熱水(shui)供應系(xi)(xi)統(tong)的(de)安裝(zhuang)技術要(yao)(yao)求與熱水(shui)采暖系(xi)(xi)統(tong)安裝(zhuang)技術要(yao)(yao)求相(xiang)同。用水(shui)點(又稱配水(shui)點)多為衛(wei)(wei)生設備,安裝(zhuang)要(yao)(yao)求見給、排(pai)水(shui)、衛(wei)(wei)生設備安裝(zhuang)相(xiang)關部分。


 熱水供應系統所需設備如圖2-52所示,主要有循環(huan)水泵、補充水泵、冷(leng)水箱、閉式膨(peng)脹(zhang)水箱、自動(dong)排氣閥(fa)、安全(quan)閥(fa)、水的加熱裝(zhuang)置(zhi)等。


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  冷(leng)水(shui)(shui)(shui)箱(xiang)可(ke)以采用(yong)熱(re)(re)水(shui)(shui)(shui)采暖中(zhong)(zhong)的(de)(de)(de)膨脹水(shui)(shui)(shui)箱(xiang),并且(qie)還可(ke)斟情(qing)省(sheng)略一些管道,設計(ji)和(he)施工(gong)中(zhong)(zhong)可(ke)采用(yong)國際中(zhong)(zhong)有(you)(you)關(guan)水(shui)(shui)(shui)箱(xiang)標準(zhun)圖。閉式膨脹水(shui)(shui)(shui)箱(xiang)完(wan)全可(ke)以采用(yong)熱(re)(re)水(shui)(shui)(shui)采暖系(xi)統(tong)(tong)中(zhong)(zhong)低位(wei)(wei)膨脹水(shui)(shui)(shui)箱(xiang),該裝(zhuang)置(zhi)接(jie)人(ren)(ren)系(xi)統(tong)(tong)后如圖2-52(b)所示(shi),啟動(dong)補水(shui)(shui)(shui)泵(beng)(beng),水(shui)(shui)(shui)被送(song)入(ru)管網時(shi)(shi),也同時(shi)(shi)送(song)入(ru)罐體膠(jiao)(jiao)(jiao)(jiao)囊(nang)(nang)內(nei)(nei)(nei),在運(yun)(yun)行(xing)壓(ya)(ya)(ya)力(li)(li)較低時(shi)(shi)(即(ji)系(xi)統(tong)(tong)用(yong)水(shui)(shui)(shui)較多、水(shui)(shui)(shui)位(wei)(wei)下降),補水(shui)(shui)(shui)泵(beng)(beng)把水(shui)(shui)(shui)不(bu)斷送(song)入(ru)系(xi)統(tong)(tong)并送(song)入(ru)膠(jiao)(jiao)(jiao)(jiao)囊(nang)(nang)內(nei)(nei)(nei),膠(jiao)(jiao)(jiao)(jiao)囊(nang)(nang)不(bu)斷向外擴大而擠壓(ya)(ya)(ya)氣(qi)(qi)室(shi),氣(qi)(qi)室(shi)的(de)(de)(de)縮小使(shi)(shi)壓(ya)(ya)(ya)力(li)(li)升高,當(dang)(dang)壓(ya)(ya)(ya)力(li)(li)達(da)到(dao)設計(ji)最高壓(ya)(ya)(ya)力(li)(li)時(shi)(shi),膠(jiao)(jiao)(jiao)(jiao)囊(nang)(nang)內(nei)(nei)(nei)的(de)(de)(de)容水(shui)(shui)(shui)量達(da)到(dao)設計(ji)值,此(ci)時(shi)(shi)膠(jiao)(jiao)(jiao)(jiao)囊(nang)(nang)內(nei)(nei)(nei)外壓(ya)(ya)(ya)力(li)(li)相等(deng),膠(jiao)(jiao)(jiao)(jiao)囊(nang)(nang)不(bu)脹不(bu)縮,處(chu)于(yu)暫時(shi)(shi)平衡狀態。補水(shui)(shui)(shui)泵(beng)(beng)通過(guo)壓(ya)(ya)(ya)力(li)(li)控(kong)制器而停運(yun)(yun)。水(shui)(shui)(shui)泵(beng)(beng)停運(yun)(yun)后,氣(qi)(qi)室(shi)中(zhong)(zhong)氣(qi)(qi)體壓(ya)(ya)(ya)力(li)(li)擠壓(ya)(ya)(ya)膠(jiao)(jiao)(jiao)(jiao)囊(nang)(nang),使(shi)(shi)膠(jiao)(jiao)(jiao)(jiao)囊(nang)(nang)內(nei)(nei)(nei)的(de)(de)(de)水(shui)(shui)(shui)流(liu)人(ren)(ren)系(xi)統(tong)(tong),氣(qi)(qi)室(shi)壓(ya)(ya)(ya)力(li)(li)也隨之減小,當(dang)(dang)氣(qi)(qi)壓(ya)(ya)(ya)降到(dao)設計(ji)最低壓(ya)(ya)(ya)力(li)(li)時(shi)(shi),通過(guo)壓(ya)(ya)(ya)力(li)(li)控(kong)制器啟動(dong)水(shui)(shui)(shui)泵(beng)(beng),又(you)使(shi)(shi)水(shui)(shui)(shui)送(song)進(jin)系(xi)統(tong)(tong)和(he)膠(jiao)(jiao)(jiao)(jiao)囊(nang)(nang),這就(jiu)既保證了用(yong)戶(hu)供(gong)(gong)熱(re)(re)水(shui)(shui)(shui)(或供(gong)(gong)冷(leng)水(shui)(shui)(shui))的(de)(de)(de)需要,又(you)使(shi)(shi)水(shui)(shui)(shui)泵(beng)(beng)有(you)(you)條(tiao)件地間(jian)斷工(gong)作(zuo),節約了電能。目(mu)前(qian)已成為(wei)熱(re)(re)水(shui)(shui)(shui)供(gong)(gong)應系(xi)統(tong)(tong)或無塔供(gong)(gong)水(shui)(shui)(shui)的(de)(de)(de)常用(yong)設備。其(qi)規格見表2-24。


