變頻器在智能(neng)建(jian)筑中管網疊壓給水設備的應用(yong)分析

     隨著科學技(ji)(ji)術的迅猛發(fa)展(zhan)，電力電子技(ji)(ji)術、微電子技(ji)(ji)術及(ji)現代控(kong)制(zhi)理(li)論的不斷(duan)進步(bu)，又因(yin)為變頻(pin)(pin)器(qi)所具有(you)的高，效率性(xing)能和良好(hao)的控(kong)制(zhi)特(te)性(xing)，目(mu)前在(zai)交流電動(dong)機的速度控(kong)制(zhi)中較多采用(yong)(yong)。使(shi)(shi)用(yong)(yong)變頻(pin)(pin)器(qi)一個突出(chu)的優點(dian)就是節(jie)省能源，而(er)且通過發(fa)揮(hui)其理(li)想的控(kong)制(zhi)特(te)性(xing)，設(she)(she)備使(shi)(shi)用(yong)(yong)性(xing)能可以大幅提高。在(zai)智能建筑中，生活恒壓給(gei)水在(zai)節(jie)能和可靠性(xing)方面要(yao)作具體分析，從而(er)選擇更(geng)合(he)理(li)控(kong)制(zhi)方式。本文介紹了西門子變頻(pin)(pin)器(qi)在(zai)在(zai)智能建筑中管網疊(die)壓給(gei)水方面的應(ying)用(yong)(yong)，對變頻(pin)(pin)器(qi)的設(she)(she)計和使(shi)(shi)用(yong)(yong)特(te)點(dian)做了詳細闡述。

一(yi)，管網疊壓(ya)給(gei)水設備概述

    在(zai)智(zhi)能建筑日(ri)益增多(duo)的現(xian)在(zai)，供水(shui)問(wen)題成(cheng)為業主比較關(guan)心的問(wen)題，所(suo)以管網疊壓給水(shui)設備自(zi)動供水(shui)便(bian)提(ti)上了(le)日(ri)程(cheng)。以前在(zai)一(yi)般(ban)建筑的建設中(zhong)往往需要建設一(yi)個二次加壓供水(shui)泵房并采用(yong)變(bian)頻器實現(xian)恒壓自(zi)動供水(shui)。一(yi)般(ban)情況下，管網疊壓給水設備自動控制(zhi)(zhi)系統通過壓(ya)(ya)(ya)力傳(chuan)感器采集管網(wang)中的壓(ya)(ya)(ya)力并(bing)將其(qi)轉(zhuan)換成模擬(ni)信號(hao)進行(xing)(xing)變頻(pin)控制(zhi)(zhi)。這樣管網(wang)疊壓(ya)(ya)(ya)給水(shui)(shui)設(she)備(bei)直接取代水(shui)(shui)塔、高位水(shui)(shui)箱及傳(chuan)統的氣壓(ya)(ya)(ya)罐供水(shui)(shui)裝置，為局部加壓(ya)(ya)(ya)供水(shui)(shui)開辟(pi)了新(xin)的途徑。另外由于(yu)水(shui)(shui)泵(beng)耗電功率與電機(ji)轉(zhuan)速(su)的三(san)次(ci)方(fang)成正比(bi)關(guan)系，所以水(shui)(shui)泵(beng)調(diao)速(su)運行(xing)(xing)的節能效果(guo)非常(chang)明顯，平均耗電量較通常(chang)供水(shui)(shui)方(fang)式節省40％。與可編(bian)程控制(zhi)(zhi)器結合使(shi)用(yong)，可實現(xian)循(xun)環變頻(pin)，電機(ji)軟啟動，具有欠壓(ya)(ya)(ya)保護、過壓(ya)(ya)(ya)保護、短路保護、過流保護功能，工(gong)作(zuo)穩(wen)定可靠，大大延(yan)長了設(she)備(bei)的使(shi)用(yong)壽命(ming)。

