1?引言
在(zai)生(sheng)(sheng)產(chan)(chan)(chan)藥(yao)品(pin)的(de)(de)潔(jie)(jie)(jie)凈(jing)廠(chang)房(fang)(fang)(fang),要(yao)(yao)滿(man)足一(yi)定的(de)(de)潔(jie)(jie)(jie)凈(jing)度要(yao)(yao)求。保(bao)證(zheng)藥(yao)品(pin)質(zhi)量(liang)(liang)的(de)(de)重(zhong)要(yao)(yao)環節(jie)是(shi)(shi)生(sheng)(sheng)產(chan)(chan)(chan)方法(fa),其優劣(lie)是(shi)(shi)由(you)生(sheng)(sheng)產(chan)(chan)(chan)技術和生(sheng)(sheng)產(chan)(chan)(chan)環境所(suo)決(jue)定的(de)(de),藥(yao)廠(chang)生(sheng)(sheng)產(chan)(chan)(chan)環境控制的(de)(de)主要(yao)(yao)目(mu)的(de)(de)是(shi)(shi)防止因污染(ran)(ran)或交叉污染(ran)(ran)等危及(ji)產(chan)(chan)(chan)品(pin)質(zhi)量(liang)(liang)的(de)(de)情(qing)況(kuang)發生(sheng)(sheng)[1]。因此對(dui)(dui)一(yi)些關鍵的(de)(de)生(sheng)(sheng)產(chan)(chan)(chan)工藝操作間(jian)(jian)(jian)(jian)(jian),在(zai)減少(shao)房(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)內污染(ran)(ran)的(de)(de)同(tong)(tong)時,保(bao)證(zheng)其相對(dui)(dui)于(yu)相鄰(lin)房(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)的(de)(de)壓(ya)差(cha),就成為保(bao)證(zheng)潔(jie)(jie)(jie)凈(jing)度從而(er)保(bao)證(zheng)藥(yao)品(pin)質(zhi)量(liang)(liang)的(de)(de)重(zhong)要(yao)(yao)因素(su)。潔(jie)(jie)(jie)凈(jing)產(chan)(chan)(chan)房(fang)(fang)(fang)設計中,生(sheng)(sheng)產(chan)(chan)(chan)過程(cheng)采用壓(ya)力梯度的(de)(de)目(mu)的(de)(de)是(shi)(shi)阻(zu)止可能出現(xian)的(de)(de)不同(tong)(tong)生(sheng)(sheng)產(chan)(chan)(chan)工藝之間(jian)(jian)(jian)(jian)(jian)的(de)(de)交叉污染(ran)(ran)。生(sheng)(sheng)產(chan)(chan)(chan)車間(jian)(jian)(jian)(jian)(jian)壓(ya)力高于(yu)走廊,即(ji)房(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)保(bao)持正壓(ya)。有污染(ran)(ran)物(wu)的(de)(de)車間(jian)(jian)(jian)(jian)(jian)保(bao)持低壓(ya)阻(zu)止污染(ran)(ran)物(wu)擴散。阻(zu)止污染(ran)(ran)物(wu)進入生(sheng)(sheng)產(chan)(chan)(chan)車間(jian)(jian)(jian)(jian)(jian),即(ji)保(bao)持房(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)負(fu)壓(ya)。某些設有工藝排(pai)風(feng)的(de)(de)房(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)出于(yu)工藝的(de)(de)需求,房(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)排(pai)風(feng)量(liang)(liang)是(shi)(shi)依據不同(tong)(tong)產(chan)(chan)(chan)品(pin)特點(dian)而(er)變化(hua)的(de)(de)。在(zai)這種風(feng)量(liang)(liang)變化(hua)情(qing)況(kuang)下(xia),保(bao)證(zheng)這些房(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)的(de)(de)壓(ya)差(cha)對(dui)(dui)整個潔(jie)(jie)(jie)凈(jing)廠(chang)房(fang)(fang)(fang)的(de)(de)壓(ya)差(cha)平衡就顯得尤(you)為重(zhong)要(yao)(yao)。本文將重(zhong)點(dian)討論變風(feng)量(liang)(liang)情(qing)況(kuang)下(xia)的(de)(de)壓(ya)差(cha)控制方法(fa)。
2?變風量房間壓差控制
