一(yi)、供(gong)熱系統與介質(zhi)
集(ji)中(zhong)(zhong)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)是指(zhi)(zhi)一個(ge)(ge)或多(duo)個(ge)(ge)集(ji)中(zhong)(zhong)的(de)熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)，通(tong)過供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)管(guan)(guan)網(wang)(wang)向(xiang)多(duo)個(ge)(ge)熱(re)(re)(re)(re)(re)(re)(re)(re)用戶供(gong)(gong)(gong)(gong)應(ying)熱(re)(re)(re)(re)(re)(re)(re)(re)能(neng)(neng)的(de)系(xi)(xi)(xi)統(tong)(tong)，它主要由熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)、熱(re)(re)(re)(re)(re)(re)(re)(re)網(wang)(wang)和(he)熱(re)(re)(re)(re)(re)(re)(re)(re)用戶組(zu)成。其中(zhong)(zhong)熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)是指(zhi)(zhi)將天然或人造的(de)能(neng)(neng)源(yuan)形態(tai)轉化(hua)為符合供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)要求的(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)(wang)是指(zhi)(zhi)由熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)向(xiang)熱(re)(re)(re)(re)(re)(re)(re)(re)用戶輸(shu)送和(he)分配(pei)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)介質(zhi)的(de)管(guan)(guan)道系(xi)(xi)(xi)統(tong)(tong)，熱(re)(re)(re)(re)(re)(re)(re)(re)用戶是指(zhi)(zhi)從熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)獲得熱(re)(re)(re)(re)(re)(re)(re)(re)能(neng)(neng)的(de)用熱(re)(re)(re)(re)(re)(re)(re)(re)裝置。集(ji)中(zhong)(zhong)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)分類方式有三種，可以根(gen)(gen)(gen)據熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)分類、根(gen)(gen)(gen)據熱(re)(re)(re)(re)(re)(re)(re)(re)媒分類、根(gen)(gen)(gen)據供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)管(guan)(guan)網(wang)(wang)分類。集(ji)中(zhong)(zhong)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)按(an)熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)形式的(de)不同可分為：熱(re)(re)(re)(re)(re)(re)(re)(re)電廠供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)、區(qu)域鍋爐房供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)、地熱(re)(re)(re)(re)(re)(re)(re)(re)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)、工業(ye)余熱(re)(re)(re)(re)(re)(re)(re)(re)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)、核供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)堆和(he)太陽能(neng)(neng)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)等。集(ji)中(zhong)(zhong)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)根(gen)(gen)(gen)據熱(re)(re)(re)(re)(re)(re)(re)(re)媒不同分為蒸汽供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)和(he)熱(re)(re)(re)(re)(re)(re)(re)(re)水供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)統(tong)(tong)。