    管網疊壓(ya)給水設備系(xi)統為可(ke)(ke)(ke)編程(cheng)控(kong)(kong)(kong)制(zhi)(zhi)的(de)變(bian)頻水壓(ya)控(kong)(kong)(kong)制(zhi)(zhi)系(xi)統。系(xi)統采(cai)用可(ke)(ke)(ke)編程(cheng)控(kong)(kong)(kong)制(zhi)(zhi)器（PLC），可(ke)(ke)(ke)實(shi)(shi)現手(shou)動(dong)開環調(diao)(diao)(diao)節(jie)(jie)、自動(dong)閉環調(diao)(diao)(diao)節(jie)(jie)、遠方控(kong)(kong)(kong)制(zhi)(zhi)及本地控(kong)(kong)(kong)制(zhi)(zhi)。每臺電(dian)(dian)機設置單獨的(de)控(kong)(kong)(kong)制(zhi)(zhi)面(mian)板(ban)，具有(you)水壓(ya)顯示(shi)、頻率顯示(shi)、工作狀態顯示(shi)功能(neng)，變(bian)頻器故障(zhang)(zhang)、可(ke)(ke)(ke)編程(cheng)控(kong)(kong)(kong)制(zhi)(zhi)器故障(zhang)(zhang)，可(ke)(ke)(ke)實(shi)(shi)現聲光報警。變(bian)頻調(diao)(diao)(diao)速器采(cai)用西(xi)門子公司產品(pin)，可(ke)(ke)(ke)實(shi)(shi)現電(dian)(dian)機的(de)平滑調(diao)(diao)(diao)節(jie)(jie)，變(bian)頻調(diao)(diao)(diao)速器加裝交流(liu)電(dian)(dian)抗器及直流(liu)電(dian)(dian)抗器，確保變(bian)頻調(diao)(diao)(diao)速器電(dian)(dian)源側諧波(bo)分量小于5%。

二，變頻(pin)控制(zhi)管(guan)網疊壓給水設(she)備分析

    大(da)家知道，水泵消(xiao)耗功(gong)率與(yu)轉速的(de)三次方(fang)成正比。即N=KN3

    N：為(wei)水(shui)泵(beng)消(xiao)耗功(gong)率(lv)；n：為(wei)水(shui)泵(beng)運行時的轉(zhuan)速；K為(wei)比例系數。而(er)水(shui)泵(beng)設(she)計是按工頻運行時設(she)計的，但(dan)供水(shui)時除(chu)高峰外，大部分(fen)時間流量(liang)較小，由(you)于命名用了變(bian)(bian)頻技(ji)術及(ji)微(wei)機(ji)技(ji)術有(you)微(wei)機(ji)控制(zhi)，因此可以使(shi)水(shui)泵(beng)運行的轉(zhuan)速隨流量(liang)的變(bian)(bian)化而(er)變(bian)(bian)化，從而(er)達(da)到節(jie)能的目的。實踐證明，使(shi)用變(bian)(bian)頻設(she)備可使(shi)水(shui)泵(beng)運行平均轉(zhuan)速比工頻轉(zhuan)速降低20%，從而(er)大大降低能耗，節(jie)能率(lv)可達(da)20%-40%。

    變(bian)頻器(qi)(qi)的作用(yong)是為電(dian)機提供可(ke)(ke)變(bian)頻率的電(dian)源，實現電(dian)機的無級調速，從(cong)而使(shi)管網水壓(ya)(ya)(ya)連續(xu)變(bian)化。傳感器(qi)(qi)的任務是檢測(ce)管網水壓(ya)(ya)(ya)。壓(ya)(ya)(ya)力(li)(li)設定(ding)單元為系統(tong)提供滿足用(yong)戶需要的水壓(ya)(ya)(ya)期(qi)望(wang)值。壓(ya)(ya)(ya)力(li)(li)設定(ding)信(xin)號(hao)(hao)和壓(ya)(ya)(ya)力(li)(li)反(fan)饋(kui)信(xin)號(hao)(hao)在(zai)(zai)輸(shu)入(ru)(ru)可(ke)(ke)編(bian)程(cheng)控制器(qi)(qi)后，經(jing)可(ke)(ke)編(bian)程(cheng)控制器(qi)(qi)內部PID控制程(cheng)序(xu)的計算，輸(shu)出給變(bian)頻器(qi)(qi)一個轉速控制信(xin)號(hao)(hao)。還有(you)一種辦法(fa)是將壓(ya)(ya)(ya)力(li)(li)設定(ding)信(xin)號(hao)(hao)和壓(ya)(ya)(ya)力(li)(li)反(fan)饋(kui)信(xin)號(hao)(hao)送(song)入(ru)(ru)PID回(hui)路調節(jie)器(qi)(qi)，由PID回(hui)路調節(jie)器(qi)(qi)在(zai)(zai)調節(jie)器(qi)(qi)內部進行(xing)運算后，輸(shu)入(ru)(ru)給變(bian)頻器(qi)(qi)一個轉速調節(jie)信(xin)號(hao)(hao)。

