一(yi)、供熱系(xi)統與(yu)介質(zhi)
集中(zhong)(zhong)供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)是(shi)指一個或多個集中(zhong)(zhong)的(de)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)，通過供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)管網(wang)向(xiang)多個熱(re)(re)(re)(re)(re)(re)(re)(re)(re)用(yong)戶供(gong)(gong)(gong)應熱(re)(re)(re)(re)(re)(re)(re)(re)(re)能的(de)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)，它主要由(you)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)、熱(re)(re)(re)(re)(re)(re)(re)(re)(re)網(wang)和熱(re)(re)(re)(re)(re)(re)(re)(re)(re)用(yong)戶組(zu)成。其中(zhong)(zhong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)是(shi)指將天然或人造的(de)能源(yuan)(yuan)形(xing)態轉化為符合供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)要求的(de)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)能裝置(zhi)。熱(re)(re)(re)(re)(re)(re)(re)(re)(re)網(wang)是(shi)指由(you)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)向(xiang)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)用(yong)戶輸送和分(fen)(fen)(fen)配供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)介質(zhi)的(de)管道系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)，熱(re)(re)(re)(re)(re)(re)(re)(re)(re)用(yong)戶是(shi)指從熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)獲得熱(re)(re)(re)(re)(re)(re)(re)(re)(re)能的(de)用(yong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)裝置(zhi)。集中(zhong)(zhong)供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)分(fen)(fen)(fen)類(lei)(lei)方式有(you)三種，可以根(gen)據(ju)(ju)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)分(fen)(fen)(fen)類(lei)(lei)、根(gen)據(ju)(ju)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)媒分(fen)(fen)(fen)類(lei)(lei)、根(gen)據(ju)(ju)供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)管網(wang)分(fen)(fen)(fen)類(lei)(lei)。集中(zhong)(zhong)供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)按(an)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)形(xing)式的(de)不同可分(fen)(fen)(fen)為：熱(re)(re)(re)(re)(re)(re)(re)(re)(re)電廠供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)、區域鍋(guo)爐房供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)、地熱(re)(re)(re)(re)(re)(re)(re)(re)(re)供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)、工業余熱(re)(re)(re)(re)(re)(re)(re)(re)(re)供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)、核供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)堆和太陽能供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)等。集中(zhong)(zhong)供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)根(gen)據(ju)(ju)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)媒不同分(fen)(fen)(fen)為蒸汽供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)和熱(re)(re)(re)(re)(re)(re)(re)(re)(re)水供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)。
