一、供熱系統與介(jie)質
集(ji)中(zhong)(zhong)供(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)是(shi)指一個或多個集(ji)中(zhong)(zhong)的(de)(de)熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)，通過(guo)供(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)管網(wang)向多個熱(re)(re)(re)(re)(re)(re)(re)(re)用(yong)(yong)戶供(gong)(gong)應熱(re)(re)(re)(re)(re)(re)(re)(re)能(neng)(neng)的(de)(de)系(xi)(xi)統(tong)(tong)，它主要(yao)由熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)、熱(re)(re)(re)(re)(re)(re)(re)(re)網(wang)和(he)(he)熱(re)(re)(re)(re)(re)(re)(re)(re)用(yong)(yong)戶組成。其中(zhong)(zhong)熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)是(shi)指將天(tian)然或人造的(de)(de)能(neng)(neng)源(yuan)(yuan)形態轉化為符合(he)供(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)要(yao)求的(de)(de)熱(re)(re)(re)(re)(re)(re)(re)(re)能(neng)(neng)裝置。熱(re)(re)(re)(re)(re)(re)(re)(re)網(wang)是(shi)指由熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)向熱(re)(re)(re)(re)(re)(re)(re)(re)用(yong)(yong)戶輸(shu)送和(he)(he)分(fen)(fen)(fen)配供(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)介質的(de)(de)管道系(xi)(xi)統(tong)(tong)，熱(re)(re)(re)(re)(re)(re)(re)(re)用(yong)(yong)戶是(shi)指從熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)獲(huo)得熱(re)(re)(re)(re)(re)(re)(re)(re)能(neng)(neng)的(de)(de)用(yong)(yong)熱(re)(re)(re)(re)(re)(re)(re)(re)裝置。集(ji)中(zhong)(zhong)供(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)分(fen)(fen)(fen)類(lei)方式(shi)(shi)有三種，可(ke)以根據(ju)熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)分(fen)(fen)(fen)類(lei)、根據(ju)熱(re)(re)(re)(re)(re)(re)(re)(re)媒(mei)分(fen)(fen)(fen)類(lei)、根據(ju)供(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)管網(wang)分(fen)(fen)(fen)類(lei)。集(ji)中(zhong)(zhong)供(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)按(an)熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)形式(shi)(shi)的(de)(de)不同可(ke)分(fen)(fen)(fen)為：熱(re)(re)(re)(re)(re)(re)(re)(re)電廠供(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)、區域鍋爐房供(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)、地(di)熱(re)(re)(re)(re)(re)(re)(re)(re)供(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)、工業(ye)余熱(re)(re)(re)(re)(re)(re)(re)(re)供(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)、核(he)供(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)堆(dui)和(he)(he)太(tai)陽能(neng)(neng)供(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)等。集(ji)中(zhong)(zhong)供(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)根據(ju)熱(re)(re)(re)(re)(re)(re)(re)(re)媒(mei)不同分(fen)(fen)(fen)為蒸汽供(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)和(he)(he)熱(re)(re)(re)(re)(re)(re)(re)(re)水供(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)。
