一、屋頂通風器的工作原理
屋頂通風器是依靠自然(ran)風(feng)壓(ya)(ya)和熱壓(ya)(ya)實(shi)現室(shi)內外空(kong)氣(qi)的(de)流動與置換,從而達到(dao)改(gai)善空(kong)氣(qi)質量的(de)目(mu)的(de)。風(feng)壓(ya)(ya)和熱壓(ya)(ya)是屋頂(ding)通(tong)風(feng)器(qi)最(zui)基本(ben)的(de)動力。
1、風壓作用下的自然通風
當風(feng)(feng)(feng)(feng)(feng)吹向(xiang)建(jian)(jian)筑(zhu)物時,建(jian)(jian)筑(zhu)物對風(feng)(feng)(feng)(feng)(feng)有阻擋作用,在迎風(feng)(feng)(feng)(feng)(feng)面(mian)(mian)產生正壓(ya)力,在建(jian)(jian)筑(zhu)的(de)各個(ge)側(ce)面(mian)(mian)及背面(mian)(mian)形(xing)成負壓(ya)力。屋頂(ding)自(zi)然通(tong)(tong)風(feng)(feng)(feng)(feng)(feng)器風(feng)(feng)(feng)(feng)(feng)壓(ya)通(tong)(tong)風(feng)(feng)(feng)(feng)(feng)就(jiu)(jiu)是利用建(jian)(jian)筑(zhu)的(de)迎風(feng)(feng)(feng)(feng)(feng)面(mian)(mian)和(he)背風(feng)(feng)(feng)(feng)(feng)面(mian)(mian)之間的(de)壓(ya)力差實現空(kong)氣(qi)的(de)流通(tong)(tong)。壓(ya)力差是影響(xiang)通(tong)(tong)風(feng)(feng)(feng)(feng)(feng)的(de)關(guan)鍵(jian)因素(su)。壓(ya)力差的(de)大(da)小與(yu)建(jian)(jian)筑(zhu)的(de)造型、建(jian)(jian)筑(zhu)周圍環境和(he)建(jian)(jian)筑(zhu)與(yu)風(feng)(feng)(feng)(feng)(feng)向(xiang)的(de)夾角有關(guan)系。另(ling)外,屋頂(ding)通(tong)(tong)風(feng)(feng)(feng)(feng)(feng)器流動空(kong)氣(qi)的(de)壓(ya)力隨其速度(du)的(de)增(zeng)加而減小,這樣就(jiu)(jiu)形(xing)成了低壓(ya)區。根據屋頂(ding)自(zi)然通(tong)(tong)風(feng)(feng)(feng)(feng)(feng)器的(de)這種(zhong)原理(li),在設計屋頂(ding)自(zi)然通(tong)(tong)風(feng)(feng)(feng)(feng)(feng)器時,要注(zhu)意(yi)通(tong)(tong)風(feng)(feng)(feng)(feng)(feng)器的(de)安裝位(wei)置。
2、熱壓作用下的自然通風
屋(wu)(wu)(wu)頂(ding)通(tong)(tong)(tong)風(feng)(feng)器(qi)的(de)(de)另一原理是(shi)利用(yong)(yong)建(jian)筑(zhu)(zhu)(zhu)內(nei)(nei)部(bu)(bu)空(kong)(kong)氣(qi)(qi)的(de)(de)熱壓差(cha)(cha),即(ji)通(tong)(tong)(tong)常(chang)講的(de)(de)“煙囪效應(ying)”來(lai)實(shi)現(xian)建(jian)筑(zhu)(zhu)(zhu)的(de)(de)自然通(tong)(tong)(tong)風(feng)(feng)。利用(yong)(yong)熱空(kong)(kong)氣(qi)(qi)上升的(de)(de)原理,在建(jian)筑(zhu)(zhu)(zhu)上部(bu)(bu)設(she)(she)排風(feng)(feng)口(kou)可(ke)將(jiang)污(wu)濁(zhuo)的(de)(de)熱空(kong)(kong)氣(qi)(qi)從室內(nei)(nei)排出(chu)(chu),室外新鮮的(de)(de)空(kong)(kong)氣(qi)(qi)則(ze)(ze)從建(jian)筑(zhu)(zhu)(zhu)周(zhou)圍的(de)(de)通(tong)(tong)(tong)風(feng)(feng)口(kou)被吸人(ren)。