一、供熱系統與介質
集(ji)(ji)中供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)是(shi)指一個(ge)或多個(ge)集(ji)(ji)中的熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)，通過(guo)供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)管(guan)網向多個(ge)熱(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)能的系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)，它主要由熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)、熱(re)(re)(re)(re)(re)(re)(re)(re)網和熱(re)(re)(re)(re)(re)(re)(re)(re)用(yong)戶組成。其中熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)是(shi)指將天然或人造的能源(yuan)(yuan)形態(tai)轉化(hua)為符合供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)要求的熱(re)(re)(re)(re)(re)(re)(re)(re)能裝置。熱(re)(re)(re)(re)(re)(re)(re)(re)網是(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)戶輸送和分(fen)配供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)介質的管(guan)道系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)，熱(re)(re)(re)(re)(re)(re)(re)(re)用(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)能的用(yong)熱(re)(re)(re)(re)(re)(re)(re)(re)裝置。集(ji)(ji)中供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)分(fen)類(lei)方(fang)式(shi)有三種(zhong)，可以根據熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)分(fen)類(lei)、根據熱(re)(re)(re)(re)(re)(re)(re)(re)媒分(fen)類(lei)、根據供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)管(guan)網分(fen)類(lei)。集(ji)(ji)中供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)按熱(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)形式(shi)的不同(tong)可分(fen)為：熱(re)(re)(re)(re)(re)(re)(re)(re)電(dian)廠(chang)供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)、區域鍋爐房供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)、地熱(re)(re)(re)(re)(re)(re)(re)(re)供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)、工業余熱(re)(re)(re)(re)(re)(re)(re)(re)供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)、核(he)供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)堆(dui)和太陽能供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)等。集(ji)(ji)中供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)根據熱(re)(re)(re)(re)(re)(re)(re)(re)媒不同(tong)分(fen)為蒸汽供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)和熱(re)(re)(re)(re)(re)(re)(re)(re)水(shui)供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)。
熱水熱力(li)(li)網(wang)(wang)供熱介質設計壓(ya)力(li)(li)小(xiao)(xiao)于(yu)或(huo)等于(yu)2.5MPa，設計溫度小(xiao)(xiao)于(yu)或(huo)等于(yu)200℃；蒸汽熱力(li)(li)網(wang)(wang)供熱介質設計壓(ya)力(li)(li)小(xiao)(xiao)于(yu)或(huo)等于(yu)1.6MPa，設計溫度小(xiao)(xiao)于(yu)或(huo)等于(yu)350℃。
