)(ya)力(li)(li)；在(zai)PLC程(cheng)序(xu)(xu)上(shang)(shang)(shang)對(dui)壓(ya)(ya)(ya)力(li)(li)信號進行(xing)了相應的處理，在(zai)程(cheng)序(xu)(xu)中設(she)置(zhi)選擇(ze)軟(ruan)開關(guan)，調度人員可以在(zai)RSView上(shang)(shang)(shang)將其中一(yi)臺壓(ya)(ya)(ya)力(li)(li)變送器(qi)的值(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)設(she)定(ding)為(wei)(wei)“控(kong)(kong)制(zhi)反饋(kui)值(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)”，另一(yi)臺壓(ya)(ya)(ya)力(li)(li)變送器(qi)的值(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)則設(she)為(wei)(wei)“參考反饋(kui)值(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)”（見(jian)圖2：變頻(pin)(pin)恒壓(ya)(ya)(ya)供水系(xi)統控(kong)(kong)制(zhi)圖形界面（RSView工作站））；對(dui)1#壓(ya)(ya)(ya)力(li)(li)和(he)2#壓(ya)(ya)(ya)力(li)(li)值(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)進行(xing)比較(jiao)，相差0.1Mpa時，判斷(duan)為(wei)(wei)，其中一(yi)只壓(ya)(ya)(ya)力(li)(li)變送器(qi)出現(xian)故障，變頻(pin)(pin)器(qi)控(kong)(kong)制(zhi)轉換(huan)為(wei)(wei)遠(yuan)(yuan)程(cheng)直(zhi)(zhi)接手動調頻(pin)(pin)控(kong)(kong)制(zhi)（通過RSView設(she)置(zhi)運(yun)行(xing)）。壓(ya)(ya)(ya)力(li)(li)變送器(qi)正常工作時，“控(kong)(kong)制(zhi)反饋(kui)值(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)”經過平均濾波(bo)處理后，分別比較(jiao)壓(ya)(ya)(ya)力(li)(li)報警(jing)上(shang)(shang)(shang)限(xian)和(he)下(xia)限(xian)值(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)，如果超出控(kong)(kong)制(zhi)范圍，變頻(pin)(pin)器(qi)控(kong)(kong)制(zhi)轉換(huan)為(wei)(wei)遠(yuan)(yuan)程(cheng)直(zhi)(zhi)接手動調頻(pin)(pin)控(kong)(kong)制(zhi)，否(fou)則“控(kong)(kong)制(zhi)反饋(kui)值(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)”作為(wei)(wei)PID調節(jie)的參數PV。

    同時為了(le)在就地(di)(di)手動(dong)控(kong)制實現(xian)在控(kong)制現(xian)場對變(bian)頻泵(beng)進行(xing)開停(ting)控(kong)制和運行(xing)數據監視。我們在變(bian)頻泵(beng)工(gong)(gong)作(zuo)現(xian)場安裝了(le)A-B公司的(de)PanelView圖(tu)形工(gong)(gong)作(zuo)終端，該工(gong)(gong)作(zuo)終端提供圖(tu)形交(jiao)(jiao)互界面和觸摸(mo)輸入(ru)方(fang)(fang)式，以從站的(de)方(fang)(fang)式與(yu)PLC進行(xing)通信，進行(xing)數據和控(kong)制命令的(de)交(jiao)(jiao)換，提供就地(di)(di)監控(kong)操作(zuo)的(de)通道(dao)。

無負壓穩(wen)壓給水設備運行效果分析(xi)

    4.1 有(you)效保證縣(xian)供(gong)水(shui)和(he)我廠自(zi)用(yong)水(shui)壓力穩(wen)定(ding)，提高(gao)我廠供(gong)水(shui) 可靠(kao)性(xing)

    圖5為數據(ju)庫采集的2001年(nian)某日我廠(chang)恒(heng)壓變(bian)頻(pin)泵(beng)出水壓力、頻(pin)率變(bian)化以及郫(pi)縣供(gong)水和自用(yong)水流(liu)量、管網(wang)壓力數據(ju)關系(xi)圖。