熱水熱力(li)網(wang)供(gong)熱介質(zhi)(zhi)設(she)計(ji)(ji)壓力(li)小于或等于2.5MPa，設(she)計(ji)(ji)溫度小于或等于200℃；蒸汽熱力(li)網(wang)供(gong)熱介質(zhi)(zhi)設(she)計(ji)(ji)壓力(li)小于或等于1.6MPa，設(she)計(ji)(ji)溫度小于或等于350℃。
對(dui)民用(yong)建筑物采暖、通風、空調(diao)及生活熱(re)水熱(re)負荷供熱(re)的城市熱(re)力網，宜采用(yong)水作供熱(re)介質。
對生(sheng)(sheng)產工藝熱(re)(re)負(fu)(fu)荷(he)和采暖、通(tong)風、空調、生(sheng)(sheng)活(huo)熱(re)(re)水(shui)熱(re)(re)負(fu)(fu)荷(he)供熱(re)(re)的(de)城市熱(re)(re)力網供熱(re)(re)介(jie)(jie)(jie)質按下列原則確定(ding)：當(dang)(dang)生(sheng)(sheng)產工藝熱(re)(re)負(fu)(fu)荷(he)為主(zhu)要負(fu)(fu)荷(he)，且(qie)(qie)必須采用(yong)(yong)蒸(zheng)(zheng)汽(qi)供熱(re)(re)時(shi)(shi)，宜采用(yong)(yong)蒸(zheng)(zheng)汽(qi)作供熱(re)(re)介(jie)(jie)(jie)質；當(dang)(dang)以水(shui)位(wei)供熱(re)(re)介(jie)(jie)(jie)質能夠(gou)滿足生(sheng)(sheng)產工藝需要（包括(kuo)在用(yong)(yong)戶處(chu)轉換為蒸(zheng)(zheng)汽(qi)），且(qie)(qie)技(ji)術經濟合(he)理時(shi)(shi)，宜采用(yong)(yong)水(shui)作供熱(re)(re)介(jie)(jie)(jie)質；當(dang)(dang)采暖、通(tong)風、空調熱(re)(re)負(fu)(fu)荷(he)為主(zhu)要負(fu)(fu)荷(he)，生(sheng)(sheng)產工藝又必須采用(yong)(yong)蒸(zheng)(zheng)汽(qi)供熱(re)(re)，經技(ji)術經濟比較認為合(he)理時(shi)(shi)，可采用(yong)(yong)水(shui)和蒸(zheng)(zheng)汽(qi)兩種供熱(re)(re)介(jie)(jie)(jie)質。
1. 國家(jia)現行(xing)標準GJJ／T 34《城鎮供(gong)(gong)熱(re)(re)(re)管網設(she)(she)計(ji)規范(fan)》適用于(yu)(yu)供(gong)(gong)熱(re)(re)(re)熱(re)(re)(re)水介質(zhi)設(she)(she)計(ji)壓(ya)力(li)小(xiao)(xiao)于(yu)(yu)或(huo)等(deng)于(yu)(yu)2.5MPa，設(she)(she)計(ji)溫度(du)小(xiao)(xiao)于(yu)(yu)或(huo)等(deng)于(yu)(yu)200℃；供(gong)(gong)熱(re)(re)(re)蒸汽介質(zhi)設(she)(she)計(ji)壓(ya)力(li)小(xiao)(xiao)于(yu)(yu)或(huo)等(deng)于(yu)(yu)1.6MPa，設(she)(she)計(ji)溫度(du)小(xiao)(xiao)于(yu)(yu)或(huo)等(deng)于(yu)(yu)350℃的下列(lie)城鎮供(gong)(gong)熱(re)(re)(re)管網的設(she)(she)計(ji)：以(yi)熱(re)(re)(re)電廠或(huo)鍋爐房(fang)為熱(re)(re)(re)源，自熱(re)(re)(re)切至建(jian)(jian)筑物(wu)熱(re)(re)(re)力(li)人口的供(gong)(gong)熱(re)(re)(re)管網，供(gong)(gong)熱(re)(re)(re)管網新(xin)建(jian)(jian)、擴(kuo)建(jian)(jian)或(huo)改建(jian)(jian)的管道(dao)、中(zhong)斷泵(beng)站和熱(re)(re)(re)力(li)站等(deng)工藝系統(tong)。
2. 國(guo)家現行標準GJJ／T 81《城(cheng)鎮(zhen)供熱(re)直埋(mai)熱(re)水管道技(ji)術規程》適用(yong)于(yu)新建(jian)、改建(jian)、擴建(jian)的設計(ji)溫度(du)小(xiao)于(yu)或等于(yu)150℃、設計(ji)壓力小(xiao)于(yu)或等于(yu)2.5MPa，DN小(xiao)于(yu)或等于(yu)1200mm的城(cheng)鎮(zhen)供熱(re)直埋(mai)熱(re)水管道的設計(ji)、施(shi)工、驗收和運行管理。
