一、供熱系統與介質(zhi)
集(ji)中(zhong)(zhong)(zhong)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)是指(zhi)(zhi)一個(ge)或多個(ge)集(ji)中(zhong)(zhong)(zhong)的熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)(yuan)，通過供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)管(guan)(guan)網(wang)(wang)(wang)向(xiang)多個(ge)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)用(yong)(yong)戶供(gong)(gong)(gong)(gong)應(ying)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)能(neng)的系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)，它主(zhu)要由熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)(yuan)、熱(re)(re)(re)(re)(re)(re)(re)(re)(re)網(wang)(wang)(wang)和(he)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)用(yong)(yong)戶組成。其中(zhong)(zhong)(zhong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)(yuan)是指(zhi)(zhi)將(jiang)天然或人造的能(neng)源(yuan)(yuan)(yuan)形態轉化(hua)為(wei)(wei)符合供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)要求的熱(re)(re)(re)(re)(re)(re)(re)(re)(re)能(neng)裝置(zhi)。熱(re)(re)(re)(re)(re)(re)(re)(re)(re)網(wang)(wang)(wang)是指(zhi)(zhi)由熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)(yuan)向(xiang)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)用(yong)(yong)戶輸送(song)和(he)分配供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)介(jie)質的管(guan)(guan)道系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)，熱(re)(re)(re)(re)(re)(re)(re)(re)(re)用(yong)(yong)戶是指(zhi)(zhi)從熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)(yuan)獲(huo)得熱(re)(re)(re)(re)(re)(re)(re)(re)(re)能(neng)的用(yong)(yong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)裝置(zhi)。集(ji)中(zhong)(zhong)(zhong)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)分類方式(shi)有三種，可(ke)以根(gen)據(ju)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)(yuan)分類、根(gen)據(ju)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)媒分類、根(gen)據(ju)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)管(guan)(guan)網(wang)(wang)(wang)分類。集(ji)中(zhong)(zhong)(zhong)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)按熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)(yuan)(yuan)形式(shi)的不同(tong)可(ke)分為(wei)(wei)：熱(re)(re)(re)(re)(re)(re)(re)(re)(re)電(dian)廠(chang)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)、區域鍋爐房(fang)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)、地(di)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)、工(gong)業余熱(re)(re)(re)(re)(re)(re)(re)(re)(re)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)、核供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)堆和(he)太陽能(neng)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)等。集(ji)中(zhong)(zhong)(zhong)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)根(gen)據(ju)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)媒不同(tong)分為(wei)(wei)蒸汽供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)和(he)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)水(shui)供(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)。