    從圖中數(shu)據可看出縣小時供(gong)水量變化很(hen)大(da)，如果采(cai)用定速(su)泵進行供(gong)水必然會導致(zhi)高峰供(gong)水時段內管網(wang)供(gong)水壓(ya)力不(bu)足(zu)，夜間用水量較小時管網(wang)壓(ya)力過(guo)高，造(zao)成爆管現象。采(cai)用變頻(pin)恒壓控制(zhi)后，變頻器的(de)(de)(de)(de)頻率隨縣(xian)用(yong)(yong)(yong)(yong)水量(liang)的(de)(de)(de)(de)變化而(er)變化，及時調(diao)節我(wo)(wo)廠(chang)對(dui)郫(pi)縣(xian)供水量(liang)，從而(er)使郫(pi)縣(xian)城區管網壓(ya)力在一(yi)個較小的(de)(de)(de)(de)范(fan)圍內變化（0.23-0.27Mpa）。另一(yi)方(fang)面，雖然我(wo)(wo)廠(chang)自(zi)用(yong)(yong)(yong)(yong)水秒流(liu)量(liang)變化不大，但由于我(wo)(wo)廠(chang)自(zi)用(yong)(yong)(yong)(yong)水和縣(xian)供水為同一(yi)水泵加(jia)壓(ya)后，分作(zuo)兩條支流(liu)，縣(xian)用(yong)(yong)(yong)(yong)水量(liang)的(de)(de)(de)(de)變化必然也(ye)會導(dao)致自(zi)用(yong)(yong)(yong)(yong)水壓(ya)力不穩定，采用(yong)(yong)(yong)(yong)恒(heng)壓(ya)變頻控制(zhi)方(fang)式，基本克(ke)服了(le)這種變化因素(su)。從上(shang)圖曲線也(ye)可看出(chu)，我(wo)(wo)廠(chang)自(zi)用(yong)(yong)(yong)(yong)水壓(ya)力基本恒(heng)定不變。這樣保(bao)證(zheng)了(le)我(wo)(wo)廠(chang)加(jia)氯水射器等重要設備的(de)(de)(de)(de)正(zheng)常工作(zuo)，保(bao)證(zheng)了(le)正(zheng)常的(de)(de)(de)(de)消毒工藝(yi)流(liu)程，從而(er)保(bao)證(zheng)我(wo)(wo)廠(chang)出(chu)廠(chang)水水質，提高(gao)我(wo)(wo)廠(chang)供水的(de)(de)(de)(de) 可靠性。

    4.2 高度有效節能(neng)

    通過(guo)采(cai)用變頻(pin)調速(su)恒壓控制，可(ke)在(zai)不(bu)同(tong)季節、全(quan)天(tian)不(bu)同(tong)時(shi)(shi)(shi)段內有效即(ji)時(shi)(shi)(shi)地調控水(shui)量，這(zhe)樣在(zai)用水(shui)量較(jiao)低時(shi)(shi)(shi)，大大節約供水(shui)量，減少電耗。

    在(zai)設定(ding)壓力(li)內跟(gen)隨用水(shui)(shui)量供水(shui)(shui)，避(bi)免了(le)傳(chuan)統供水(shui)(shui)方式的損耗(hao)，降低(di)噸水(shui)(shui)消(xiao)耗(hao)。

    4.3 提(ti)高(gao)自動化水平

    根據(ju)我廠建立自(zi)動控制(zhi)系(xi)統的原則“分(fen)散控制(zhi)、集中(zhong)管(guan)理、現場無(wu)人(ren)值守(shou)”，無(wu)負(fu)壓穩壓給水技術的應用提高了(le)我廠自(zi)控系(xi)統的整體(ti)水平，真正作到了(le)操作簡便 ，現場無(wu)人(ren)職守(shou)，運行(xing) 可靠。