    由(you)于變(bian)頻器(qi)的(de)(de)(de)(de)(de)轉速控(kong)(kong)(kong)制(zhi)(zhi)信號(hao)是由(you)可(ke)(ke)編(bian)程(cheng)(cheng)(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)器(qi)或PID回路(lu)調(diao)節(jie)器(qi)給出(chu)(chu)的(de)(de)(de)(de)(de)，所以對(dui)可(ke)(ke)編(bian)程(cheng)(cheng)(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)器(qi)來計(ji)時，既要有(you)(you)(you)模(mo)擬(ni)(ni)量(liang)(liang)(liang)(liang)輸(shu)入(ru)(ru)(ru)接(jie)口，又(you)要有(you)(you)(you)模(mo)擬(ni)(ni)量(liang)(liang)(liang)(liang)輸(shu)出(chu)(chu)接(jie)口。由(you)于帶模(mo)擬(ni)(ni)量(liang)(liang)(liang)(liang)輸(shu)入(ru)(ru)(ru)/輸(shu)出(chu)(chu)接(jie)口的(de)(de)(de)(de)(de)可(ke)(ke)編(bian)程(cheng)(cheng)(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)器(qi)價格很高，這無形中就增加了(le)供水(shui)設(she)備(bei)(bei)的(de)(de)(de)(de)(de)成(cheng)本。若采用帶有(you)(you)(you)模(mo)擬(ni)(ni)量(liang)(liang)(liang)(liang)輸(shu)入(ru)(ru)(ru)/數(shu)字量(liang)(liang)(liang)(liang)輸(shu)出(chu)(chu)的(de)(de)(de)(de)(de)可(ke)(ke)編(bian)程(cheng)(cheng)(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)器(qi)，則要在可(ke)(ke)編(bian)程(cheng)(cheng)(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)器(qi)的(de)(de)(de)(de)(de)數(shu)字量(liang)(liang)(liang)(liang)輸(shu)出(chu)(chu)口另接(jie)一(yi)塊PWM調(diao)制(zhi)(zhi)板，將可(ke)(ke)編(bian)程(cheng)(cheng)(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)器(qi)輸(shu)出(chu)(chu)的(de)(de)(de)(de)(de)數(shu)字量(liang)(liang)(liang)(liang)信號(hao)轉變(bian)為(wei)控(kong)(kong)(kong)制(zhi)(zhi)器(qi)的(de)(de)(de)(de)(de)成(cheng)本沒有(you)(you)(you)降(jiang)低，還(huan)增加了(le)連(lian)線和附(fu)加設(she)備(bei)(bei)，降(jiang)低了(le)整套設(she)備(bei)(bei)的(de)(de)(de)(de)(de)可(ke)(ke)靠性(xing)。如果采用一(yi)個開關(guan)量(liang)(liang)(liang)(liang)輸(shu)入(ru)(ru)(ru)/輸(shu)出(chu)(chu)的(de)(de)(de)(de)(de)可(ke)(ke)編(bian)程(cheng)(cheng)(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)器(qi)和一(yi)個PID回路(lu)調(diao)節(jie)器(qi)，其成(cheng)本也(ye)和帶模(mo)擬(ni)(ni)量(liang)(liang)(liang)(liang)輸(shu)入(ru)(ru)(ru)/輸(shu)出(chu)(chu)的(de)(de)(de)(de)(de)可(ke)(ke)編(bian)程(cheng)(cheng)(cheng)(cheng)控(kong)(kong)(kong)制(zhi)(zhi)器(qi)差不多。所以，在變(bian)頻調(diao)速恒壓給水(shui)控(kong)(kong)(kong)制(zhi)(zhi)設(she)備(bei)(bei)中，PID控(kong)(kong)(kong)制(zhi)(zhi)信號(hao)的(de)(de)(de)(de)(de)產生和輸(shu)出(chu)(chu)就成(cheng)為(wei)降(jiang)低給水(shui)設(she)備(bei)(bei)成(cheng)本的(de)(de)(de)(de)(de)一(yi)個關(guan)鍵環節(jie)。