針(zhen)對某藥廠制(zhi)劑(ji)車(che)間(jian)(jian)的(de)壓差(cha)平衡(heng)問(wen)題改造(zao)設計。該(gai)制(zhi)劑(ji)車(che)間(jian)(jian)共有三層,潔凈度為(wei)十萬級。根(gen)據GMP的(de)相關條款(kuan),該(gai)制(zhi)劑(ji)車(che)間(jian)(jian)的(de)空(kong)調系統需保證生(sheng)產中整(zheng)體風量平衡(heng)、壓差(cha)穩定(ding)、氣流走向符合工藝(yi)流線要(yao)求。經過對該(gai)制(zhi)劑(ji)車(che)間(jian)(jian)摸底調查和初步調試,發現存在(zai)以(yi)下(xia)問(wen)題:
(1)空調系統出力不足。實際送(song)風量小于(yu)設計值(zhi)。
(2)工(gong)藝排風(feng)所引起的(de)不平(ping)衡。部分(fen)房間由(you)于工(gong)藝要求,房間排風(feng)量是變化的(de)。原(yuan)設計未(wei)考慮排風(feng)量變化造成的(de)房間壓差的(de)變化,所以有工(gong)藝排風(feng)
的(de)房間都不能滿足壓差的(de)設(she)計要求(qiu)。
對于整個(ge)(ge)制劑(ji)(ji)車(che)間來(lai)說(shuo),個(ge)(ge)別房間壓(ya)(ya)差的(de)(de)少許變(bian)化必將影(ying)響車(che)間壓(ya)(ya)差的(de)(de)整體平衡(heng)。所以這些排風量變(bian)化房間的(de)(de)壓(ya)(ya)差混亂是(shi)造(zao)成該制劑(ji)(ji)車(che)間壓(ya)(ya)差混亂的(de)(de)主要原因。
2.1?房間(jian)漏(lou)風量(liang)計算
當潔凈室與相(xiang)鄰的(de)(de)空間(jian)之間(jian)有門(men)(men)窗和任何(he)形式的(de)(de)孔口存在(zai)時,在(zai)這(zhe)些門(men)(men)窗、孔口處于關閉情況下,潔凈室與相(xiang)鄰空間(jian)應維持(chi)一個相(xiang)對壓差(cha),這(zhe)個壓差(cha)就是以(yi)一定風(feng)量通過這(zhe)些關閉的(de)(de)門(men)(men)窗、孔口的(de)(de)縫隙時的(de)(de)阻(zu)(zu)力(li)(li),所以(yi)靜壓差(cha)反映的(de)(de)是縫隙的(de)(de)阻(zu)(zu)力(li)(li)特(te)性。
從靜(jing)壓差(cha)的物理特性可(ke)見房間的壓差(cha)與房間的漏(lou)風(feng)量(liang)(liang)有很大關系。針對(dui)制劑車(che)間具體情況,在實地對(dui)不同房門類型在不同壓差(cha)條件(jian)下的門縫(feng)單位(wei)長度漏(lou)風(feng)量(liang)(liang)進行測試,實驗結果如表1所(suo)示。
根據實際情(qing)況(kuang)(kuang):自動門(men)在房(fang)間壓(ya)(ya)差不(bu)同(tong)的情(qing)況(kuang)(kuang)下表現出(chu)來的漏風(feng)量是(shi)不(bu)同(tong)的,因此針(zhen)對具(ju)體情(qing)況(kuang)(kuang)區分(fen)為(wei)正壓(ya)(ya)和(he)負壓(ya)(ya)情(qing)況(kuang)(kuang)分(fen)別(bie)考慮。正壓(ya)(ya)情(qing)況(kuang)(kuang)表現為(wei)非(fei)密(mi)(mi)(mi)閉(bi)門(men)形式,而負壓(ya)(ya)情(qing)況(kuang)(kuang)密(mi)(mi)(mi)閉(bi)效果較好,表現為(wei)密(mi)(mi)(mi)閉(bi)門(men)形式。測試值(zhi)與5潔凈廠房(fang)設計規(gui)范(fan)6推(tui)薦(jian)值(zhi)相(xiang)差不(bu)大。對開門(men)密(mi)(mi)(mi)閉(bi)效果不(bu)好,測試值(zhi)大于(yu)(yu)5潔凈廠房(fang)設計規(gui)范(fan)6中關于(yu)(yu)非(fei)密(mi)(mi)(mi)閉(bi)門(men)的推(tui)薦(jian)值(zhi)。對于(yu)(yu)單開門(men)密(mi)(mi)(mi)閉(bi)效果較好,測試值(zhi)與5潔凈廠房(fang)設計規(gui)范(fan)6密(mi)(mi)(mi)閉(bi)門(men)推(tui)薦(jian)值(zhi)十分(fen)接近。具(ju)體情(qing)況(kuang)(kuang)如表2所示。
美(mei)國標(biao)準(zhun)研究所(suo)(ANSI)與美(mei)國工業衛生協會(AIHA)支(zhi)持采用漏風(feng)量(liang)(liang)(liang)方法解(jie)決(jue)房間壓(ya)(ya)差控(kong)制問題。ANSI的(de)標(biao)準(zhun)Z9.5認(ren)為/規定定量(liang)(liang)(liang)壓(ya)(ya)差是不好的(de)設(she)計依(yi)據[4],真正(zheng)需要的(de)是漏風(feng)量(liang)(liang)(liang)。通過(guo)實際檢測發(fa)現該制劑車間門(men)的(de)密閉效果(guo)較差,漏風(feng)量(liang)(liang)(liang)較大。所(suo)以本(ben)次設(she)計門(men)的(de)設(she)計漏風(feng)量(liang)(liang)(liang)如下:單開門(men)200m3/h,對開門(men)400m3/h,電(dian)動(dong)門(men)600m3/h。
2.2?房(fang)間壓差(cha)控制