對民(min)用建筑物(wu)采暖、通風、空調及生活熱(re)(re)(re)水熱(re)(re)(re)負(fu)荷供熱(re)(re)(re)的城(cheng)市熱(re)(re)(re)力網，宜采用水作供熱(re)(re)(re)介質(zhi)。
對生(sheng)產(chan)(chan)(chan)(chan)工藝熱(re)負荷(he)(he)和(he)采(cai)暖、通(tong)風、空調、生(sheng)活熱(re)水熱(re)負荷(he)(he)供(gong)(gong)(gong)(gong)熱(re)的(de)城市熱(re)力網供(gong)(gong)(gong)(gong)熱(re)介(jie)(jie)質按下(xia)列原(yuan)則(ze)確定(ding)：當(dang)生(sheng)產(chan)(chan)(chan)(chan)工藝熱(re)負荷(he)(he)為(wei)(wei)(wei)主要(yao)負荷(he)(he)，且必(bi)須(xu)采(cai)用(yong)蒸汽供(gong)(gong)(gong)(gong)熱(re)時，宜采(cai)用(yong)蒸汽作供(gong)(gong)(gong)(gong)熱(re)介(jie)(jie)質；當(dang)以(yi)水位(wei)供(gong)(gong)(gong)(gong)熱(re)介(jie)(jie)質能夠滿(man)足(zu)生(sheng)產(chan)(chan)(chan)(chan)工藝需要(yao)（包(bao)括(kuo)在用(yong)戶(hu)處轉(zhuan)換為(wei)(wei)(wei)蒸汽），且技(ji)術(shu)(shu)經濟(ji)(ji)合理(li)(li)時，宜采(cai)用(yong)水作供(gong)(gong)(gong)(gong)熱(re)介(jie)(jie)質；當(dang)采(cai)暖、通(tong)風、空調熱(re)負荷(he)(he)為(wei)(wei)(wei)主要(yao)負荷(he)(he)，生(sheng)產(chan)(chan)(chan)(chan)工藝又(you)必(bi)須(xu)采(cai)用(yong)蒸汽供(gong)(gong)(gong)(gong)熱(re)，經技(ji)術(shu)(shu)經濟(ji)(ji)比較認為(wei)(wei)(wei)合理(li)(li)時，可采(cai)用(yong)水和(he)蒸汽兩種(zhong)供(gong)(gong)(gong)(gong)熱(re)介(jie)(jie)質。
1. 國家現行(xing)標準GJJ／T 34《城鎮供(gong)熱管(guan)網(wang)設(she)計(ji)規范》適用(yong)于(yu)(yu)供(gong)熱熱水(shui)介(jie)質設(she)計(ji)壓(ya)力小于(yu)(yu)或等于(yu)(yu)2.5MPa，設(she)計(ji)溫度小于(yu)(yu)或等于(yu)(yu)200℃；供(gong)熱蒸汽介(jie)質設(she)計(ji)壓(ya)力小于(yu)(yu)或等于(yu)(yu)1.6MPa，設(she)計(ji)溫度小于(yu)(yu)或等于(yu)(yu)350℃的(de)(de)(de)下列城鎮供(gong)熱管(guan)網(wang)的(de)(de)(de)設(she)計(ji)：以熱電廠或鍋爐房(fang)為熱源，自熱切至建(jian)筑物熱力人口(kou)的(de)(de)(de)供(gong)熱管(guan)網(wang)，供(gong)熱管(guan)網(wang)新(xin)建(jian)、擴建(jian)或改建(jian)的(de)(de)(de)管(guan)道(dao)、中斷(duan)泵站和熱力站等工藝系(xi)統。
2. 國家現行(xing)標準(zhun)GJJ／T 81《城鎮供熱(re)(re)直埋熱(re)(re)水(shui)管(guan)(guan)道(dao)技術(shu)規程(cheng)》適用于(yu)(yu)新建(jian)、改建(jian)、擴(kuo)建(jian)的(de)(de)設(she)計(ji)溫(wen)度小于(yu)(yu)或等(deng)于(yu)(yu)150℃、設(she)計(ji)壓(ya)力小于(yu)(yu)或等(deng)于(yu)(yu)2.5MPa，DN小于(yu)(yu)或等(deng)于(yu)(yu)1200mm的(de)(de)城鎮供熱(re)(re)直埋熱(re)(re)水(shui)管(guan)(guan)道(dao)的(de)(de)設(she)計(ji)、施工、驗收和運行(xing)管(guan)(guan)理。
3. 國家現行(xing)(xing)標準(zhun)GJJ／T 104《城鎮(zhen)供熱直(zhi)埋蒸(zheng)汽管(guan)道技(ji)術規(gui)程》適用于(yu)工作壓力小于(yu)或(huo)等(deng)于(yu)2.5MPa，溫(wen)(wen)度小于(yu)或(huo)等(deng)于(yu)350℃，直(zhi)接埋地敷設(she)的鋼質外護蒸(zheng)汽保(bao)溫(wen)(wen)管(guan)道的設(she)計、施(shi)工、驗收及(ji)運(yun)行(xing)(xing)維護。
