一(yi)、供熱系統與介質
集(ji)(ji)(ji)中(zhong)(zhong)供(gong)(gong)熱(re)(re)(re)系(xi)(xi)(xi)(xi)(xi)統(tong)是(shi)指一個(ge)或多(duo)(duo)個(ge)集(ji)(ji)(ji)中(zhong)(zhong)的熱(re)(re)(re)源(yuan)(yuan)，通過(guo)供(gong)(gong)熱(re)(re)(re)管(guan)網向多(duo)(duo)個(ge)熱(re)(re)(re)用(yong)戶(hu)(hu)供(gong)(gong)應熱(re)(re)(re)能(neng)的系(xi)(xi)(xi)(xi)(xi)統(tong)，它主要由熱(re)(re)(re)源(yuan)(yuan)、熱(re)(re)(re)網和(he)熱(re)(re)(re)用(yong)戶(hu)(hu)組成。其中(zhong)(zhong)熱(re)(re)(re)源(yuan)(yuan)是(shi)指將天然(ran)或人造的能(neng)源(yuan)(yuan)形(xing)(xing)態轉化為(wei)符合供(gong)(gong)熱(re)(re)(re)要求的熱(re)(re)(re)能(neng)裝置。熱(re)(re)(re)網是(shi)指由熱(re)(re)(re)源(yuan)(yuan)向熱(re)(re)(re)用(yong)戶(hu)(hu)輸送(song)和(he)分配供(gong)(gong)熱(re)(re)(re)介質的管(guan)道系(xi)(xi)(xi)(xi)(xi)統(tong)，熱(re)(re)(re)用(yong)戶(hu)(hu)是(shi)指從熱(re)(re)(re)源(yuan)(yuan)獲得熱(re)(re)(re)能(neng)的用(yong)熱(re)(re)(re)裝置。集(ji)(ji)(ji)中(zhong)(zhong)供(gong)(gong)熱(re)(re)(re)系(xi)(xi)(xi)(xi)(xi)統(tong)分類(lei)方式有三種，可以根(gen)據(ju)熱(re)(re)(re)源(yuan)(yuan)分類(lei)、根(gen)據(ju)熱(re)(re)(re)媒分類(lei)、根(gen)據(ju)供(gong)(gong)熱(re)(re)(re)管(guan)網分類(lei)。集(ji)(ji)(ji)中(zhong)(zhong)供(gong)(gong)熱(re)(re)(re)系(xi)(xi)(xi)(xi)(xi)統(tong)按熱(re)(re)(re)源(yuan)(yuan)形(xing)(xing)式的不同可分為(wei)：熱(re)(re)(re)電廠供(gong)(gong)熱(re)(re)(re)系(xi)(xi)(xi)(xi)(xi)統(tong)、區域鍋(guo)爐房(fang)供(gong)(gong)熱(re)(re)(re)系(xi)(xi)(xi)(xi)(xi)統(tong)、地熱(re)(re)(re)供(gong)(gong)熱(re)(re)(re)系(xi)(xi)(xi)(xi)(xi)統(tong)、工業余熱(re)(re)(re)供(gong)(gong)熱(re)(re)(re)系(xi)(xi)(xi)(xi)(xi)統(tong)、核供(gong)(gong)熱(re)(re)(re)堆和(he)太陽能(neng)供(gong)(gong)熱(re)(re)(re)系(xi)(xi)(xi)(xi)(xi)統(tong)等。集(ji)(ji)(ji)中(zhong)(zhong)供(gong)(gong)熱(re)(re)(re)系(xi)(xi)(xi)(xi)(xi)統(tong)根(gen)據(ju)熱(re)(re)(re)媒不同分為(wei)蒸汽(qi)供(gong)(gong)熱(re)(re)(re)系(xi)(xi)(xi)(xi)(xi)統(tong)和(he)熱(re)(re)(re)水供(gong)(gong)熱(re)(re)(re)系(xi)(xi)(xi)(xi)(xi)統(tong)。
熱(re)水熱(re)力(li)網供熱(re)介(jie)質設計(ji)(ji)壓力(li)小(xiao)于(yu)或(huo)等(deng)(deng)于(yu)2.5MPa，設計(ji)(ji)溫度小(xiao)于(yu)或(huo)等(deng)(deng)于(yu)200℃；蒸汽熱(re)力(li)網供熱(re)介(jie)質設計(ji)(ji)壓力(li)小(xiao)于(yu)或(huo)等(deng)(deng)于(yu)1.6MPa，設計(ji)(ji)溫度小(xiao)于(yu)或(huo)等(deng)(deng)于(yu)350℃。
對(dui)民用(yong)建(jian)筑物采(cai)暖、通風、空調及生活(huo)熱(re)(re)水熱(re)(re)負荷供熱(re)(re)的(de)城市熱(re)(re)力(li)網，宜(yi)采(cai)用(yong)水作供熱(re)(re)介質。