熱水熱力(li)網(wang)(wang)供熱介(jie)質設(she)(she)計(ji)壓(ya)力(li)小于(yu)(yu)(yu)或等于(yu)(yu)(yu)2.5MPa，設(she)(she)計(ji)溫(wen)度(du)小于(yu)(yu)(yu)或等于(yu)(yu)(yu)200℃；蒸汽熱力(li)網(wang)(wang)供熱介(jie)質設(she)(she)計(ji)壓(ya)力(li)小于(yu)(yu)(yu)或等于(yu)(yu)(yu)1.6MPa，設(she)(she)計(ji)溫(wen)度(du)小于(yu)(yu)(yu)或等于(yu)(yu)(yu)350℃。
對(dui)民用(yong)建筑物采暖、通風、空(kong)調及生活(huo)熱(re)水(shui)熱(re)負荷供(gong)熱(re)的城市熱(re)力網，宜(yi)采用(yong)水(shui)作供(gong)熱(re)介質。
對生產(chan)工(gong)藝(yi)熱(re)(re)負(fu)荷(he)(he)和采暖、通(tong)風、空(kong)調(diao)(diao)、生活熱(re)(re)水(shui)(shui)(shui)熱(re)(re)負(fu)荷(he)(he)供熱(re)(re)的城市熱(re)(re)力網供熱(re)(re)介質(zhi)(zhi)按下列原則確(que)定：當(dang)(dang)(dang)生產(chan)工(gong)藝(yi)熱(re)(re)負(fu)荷(he)(he)為(wei)(wei)主要負(fu)荷(he)(he)，且必須(xu)采用(yong)蒸(zheng)汽供熱(re)(re)時(shi)，宜(yi)采用(yong)蒸(zheng)汽作(zuo)供熱(re)(re)介質(zhi)(zhi)；當(dang)(dang)(dang)以水(shui)(shui)(shui)位供熱(re)(re)介質(zhi)(zhi)能夠(gou)滿足生產(chan)工(gong)藝(yi)需要（包括(kuo)在用(yong)戶處(chu)轉換為(wei)(wei)蒸(zheng)汽），且技術經濟合理時(shi)，宜(yi)采用(yong)水(shui)(shui)(shui)作(zuo)供熱(re)(re)介質(zhi)(zhi)；當(dang)(dang)(dang)采暖、通(tong)風、空(kong)調(diao)(diao)熱(re)(re)負(fu)荷(he)(he)為(wei)(wei)主要負(fu)荷(he)(he)，生產(chan)工(gong)藝(yi)又必須(xu)采用(yong)蒸(zheng)汽供熱(re)(re)，經技術經濟比較認為(wei)(wei)合理時(shi)，可采用(yong)水(shui)(shui)(shui)和蒸(zheng)汽兩種供熱(re)(re)介質(zhi)(zhi)。
1. 國家現行標準GJJ／T 34《城鎮供(gong)熱(re)(re)(re)管(guan)(guan)網(wang)設(she)(she)計(ji)(ji)規范》適用于(yu)(yu)(yu)供(gong)熱(re)(re)(re)熱(re)(re)(re)水介質設(she)(she)計(ji)(ji)壓力(li)小(xiao)于(yu)(yu)(yu)或(huo)等(deng)(deng)于(yu)(yu)(yu)2.5MPa，設(she)(she)計(ji)(ji)溫度小(xiao)于(yu)(yu)(yu)或(huo)等(deng)(deng)于(yu)(yu)(yu)200℃；供(gong)熱(re)(re)(re)蒸汽(qi)介質設(she)(she)計(ji)(ji)壓力(li)小(xiao)于(yu)(yu)(yu)或(huo)等(deng)(deng)于(yu)(yu)(yu)1.6MPa，設(she)(she)計(ji)(ji)溫度小(xiao)于(yu)(yu)(yu)或(huo)等(deng)(deng)于(yu)(yu)(yu)350℃的(de)(de)下列城鎮供(gong)熱(re)(re)(re)管(guan)(guan)網(wang)的(de)(de)設(she)(she)計(ji)(ji)：以熱(re)(re)(re)電廠或(huo)鍋爐房為熱(re)(re)(re)源，自熱(re)(re)(re)切至建(jian)(jian)筑物熱(re)(re)(re)力(li)人口的(de)(de)供(gong)熱(re)(re)(re)管(guan)(guan)網(wang)，供(gong)熱(re)(re)(re)管(guan)(guan)網(wang)新(xin)建(jian)(jian)、擴建(jian)(jian)或(huo)改建(jian)(jian)的(de)(de)管(guan)(guan)道、中斷泵(beng)站和熱(re)(re)(re)力(li)站等(deng)(deng)工藝(yi)系(xi)統。
2. 國家現行(xing)標準(zhun)GJJ／T 81《城(cheng)鎮(zhen)供(gong)熱(re)直埋熱(re)水(shui)管道技術規程》適(shi)用于(yu)新(xin)建(jian)、改(gai)建(jian)、擴建(jian)的(de)設(she)計溫(wen)度小于(yu)或等(deng)(deng)于(yu)150℃、設(she)計壓力小于(yu)或等(deng)(deng)于(yu)2.5MPa，DN小于(yu)或等(deng)(deng)于(yu)1200mm的(de)城(cheng)鎮(zhen)供(gong)熱(re)直埋熱(re)水(shui)管道的(de)設(she)計、施工(gong)、驗收(shou)和(he)運行(xing)管理。