如圖1所(suo)示:對于排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)隨(sui)時(shi)(shi)(shi)變(bian)(bian)化(hua)而(er)(er)同時(shi)(shi)(shi)設(she)(she)置(zhi)(zhi)了(le)回(hui)(hui)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)的(de)(de)房(fang)(fang)(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian),增(zeng)(zeng)設(she)(she)一(yi)個(ge)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)口(kou),通(tong)(tong)過(guo)管(guan)(guan)(guan)道(dao)接入新(xin)增(zeng)(zeng)設(she)(she)的(de)(de)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)系統(tong),并在新(xin)增(zeng)(zeng)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)管(guan)(guan)(guan)道(dao)上安(an)裝文丘里(li)流量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)控制閥(fa)(fa)(fa)門(men)(men)。新(xin)設(she)(she)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)口(kou)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)隨(sui)原(yuan)有(you)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)口(kou)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)變(bian)(bian)化(hua)而(er)(er)變(bian)(bian)化(hua)。原(yuan)有(you)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)口(kou)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)減少,則(ze)新(xin)設(she)(she)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)口(kou)閥(fa)(fa)(fa)門(men)(men)開大,新(xin)設(she)(she)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)管(guan)(guan)(guan)道(dao)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)增(zeng)(zeng)加;原(yuan)有(you)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)口(kou)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)增(zeng)(zeng)加,則(ze)新(xin)設(she)(she)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)口(kou)閥(fa)(fa)(fa)門(men)(men)關小,新(xin)設(she)(she)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)管(guan)(guan)(guan)道(dao)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)減少。總(zong)之,通(tong)(tong)過(guo)文丘里(li)流量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)控制閥(fa)(fa)(fa)控制房(fang)(fang)(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)總(zong)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)恒定(ding)(ding),為(wei)房(fang)(fang)(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)更大排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)。房(fang)(fang)(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)送(song)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)根(gen)據房(fang)(fang)(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)潔凈(jing)度要(yao)求的(de)(de)換(huan)氣(qi)(qi)次(ci)數確(que)(que)定(ding)(ding)。