對生(sheng)(sheng)產(chan)工藝(yi)熱(re)(re)負荷(he)(he)(he)和(he)采暖、通風(feng)、空(kong)調、生(sheng)(sheng)活熱(re)(re)水(shui)熱(re)(re)負荷(he)(he)(he)供(gong)(gong)熱(re)(re)的(de)城(cheng)市(shi)熱(re)(re)力(li)網供(gong)(gong)熱(re)(re)介(jie)質(zhi)按下列原則確(que)定：當(dang)(dang)生(sheng)(sheng)產(chan)工藝(yi)熱(re)(re)負荷(he)(he)(he)為主要負荷(he)(he)(he)，且必須(xu)采用(yong)(yong)蒸(zheng)汽(qi)(qi)供(gong)(gong)熱(re)(re)時，宜采用(yong)(yong)蒸(zheng)汽(qi)(qi)作供(gong)(gong)熱(re)(re)介(jie)質(zhi)；當(dang)(dang)以水(shui)位供(gong)(gong)熱(re)(re)介(jie)質(zhi)能夠滿足(zu)生(sheng)(sheng)產(chan)工藝(yi)需要（包括(kuo)在用(yong)(yong)戶處轉換(huan)為蒸(zheng)汽(qi)(qi)），且技(ji)術(shu)經濟合(he)理時，宜采用(yong)(yong)水(shui)作供(gong)(gong)熱(re)(re)介(jie)質(zhi)；當(dang)(dang)采暖、通風(feng)、空(kong)調熱(re)(re)負荷(he)(he)(he)為主要負荷(he)(he)(he)，生(sheng)(sheng)產(chan)工藝(yi)又必須(xu)采用(yong)(yong)蒸(zheng)汽(qi)(qi)供(gong)(gong)熱(re)(re)，經技(ji)術(shu)經濟比較認為合(he)理時，可采用(yong)(yong)水(shui)和(he)蒸(zheng)汽(qi)(qi)兩種供(gong)(gong)熱(re)(re)介(jie)質(zhi)。
1. 國家(jia)現(xian)行標準(zhun)GJJ／T 34《城鎮供(gong)(gong)熱(re)(re)管(guan)網(wang)設(she)計(ji)(ji)(ji)(ji)規范》適用(yong)于(yu)(yu)供(gong)(gong)熱(re)(re)熱(re)(re)水介(jie)(jie)質設(she)計(ji)(ji)(ji)(ji)壓力小(xiao)(xiao)于(yu)(yu)或(huo)(huo)(huo)等于(yu)(yu)2.5MPa，設(she)計(ji)(ji)(ji)(ji)溫度小(xiao)(xiao)于(yu)(yu)或(huo)(huo)(huo)等于(yu)(yu)200℃；供(gong)(gong)熱(re)(re)蒸(zheng)汽介(jie)(jie)質設(she)計(ji)(ji)(ji)(ji)壓力小(xiao)(xiao)于(yu)(yu)或(huo)(huo)(huo)等于(yu)(yu)1.6MPa，設(she)計(ji)(ji)(ji)(ji)溫度小(xiao)(xiao)于(yu)(yu)或(huo)(huo)(huo)等于(yu)(yu)350℃的(de)(de)下列城鎮供(gong)(gong)熱(re)(re)管(guan)網(wang)的(de)(de)設(she)計(ji)(ji)(ji)(ji)：以熱(re)(re)電(dian)廠或(huo)(huo)(huo)鍋(guo)爐(lu)房為熱(re)(re)源，自熱(re)(re)切至建筑(zhu)物熱(re)(re)力人口(kou)的(de)(de)供(gong)(gong)熱(re)(re)管(guan)網(wang)，供(gong)(gong)熱(re)(re)管(guan)網(wang)新建、擴建或(huo)(huo)(huo)改建的(de)(de)管(guan)道、中斷泵(beng)站(zhan)和熱(re)(re)力站(zhan)等工藝系統。
2. 國家現行(xing)標準GJJ／T 81《城鎮(zhen)供熱直埋(mai)熱水管(guan)道技術規程》適(shi)用于(yu)新建(jian)(jian)、改建(jian)(jian)、擴建(jian)(jian)的(de)設計(ji)溫度(du)小(xiao)于(yu)或等(deng)(deng)于(yu)150℃、設計(ji)壓(ya)力(li)小(xiao)于(yu)或等(deng)(deng)于(yu)2.5MPa，DN小(xiao)于(yu)或等(deng)(deng)于(yu)1200mm的(de)城鎮(zhen)供熱直埋(mai)熱水管(guan)道的(de)設計(ji)、施工、驗(yan)收和運行(xing)管(guan)理(li)。
3. 國家現行(xing)(xing)標準GJJ／T 104《城(cheng)鎮供(gong)熱直埋蒸汽管(guan)道技術規程》適用于(yu)工(gong)作壓力小于(yu)或等于(yu)2.5MPa，溫(wen)度小于(yu)或等于(yu)350℃，直接埋地敷設的(de)鋼質外護蒸汽保溫(wen)管(guan)道的(de)設計、施工(gong)、驗收(shou)及運行(xing)(xing)維護。