熱(re)(re)水熱(re)(re)力(li)網供熱(re)(re)介質(zhi)(zhi)設(she)計(ji)壓力(li)小(xiao)于(yu)或等于(yu)2.5MPa，設(she)計(ji)溫度小(xiao)于(yu)或等于(yu)200℃；蒸汽(qi)熱(re)(re)力(li)網供熱(re)(re)介質(zhi)(zhi)設(she)計(ji)壓力(li)小(xiao)于(yu)或等于(yu)1.6MPa，設(she)計(ji)溫度小(xiao)于(yu)或等于(yu)350℃。
對民用(yong)建(jian)筑(zhu)物采暖、通風、空調(diao)及生活熱(re)(re)水熱(re)(re)負荷供熱(re)(re)的城市熱(re)(re)力網，宜采用(yong)水作供熱(re)(re)介質(zhi)。
對生(sheng)(sheng)產(chan)工藝熱(re)(re)(re)負(fu)(fu)荷(he)(he)(he)和采暖、通(tong)風、空調、生(sheng)(sheng)活熱(re)(re)(re)水(shui)熱(re)(re)(re)負(fu)(fu)荷(he)(he)(he)供(gong)熱(re)(re)(re)的城(cheng)市熱(re)(re)(re)力網(wang)供(gong)熱(re)(re)(re)介質(zhi)按下(xia)列原(yuan)則確定(ding)：當生(sheng)(sheng)產(chan)工藝熱(re)(re)(re)負(fu)(fu)荷(he)(he)(he)為(wei)(wei)主要(yao)負(fu)(fu)荷(he)(he)(he)，且(qie)必須(xu)采用(yong)(yong)蒸汽(qi)供(gong)熱(re)(re)(re)時，宜(yi)采用(yong)(yong)蒸汽(qi)作(zuo)供(gong)熱(re)(re)(re)介質(zhi)；當以水(shui)位供(gong)熱(re)(re)(re)介質(zhi)能夠滿足(zu)生(sheng)(sheng)產(chan)工藝需(xu)要(yao)（包括在用(yong)(yong)戶(hu)處轉換為(wei)(wei)蒸汽(qi)），且(qie)技術經濟合(he)理時，宜(yi)采用(yong)(yong)水(shui)作(zuo)供(gong)熱(re)(re)(re)介質(zhi)；當采暖、通(tong)風、空調熱(re)(re)(re)負(fu)(fu)荷(he)(he)(he)為(wei)(wei)主要(yao)負(fu)(fu)荷(he)(he)(he)，生(sheng)(sheng)產(chan)工藝又必須(xu)采用(yong)(yong)蒸汽(qi)供(gong)熱(re)(re)(re)，經技術經濟比較認為(wei)(wei)合(he)理時，可(ke)采用(yong)(yong)水(shui)和蒸汽(qi)兩種供(gong)熱(re)(re)(re)介質(zhi)。
1. 國家現行標準GJJ／T 34《城鎮供(gong)(gong)熱(re)(re)管(guan)(guan)網設(she)(she)(she)計規范》適用于供(gong)(gong)熱(re)(re)熱(re)(re)水介質設(she)(she)(she)計壓(ya)力(li)小于或(huo)等(deng)(deng)于2.5MPa，設(she)(she)(she)計溫(wen)度小于或(huo)等(deng)(deng)于200℃；供(gong)(gong)熱(re)(re)蒸汽介質設(she)(she)(she)計壓(ya)力(li)小于或(huo)等(deng)(deng)于1.6MPa，設(she)(she)(she)計溫(wen)度小于或(huo)等(deng)(deng)于350℃的(de)(de)下列(lie)城鎮供(gong)(gong)熱(re)(re)管(guan)(guan)網的(de)(de)設(she)(she)(she)計：以熱(re)(re)電(dian)廠或(huo)鍋爐房為熱(re)(re)源，自熱(re)(re)切至建筑物熱(re)(re)力(li)人口的(de)(de)供(gong)(gong)熱(re)(re)管(guan)(guan)網，供(gong)(gong)熱(re)(re)管(guan)(guan)網新建、擴建或(huo)改建的(de)(de)管(guan)(guan)道、中斷泵站和熱(re)(re)力(li)站等(deng)(deng)工藝系(xi)統。
2. 國家現行(xing)標準GJJ／T 81《城鎮供(gong)熱直埋(mai)熱水(shui)管道技術規程》適用于(yu)(yu)(yu)新建、改建、擴建的設計溫(wen)度小(xiao)于(yu)(yu)(yu)或(huo)等(deng)于(yu)(yu)(yu)150℃、設計壓力小(xiao)于(yu)(yu)(yu)或(huo)等(deng)于(yu)(yu)(yu)2.5MPa，DN小(xiao)于(yu)(yu)(yu)或(huo)等(deng)于(yu)(yu)(yu)1200mm的城鎮供(gong)熱直埋(mai)熱水(shui)管道的設計、施(shi)工、驗收(shou)和運行(xing)管理(li)。