回(hui)(hui)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)根(gen)據送(song)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)、房(fang)(fang)(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)漏風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)及房(fang)(fang)(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)更大排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)確(que)(que)定(ding)(ding),由送(song)回(hui)(hui)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)保證房(fang)(fang)(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)的(de)(de)壓(ya)差。對于排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)隨(sui)時(shi)(shi)(shi)變(bian)(bian)化(hua)而(er)(er)沒(mei)有(you)設(she)(she)置(zhi)(zhi)回(hui)(hui)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)的(de)(de)房(fang)(fang)(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian),增(zeng)(zeng)設(she)(she)一(yi)個(ge)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)口(kou),通(tong)(tong)過(guo)管(guan)(guan)(guan)道(dao)接入新(xin)增(zeng)(zeng)設(she)(she)的(de)(de)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)系統(tong),并在新(xin)增(zeng)(zeng)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)管(guan)(guan)(guan)道(dao)上安(an)裝文丘里(li)流量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)控制閥(fa)(fa)(fa),保證房(fang)(fang)(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)總(zong)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)恒定(ding)(ding)。房(fang)(fang)(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)壓(ya)差控制原(yuan)理同上。房(fang)(fang)(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)送(song)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)根(gen)據房(fang)(fang)(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)潔凈(jing)度要(yao)求的(de)(de)換(huan)氣(qi)(qi)次(ci)數確(que)(que)定(ding)(ding)。房(fang)(fang)(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)總(zong)排(pai)(pai)(pai)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)根(gen)據房(fang)(fang)(fang)(fang)(fang)間(jian)(jian)(jian)(jian)(jian)送(song)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)和漏風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)量(liang)(liang)(liang)(liang)(liang)(liang)(liang)(liang)計算確(que)(que)定(ding)(ding)。
2.3?新(xin)增排風靜壓系統(tong)
新(xin)增排風靜壓系統如圖2所示:
(1)在排風(feng)總管上安裝壓力變送器(qi),將測量信號(hao)反饋給(gei)控制器(qi),控制排風(feng)分機變頻器(qi)輸出(chu)頻率,保持風(feng)壓恒定。
(2)在新(xin)增的(de)排(pai)風支管道(dao)上安裝EXV系列文丘里控(kong)制(zhi)閥,根據各(ge)房(fang)(fang)間的(de)壓(ya)差分別(bie)控(kong)制(zhi)文丘里控(kong)制(zhi)閥的(de)開啟(qi)度,確保每(mei)時刻房(fang)(fang)間的(de)總排(pai)風量(新(xin)增排(pai)風口(kou)與(yu)原有排(pai)風口(kou)排(pai)風風量的(de)和)恒定(ding)為(wei)房(fang)(fang)間更大(da)排(pai)風量。
