熱(re)水(shui)(shui)供應系(xi)統的(de)安(an)裝技(ji)術(shu)要求與熱(re)水(shui)(shui)采(cai)暖系(xi)統安(an)裝技(ji)術(shu)要求相同。用(yong)水(shui)(shui)點(dian)(又稱配水(shui)(shui)點(dian))多為衛(wei)生設備,安(an)裝要求見給(gei)、排水(shui)(shui)、衛(wei)生設備安(an)裝相關部分。
熱(re)水(shui)供應系統所(suo)需(xu)設備如圖2-52所(suo)示(shi),主要有循環水(shui)泵、補充水(shui)泵、冷水(shui)箱、閉式膨(peng)脹水(shui)箱、自動(dong)排氣閥(fa)、安全閥(fa)、水(shui)的加(jia)熱(re)裝置等。

冷水(shui)(shui)(shui)(shui)(shui)(shui)箱可以采(cai)(cai)用(yong)(yong)熱(re)水(shui)(shui)(shui)(shui)(shui)(shui)采(cai)(cai)暖(nuan)中(zhong)(zhong)的(de)膨脹水(shui)(shui)(shui)(shui)(shui)(shui)箱,并且(qie)還可斟情省略一些(xie)管道,設(she)計和施工中(zhong)(zhong)可采(cai)(cai)用(yong)(yong)國際中(zhong)(zhong)有(you)關水(shui)(shui)(shui)(shui)(shui)(shui)箱標準(zhun)圖。閉式膨脹水(shui)(shui)(shui)(shui)(shui)(shui)箱完(wan)全可以采(cai)(cai)用(yong)(yong)熱(re)水(shui)(shui)(shui)(shui)(shui)(shui)采(cai)(cai)暖(nuan)系(xi)(xi)(xi)(xi)(xi)統(tong)中(zhong)(zhong)低(di)位(wei)膨脹水(shui)(shui)(shui)(shui)(shui)(shui)箱,該裝(zhuang)置接人系(xi)(xi)(xi)(xi)(xi)統(tong)后如圖2-52(b)所示,啟(qi)動(dong)補水(shui)(shui)(shui)(shui)(shui)(shui)泵(beng)(beng)(beng)(beng),水(shui)(shui)(shui)(shui)(shui)(shui)被送(song)(song)入(ru)管網(wang)時(shi),也同時(shi)送(song)(song)入(ru)罐體膠(jiao)(jiao)囊(nang)內(nei),在(zai)運行壓(ya)(ya)(ya)(ya)力(li)(li)(li)較低(di)時(shi)(即系(xi)(xi)(xi)(xi)(xi)統(tong)用(yong)(yong)水(shui)(shui)(shui)(shui)(shui)(shui)較多、水(shui)(shui)(shui)(shui)(shui)(shui)位(wei)下降),補水(shui)(shui)(shui)(shui)(shui)(shui)泵(beng)(beng)(beng)(beng)把(ba)水(shui)(shui)(shui)(shui)(shui)(shui)不(bu)(bu)斷(duan)送(song)(song)入(ru)系(xi)(xi)(xi)(xi)(xi)統(tong)并送(song)(song)入(ru)膠(jiao)(jiao)囊(nang)內(nei),膠(jiao)(jiao)囊(nang)不(bu)(bu)斷(duan)向(xiang)外擴(kuo)大而(er)(er)擠壓(ya)(ya)(ya)(ya)氣(qi)室(shi),氣(qi)室(shi)的(de)縮小使壓(ya)(ya)(ya)(ya)力(li)(li)(li)升高(gao),當壓(ya)(ya)(ya)(ya)力(li)(li)(li)達(da)到(dao)設(she)計最(zui)高(gao)壓(ya)(ya)(ya)(ya)力(li)(li)(li)時(shi),膠(jiao)(jiao)囊(nang)內(nei)的(de)容水(shui)(shui)(shui)(shui)(shui)(shui)量(liang)達(da)到(dao)設(she)計值,此時(shi)膠(jiao)(jiao)囊(nang)內(nei)外壓(ya)(ya)(ya)(ya)力(li)(li)(li)相等(deng),膠(jiao)(jiao)囊(nang)不(bu)(bu)脹不(bu)(bu)縮,處于暫時(shi)平(ping)衡狀態。補水(shui)(shui)(shui)(shui)(shui)(shui)泵(beng)(beng)(beng)(beng)通(tong)過壓(ya)(ya)(ya)(ya)力(li)(li)(li)控制(zhi)器而(er)(er)停(ting)運。水(shui)(shui)(shui)(shui)(shui)(shui)泵(beng)(beng)(beng)(beng)停(ting)運后,氣(qi)室(shi)中(zhong)(zhong)氣(qi)體壓(ya)(ya)(ya)(ya)力(li)(li)(li)擠壓(ya)(ya)(ya)(ya)膠(jiao)(jiao)囊(nang),使膠(jiao)(jiao)囊(nang)內(nei)的(de)水(shui)(shui)(shui)(shui)(shui)(shui)流(liu)人系(xi)(xi)(xi)(xi)(xi)統(tong),氣(qi)室(shi)壓(ya)(ya)(ya)(ya)力(li)(li)(li)也隨(sui)之減(jian)小,當氣(qi)壓(ya)(ya)(ya)(ya)降到(dao)設(she)計最(zui)低(di)壓(ya)(ya)(ya)(ya)力(li)(li)(li)時(shi),通(tong)過壓(ya)(ya)(ya)(ya)力(li)(li)(li)控制(zhi)器啟(qi)動(dong)水(shui)(shui)(shui)(shui)(shui)(shui)泵(beng)(beng)(beng)(beng),又使水(shui)(shui)(shui)(shui)(shui)(shui)送(song)(song)進系(xi)(xi)(xi)(xi)(xi)統(tong)和膠(jiao)(jiao)囊(nang),這就既保證了(le)用(yong)(yong)戶供熱(re)水(shui)(shui)(shui)(shui)(shui)(shui)(或(huo)供冷水(shui)(shui)(shui)(shui)(shui)(shui))的(de)需要(yao),又使水(shui)(shui)(shui)(shui)(shui)(shui)泵(beng)(beng)(beng)(beng)有(you)條(tiao)件地間斷(duan)工作(zuo),節約了(le)電能。目前已成為熱(re)水(shui)(shui)(shui)(shui)(shui)(shui)供應系(xi)(xi)(xi)(xi)(xi)統(tong)或(huo)無塔(ta)供水(shui)(shui)(shui)(shui)(shui)(shui)的(de)常(chang)用(yong)(yong)設(she)備。其規格見表2-24。