三，管網疊(die)壓(ya)給水設備(bei)變頻器選用原則

    變(bian)頻(pin)器是(shi)中贏公(gong)司(si)推出的用于風機(ji)、水泵等設備調速節能運行(xing)的專用變(bian)頻(pin)器。其主要(yao)特點(dian)是(shi)：

    ⑴變(bian)頻器安(an)裝調試(shi)容易，維護和運行(xing)費用低(di)(di)。由于變(bian)頻器的特定功能(neng)使其產品(pin)的成本(ben)降低(di)(di)，價格便宜，降低(di)(di)了整套系統的成本(ben)。

    ⑵變頻器(qi)能(neng)(neng)夠自動地跟隨設定點(dian)，可使系統有較(jiao)好的性(xing)能(neng)(neng)。

    ⑶內(nei)置PID調節采用了標(biao)準比例、積分、微分控制(zhi)的閉環過程(cheng)控制(zhi)，并(bing)為反饋傳感(gan)器(qi)提供(gong)了標(biao)準電源(yuan)。

    ⑷在(zai)運行(xing)噪聲的控制方(fang)面(mian)采(cai)用了自動開關頻(pin)率優化，從而(er)降低電機運行(xing)時的噪聲。

    ⑸變頻(pin)(pin)器(qi)針(zhen)對風機(ji)(ji)、水(shui)泵節(jie)能(neng)運(yun)行的(de)需要，設置了能(neng)量(liang)(liang)優(you)化控(kong)制程(cheng)序，為在(zai)運(yun)行中搜(sou)尋小(xiao)能(neng)量(liang)(liang)消(xiao)(xiao)(xiao)耗(hao)點，自動升(sheng)高(gao)(gao)(gao)和降低電(dian)(dian)(dian)機(ji)(ji)電(dian)(dian)(dian)壓(ya)。當電(dian)(dian)(dian)機(ji)(ji)達(da)到(dao)穩(wen)定點的(de)速(su)度（即(ji)加速(su)過程(cheng)結束時(shi)(shi)(shi)）時(shi)(shi)(shi)通用(yong)變頻(pin)(pin)器(qi)即(ji)在(zai)這(zhe)個速(su)度下運(yun)行，而(er)變頻(pin)(pin)器(qi)此時(shi)(shi)(shi)開(kai)始分(fen)析電(dian)(dian)(dian)機(ji)(ji)的(de)功(gong)(gong)率(lv)消(xiao)(xiao)(xiao)耗(hao)。然后開(kai)始微小(xiao)地升(sheng)高(gao)(gao)(gao)或降低變頻(pin)(pin)器(qi)的(de)輸出(chu)電(dian)(dian)(dian)壓(ya)來(lai)搜(sou)索適合頻(pin)(pin)率(lv)，即(ji)較(jiao)低的(de)功(gong)(gong)率(lv)消(xiao)(xiao)(xiao)耗(hao)。如果(guo)變頻(pin)(pin)器(qi)檢(jian)測(ce)出(chu)在(zai)升(sheng)高(gao)(gao)(gao)電(dian)(dian)(dian)機(ji)(ji)電(dian)(dian)(dian)壓(ya)時(shi)(shi)(shi)，功(gong)(gong)率(lv)消(xiao)(xiao)(xiao)耗(hao)增(zeng)加了，則(ze)變頻(pin)(pin)器(qi)的(de)控(kong)制策略（能(neng)量(liang)(liang)優(you)化控(kong)制程(cheng)序）就開(kai)始降低電(dian)(dian)(dian)機(ji)(ji)電(dian)(dian)(dian)壓(ya)，以搜(sou)索低的(de)功(gong)(gong)率(lv)消(xiao)(xiao)(xiao)耗(hao)水(shui)平，如果(guo)檢(jian)測(ce)出(chu)在(zai)降低電(dian)(dian)(dian)機(ji)(ji)電(dian)(dian)(dian)壓(ya)時(shi)(shi)(shi)，功(gong)(gong)率(lv)消(xiao)(xiao)(xiao)耗(hao)增(zeng)加，則(ze)升(sheng)高(gao)(gao)(gao)電(dian)(dian)(dian)機(ji)(ji)電(dian)(dian)(dian)壓(ya)。這(zhe)樣(yang)就可(ke)搜(sou)尋到(dao)效率(lv)較(jiao)高(gao)(gao)(gao)，功(gong)(gong)率(lv)消(xiao)(xiao)(xiao)耗(hao)較(jiao)小(xiao)點并在(zai)此處(chu)運(yun)行。用(yong)這(zhe)種優(you)化節(jie)能(neng)程(cheng)序（典型(xing)）可(ke)節(jie)約2%～5%的(de)額定容量(liang)(liang)的(de)電(dian)(dian)(dian)能(neng)。