(3)房間(jian)靜壓信(xin)號(hao)通過信(xin)號(hao)分配器,一路給文丘里控制(zhi)閥進行自(zi)動(dong)控制(zhi),一路進MEC控制(zhi)器在(zai)中控室(shi)自(zi)動(dong)顯(xian)示房間(jian)靜壓。
3?變風量控制器的選擇
3.1?氣流(liu)控制閥特性
好的氣流控制閥應具備:良(liang)好的可(ke)調率;高精度;快速響應。
(1)可調率
如圖3所示,當需(xu)要房(fang)間(jian)漏風量為常量200m3/h,排風量在300~1500m3/h變化,則需(xu)要送風要有超過10B1的(de)調節比。
(2)高精度
如圖4所示,當房間(jian)處于最不(bu)利(li)情(qing)況下,即送(song)風量是945m3/h,排風量是950m3/h時(shi),高精(jing)度的控制閥能夠保證房間(jian)的負壓。
(3)快速響應
房間送風(feng)和排風(feng)控制系(xi)統必(bi)須快速響應(ying)維持房間的(de)正確(que)壓力。圖5顯示(shi)房間壓力如何因為送風(feng)流量響應(ying)緩慢(man)而(er)變(bian)成正壓的(de)。圖中陰影部(bu)分為
送風緩(huan)慢引起(qi)的正(zheng)壓期(qi)間。
3.2?變(bian)風量閥工(gong)作原(yuan)理(li)
典型的(de)節流式調節風(feng)(feng)(feng)閥(fa)內(nei)部有(you)一(yi)個彈簧(huang)的(de)錐(zhui)體(ti)構(gou)件,即(ji)(ji)風(feng)(feng)(feng)量(liang)調節機(ji)構(gou)。它具有(you)兩個獨立的(de)動作(zuo)(zuo)部分(fen):一(yi)是隨室(shi)內(nei)壓(ya)差變化由(you)房間靜(jing)壓(ya)信號(hao)來(lai)動作(zuo)(zuo)的(de)部分(fen),由(you)執行機(ji)構(gou)控制錐(zhui)體(ti)中心的(de)閥(fa)桿(gan),使(shi)錐(zhui)體(ti)在(zai)文(wen)氏管內(nei)移(yi)動,即(ji)(ji)調節錐(zhui)體(ti)與管道(dao)間的(de)開(kai)口面(mian)積(ji),來(lai)調節風(feng)(feng)(feng)量(liang);另(ling)一(yi)個是定(ding)風(feng)(feng)(feng)量(liang)機(ji)構(gou),即(ji)(ji)不會因為(wei)調節其它風(feng)(feng)(feng)口而引起(qi)風(feng)(feng)(feng)量(liang)的(de)再分(fen)配(pei)。定(ding)風(feng)(feng)(feng)量(liang)機(ji)構(gou)依靠錐(zhui)體(ti)構(gou)件內(nei)彈簧(huang)的(de)補償作(zuo)(zuo)用來(lai)實現。在(zai)上(shang)游靜(jing)壓(ya)的(de)作(zuo)(zuo)用下彈簧(huang)伸縮(suo)使(shi)錐(zhui)體(ti)構(gou)件沿閥(fa)桿(gan)位(wei)移(yi),以(yi)平衡(heng)管內(nei)壓(ya)力的(de)變化,維持要求的(de)風(feng)(feng)(feng)量(liang)[5]。
3.3?文(wen)丘里閥與VAV蝶閥對比(bi)
在工程中常用的兩種變風量蝶閥(fa)(fa)文丘里閥(fa)(fa)與VAV蝶閥(fa)(fa)作(zuo)簡單的對比,如表3所示。
由表(biao)3對比(bi)可看出在(zai)可調率、高精度、入/出口的條件要求(qiu)以及快速響應等方面文丘里(li)閥在(zai)性(xing)能上要優于VAV蝶閥。
4?結論
通(tong)過對不同(tong)房門(men)類型在(zai)(zai)不同(tong)壓(ya)差條件下的(de)門(men)縫單位長度漏風(feng)量進(jin)行測試分析變風(feng)量情況下房間(jian)壓(ya)差變化的(de)原因,討(tao)論了變風(feng)量情況下房間(jian)壓(ya)差控(kong)制(zhi)方(fang)法,并且介紹了常用(yong)(yong)變風(feng)量末端裝置的(de)基(ji)本工(gong)作原理,對工(gong)程(cheng)(cheng)(cheng)中(zhong)常用(yong)(yong)的(de)兩種變風(feng)量裝置文(wen)丘里閥(fa)(fa)(fa)及(ji)VAV蝶閥(fa)(fa)(fa)的(de)性(xing)能(neng)進(jin)行了對比(bi),文(wen)丘里閥(fa)(fa)(fa)在(zai)(zai)性(xing)能(neng)上(shang)要(yao)優于VAV蝶閥(fa)(fa)(fa),在(zai)(zai)價格上(shang)要(yao)遠高于VAV閥(fa)(fa)(fa),對氣流(liu)控(kong)制(zhi)要(yao)求不是很高的(de)工(gong)程(cheng)(cheng)(cheng)中(zhong)采(cai)用(yong)(yong)VAV蝶閥(fa)(fa)(fa),對氣流(liu)控(kong)制(zhi)有獨特要(yao)求的(de)實驗室則文(wen)丘里閥(fa)(fa)(fa)可以達(da)到所需的(de)技術標準(zhun)。因此,在(zai)(zai)選用(yong)(yong)變風(feng)量閥(fa)(fa)(fa)時,根據工(gong)程(cheng)(cheng)(cheng)的(de)具(ju)體(ti)情況和使(shi)用(yong)(yong)要(yao)求選擇適合工(gong)程(cheng)(cheng)(cheng)需要(yao)的(de),性(xing)能(neng)價格比(bi)高的(de)產品(pin)。