水(shui)(shui)的(de)加(jia)熱(re)設備是熱(re)水(shui)(shui)供應的(de)熱(re)源部分(fen),又稱加(jia)熱(re)器(qi)。根據(ju)系統范(fan)圍大小可采用水(shui)(shui)-水(shui)(shui)熱(re)交換(huan)器(qi)、汽一(yi)(yi)水(shui)(shui)熱(re)交換(huan)器(qi)、電熱(re)水(shui)(shui)器(qi)、燃氣熱(re)水(shui)(shui)器(qi)、太陽能熱(re)水(shui)(shui)器(qi)等多種(zhong)。如要(yao)(yao)求這些熱(re)水(shui)(shui)器(qi)不(bu)僅起(qi)加(jia)熱(re)作用,還要(yao)(yao)有(you)貯存和調節水(shui)(shui)量(liang)的(de)功能,就(jiu)必(bi)須(xu)有(you)一(yi)(yi)定(ding)的(de)盛(sheng)水(shui)(shui)體積(ji),這種(zhong)加(jia)熱(re)器(qi)稱為容積(ji)式,對于只起(qi)加(jia)熱(re)稱為快速式。
容積(ji)式(shi)加(jia)熱(re)(re)器(qi)的結構如圖2-52所示,由罐體、盤管(guan)等(deng)組成。盤管(guan)內送人高溫(wen)(wen)熱(re)(re)水(shui)或蒸(zheng)汽(qi)(qi),將熱(re)(re)量(liang)通過盤管(guan)表面積(ji)傳(chuan)給冷水(shui)。罐體由支座直接用(yong)(yong)地(di)腳螺栓固定在地(di)基上,高溫(wen)(wen)熱(re)(re)水(shui)或蒸(zheng)汽(qi)(qi)通過管(guan)道與加(jia)熱(re)(re)器(qi)相連接。采用(yong)(yong)蒸(zheng)汽(qi)(qi)加(jia)熱(re)(re)時其蒸(zheng)汽(qi)(qi)凝(ning)結水(shui)出口還要連接疏(shu)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(xiu)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。

板式(shi)換熱(re)器豎直地用(yong)(yong)地腳螺(luo)栓固(gu)定在混(hun)凝(ning)土(tu)地坪上,四周(zhou)留有一定距離,以便于管道、附件的(de)(de)安(an)裝及設備的(de)(de)檢(jian)修(xiu)。換熱(re)器使(shi)用(yong)(yong)前(qian)應(ying)對(dui)熱(re)側、冷(leng)側分別進(jin)行(xing)水壓試驗,其試驗壓力(li)(li)為(wei)設計壓力(li)(li)的(de)(de)1.25倍(bei),并保壓20min,確認各密封部位無滲漏后方可投入使(shi)用(yong)(yong)。
在作采暖時,循(xun)環(huan)水(shui)進(jin)出口均裝壓(ya)(ya)力表,在使用中若(ruo)壓(ya)(ya)降增大說明內部產生結垢(gou)淤(yu)塞(sai),此時應松開夾緊螺栓,移動(dong)活(huo)動(dong)壓(ya)(ya)緊板(ban)(ban)(ban),然后進(jin)行(xing)清洗(xi)。清洗(xi)板(ban)(ban)(ban)片(pian)時要用棕(zong)刷,切勿用鋼(gang)絲刷,以免劃(hua)傷板(ban)(ban)(ban)片(pian)和橡膠墊。損壞的(de)板(ban)(ban)(ban)片(pian)要更(geng)換(huan),若(ruo)沒(mei)有備用板(ban)(ban)(ban)片(pian),可拆(chai)下兩個相鄰(lin)的(de)板(ban)(ban)(ban)片(pian),然后夾緊使用。
特別提醒(xing):老化(hua)的(de)密(mi)(mi)(mi)(mi)封(feng)橡膠墊要及(ji)時更新,要把板片的(de)密(mi)(mi)(mi)(mi)封(feng)槽(cao)清洗干(gan)凈后涂粘結劑,再(zai)把密(mi)(mi)(mi)(mi)封(feng)膠墊鑲嵌在密(mi)(mi)(mi)(mi)封(feng)槽(cao)內。

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(zhi)閥。