熱(re)水熱(re)力(li)網供熱(re)介質設計壓(ya)(ya)力(li)小(xiao)于(yu)(yu)或(huo)等(deng)于(yu)(yu)2.5MPa，設計溫度小(xiao)于(yu)(yu)或(huo)等(deng)于(yu)(yu)200℃；蒸汽(qi)熱(re)力(li)網供熱(re)介質設計壓(ya)(ya)力(li)小(xiao)于(yu)(yu)或(huo)等(deng)于(yu)(yu)1.6MPa，設計溫度小(xiao)于(yu)(yu)或(huo)等(deng)于(yu)(yu)350℃。
對(dui)民用建筑物(wu)采(cai)暖(nuan)、通風、空(kong)調(diao)及生活熱(re)(re)(re)水熱(re)(re)(re)負(fu)荷供(gong)熱(re)(re)(re)的城市熱(re)(re)(re)力網，宜采(cai)用水作供(gong)熱(re)(re)(re)介質。
對生產(chan)工藝(yi)(yi)熱(re)(re)(re)(re)(re)負(fu)荷和采(cai)暖、通風(feng)、空調、生活熱(re)(re)(re)(re)(re)水熱(re)(re)(re)(re)(re)負(fu)荷供(gong)(gong)熱(re)(re)(re)(re)(re)的城市熱(re)(re)(re)(re)(re)力網供(gong)(gong)熱(re)(re)(re)(re)(re)介(jie)質按(an)下列原則確(que)定：當生產(chan)工藝(yi)(yi)熱(re)(re)(re)(re)(re)負(fu)荷為主(zhu)要(yao)負(fu)荷，且(qie)必(bi)須采(cai)用蒸汽(qi)(qi)(qi)供(gong)(gong)熱(re)(re)(re)(re)(re)時(shi)，宜采(cai)用蒸汽(qi)(qi)(qi)作供(gong)(gong)熱(re)(re)(re)(re)(re)介(jie)質；當以水位供(gong)(gong)熱(re)(re)(re)(re)(re)介(jie)質能夠滿足生產(chan)工藝(yi)(yi)需(xu)要(yao)（包(bao)括在(zai)用戶處(chu)轉換為蒸汽(qi)(qi)(qi)），且(qie)技術經(jing)濟合理時(shi)，宜采(cai)用水作供(gong)(gong)熱(re)(re)(re)(re)(re)介(jie)質；當采(cai)暖、通風(feng)、空調熱(re)(re)(re)(re)(re)負(fu)荷為主(zhu)要(yao)負(fu)荷，生產(chan)工藝(yi)(yi)又(you)必(bi)須采(cai)用蒸汽(qi)(qi)(qi)供(gong)(gong)熱(re)(re)(re)(re)(re)，經(jing)技術經(jing)濟比較認為合理時(shi)，可采(cai)用水和蒸汽(qi)(qi)(qi)兩種供(gong)(gong)熱(re)(re)(re)(re)(re)介(jie)質。
1. 國家現行標準GJJ／T 34《城鎮供熱管網(wang)設計(ji)規(gui)范(fan)》適(shi)用于(yu)(yu)供熱熱水介質設計(ji)壓力小于(yu)(yu)或(huo)等(deng)于(yu)(yu)2.5MPa，設計(ji)溫度小于(yu)(yu)或(huo)等(deng)于(yu)(yu)200℃；供熱蒸汽介質設計(ji)壓力小于(yu)(yu)或(huo)等(deng)于(yu)(yu)1.6MPa，設計(ji)溫度小于(yu)(yu)或(huo)等(deng)于(yu)(yu)350℃的(de)下列(lie)城鎮供熱管網(wang)的(de)設計(ji)：以熱電廠或(huo)鍋爐房為熱源，自熱切至(zhi)建(jian)筑物(wu)熱力人口的(de)供熱管網(wang)，供熱管網(wang)新(xin)建(jian)、擴建(jian)或(huo)改(gai)建(jian)的(de)管道、中(zhong)斷泵站(zhan)和熱力站(zhan)等(deng)工藝系統。
2. 國(guo)家現行標準GJJ／T 81《城(cheng)(cheng)鎮供熱直埋熱水管道技術規程》適用于(yu)(yu)新建(jian)(jian)、改建(jian)(jian)、擴建(jian)(jian)的設(she)計溫度(du)小于(yu)(yu)或等于(yu)(yu)150℃、設(she)計壓力(li)小于(yu)(yu)或等于(yu)(yu)2.5MPa，DN小于(yu)(yu)或等于(yu)(yu)1200mm的城(cheng)(cheng)鎮供熱直埋熱水管道的設(she)計、施工、驗(yan)收(shou)和運(yun)行管理。
3. 國家現行標準GJJ／T 104《城(cheng)鎮供熱直(zhi)埋(mai)蒸汽管道技術規程(cheng)》適用于(yu)工(gong)作(zuo)壓力小于(yu)或(huo)等(deng)于(yu)2.5MPa，溫度小于(yu)或(huo)等(deng)于(yu)350℃，直(zhi)接埋(mai)地敷設(she)的鋼質外護(hu)(hu)蒸汽保(bao)溫管道的設(she)計(ji)、施工(gong)、驗收及運行維(wei)護(hu)(hu)。
二、熱力網的形式