熱壓作用(yong)(yong)與進、出(chu)(chu)風(feng)(feng)口(kou)的(de)(de)高差(cha)(cha)和室內(nei)(nei)外的(de)(de)溫(wen)差(cha)(cha)有關(guan),室內(nei)(nei)外溫(wen)差(cha)(cha)和進、出(chu)(chu)風(feng)(feng)口(kou)的(de)(de)高差(cha)(cha)越(yue)大(da),則(ze)(ze)熱壓作用(yong)(yong)越(yue)明顯。屋(wu)(wu)(wu)頂(ding)通(tong)(tong)(tong)風(feng)(feng)器(qi)在建(jian)筑(zhu)(zhu)(zhu)設(she)(she)計中,可(ke)利用(yong)(yong)建(jian)筑(zhu)(zhu)(zhu)物內(nei)(nei)部(bu)(bu)貫(guan)穿多(duo)層的(de)(de)豎向空(kong)(kong)腔(qiang)。在夏季,可(ke)將(jiang)閥板打開,就(jiu)像是(shi)大(da)型的(de)(de)天窗。這樣,經(jing)過(guo)屋(wu)(wu)(wu)頂(ding)通(tong)(tong)(tong)風(feng)(feng)器(qi)冷卻(que)的(de)(de)冷空(kong)(kong)氣(qi)(qi)便可(ke)吹向內(nei)(nei)部(bu)(bu),而室內(nei)(nei)的(de)(de)熱空(kong)(kong)氣(qi)(qi)則(ze)(ze)由屋(wu)(wu)(wu)頂(ding)通(tong)(tong)(tong)風(feng)(feng)器(qi)排出(chu)(chu)。除(chu)此以(yi)外,屋(wu)(wu)(wu)頂(ding)通(tong)(tong)(tong)風(feng)(feng)器(qi)還設(she)(she)有調節室溫(wen)的(de)(de)啟(qi)閉系統。
二、屋頂通風器的優點
1、省電(dian):屋頂通風(feng)器不需要使用電(dian)力,通過自然氣(qi)流實現通風(feng),具有節能(neng)環保的優點。
2、安全(quan):相比于電力驅動的通風設備(bei),屋(wu)頂通風器不易(yi)發生火災和爆炸等事(shi)故,提高(gao)了(le)安全(quan)性(xing)。
3、通風效果好:屋頂通風器能夠(gou)通過自然氣(qi)流形成(cheng)氣(qi)流循(xun)環,從而(er)能夠(gou)有效地排出內的有害氣(qi)體和煙霧,保持(chi)空(kong)氣(qi)清新。
4、低(di)維護成本:由(you)于(yu)屋頂通風器沒(mei)有(you)電動(dong)部分(fen),因此維護成本相(xiang)對較低(di)。
5、安裝(zhuang)方便(bian):屋頂通風器的安裝(zhuang)相對(dui)較簡(jian)單,不需要進行復雜的電氣布(bu)線(xian)等工作。
三、屋頂通風器的缺點
1、受天氣影響:屋頂通風(feng)器的通風(feng)效果(guo)(guo)會受到天氣因素的影響,如無風(feng)或風(feng)速較(jiao)低時,通風(feng)效果(guo)(guo)不佳(jia)。
2、不(bu)能(neng)精(jing)確調節:由于(yu)屋頂通(tong)風器不(bu)能(neng)精(jing)確調節通(tong)風量,因此在某些情況(kuang)下可能(neng)需要輔助使用其他通(tong)風設(she)備。
3、風(feng)噪音較大:在風(feng)速較高時,屋頂通(tong)風(feng)器(qi)可能(neng)會(hui)產(chan)生較大的噪音,影響工作環境。
4、適用范圍有限:屋頂通風器的(de)通風效果(guo)和(he)受(shou)到大小和(he)結構(gou)的(de)限制,不適用于某些(xie)特殊工藝(yi)和(he)環(huan)境。