無負壓(ya)(ya)穩壓(ya)(ya)給水設備產品概述：

      無負壓(ya)穩壓(ya)給水(shui)設備是我公司(si)(si)專業技術人員在氣(qi)壓(ya)(ya)給水(shui)(shui)(shui)(shui)設備(bei)的基礎上開發(fa)的一種能(neng)(neng)(neng)直接(jie)與自(zi)(zi)來(lai)水(shui)(shui)(shui)(shui)管(guan)(guan)網連(lian)接(jie)、且對(dui)自(zi)(zi)來(lai)水(shui)(shui)(shui)(shui)管(guan)(guan)網不產生任何負作用的成(cheng)套(tao)給水(shui)(shui)(shui)(shui)設備(bei)。它(ta)可(ke)以(yi)取(qu)代蓄水(shui)(shui)(shui)(shui)池，能(neng)(neng)(neng)直接(jie)供水(shui)(shui)(shui)(shui)或間接(jie)供水(shui)(shui)(shui)(shui)，形成(cheng)連(lian)續密(mi)閉的接(jie)力增壓(ya)(ya)供水(shui)(shui)(shui)(shui)方式(shi)。避免了(le)二次增壓(ya)(ya)供水(shui)(shui)(shui)(shui)系統造成(cheng)的能(neng)(neng)(neng)源的二次浪費和二次污染(ran)，我公司(si)(si)生產的設備(bei)與其它(ta)廠家(jia)的產品不同，因解決了(le)自(zi)(zi)動采樣控制等有(you)關技術方面問題。而采用的是隔(ge)膜式(shi)負壓(ya)(ya)罐，保證水(shui)(shui)(shui)(shui)源與空氣(qi)隔(ge)絕。 保持(chi)了(le)市政水(shui)(shui)(shui)(shui)質標準；充分利(li)用市政水(shui)(shui)(shui)(shui)源本身壓(ya)(ya)力勢能(neng)(neng)(neng)，差多(duo)(duo)少，補多(duo)(duo)少，切實有(you)效地(di)、 大限度(du)地(di)發(fa)揮了(le)變(bian)頻調(diao)速的節能(neng)(neng)(neng)效果；大幅度(du)地(di)節省了(le)基建投資并縮短了(le)施工(gong)(gong)工(gong)(gong)期。

產品設計中很好(hao)地解決(jue)了接力增(zeng)壓供(gong)水(shui)方(fang)式帶來的2大問題：

1) 水(shui)泵大幅(fu)(fu)變(bian)工況(kuang)運行問(wen)題。設計了(le)全變(bian)頻控制系統。可較好的適(shi)應于水(shui)泵在大幅(fu)(fu)工況(kuang)運行問(wen)題。

2) 特別配套設計了各(ge)種緩沖罐、水源(yuan)罐，對市(shi)(shi)政水源(yuan)有(you)很好的(de)緩沖與削峰補償作用(yong)，避免對市(shi)(shi)政水源(yuan)的(de)過度抽吸。 產品設計充分考慮應(ying)用(yong)的(de)靈活性，自(zi)適應(ying)性強，可滿足不同用(yong)戶具體工程應(ying)用(yong)要求的(de)差異(yi)。

無負壓(ya)穩(wen)壓(ya)給水設備工作條件(jian)：

具有足夠承重能(neng)(neng)力(li)的混凝土平臺(tai)或能(neng)(neng)保證正常工作要求的平整地面

電(dian)源：TN-S制(zhi)、3相5線、380V（+10%、-15%）、50Hz（±5%）、接(jie)地電(dian)阻小于4歐

環境：室內安裝(zhuang)使用、0-40℃不凍結(jie)、90%RH以下不結(jie)露、無腐(fu)蝕、易燃(ran)、易爆氣體(ti)

海拔1000m以(yi)下(xia)，5.9m/s（0.6g）以(yi)下(xia)。

無(wu)負壓穩(wen)壓給水設備特(te)點：

1、 無需建高(gao)位(wei)水(shui)箱(xiang)、地(di)面（地(di)下）水(shui)池水(shui)箱(xiang)-潔凈衛生、高(gao)度有效、節能、節資

