冷卻塔通風阻力計算

通(tong)風(feng)(feng)(feng)阻(zu)力(li)(li)(li)計(ji)算的(de)(de)目的(de)(de)是根據設計(ji)風(feng)(feng)(feng)量和風(feng)(feng)(feng)壓，以確定風(feng)(feng)(feng)筒(tong)內高(gao)度(du)或(huo)選用適當的(de)(de)風(feng)(feng)(feng)機(ji)。在冷(leng)(leng)卻(que)塔(ta)的(de)(de)工作(zuo)條件下(xia)，風(feng)(feng)(feng)機(ji)的(de)(de)通(tong)風(feng)(feng)(feng)量決(jue)定于冷(leng)(leng)卻(que)塔(ta)的(de)(de)全(quan)部空氣(qi)動(dong)力(li)(li)(li)阻(zu)力(li)(li)(li)，而這一阻(zu)力(li)(li)(li)等于風(feng)(feng)(feng)機(ji)的(de)(de)全(quan)風(feng)(feng)(feng)壓。風(feng)(feng)(feng)機(ji)的(de)(de)工作(zuo)點(dian)可用風(feng)(feng)(feng)機(ji)的(de)(de)特性曲線與冷(leng)(leng)卻(que)塔(ta)的(de)(de)空氣(qi)動(dong)力(li)(li)(li)阻(zu)力(li)(li)(li)性能曲線的(de)(de)交點(dian)來(lai)表(biao)示(shi)。通(tong)風(feng)(feng)(feng)阻(zu)力(li)(li)(li)計(ji)算的(de)(de)方法有(you)：按(an)經驗公式計(ji)算和采用同型(xing)塔(ta)實(shi)測(ce)數據計(ji)算。