表 24.jpg


 水(shui)(shui)(shui)(shui)的加(jia)(jia)熱(re)(re)設(she)備是熱(re)(re)水(shui)(shui)(shui)(shui)供(gong)應(ying)的熱(re)(re)源部分(fen),又稱加(jia)(jia)熱(re)(re)器(qi)。根據系統范圍大小可(ke)采用水(shui)(shui)(shui)(shui)-水(shui)(shui)(shui)(shui)熱(re)(re)交換(huan)器(qi)、汽一(yi)水(shui)(shui)(shui)(shui)熱(re)(re)交換(huan)器(qi)、電(dian)熱(re)(re)水(shui)(shui)(shui)(shui)器(qi)、燃氣熱(re)(re)水(shui)(shui)(shui)(shui)器(qi)、太陽能(neng)熱(re)(re)水(shui)(shui)(shui)(shui)器(qi)等多種(zhong)。如要求這(zhe)些熱(re)(re)水(shui)(shui)(shui)(shui)器(qi)不僅起加(jia)(jia)熱(re)(re)作用,還要有(you)貯存(cun)和(he)調節水(shui)(shui)(shui)(shui)量的功能(neng),就必須(xu)有(you)一(yi)定的盛水(shui)(shui)(shui)(shui)體積,這(zhe)種(zhong)加(jia)(jia)熱(re)(re)器(qi)稱為容積式,對于(yu)只起加(jia)(jia)熱(re)(re)稱為快(kuai)速式。


 容(rong)積式(shi)加(jia)(jia)熱(re)器的(de)結(jie)構如(ru)圖2-52所示,由罐體(ti)、盤管(guan)等(deng)組(zu)成(cheng)。盤管(guan)內送人高溫熱(re)水(shui)或蒸(zheng)(zheng)汽(qi),將熱(re)量(liang)通(tong)過盤管(guan)表面積傳給冷(leng)水(shui)。罐體(ti)由支(zhi)座直接用地腳螺栓固定在地基上,高溫熱(re)水(shui)或蒸(zheng)(zheng)汽(qi)通(tong)過管(guan)道與加(jia)(jia)熱(re)器相連接。采(cai)用蒸(zheng)(zheng)汽(qi)加(jia)(jia)熱(re)時其蒸(zheng)(zheng)汽(qi)凝結(jie)水(shui)出口還要連接疏水(shui)閥等(deng)附件。


