一、供熱(re)系統與介質
集中(zhong)供(gong)熱(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)是(shi)指(zhi)(zhi)一個(ge)或(huo)多個(ge)集中(zhong)的熱(re)(re)(re)(re)(re)源，通過供(gong)熱(re)(re)(re)(re)(re)管(guan)網(wang)向多個(ge)熱(re)(re)(re)(re)(re)用(yong)戶(hu)供(gong)應熱(re)(re)(re)(re)(re)能(neng)(neng)的系(xi)(xi)統(tong)(tong)(tong)，它主(zhu)要由熱(re)(re)(re)(re)(re)源、熱(re)(re)(re)(re)(re)網(wang)和(he)熱(re)(re)(re)(re)(re)用(yong)戶(hu)組成。其(qi)中(zhong)熱(re)(re)(re)(re)(re)源是(shi)指(zhi)(zhi)將天然或(huo)人造(zao)的能(neng)(neng)源形態轉化為符合供(gong)熱(re)(re)(re)(re)(re)要求的熱(re)(re)(re)(re)(re)能(neng)(neng)裝(zhuang)置。熱(re)(re)(re)(re)(re)網(wang)是(shi)指(zhi)(zhi)由熱(re)(re)(re)(re)(re)源向熱(re)(re)(re)(re)(re)用(yong)戶(hu)輸送和(he)分(fen)配供(gong)熱(re)(re)(re)(re)(re)介(jie)質的管(guan)道(dao)系(xi)(xi)統(tong)(tong)(tong)，熱(re)(re)(re)(re)(re)用(yong)戶(hu)是(shi)指(zhi)(zhi)從熱(re)(re)(re)(re)(re)源獲(huo)得熱(re)(re)(re)(re)(re)能(neng)(neng)的用(yong)熱(re)(re)(re)(re)(re)裝(zhuang)置。集中(zhong)供(gong)熱(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)分(fen)類(lei)方式有三種，可以(yi)根(gen)據(ju)熱(re)(re)(re)(re)(re)源分(fen)類(lei)、根(gen)據(ju)熱(re)(re)(re)(re)(re)媒分(fen)類(lei)、根(gen)據(ju)供(gong)熱(re)(re)(re)(re)(re)管(guan)網(wang)分(fen)類(lei)。集中(zhong)供(gong)熱(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)按熱(re)(re)(re)(re)(re)源形式的不同(tong)可分(fen)為：熱(re)(re)(re)(re)(re)電廠供(gong)熱(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)、區域(yu)鍋爐(lu)房供(gong)熱(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)、地熱(re)(re)(re)(re)(re)供(gong)熱(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)、工(gong)業(ye)余熱(re)(re)(re)(re)(re)供(gong)熱(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)、核供(gong)熱(re)(re)(re)(re)(re)堆(dui)和(he)太陽能(neng)(neng)供(gong)熱(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)等。集中(zhong)供(gong)熱(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)根(gen)據(ju)熱(re)(re)(re)(re)(re)媒不同(tong)分(fen)為蒸汽供(gong)熱(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)和(he)熱(re)(re)(re)(re)(re)水供(gong)熱(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)。