    ⑹在選擇(ze)變頻器(qi)時，不能用(yong)它驅動(dong)額(e)定功率比(bi)它大(da)或者額(e)定功率不足其一半(ban)的(de)(de)電機，否則會(hui)影響(xiang)變頻器(qi)的(de)(de)性能甚至造(zao)成損(sun)壞(huai)。

四,管網疊(die)壓給水設備控制系統詳(xiang)解

    為(wei)了保持(chi)供(gong)水系(xi)統水壓的(de)基本(ben)恒定(ding)(ding)，需要變(bian)頻器(qi)根據給定(ding)(ding)的(de)壓力信號(hao)與(yu)管網水壓的(de)反饋信號(hao)進(jin)行比較(jiao)，以調節水泵的(de)轉速，達(da)到(dao)供(gong)水、水壓恒定(ding)(ding)的(de)目的(de)。

    當管網疊壓給水設備系(xi)統處于自(zi)(zi)動(dong)(dong)調節(jie)狀態(tai)時，自(zi)(zi)動(dong)(dong)控(kong)制(zhi)(zhi)指示燈亮(liang)，系(xi)統進入自(zi)(zi)動(dong)(dong)控(kong)制(zhi)(zhi)狀態(tai)。系(xi)統由管網水(shui)(shui)壓(ya)傳感(gan)器作(zuo)為系(xi)統的反饋信(xin)號，反饋信(xin)號采用4-20mA電流(liu)信(xin)號，恒(heng)壓(ya)值的設定(ding)可在可編程(cheng)(cheng)控(kong)制(zhi)(zhi)器（PLC）中人為設定(ding)，通(tong)過(guo)使用變頻器內部(bu)的PID控(kong)制(zhi)(zhi)功能，啟動(dong)(dong)水(shui)(shui)泵作(zuo)變頻調節(jie)運行，并達到恒(heng)定(ding)的壓(ya)力(li)值，開成一個動(dong)(dong)態(tai)平衡過(guo)程(cheng)(cheng)。若設定(ding)恒(heng)壓(ya)值為Y0，過(guo)程(cheng)(cheng)壓(ya)力(li)值為Yi，當用水(shui)(shui)量增(zeng)加Yi＜Y0時，則(ze)變頻器輸出(chu)頻率上升，轉(zhuan)速提高(gao)，供水(shui)(shui)量增(zeng)大，仍達到恒(heng)定(ding)的設定(ding)壓(ya)力(li)值，從而開成一個新(xin)的動(dong)(dong)態(tai)平衡過(guo)程(cheng)(cheng)，實(shi)現(xian)系(xi)統的自(zi)(zi)動(dong)(dong)控(kong)制(zhi)(zhi)功能。

    管網疊壓(ya)給水(shui)設(she)備系統(tong)也可進(jin)行(xing)(xing)手(shou)動(dong)開環(huan)調(diao)節運行(xing)(xing)。如管網水(shui)壓(ya)傳感器(qi)出(chu)現故(gu)障時(shi)，人為(wei)將(jiang)手(shou)動(dong)/自動(dong)開關置(zhi)于(yu)手(shou)動(dong)位置(zhi)，系統(tong)處于(yu)手(shou)動(dong)調(diao)節狀(zhuang)態，手(shou)動(dong)控(kong)制指示燈亮，可在控(kong)制面板實現頻(pin)(pin)率(lv)（液位）手(shou)動(dong)設(she)定，并變頻(pin)(pin)啟動(dong)水(shui)泵。如所(suo)需水(shui)壓(ya)值(zhi)低于(yu)實際水(shui)壓(ya)值(zhi)時(shi)，可人為(wei)調(diao)整變頻(pin)(pin)調(diao)速器(qi)的輸出(chu)頻(pin)(pin)率(lv)，達到所(suo)需的恒壓(ya)值(zhi)。