3. 國家現行(xing)標準GJJ／T 104《城鎮供熱直(zhi)埋(mai)蒸汽(qi)管道技術規程》適用于(yu)工作(zuo)壓力小于(yu)或(huo)(huo)等(deng)于(yu)2.5MPa，溫度小于(yu)或(huo)(huo)等(deng)于(yu)350℃，直(zhi)接埋(mai)地(di)敷設的鋼質外(wai)護(hu)蒸汽(qi)保(bao)溫管道的設計、施工、驗(yan)收及運行(xing)維護(hu)。
二(er)、熱力網的(de)形式
供熱管網(wang)按其平面布置形式可分為枝狀管網(wang)、環狀管網(wang)和多(duo)管制管網(wang)。其特點是：
1. 枝狀管網(wang)
從熱(re)(re)源引(yin)出主干線(xian)沿城鎮道路(lu)向各熱(re)(re)用戶供(gong)熱(re)(re)，形(xing)成類似樹枝(zhi)狀(zhuang)的管網(wang)叫枝(zhi)狀(zhuang)管網(wang)。枝(zhi)狀(zhuang)管網(wang)是目前我國城鎮供(gong)熱(re)(re)中(zhong)普遍(bian)采(cai)用的形(xing)式(shi)，它形(xing)式(shi)簡單、投資(zi)費用低，且運行管理方便，但安全可靠(kao)性較(jiao)差(cha)，當管網(wang)中(zhong)距離熱(re)(re)源較(jiao)近的主干線(xian)發(fa)生故(gu)障時(shi)，會影響較(jiao)多(duo)的熱(re)(re)用戶用熱(re)(re)。
2. 環(huan)狀管網
供熱管網的主干線(xian)之(zhi)間在適(shi)當位置連(lian)通構成(cheng)環形，環狀管網運(yun)行(xing)較安全可靠，局部發(fa)生故(gu)障(zhang)可通過環網供熱。但投資費(fei)用(yong)高。
3. 多管制管網
一般用(yong)于(yu)以(yi)下情況：不(bu)能間斷的熱用(yong)戶；供(gong)熱系統(tong)中(zhong)熱用(yong)戶所需介質(zhi)參數差別較(jiao)大；熱負(fu)荷(he)(he)變化較(jiao)大：季節性熱負(fu)荷(he)(he)占全(quan)年總負(fu)荷(he)(he)比例較(jiao)大。
三、熱(re)水熱(re)力網(wang)形式的確定
熱(re)(re)(re)(re)(re)水熱(re)(re)(re)(re)(re)力網宜采(cai)(cai)用閉(bi)式雙管(guan)制(zhi)。以熱(re)(re)(re)(re)(re)電(dian)廠(chang)為(wei)熱(re)(re)(re)(re)(re)源的(de)熱(re)(re)(re)(re)(re)水熱(re)(re)(re)(re)(re)力網，同(tong)時有工(gong)(gong)藝、采(cai)(cai)暖(nuan)(nuan)、通風、空調、生活熱(re)(re)(re)(re)(re)水多(duo)種熱(re)(re)(re)(re)(re)負(fu)(fu)荷，在生產工(gong)(gong)藝熱(re)(re)(re)(re)(re)負(fu)(fu)荷與采(cai)(cai)暖(nuan)(nuan)熱(re)(re)(re)(re)(re)負(fu)(fu)荷所需供熱(re)(re)(re)(re)(re)介質參(can)數相差較大(da)，或季節性熱(re)(re)(re)(re)(re)負(fu)(fu)荷占總(zong)熱(re)(re)(re)(re)(re)負(fu)(fu)荷比例較大(da)，且技(ji)術(shu)經濟合理時，可采(cai)(cai)用閉(bi)式多(duo)管(guan)制(zhi)。
當熱水熱力網(wang)具有水處理費(fei)用(yong)較低的豐富的補給水資(zi)源，且(qie)技術經濟合理時，可(ke)采用(yong)開(kai)式熱力網(wang)。
當熱(re)水(shui)熱(re)力(li)網(wang)具有(you)與生活熱(re)水(shui)熱(re)負荷相適應(ying)的廉價低(di)位能熱(re)源，且技(ji)術經濟(ji)合理(li)時，可(ke)采用開式熱(re)水(shui)網(wang)。
開式熱(re)(re)水熱(re)(re)力網在生活熱(re)(re)水熱(re)(re)負荷足夠大且技術(shu)經濟合理時，可不設回水管。
四、蒸汽熱力網形式的確定
蒸汽(qi)熱(re)力網宜采用(yong)單管制(zhi)。當各(ge)用(yong)戶間所需蒸汽(qi)參數相差較大或(huo)季節(jie)性熱(re)負荷(he)(he)占總熱(re)負荷(he)(he)比(bi)例較大且技術經濟合理時(shi)，蒸汽(qi)熱(re)力網可采用(yong)雙(shuang)管或(huo)多管制(zhi)。
蒸汽(qi)(qi)熱力(li)網的熱負荷分(fen)期增長時，可采(cai)(cai)用雙管(guan)或(huo)多管(guan)制。蒸汽(qi)(qi)供熱系統(tong)應創(chuang)造(zao)條件采(cai)(cai)用間接換熱系統(tong)。當被(bei)加熱介質泄漏不(bu)會產生危害時，其凝(ning)(ning)結水應全部(bu)回(hui)收并(bing)設置凝(ning)(ning)結水管(guan)道。
當凝結水(shui)回(hui)收(shou)時，用戶熱(re)力(li)站應設閉式凝結水(shui)箱，用水(shui)泵將凝結水(shui)送回(hui)熱(re)源。
五、多供熱(re)源熱(re)力網形式的(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。
