1． 系統漏(lou)風(feng)量測試規定和(he)原則
《規(gui)范》中(zhong)(zhong)規(gui)定，風管系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)安裝(zhuang)完畢(bi)后，應(ying)按系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)類別進行嚴(yan)密性(xing)檢(jian)驗，根據(ju)風管系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)的工(gong)(gong)作(zuo)壓(ya)(ya)力(li)(li)可劃分為(wei)(wei)三個類別，系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)工(gong)(gong)作(zuo)壓(ya)(ya)力(li)(li)p≤500pa為(wei)(wei)低壓(ya)(ya)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)；系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)工(gong)(gong)作(zuo)壓(ya)(ya)力(li)(li)500pa1500pa為(wei)(wei)高壓(ya)(ya)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)。民(min)用建筑中(zhong)(zhong)通(tong)風空(kong)調系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)通(tong)常是低、中(zhong)(zhong)壓(ya)(ya)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)。
高壓(ya)系統風管嚴密性(xing)檢驗，為全數進行漏(lou)風量測試(shi)；中(zhong)壓(ya)系統大都為低級別的(de)凈化空調(diao)系統、恒溫恒濕
與排(pai)煙系(xi)(xi)統(tong)等(deng)。風管(guan)的嚴密性檢(jian)驗(yan)，應在漏(lou)光(guang)法(fa)檢(jian)測合格后(hou)，對系(xi)(xi)統(tong)漏(lou)風量(liang)測試進行抽(chou)(chou)檢(jian)，抽(chou)(chou)檢(jian)率為(wei)20％，且不(bu)(bu)得少于(yu)1個系(xi)(xi)統(tong)。低(di)壓系(xi)(xi)統(tong)大都為(wei)一般的通風、排(pai)氣和舒(shu)適性空調系(xi)(xi)統(tong)，在加工工藝得到(dao)保(bao)證(zheng)的前(qian)提下，采用漏(lou)光(guang)法(fa)檢(jian)測，當漏(lou)光(guang)法(fa)檢(jian)測結果符合規范要求時，可(ke)不(bu)(bu)進行漏(lou)風量(liang)測試。如(ru)當漏(lou)光(guang)檢(jian)測達不(bu)(bu)到(dao)要求時，應按規定的抽(chou)(chou)檢(jian)率做漏(lou)風量(liang)測試抽(chou)(chou)檢(jian)，抽(chou)(chou)檢(jian)率為(wei)5％，且不(bu)(bu)得少于(yu)1個系(xi)(xi)統(tong)。
矩形風管的允許(xu)漏風量(liang)應符合以下規定：
低壓系統風管 QL≤0．1056p0.65
中壓系統風管 QN≤0．0352p0.65
高(gao)壓系統風管QH≤0．0117p0.65
式中QL、QN 、QH為系(xi)統風管(guan)在相應(ying)工(gong)作(zuo)壓力下，單位面(mian)積風管(guan)單位時間內的允許漏(lou)風量[ m 3／(h·m2)]；p為指(zhi)風管(guan)系(xi)統的工(gong)作(zuo)壓力(pa)
低壓、中壓圓(yuan)形(xing)金屬(shu)(shu)風管(guan)、復合(he)材料風管(guan)以(yi)及(ji)采用非法蘭形(xing)式的(de)非金屬(shu)(shu)風管(guan)的(de)允許(xu)漏風量，應為矩形(xing)風管(guan)
規(gui)定(ding)值(zhi)的50％；磚(zhuan)，混凝土風(feng)(feng)道的允許漏風(feng)(feng)量不應(ying)大于(yu)矩形低壓系統風(feng)(feng)管(guan)規(gui)定(ding)值(zhi)的1．5倍(bei)；排煙、除(chu)塵、低溫送風(feng)(feng)系統按中(zhong)壓系統風(feng)(feng)管(guan)的規(gui)定(ding)，1～5級凈化空調系統按高壓系統風(feng)(feng)管(guan)的規(gui)定(ding)。
從風(feng)(feng)管(guan)系(xi)統(tong)(tong)漏風(feng)(feng)的機(ji)理(li)分(fen)析，系(xi)統(tong)(tong)末端(duan)的靜壓(ya)小，相對的漏風(feng)(feng)量也小，故風(feng)(feng)管(guan)系(xi)統(tong)(tong)嚴密性檢(jian)驗原則以主、干(gan)管(guan)為(wei)(wei)主。可整(zheng)個系(xi)統(tong)(tong)測(ce)試(shi)(shi)，也可分(fen)段進(jin)行(xing)，分(fen)段的方法實施較(jiao)為(wei)(wei)靈活、方便；整(zheng)段測(ce)試(shi)(shi)時，應該考慮測(ce)試(shi)(shi)裝置風(feng)(feng)機(ji)應有足夠的風(feng)(feng)量和風(feng)(feng)壓(ya)，以滿足測(ce)試(shi)(shi)要求。
2． 技(ji)術難點和(he)方案選擇(ze)
(1)技(ji)術難點。為(wei)保(bao)證被測系(xi)統嚴(yan)密，測量(liang)結果真實，因此必(bi)(bi)須(xu)(xu)對系(xi)統中(zhong)的(de)(de)開口(風(feng)口)進行嚴(yan)格封堵，確保(bao)不(bu)漏風(feng)。另外，測試裝(zhuang)置(zhi)的(de)(de)關(guan)鍵部位(wei)的(de)(de)連(lian)接部分必(bi)(bi)須(xu)(xu)嚴(yan)密不(bu)漏風(feng)，標準(zhun)長頸噴嘴(指風(feng)室(shi)式測試裝(zhuang)置(zhi))的(de)(de)幾何(he)尺寸必(bi)(bi)須(xu)(xu)符合要求，否則會引起較大(da)的(de)(de)測量(liang)誤(wu)差。而噴嘴的(de)(de)流量(liang)系(xi)數受環境溫度(du)、雷諾數Re等(deng)影(ying)響，在(zai)(zai)工程應 用中(zhong)確定起來較困難，存在(zai)(zai)一(yi)定的(de)(de)誤(wu)差，不(bu)過該(gai)誤(wu)差通常在(zai)(zai)允(yun)許的(de)(de)范圍內。
(2)方案選擇。采(cai)用正壓(ya)風室式(噴(pen)嘴)漏風量測(ce)試(shi)裝(zhuang)置(zhi)，由于該裝(zhuang)置(zhi)與國際上技術先進的(de)標準一致，和(he)風管式(孔板)漏風量測(ce)試(shi)裝(zhuang)置(zhi)相比(bi)測(ce)量精度高。測(ce)試(shi)裝(zhuang)置(zhi)由風機、連接風管、傾斜式微壓(ya)計(ji)、均流板、風室、隔板和(he)噴(pen)嘴等組(zu)成(cheng)。