六(liu),管網(wang)疊壓給(gei)水(shui)設備(bei)結語

    在智能建(jian)筑中管(guan)網(wang)疊壓給水(shui)(shui)(shui)設(she)備(bei)供(gong)水(shui)(shui)(shui)方式(shi)與過去的(de)(de)(de)(de)水(shui)(shui)(shui)塔或高(gao)位水(shui)(shui)(shui)箱以(yi)及氣壓供(gong)水(shui)(shui)(shui)方式(shi)相比，不論(lun)是設(she)備(bei)的(de)(de)(de)(de)投(tou)資(zi)，運行的(de)(de)(de)(de)經濟性，還是系(xi)統(tong)的(de)(de)(de)(de)穩定性、可靠性、自動化程(cheng)度等方面都具有(you)(you)無法比擬的(de)(de)(de)(de)優(you)勢(shi)，而(er)且具有(you)(you)顯(xian)著(zhu)(zhu)的(de)(de)(de)(de)節能效果。恒(heng)壓供(gong)水(shui)(shui)(shui)調速(su)(su)系(xi)統(tong)的(de)(de)(de)(de)這些(xie)優(you)越性，引起國內幾乎所有(you)(you)供(gong)水(shui)(shui)(shui)設(she)備(bei)廠家的(de)(de)(de)(de)高(gao)度重(zhong)視(shi)，并(bing)不斷投(tou)入開發、生產(chan)這一(yi)高(gao)新(xin)技術產(chan)品。在給水(shui)(shui)(shui)系(xi)統(tong)中，用(yong)水(shui)(shui)(shui)管(guan)式(shi)傳感器(qi)(qi)檢(jian)測(ce)水(shui)(shui)(shui)泵(beng)輸出(chu)管(guan)網(wang)壓力(li)，在現場控(kong)制(zhi)(zhi)器(qi)(qi)與設(she)定值比較(jiao)，比較(jiao)后去控(kong)制(zhi)(zhi)變頻器(qi)(qi)的(de)(de)(de)(de)輸出(chu)頻率(lv)(lv)，達到(dao)控(kong)制(zhi)(zhi)水(shui)(shui)(shui)泵(beng)轉(zhuan)速(su)(su)的(de)(de)(de)(de)目的(de)(de)(de)(de)。如(ru)給水(shui)(shui)(shui)管(guan)網(wang)用(yong)戶用(yong)水(shui)(shui)(shui)量增(zeng)多(duo)，管(guan)網(wang)壓力(li)減少(shao)，控(kong)制(zhi)(zhi)器(qi)(qi)控(kong)制(zhi)(zhi)變頻器(qi)(qi)輸出(chu)頻率(lv)(lv)增(zeng)加，水(shui)(shui)(shui)泵(beng)轉(zhuan)速(su)(su)隨著(zhu)(zhu)增(zeng)加，增(zeng)加供(gong)水(shui)(shui)(shui)量以(yi)滿足用(yong)戶的(de)(de)(de)(de)需求。如(ru)給水(shui)(shui)(shui)管(guan)網(wang)用(yong)戶用(yong)水(shui)(shui)(shui)量減少(shao)，管(guan)網(wang)壓力(li)增(zeng)大，控(kong)制(zhi)(zhi)器(qi)(qi)控(kong)制(zhi)(zhi)變頻器(qi)(qi)輸出(chu)頻率(lv)(lv)降低(di)，水(shui)(shui)(shui)泵(beng)轉(zhuan)速(su)(su)隨著(zhu)(zhu)減少(shao)，減少(shao)供(gong)水(shui)(shui)(shui)量，從而(er)達到(dao)節能的(de)(de)(de)(de)目的(de)(de)(de)(de)。