二(er)、熱力網的形式(shi)
供熱管(guan)網(wang)按其平面布置形式可分(fen)為(wei)枝狀(zhuang)管(guan)網(wang)、環狀(zhuang)管(guan)網(wang)和(he)多管(guan)制(zhi)管(guan)網(wang)。其特點是：
1. 枝狀管網
從(cong)熱源引出主干線沿城鎮道路向各熱用(yong)(yong)戶供熱，形成類似樹枝(zhi)狀(zhuang)的(de)管網叫枝(zhi)狀(zhuang)管網。枝(zhi)狀(zhuang)管網是目前我國城鎮供熱中普(pu)遍采用(yong)(yong)的(de)形式，它(ta)形式簡單、投資費(fei)用(yong)(yong)低，且運(yun)行管理方便，但(dan)安(an)全可(ke)靠性較差，當管網中距離熱源較近的(de)主干線發(fa)生(sheng)故障時，會影響較多的(de)熱用(yong)(yong)戶用(yong)(yong)熱。
2. 環(huan)狀(zhuang)管網
供(gong)熱管網(wang)的主干線(xian)之間在(zai)適當位(wei)置(zhi)連(lian)通構成環(huan)(huan)形，環(huan)(huan)狀管網(wang)運(yun)行(xing)較安全可(ke)(ke)靠，局部(bu)發生故障可(ke)(ke)通過環(huan)(huan)網(wang)供(gong)熱。但投(tou)資費用高。
3. 多管(guan)制管(guan)網(wang)
一般(ban)用(yong)于以下情況：不(bu)能間斷的熱(re)(re)用(yong)戶(hu)(hu)；供熱(re)(re)系統中熱(re)(re)用(yong)戶(hu)(hu)所需介(jie)質參(can)數差別較(jiao)(jiao)大；熱(re)(re)負荷變化較(jiao)(jiao)大：季節(jie)性熱(re)(re)負荷占(zhan)全(quan)年總負荷比例(li)較(jiao)(jiao)大。
三(san)、熱水熱力網形式的確定
熱(re)(re)水熱(re)(re)力網宜采(cai)(cai)用閉式雙管制(zhi)。以熱(re)(re)電廠(chang)為熱(re)(re)源的熱(re)(re)水熱(re)(re)力網，同時(shi)有工(gong)藝、采(cai)(cai)暖、通風、空調(diao)、生活熱(re)(re)水多種熱(re)(re)負(fu)荷，在(zai)生產工(gong)藝熱(re)(re)負(fu)荷與(yu)采(cai)(cai)暖熱(re)(re)負(fu)荷所需供(gong)熱(re)(re)介質參(can)數相差較大，或季節性熱(re)(re)負(fu)荷占總(zong)熱(re)(re)負(fu)荷比例較大，且技(ji)術經(jing)濟合(he)理時(shi)，可采(cai)(cai)用閉式多管制(zhi)。
當熱(re)水熱(re)力網具有水處理(li)費用較低的(de)豐富的(de)補給水資(zi)源(yuan)，且技術經濟合理(li)時，可采(cai)用開式熱(re)力網。
當熱(re)(re)水(shui)熱(re)(re)力(li)網(wang)具(ju)有與生活熱(re)(re)水(shui)熱(re)(re)負荷相適(shi)應的(de)廉價低位能(neng)熱(re)(re)源，且技術經濟合理時，可(ke)采用開(kai)式熱(re)(re)水(shui)網(wang)。
開式熱水熱力網在(zai)生活熱水熱負荷足夠大(da)且技術經濟合理時，可不設回(hui)水管。
四、蒸汽熱力網形(xing)式的(de)確定
蒸(zheng)(zheng)汽熱(re)(re)力網宜采(cai)用單管制。當各用戶間所需蒸(zheng)(zheng)汽參數(shu)相差(cha)較大或季節性熱(re)(re)負(fu)荷(he)占總熱(re)(re)負(fu)荷(he)比(bi)例(li)較大且(qie)技術(shu)經濟(ji)合理時，蒸(zheng)(zheng)汽熱(re)(re)力網可采(cai)用雙管或多(duo)管制。
蒸(zheng)汽熱(re)力網(wang)的熱(re)負荷分期增長(chang)時，可(ke)采(cai)用雙(shuang)管或多管制(zhi)。蒸(zheng)汽供熱(re)系(xi)統(tong)應(ying)創造條件采(cai)用間接換熱(re)系(xi)統(tong)。當被加熱(re)介質泄漏不會產生(sheng)危(wei)害時，其(qi)凝結水(shui)應(ying)全部回收(shou)并設置凝結水(shui)管道。
當凝(ning)結(jie)水(shui)回收時(shi)，用(yong)戶熱(re)力站應設閉式凝(ning)結(jie)水(shui)箱(xiang)，用(yong)水(shui)泵將凝(ning)結(jie)水(shui)送(song)回熱(re)源。
五、多供熱源熱力網形式的(de)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。