供熱管網(wang)按其(qi)平(ping)面布(bu)置形式可分為枝狀(zhuang)管網(wang)、環狀(zhuang)管網(wang)和多管制管網(wang)。其(qi)特(te)點(dian)是：
1. 枝狀管網
從熱(re)(re)(re)源(yuan)引出主干(gan)線(xian)沿城鎮道路向各熱(re)(re)(re)用(yong)(yong)(yong)戶供熱(re)(re)(re)，形成類似樹枝(zhi)狀(zhuang)的管(guan)(guan)網叫枝(zhi)狀(zhuang)管(guan)(guan)網。枝(zhi)狀(zhuang)管(guan)(guan)網是(shi)目(mu)前(qian)我國城鎮供熱(re)(re)(re)中(zhong)普遍采用(yong)(yong)(yong)的形式(shi)，它形式(shi)簡單、投資費用(yong)(yong)(yong)低(di)，且運(yun)行管(guan)(guan)理(li)方便，但安全可(ke)靠性較(jiao)差，當管(guan)(guan)網中(zhong)距(ju)離熱(re)(re)(re)源(yuan)較(jiao)近的主干(gan)線(xian)發生(sheng)故障時，會(hui)影響較(jiao)多的熱(re)(re)(re)用(yong)(yong)(yong)戶用(yong)(yong)(yong)熱(re)(re)(re)。
2. 環狀管網
供(gong)熱管(guan)網的主干(gan)線之間在適當位置連通構成環形，環狀管(guan)網運(yun)行較(jiao)安全可(ke)靠，局部(bu)發(fa)生(sheng)故(gu)障可(ke)通過(guo)環網供(gong)熱。但投資費(fei)用高。
3. 多管制(zhi)管網
一般用(yong)于以下情況：不(bu)能間斷的熱(re)用(yong)戶(hu)(hu)；供熱(re)系統(tong)中熱(re)用(yong)戶(hu)(hu)所需介(jie)質參(can)數差(cha)別較(jiao)(jiao)大；熱(re)負(fu)荷(he)變化較(jiao)(jiao)大：季(ji)節性熱(re)負(fu)荷(he)占全年(nian)總(zong)負(fu)荷(he)比例較(jiao)(jiao)大。
三、熱(re)水(shui)熱(re)力(li)網(wang)形式的確定
熱(re)(re)(re)(re)(re)(re)水熱(re)(re)(re)(re)(re)(re)力(li)網(wang)宜采(cai)用閉式(shi)雙(shuang)管(guan)制。以熱(re)(re)(re)(re)(re)(re)電廠為(wei)熱(re)(re)(re)(re)(re)(re)源(yuan)的熱(re)(re)(re)(re)(re)(re)水熱(re)(re)(re)(re)(re)(re)力(li)網(wang)，同時(shi)有工藝、采(cai)暖、通風、空調、生活(huo)熱(re)(re)(re)(re)(re)(re)水多種熱(re)(re)(re)(re)(re)(re)負荷(he)，在生產(chan)工藝熱(re)(re)(re)(re)(re)(re)負荷(he)與采(cai)暖熱(re)(re)(re)(re)(re)(re)負荷(he)所(suo)需供熱(re)(re)(re)(re)(re)(re)介質參數相差較(jiao)大，或季節性(xing)熱(re)(re)(re)(re)(re)(re)負荷(he)占總熱(re)(re)(re)(re)(re)(re)負荷(he)比例(li)較(jiao)大，且技術經濟(ji)合理時(shi)，可采(cai)用閉式(shi)多管(guan)制。
當(dang)熱(re)水熱(re)力(li)網(wang)具(ju)有(you)水處理(li)費用較(jiao)低的豐富的補給水資源，且技術經濟合理(li)時，可采(cai)用開式熱(re)力(li)網(wang)。
當熱(re)水熱(re)力網(wang)具有與(yu)生活(huo)熱(re)水熱(re)負荷相適應的(de)廉價低位能(neng)熱(re)源，且技術經濟合理時，可采(cai)用開式熱(re)水網(wang)。
開式熱(re)(re)水(shui)熱(re)(re)力網(wang)在生活熱(re)(re)水(shui)熱(re)(re)負荷足夠大且技術經濟合理時(shi)，可不設回水(shui)管。
四、蒸汽熱(re)力(li)網形式的確定
蒸汽熱(re)(re)力(li)網(wang)宜采(cai)用(yong)單管(guan)制。當(dang)各用(yong)戶間所需(xu)蒸汽參數相(xiang)差較大或(huo)季節(jie)性熱(re)(re)負荷(he)(he)占總熱(re)(re)負荷(he)(he)比(bi)例較大且技術經濟(ji)合理時，蒸汽熱(re)(re)力(li)網(wang)可(ke)采(cai)用(yong)雙管(guan)或(huo)多管(guan)制。
蒸汽熱(re)力(li)網的熱(re)負荷分期增(zeng)長時，可采用雙管(guan)或多(duo)管(guan)制。蒸汽供熱(re)系統應創造(zao)條件采用間接換(huan)熱(re)系統。當被加熱(re)介質泄(xie)漏不會產生危害時，其凝(ning)結水應全(quan)部(bu)回收并設置凝(ning)結水管(guan)道。
當(dang)凝(ning)結(jie)水回(hui)(hui)收時，用戶熱力站(zhan)應設閉式(shi)凝(ning)結(jie)水箱，用水泵(beng)將凝(ning)結(jie)水送(song)回(hui)(hui)熱源。
五、多(duo)供(gong)熱(re)源熱(re)力網形式(shi)的(de)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。