冷卻塔風筒或擴散筒高度

1、風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)筒(tong)(tong)(tong)(tong)高(gao)(gao)(gao)度(du)：風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)筒(tong)(tong)(tong)(tong)分垂直(zhi)(zhi)(zhi)式的(de)(de)(de)(de)(de)(de)(de)和擴(kuo)(kuo)(kuo)散(san)(san)(san)式的(de)(de)(de)(de)(de)(de)(de)兩種，垂直(zhi)(zhi)(zhi)式的(de)(de)(de)(de)(de)(de)(de)直(zhi)(zhi)(zhi)圓風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)筒(tong)(tong)(tong)(tong)高(gao)(gao)(gao)度(du)沒有一(yi)個統一(yi)的(de)(de)(de)(de)(de)(de)(de)標準，由環境條件、出(chu)(chu)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)氣流對進(jin)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)口(kou)環流的(de)(de)(de)(de)(de)(de)(de)影響及風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)機(ji)(ji)(ji)(ji)噪(zao)(zao)聲對周圍環境的(de)(de)(de)(de)(de)(de)(de)影響等因素決定。當采用圓弧形或近似直(zhi)(zhi)(zhi)角形的(de)(de)(de)(de)(de)(de)(de)大型(xing)塔(ta)的(de)(de)(de)(de)(de)(de)(de)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)機(ji)(ji)(ji)(ji)進(jin)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)口(kou)來說(shuo)，風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)筒(tong)(tong)(tong)(tong)高(gao)(gao)(gao)度(du)為(wei)1、5～3、0m的(de)(de)(de)(de)(de)(de)(de)直(zhi)(zhi)(zhi)圓筒(tong)(tong)(tong)(tong)。通(tong)常(chang)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)筒(tong)(tong)(tong)(tong)高(gao)(gao)(gao)度(du)不小(xiao)(xiao)于(yu)(yu)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)機(ji)(ji)(ji)(ji)直(zhi)(zhi)(zhi)徑(jing)(jing)的(de)(de)(de)(de)(de)(de)(de)20%～30%即0、2Db～0、3Db，如(ru)前面設計(ji)計(ji)算(suan)的(de)(de)(de)(de)(de)(de)(de)100m3h逆流式冷(leng)卻(que)塔(ta)，直(zhi)(zhi)(zhi)圓形風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)筒(tong)(tong)(tong)(tong)高(gao)(gao)(gao)為(wei)600+50=650mm、風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)機(ji)(ji)(ji)(ji)直(zhi)(zhi)(zhi)徑(jing)(jing)為(wei)2100mm，則風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)筒(tong)(tong)(tong)(tong)高(gao)(gao)(gao)度(du)占(zhan)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)機(ji)(ji)(ji)(ji)直(zhi)(zhi)(zhi)徑(jing)(jing)的(de)(de)(de)(de)(de)(de)(de)30、95%≈31%。2、擴(kuo)(kuo)(kuo)散(san)(san)(san)筒(tong)(tong)(tong)(tong)高(gao)(gao)(gao)度(du)設擴(kuo)(kuo)(kuo)散(san)(san)(san)筒(tong)(tong)(tong)(tong)的(de)(de)(de)(de)(de)(de)(de)基本作用是(shi)減(jian)少空氣從塔(ta)中(zhong)(zhong)流出(chu)(chu)時，因撞擊引起的(de)(de)(de)(de)(de)(de)(de)阻力(li)損失，防止從風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)筒(tong)(tong)(tong)(tong)流出(chu)(chu)的(de)(de)(de)(de)(de)(de)(de)濕熱空氣回流到進(jin)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)口(kou)和減(jian)少風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)機(ji)(ji)(ji)(ji)噪(zao)(zao)聲。因擴(kuo)(kuo)(kuo)散(san)(san)(san)筒(tong)(tong)(tong)(tong)會(hui)影響風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)機(ji)(ji)(ji)(ji)的(de)(de)(de)(de)(de)(de)(de)效率，因此(ci)(ci)，選(xuan)擇擴(kuo)(kuo)(kuo)散(san)(san)(san)筒(tong)(tong)(tong)(tong)尺寸(cun)時要進(jin)行風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)機(ji)(ji)(ji)(ji)的(de)(de)(de)(de)(de)(de)(de)空氣動力(li)計(ji)算(suan)。設擴(kuo)(kuo)(kuo)散(san)(san)(san)筒(tong)(tong)(tong)(tong)的(de)(de)(de)(de)(de)(de)(de)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)筒(tong)(tong)(tong)(tong)高(gao)(gao)(gao)度(du)由兩部(bu)分組成：一(yi)部(bu)分是(shi)安(an)裝(zhuang)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)機(ji)(ji)(ji)(ji)的(de)(de)(de)(de)(de)(de)(de)直(zhi)(zhi)(zhi)圓筒(tong)(tong)(tong)(tong)，另一(yi)部(bu)分是(shi)擴(kuo)(kuo)(kuo)散(san)(san)(san)筒(tong)(tong)(tong)(tong)。安(an)裝(zhuang)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)機(ji)(ji)(ji)(ji)的(de)(de)(de)(de)(de)(de)(de)直(zhi)(zhi)(zhi)圓筒(tong)(tong)(tong)(tong)部(bu)分高(gao)(gao)(gao)度(du)，按風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)機(ji)(ji)(ji)(ji)說(shuo)明書(shu)確定。設計(ji)時如(ru)無說(shuo)明書(shu)，這(zhe)部(bu)分高(gao)(gao)(gao)度(du)可(ke)取0、16Db以能在筒(tong)(tong)(tong)(tong)體內布置風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)機(ji)(ji)(ji)(ji)葉(xie)片并(bing)能調整(zheng)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)機(ji)(ji)(ji)(ji)葉(xie)片前的(de)(de)(de)(de)(de)(de)(de)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)速分布為(wei)前提；擴(kuo)(kuo)(kuo)散(san)(san)(san)筒(tong)(tong)(tong)(tong)的(de)(de)(de)(de)(de)(de)(de)圓錐角亦稱中(zhong)(zhong)心展開角為(wei)10°～18°見圖(tu)7-16，其(qi)高(gao)(gao)(gao)度(du)不宜小(xiao)(xiao)于(yu)(yu)風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)機(ji)(ji)(ji)(ji)的(de)(de)(de)(de)(de)(de)(de)半徑(jing)(jing)，常(chang)采用0、7Db風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)機(ji)(ji)(ji)(ji)直(zhi)(zhi)(zhi)徑(jing)(jing)。按公(gong)式計(ji)算(suan)為(wei)：此(ci)(ci)式基本上(shang)與式7-48相同，式中(zhong)(zhong)符號尺寸(cun)不同：D1——風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)機(ji)(ji)(ji)(ji)處風(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)筒(tong)(tong)(tong)(tong)直(zhi)(zhi)(zhi)徑(jing)(jing)m；D0——擴(kuo)(kuo)(kuo)散(san)(san)(san)筒(tong)(tong)(tong)(tong)出(chu)(chu)口(kou)直(zhi)(zhi)(zhi)徑(jing)(jing)m；α——擴(kuo)(kuo)(kuo)散(san)(san)(san)筒(tong)(tong)(tong)(tong)圓錐角；L——擴(kuo)(kuo)(kuo)散(san)(san)(san)筒(tong)(tong)(tong)(tong)高(gao)(gao)(gao)度(du)。