3. 國(guo)家現行(xing)標準(zhun)GJJ／T 104《城鎮供熱直埋蒸汽管(guan)道技術規程》適用于(yu)(yu)工作壓力小于(yu)(yu)或等(deng)于(yu)(yu)2.5MPa，溫度小于(yu)(yu)或等(deng)于(yu)(yu)350℃，直接(jie)埋地敷設的鋼質外護蒸汽保溫管(guan)道的設計(ji)、施工、驗收及運行(xing)維(wei)護。
二、熱(re)力網的形式
供(gong)熱管(guan)網按其平面(mian)布(bu)置形式可分(fen)為枝(zhi)狀管(guan)網、環狀管(guan)網和多管(guan)制(zhi)管(guan)網。其特(te)點是(shi)：
1. 枝狀管網
從熱(re)源引出主(zhu)(zhu)干線(xian)沿城(cheng)鎮道(dao)路向各熱(re)用(yong)(yong)(yong)戶(hu)供熱(re)，形成類似樹枝(zhi)狀(zhuang)的管(guan)網(wang)(wang)叫(jiao)枝(zhi)狀(zhuang)管(guan)網(wang)(wang)。枝(zhi)狀(zhuang)管(guan)網(wang)(wang)是目(mu)前我(wo)國城(cheng)鎮供熱(re)中普遍(bian)采用(yong)(yong)(yong)的形式(shi)，它形式(shi)簡單、投資(zi)費用(yong)(yong)(yong)低(di)，且運行(xing)管(guan)理方便，但安全可靠性(xing)較(jiao)(jiao)差，當管(guan)網(wang)(wang)中距離熱(re)源較(jiao)(jiao)近的主(zhu)(zhu)干線(xian)發生故(gu)障時，會(hui)影響較(jiao)(jiao)多的熱(re)用(yong)(yong)(yong)戶(hu)用(yong)(yong)(yong)熱(re)。
2. 環狀管網(wang)
供熱管(guan)網的主干線之(zhi)間在適當位置(zhi)連通構成環(huan)形(xing)，環(huan)狀管(guan)網運行較(jiao)安全可靠，局部發生故障可通過(guo)環(huan)網供熱。但(dan)投資費(fei)用高。
3. 多管(guan)制(zhi)管(guan)網
一般用(yong)于以下情況：不能間斷的熱用(yong)戶；供熱系統中熱用(yong)戶所需介(jie)質參(can)數差別較大；熱負(fu)荷(he)變化較大：季節(jie)性熱負(fu)荷(he)占全(quan)年總(zong)負(fu)荷(he)比例(li)較大。
三、熱水熱力網形式(shi)的確定
熱(re)(re)水(shui)熱(re)(re)力(li)網(wang)宜采(cai)用(yong)閉式(shi)雙(shuang)管制。以熱(re)(re)電廠為熱(re)(re)源的熱(re)(re)水(shui)熱(re)(re)力(li)網(wang)，同時有(you)工藝(yi)、采(cai)暖(nuan)、通(tong)風(feng)、空調、生(sheng)(sheng)活(huo)熱(re)(re)水(shui)多種熱(re)(re)負(fu)荷(he)，在生(sheng)(sheng)產工藝(yi)熱(re)(re)負(fu)荷(he)與采(cai)暖(nuan)熱(re)(re)負(fu)荷(he)所(suo)需供熱(re)(re)介(jie)質參數(shu)相差較大，或季節(jie)性熱(re)(re)負(fu)荷(he)占總熱(re)(re)負(fu)荷(he)比例較大，且技術經濟合(he)理時，可采(cai)用(yong)閉式(shi)多管制。
當熱水熱力網(wang)具(ju)有水處理(li)費用較低的(de)豐(feng)富的(de)補(bu)給水資源，且技術(shu)經濟合(he)理(li)時，可采用開式(shi)熱力網(wang)。
當熱(re)(re)(re)水熱(re)(re)(re)力(li)網(wang)具(ju)有與(yu)生(sheng)活熱(re)(re)(re)水熱(re)(re)(re)負荷相適應(ying)的(de)廉價(jia)低位能熱(re)(re)(re)源，且技術經(jing)濟合理時，可采用開式(shi)熱(re)(re)(re)水網(wang)。
開式熱(re)水(shui)熱(re)力(li)網在生活熱(re)水(shui)熱(re)負荷(he)足夠大且技術經濟(ji)合理時，可不設回水(shui)管。
四、蒸汽熱力網形(xing)式的確定
蒸(zheng)汽熱力網宜采(cai)(cai)用單(dan)管制。當各用戶間所需蒸(zheng)汽參數相差較大或(huo)季節性熱負荷(he)占總(zong)熱負荷(he)比例較大且技術經(jing)濟合理(li)時，蒸(zheng)汽熱力網可采(cai)(cai)用雙管或(huo)多管制。
蒸汽熱(re)力網的熱(re)負荷(he)分期(qi)增長時，可采用(yong)雙管(guan)或(huo)多管(guan)制(zhi)。蒸汽供熱(re)系(xi)統應(ying)(ying)創造條件采用(yong)間接換熱(re)系(xi)統。當被(bei)加(jia)熱(re)介(jie)質泄漏不會產(chan)生危害時，其(qi)凝(ning)結水(shui)應(ying)(ying)全(quan)部(bu)回收并設置凝(ning)結水(shui)管(guan)道。
當凝(ning)結水(shui)(shui)回(hui)收(shou)時，用戶熱(re)力站(zhan)應設閉式凝(ning)結水(shui)(shui)箱，用水(shui)(shui)泵將凝(ning)結水(shui)(shui)送回(hui)熱(re)源(yuan)。
五(wu)、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。