熱(re)水熱(re)力(li)網(wang)供熱(re)介(jie)質設(she)計壓(ya)力(li)小(xiao)于(yu)(yu)或(huo)等于(yu)(yu)2.5MPa，設(she)計溫度小(xiao)于(yu)(yu)或(huo)等于(yu)(yu)200℃；蒸汽熱(re)力(li)網(wang)供熱(re)介(jie)質設(she)計壓(ya)力(li)小(xiao)于(yu)(yu)或(huo)等于(yu)(yu)1.6MPa，設(she)計溫度小(xiao)于(yu)(yu)或(huo)等于(yu)(yu)350℃。
對民用建筑物采暖、通風、空調及生活熱(re)水熱(re)負荷供熱(re)的城市(shi)熱(re)力網，宜采用水作供熱(re)介質。
對生產工藝(yi)熱(re)負(fu)荷和采(cai)暖、通風(feng)、空調、生活熱(re)水(shui)熱(re)負(fu)荷供熱(re)的城(cheng)市(shi)熱(re)力網(wang)供熱(re)介質(zhi)按下列原則(ze)確定：當(dang)生產工藝(yi)熱(re)負(fu)荷為主要負(fu)荷，且必須(xu)采(cai)用(yong)(yong)蒸(zheng)(zheng)汽(qi)(qi)(qi)供熱(re)時(shi)，宜(yi)采(cai)用(yong)(yong)蒸(zheng)(zheng)汽(qi)(qi)(qi)作供熱(re)介質(zhi)；當(dang)以水(shui)位供熱(re)介質(zhi)能夠滿足生產工藝(yi)需(xu)要（包括(kuo)在(zai)用(yong)(yong)戶處轉換為蒸(zheng)(zheng)汽(qi)(qi)(qi)），且技術(shu)經濟合理(li)時(shi)，宜(yi)采(cai)用(yong)(yong)水(shui)作供熱(re)介質(zhi)；當(dang)采(cai)暖、通風(feng)、空調熱(re)負(fu)荷為主要負(fu)荷，生產工藝(yi)又必須(xu)采(cai)用(yong)(yong)蒸(zheng)(zheng)汽(qi)(qi)(qi)供熱(re)，經技術(shu)經濟比較認為合理(li)時(shi)，可采(cai)用(yong)(yong)水(shui)和蒸(zheng)(zheng)汽(qi)(qi)(qi)兩種(zhong)供熱(re)介質(zhi)。
1. 國(guo)家現行(xing)標準(zhun)GJJ／T 34《城鎮供(gong)(gong)熱(re)(re)管(guan)(guan)網(wang)(wang)設(she)計規范》適用于(yu)(yu)供(gong)(gong)熱(re)(re)熱(re)(re)水介(jie)質設(she)計壓力小(xiao)于(yu)(yu)或(huo)等于(yu)(yu)2.5MPa，設(she)計溫度小(xiao)于(yu)(yu)或(huo)等于(yu)(yu)200℃；供(gong)(gong)熱(re)(re)蒸汽介(jie)質設(she)計壓力小(xiao)于(yu)(yu)或(huo)等于(yu)(yu)1.6MPa，設(she)計溫度小(xiao)于(yu)(yu)或(huo)等于(yu)(yu)350℃的(de)下列城鎮供(gong)(gong)熱(re)(re)管(guan)(guan)網(wang)(wang)的(de)設(she)計：以熱(re)(re)電廠或(huo)鍋爐房(fang)為(wei)熱(re)(re)源，自熱(re)(re)切至建筑物熱(re)(re)力人口的(de)供(gong)(gong)熱(re)(re)管(guan)(guan)網(wang)(wang)，供(gong)(gong)熱(re)(re)管(guan)(guan)網(wang)(wang)新建、擴建或(huo)改建的(de)管(guan)(guan)道、中斷泵站(zhan)(zhan)和熱(re)(re)力站(zhan)(zhan)等工藝系統(tong)。
2. 國家現行標準(zhun)GJJ／T 81《城鎮(zhen)供熱(re)直埋(mai)熱(re)水管(guan)道技術(shu)規程》適用于新建(jian)、改建(jian)、擴(kuo)建(jian)的(de)設計溫度小于或等于150℃、設計壓(ya)力小于或等于2.5MPa，DN小于或等于1200mm的(de)城鎮(zhen)供熱(re)直埋(mai)熱(re)水管(guan)道的(de)設計、施工、驗收(shou)和運行管(guan)理(li)。
3. 國(guo)家現行標(biao)準GJJ／T 104《城(cheng)鎮(zhen)供熱直埋蒸汽(qi)管道(dao)技術規程》適用于(yu)(yu)工作壓力小(xiao)(xiao)于(yu)(yu)或等(deng)于(yu)(yu)2.5MPa，溫(wen)度小(xiao)(xiao)于(yu)(yu)或等(deng)于(yu)(yu)350℃，直接埋地敷設的鋼質外護蒸汽(qi)保溫(wen)管道(dao)的設計、施(shi)工、驗(yan)收及運行維(wei)護。
二(er)、熱力(li)網(wang)的形式
供熱管(guan)(guan)網按其平面布(bu)置形式可分(fen)為枝狀管(guan)(guan)網、環狀管(guan)(guan)網和多管(guan)(guan)制(zhi)管(guan)(guan)網。其特點是：