二、熱力網的形式
供熱管(guan)網(wang)按其平(ping)面(mian)布(bu)置形式可分為枝狀管(guan)網(wang)、環(huan)狀管(guan)網(wang)和多(duo)管(guan)制(zhi)管(guan)網(wang)。其特點是：
1. 枝狀管(guan)網
從熱(re)源(yuan)引出主干(gan)(gan)線沿城(cheng)鎮道(dao)路向各熱(re)用(yong)(yong)戶供(gong)熱(re)，形成類似樹枝狀(zhuang)的(de)管(guan)網叫枝狀(zhuang)管(guan)網。枝狀(zhuang)管(guan)網是目前(qian)我國城(cheng)鎮供(gong)熱(re)中普遍采(cai)用(yong)(yong)的(de)形式(shi)，它形式(shi)簡(jian)單(dan)、投資(zi)費用(yong)(yong)低(di)，且運(yun)行管(guan)理(li)方便，但安全可靠性較差，當(dang)管(guan)網中距(ju)離熱(re)源(yuan)較近的(de)主干(gan)(gan)線發生故障時(shi)，會影響較多的(de)熱(re)用(yong)(yong)戶用(yong)(yong)熱(re)。
2. 環狀管網
供(gong)熱管網的主干線之間(jian)在(zai)適(shi)當(dang)位置(zhi)連通(tong)構成環形，環狀管網運行較安全(quan)可(ke)靠，局(ju)部發生故障可(ke)通(tong)過(guo)環網供(gong)熱。但(dan)投資費用(yong)高。
3. 多(duo)管(guan)(guan)制(zhi)管(guan)(guan)網(wang)
一般用于以下情(qing)況：不能間(jian)斷的熱(re)用戶；供熱(re)系統中熱(re)用戶所需介質參數差(cha)別(bie)較大(da)；熱(re)負(fu)荷變化較大(da)：季節性熱(re)負(fu)荷占全年總負(fu)荷比例較大(da)。
三(san)、熱水熱力網形(xing)式的(de)確(que)定
熱(re)(re)(re)水熱(re)(re)(re)力網宜采(cai)用閉(bi)式(shi)雙管(guan)制。以熱(re)(re)(re)電廠(chang)為熱(re)(re)(re)源的(de)熱(re)(re)(re)水熱(re)(re)(re)力網，同時(shi)有工(gong)藝(yi)、采(cai)暖(nuan)、通(tong)風(feng)、空調(diao)、生(sheng)活熱(re)(re)(re)水多種熱(re)(re)(re)負荷(he)(he)，在生(sheng)產工(gong)藝(yi)熱(re)(re)(re)負荷(he)(he)與采(cai)暖(nuan)熱(re)(re)(re)負荷(he)(he)所需供熱(re)(re)(re)介質參數相差(cha)較大，或季(ji)節(jie)性熱(re)(re)(re)負荷(he)(he)占總(zong)熱(re)(re)(re)負荷(he)(he)比例較大，且技術經濟合理時(shi)，可采(cai)用閉(bi)式(shi)多管(guan)制。
當熱(re)水(shui)熱(re)力網(wang)具有水(shui)處理(li)費(fei)用(yong)較低(di)的(de)豐富的(de)補給水(shui)資(zi)源(yuan)，且技術經(jing)濟合理(li)時，可采(cai)用(yong)開式熱(re)力網(wang)。
當熱水(shui)(shui)熱力網具有與生活(huo)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(he)理(li)時(shi)，可采用(yong)開式(shi)熱水(shui)(shui)網。
開式(shi)熱(re)水(shui)熱(re)力網在(zai)生活熱(re)水(shui)熱(re)負荷足(zu)夠大且技(ji)術經濟合理時，可不設(she)回(hui)水(shui)管。
四、蒸汽熱(re)力網(wang)形式的確定
蒸(zheng)汽(qi)(qi)熱(re)(re)力(li)網宜(yi)采(cai)用單管(guan)制(zhi)(zhi)。當各用戶(hu)間所需蒸(zheng)汽(qi)(qi)參數相差(cha)較大或(huo)季節性熱(re)(re)負荷占總熱(re)(re)負荷比例較大且技術經濟合(he)理時，蒸(zheng)汽(qi)(qi)熱(re)(re)力(li)網可(ke)采(cai)用雙(shuang)管(guan)或(huo)多管(guan)制(zhi)(zhi)。
蒸汽熱(re)力網的熱(re)負(fu)荷分期(qi)增長(chang)時，可采用雙管或多管制。蒸汽供熱(re)系統應創造條件采用間接換熱(re)系統。當(dang)被加熱(re)介質泄漏不會產生危害時，其凝結水應全部回(hui)收并設置凝結水管道(dao)。
當凝(ning)(ning)(ning)結(jie)水(shui)(shui)回收時，用戶熱力站應設閉(bi)式凝(ning)(ning)(ning)結(jie)水(shui)(shui)箱(xiang)，用水(shui)(shui)泵(beng)將(jiang)凝(ning)(ning)(ning)結(jie)水(shui)(shui)送回熱源。
五、多供熱源熱力網形(xing)式(shi)的確(que)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。