3. 國家現(xian)行標準GJJ／T 104《城鎮供(gong)熱直(zhi)埋蒸(zheng)汽管(guan)道(dao)技術規程(cheng)》適(shi)用于(yu)(yu)工作壓力小于(yu)(yu)或(huo)等于(yu)(yu)2.5MPa，溫(wen)度小于(yu)(yu)或(huo)等于(yu)(yu)350℃，直(zhi)接埋地敷(fu)設(she)的鋼質外護蒸(zheng)汽保溫(wen)管(guan)道(dao)的設(she)計、施工、驗(yan)收(shou)及(ji)運行維護。
二(er)、熱力網的形(xing)式
供熱(re)管網(wang)按其平面(mian)布(bu)置(zhi)形(xing)式可分(fen)為枝狀(zhuang)管網(wang)、環(huan)狀(zhuang)管網(wang)和多管制(zhi)管網(wang)。其特點是(shi)：
1. 枝狀(zhuang)管網
從熱(re)(re)源(yuan)引出主干(gan)線(xian)沿(yan)城鎮(zhen)道(dao)路向各熱(re)(re)用(yong)(yong)戶供熱(re)(re)，形(xing)成類似樹枝(zhi)(zhi)狀的管(guan)網叫枝(zhi)(zhi)狀管(guan)網。枝(zhi)(zhi)狀管(guan)網是目前(qian)我國城鎮(zhen)供熱(re)(re)中普遍(bian)采用(yong)(yong)的形(xing)式(shi)，它形(xing)式(shi)簡單、投資費用(yong)(yong)低，且運行管(guan)理方便，但安全(quan)可靠性較(jiao)(jiao)差，當管(guan)網中距離熱(re)(re)源(yuan)較(jiao)(jiao)近的主干(gan)線(xian)發生故障時(shi)，會影(ying)響較(jiao)(jiao)多的熱(re)(re)用(yong)(yong)戶用(yong)(yong)熱(re)(re)。
2. 環狀管網
供(gong)熱管(guan)網(wang)的主(zhu)干(gan)線之間在適當(dang)位(wei)置(zhi)連通構成環形，環狀管(guan)網(wang)運行較安全可靠，局部發(fa)生(sheng)故障可通過環網(wang)供(gong)熱。但投資費用高。
3. 多管制管網(wang)
一般用(yong)于(yu)以下情況：不能間斷的(de)熱(re)用(yong)戶；供熱(re)系統中(zhong)熱(re)用(yong)戶所(suo)需介(jie)質參數差別較(jiao)大；熱(re)負(fu)(fu)荷變化較(jiao)大：季(ji)節性熱(re)負(fu)(fu)荷占全年總(zong)負(fu)(fu)荷比例較(jiao)大。
三、熱(re)(re)水熱(re)(re)力網形式的確定(ding)
熱(re)(re)水熱(re)(re)力網宜采(cai)用(yong)閉式雙管制。以熱(re)(re)電廠為熱(re)(re)源的熱(re)(re)水熱(re)(re)力網，同時有工(gong)藝、采(cai)暖、通風、空(kong)調、生活熱(re)(re)水多種(zhong)熱(re)(re)負(fu)荷(he)，在生產工(gong)藝熱(re)(re)負(fu)荷(he)與(yu)采(cai)暖熱(re)(re)負(fu)荷(he)所需供熱(re)(re)介質參數(shu)相(xiang)差較(jiao)(jiao)大(da)(da)，或季節(jie)性(xing)熱(re)(re)負(fu)荷(he)占(zhan)總(zong)熱(re)(re)負(fu)荷(he)比例較(jiao)(jiao)大(da)(da)，且技(ji)術(shu)經(jing)濟合理時，可采(cai)用(yong)閉式多管制。
當熱(re)(re)水(shui)熱(re)(re)力網(wang)具有水(shui)處理費用(yong)較(jiao)低的豐富(fu)的補給水(shui)資源，且技術經濟合理時，可(ke)采用(yong)開(kai)式熱(re)(re)力網(wang)。
當熱水(shui)(shui)熱力網具(ju)有與生(sheng)活熱水(shui)(shui)熱負荷相(xiang)適應的廉價低位能熱源，且技術經濟合理(li)時，可采用開式熱水(shui)(shui)網。
開式熱水熱力網在生活(huo)熱水熱負荷足夠大且技術經濟合理(li)時(shi)，可不設回水管。
四、蒸汽(qi)熱(re)力(li)網形式的確定
蒸(zheng)汽熱(re)(re)力網(wang)宜采用(yong)單管制。當各用(yong)戶間所需蒸(zheng)汽參數相(xiang)差較(jiao)大或季節性熱(re)(re)負(fu)荷占(zhan)總(zong)熱(re)(re)負(fu)荷比例較(jiao)大且技術(shu)經濟合理時，蒸(zheng)汽熱(re)(re)力網(wang)可采用(yong)雙(shuang)管或多管制。
蒸(zheng)汽(qi)熱力網的熱負荷分期增長時，可采(cai)用(yong)雙管或(huo)多管制。蒸(zheng)汽(qi)供熱系(xi)統應創(chuang)造(zao)條件采(cai)用(yong)間接換(huan)熱系(xi)統。當(dang)被加(jia)熱介(jie)質泄漏(lou)不會產生危害時，其凝結水應全部回收并(bing)設置凝結水管道。
當(dang)凝結(jie)水回收時(shi)，用戶熱力(li)站(zhan)應設閉式凝結(jie)水箱，用水泵將凝結(jie)水送回熱源。
五、多供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。