      經(jing)濟衛(wei)生、充分利用市(shi)政水(shui)源(yuan)本(ben)身(shen)壓(ya)力勢能， 大(da)限度(du)地發揮了變頻調速的(de)節能效(xiao)果(guo)。實踐證(zheng)明：使(shi)用直聯式中贏無負壓(ya)穩壓(ya)給水(shui)設備可(ke)節省50%以上(shang)的(de)興建(jian)水池費(fei)用，與(yu)其他供水設備相(xiang)比(bi)，可(ke)節電(dian)20%-40%。

2、 運行噪聲低

   ;   采(cai)用變頻調(diao)速運行，特(te)(te)別是采(cai)用全變頻控制系(xi)統，大部分時(shi)間(jian)特(te)(te)別是夜間(jian)處于低速低噪(zao)聲運行工況(kuang)。

3、 采用(yong)(yong)全密閉的兼有緩沖及動態補償作用(yong)(yong)的隔膜(mo)罐，與目前市場上的普通無負壓給(gei)水設(she)備(bei)更(geng)有實際意義(yi)。并使控制系統得(de)以簡化。

4、 產品先(xian)進(jin)，質(zhi)量可靠，標準化程(cheng)度高，通用性好

      采用(yong)規范(fan)通用(yong)的(de)控制系統技術方案，產(chan)品中關鍵零部件(jian),如:電機(ji)、水(shui)泵軸承、變(bian)頻器、調節器、PLC、和其他元器件(jian)采用(yong)了高品質產(chan)品，還可換用(yong)任意廠(chang)商的(de)相應部件(jian)，調試維修方便。

5、 功能全、智能化程(cheng)度高，自適應性強

      中贏無(wu)負壓(ya)穩壓(ya)給(gei)水(shui)設備采用了先(xian)進(jin)的(de)變頻(pin)(pin)控(kong)制(zhi)技術、軟(ruan)起動、有過載，短(duan)路、過壓、欠壓、缺相、過熱(re)和失速(su)保護等功(gong)能。在異常情況(kuang)下能進(jin)行(xing)信號報警、自(zi)檢、故(gu)(gu)障判斷等，還可(ke)根據(ju)用水(shui)量的(de)高低(di)自(zi)動調(diao)節供水(shui)流(liu)量。變頻(pin)(pin)器故(gu)(gu)障時(shi)(shi)自(zi)動降級運行(xing)（成為工頻(pin)(pin)自(zi)動給水(shui)設備(bei)(bei)），自(zi)動系統(tong)故(gu)(gu)障時(shi)(shi)，還可(ke)手(shou)動操作應急備(bei)(bei)用，贏得維(wei)修時(shi)(shi)間。

6、 個(ge)性(xing)化設計、壽命長

      若用戶需要(yao)，可設(she)(she)計符合用戶需要(yao)參數的設(she)(she)備及安(an)裝形(xing)式。

可(ke)(ke)按要求選配各(ge)種通(tong)訊接(jie)口、協議，從而可(ke)(ke)連(lian)接(jie)各(ge)種人機界(jie)面、監控(kong)(kong)計算機、可(ke)(ke)與各(ge)種控(kong)(kong)制(zhi)網絡(luo)、通(tong)信(xin)網絡(luo)相接(jie)，適用(yong)于特殊(shu)、復雜的運行控(kong)(kong)制(zhi)和(he)聯網監控(kong)(kong)要求。可(ke)(ke)為用(yong)戶開發(fa)配套監控(kong)(kong)軟件。 

無負壓穩(wen)壓給水設備主要用途(tu)：

 適用(yong)于任何自來(lai)水壓(ya)力不(bu)足地區的加壓(ya)供水。

 1、工礦企業(ye)的(de)生產、生活用水及(ji)各種補水系統；

 2、新建住宅小區或寫字樓生活(huo)用水；

 3、已建好的水(shui)(shui)池(chi)，可以采(cai)用無負壓(ya)供水(shui)(shui)設備與水(shui)(shui)池(chi)共(gong)用的供水(shui)(shui)方式，進一步節能；

 4、對原有氣壓供水設備進行改造，可(ke)以充(chong)分利用原有的氣壓罐；

 5、各(ge)種(zhong)循環系(xi)統(tong)，自來水廠的中間加(jia)壓泵站(zhan)。