1. 枝狀管網
從熱(re)源引出主(zhu)干線(xian)沿城鎮道(dao)路(lu)向各熱(re)用(yong)戶(hu)供熱(re)，形成類似樹(shu)枝狀的(de)管網(wang)叫枝狀管網(wang)。枝狀管網(wang)是目前我國城鎮供熱(re)中(zhong)普遍采用(yong)的(de)形式，它(ta)形式簡單、投(tou)資費用(yong)低，且運行管理方便，但安(an)全可靠性較(jiao)差，當管網(wang)中(zhong)距離熱(re)源較(jiao)近的(de)主(zhu)干線(xian)發生故(gu)障時，會影響較(jiao)多的(de)熱(re)用(yong)戶(hu)用(yong)熱(re)。
2. 環狀管網
供(gong)(gong)熱管網(wang)的主(zhu)干線(xian)之間在適當位置連(lian)通構成環形(xing)，環狀管網(wang)運行較安全(quan)可靠，局部發生故(gu)障可通過(guo)環網(wang)供(gong)(gong)熱。但(dan)投資費用高。
3. 多管制管網
一般用(yong)于以下(xia)情況：不能間斷的熱(re)(re)用(yong)戶(hu)；供熱(re)(re)系統中熱(re)(re)用(yong)戶(hu)所需介質參數差別較(jiao)大(da)(da)；熱(re)(re)負(fu)(fu)荷變(bian)化較(jiao)大(da)(da)：季節性熱(re)(re)負(fu)(fu)荷占全年(nian)總(zong)負(fu)(fu)荷比例(li)較(jiao)大(da)(da)。
三、熱(re)水熱(re)力網形(xing)式的(de)確(que)定(ding)
熱(re)(re)水(shui)熱(re)(re)力網宜(yi)采(cai)(cai)用(yong)閉(bi)式雙管制。以熱(re)(re)電廠為熱(re)(re)源的(de)熱(re)(re)水(shui)熱(re)(re)力網，同時有工藝(yi)、采(cai)(cai)暖、通風、空調、生活熱(re)(re)水(shui)多(duo)種熱(re)(re)負荷，在生產工藝(yi)熱(re)(re)負荷與(yu)采(cai)(cai)暖熱(re)(re)負荷所需供熱(re)(re)介質參數相差較大(da)，或季節性熱(re)(re)負荷占總熱(re)(re)負荷比例較大(da)，且技(ji)術經(jing)濟合理時，可采(cai)(cai)用(yong)閉(bi)式多(duo)管制。
當(dang)熱水(shui)(shui)熱力(li)(li)網(wang)具有水(shui)(shui)處(chu)理費(fei)用較低(di)的豐富的補給(gei)水(shui)(shui)資(zi)源，且(qie)技術經濟合(he)理時，可采(cai)用開式(shi)熱力(li)(li)網(wang)。
當熱(re)水(shui)熱(re)力網具有與生活(huo)熱(re)水(shui)熱(re)負(fu)荷相適應的廉價低位能(neng)熱(re)源，且技(ji)術經濟合理時，可采用開式熱(re)水(shui)網。
開(kai)式(shi)熱水(shui)熱力網(wang)在(zai)生活熱水(shui)熱負荷足夠大且技術(shu)經濟合理時(shi)，可(ke)不(bu)設(she)回水(shui)管。
四(si)、蒸汽熱力網形式的(de)確(que)定
蒸汽(qi)(qi)熱(re)力網宜(yi)采用(yong)單(dan)管制。當各用(yong)戶間(jian)所(suo)需蒸汽(qi)(qi)參數相差較大或季(ji)節性熱(re)負(fu)荷(he)占總熱(re)負(fu)荷(he)比例較大且技術(shu)經濟合(he)理時，蒸汽(qi)(qi)熱(re)力網可采用(yong)雙管或多(duo)管制。
蒸(zheng)(zheng)汽熱(re)力網(wang)的熱(re)負荷分(fen)期增長時(shi)，可采用雙管(guan)或多管(guan)制。蒸(zheng)(zheng)汽供熱(re)系統(tong)應(ying)創(chuang)造條件采用間接換(huan)熱(re)系統(tong)。當被(bei)加熱(re)介質泄漏不會產生危(wei)害時(shi)，其凝(ning)結水(shui)應(ying)全部回收并(bing)設置凝(ning)結水(shui)管(guan)道。
當凝(ning)結(jie)水(shui)回收(shou)時，用戶熱力站應設閉式凝(ning)結(jie)水(shui)箱，用水(shui)泵將(jiang)凝(ning)結(jie)水(shui)送(song)回熱源(yuan)。
五、多供(gong)熱源熱力網形式的確定
供熱建筑面積大于1000×104㎡的供熱系統應采用多熱源供熱，且各熱源熱力干線應連通。在技術經濟合理時，熱力網干線可連接成環狀管網。對供熱可靠性有特殊要求的用戶，有條件時應由兩個熱源供熱，或者設自備熱源。