 板式換熱器是應用最多的非容積式加熱器,廣泛用于采暖和熱水供應的換熱上。板式換熱器的結構為框架式,如圖2-53所示。框架由固定壓緊板、上導梁、下導梁和支柱組成。活動壓緊板通過滾輪懸掛在上導梁上,傳熱板片置于固定壓緊板與活動壓緊板之間,大型板式換熱器的傳熱片是用掛鉤掛在上導梁上,上部卡在下導梁上。傳熱板是用0.8mm厚的不銹鋼板壓制成雙人字形波紋板片,四角沖制圓孔洞。板片四周及圓孔處均鑲嵌有密封橡膠墊起密封作用。組裝時傳熱板片相互倒置排列,使傳熱板片上波紋的波峰與波峰間互相接觸形成網狀流道,既強化了傳熱又增加了傳熱板的剛度,同時提高了板式換熱器的承壓能力。傳熱板通過夾緊螺栓,并按照組裝尺寸要求(或傳熱面積一片數),夾緊固定壓緊板和活動壓緊板之間。固定壓緊板和活動壓緊板的四角根據工藝的需要均設孔洞,并裝有與外部管道連接用的帶法蘭的短管,與傳熱片組裝在一起,構成了供冷熱介質流動的通道。圖2-54給出了傳熱板片并聯流程組合流程圖,每兩張傳熱板片間就構成一個流道,冷熱介質交替地流過傳熱板片,同時熱量通過傳熱板片由熱介質傳給了冷介質。由于雙人字形傳熱板片的結構特性所決定,介質在傳熱板片流動時,在低流速下即可激發湍流,使冷熱介質進行強烈地熱交換,因此板式換熱器與其他換熱器相比,具有較高的傳熱系數。根據冷介質的出口溫度要求,流程可以組成串聯、并聯、混合等多種形式,在設計時提出要求,生產企業按要求進行組裝供貨。


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 板式換(huan)熱(re)器豎(shu)直地用(yong)地腳(jiao)螺栓固定在(zai)混凝(ning)土地坪(ping)上,四(si)周留(liu)有一定距離,以(yi)便于管道、附(fu)件的(de)安(an)裝及設(she)備的(de)檢修(xiu)。換(huan)熱(re)器使用(yong)前應對熱(re)側、冷側分別進行水(shui)壓(ya)試驗,其試驗壓(ya)力為設(she)計壓(ya)力的(de)1.25倍(bei),并(bing)保壓(ya)20min,確認各密(mi)封部(bu)位無滲漏后方可投(tou)入使用(yong)。


 在作采暖時,循環水進出口(kou)均裝壓(ya)(ya)力表,在使用(yong)中若(ruo)壓(ya)(ya)降(jiang)增大說(shuo)明內部產生結垢淤塞,此時應(ying)松開夾緊螺栓,移動(dong)活動(dong)壓(ya)(ya)緊板(ban),然后進行清洗。清洗板(ban)片時要(yao)用(yong)棕刷,切勿用(yong)鋼(gang)絲刷,以免(mian)劃傷板(ban)片和(he)橡膠墊。損壞(huai)的板(ban)片要(yao)更換,若(ruo)沒(mei)有備用(yong)板(ban)片,可拆下兩個(ge)相鄰的板(ban)片,然后夾緊使用(yong)。


 特別提醒:老化(hua)的密(mi)(mi)(mi)封(feng)(feng)(feng)橡膠(jiao)墊(dian)要及時(shi)更新,要把板(ban)片的密(mi)(mi)(mi)封(feng)(feng)(feng)槽清洗干凈后涂粘結劑,再把密(mi)(mi)(mi)封(feng)(feng)(feng)膠(jiao)墊(dian)鑲嵌在密(mi)(mi)(mi)封(feng)(feng)(feng)槽內(nei)。


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 在實際工程中,使用蒸汽直接與冷水混合產生熱水的方法也比較普遍,這種方法簡單、投資小、維修方便,但噪聲大,冷凝水不能回收利用。常用的方法有多孔管放在水箱內,送入蒸汽,蒸汽從小孔中噴出與水混合,也可采用專用的汽水混合加熱器,其構造如圖2-55所示。在外殼內裝有錐形管,管壁上布滿小孔,冷水在流動中與蒸汽在錐形管內混合,適用于具有蒸汽熱源的熱水采暖系統與熱水供應系統,同時隨熱負荷的改變,調整蒸汽閥門的開啟度即可實現溫度調節。該國標圖集供、回水溫差大小分為25℃、40℃、60℃三種型號按噴管喉口直徑大小分為6、8、10、12、14、16、18、20、25、30、35、40、50、60、70(mm)共15個型號。供熱水和采暖系統管道連接方式如圖2-56、圖2-57所示。為防止供水溫度過熱,在蒸汽管道入口設置溫度自動控制系統,如安裝自力式溫度調節閥。為防止系統水倒灌入蒸汽系統中,在蒸汽管路上安裝逆止閥



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