一(yi)、供熱(re)系統(tong)與(yu)介質
集中供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)系統(tong)(tong)(tong)是(shi)指一個(ge)或(huo)多個(ge)集中的(de)(de)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)源，通(tong)過(guo)供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)管網向多個(ge)熱(re)(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)(re)能(neng)的(de)(de)系統(tong)(tong)(tong)，它(ta)主(zhu)要由熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)源、熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)網和熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)用(yong)戶組成。其中熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)源是(shi)指將天然或(huo)人造的(de)(de)能(neng)源形(xing)態轉化為(wei)符(fu)合供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)要求的(de)(de)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)能(neng)裝(zhuang)置(zhi)。熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)網是(shi)指由熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)源向熱(re)(re)(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)(re)(re)介質的(de)(de)管道系統(tong)(tong)(tong)，熱(re)(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)(re)源獲得熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)能(neng)的(de)(de)用(yong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)裝(zhuang)置(zhi)。集中供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)系統(tong)(tong)(tong)分(fen)類方式(shi)有三種(zhong)，可以根據熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)源分(fen)類、根據熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)媒(mei)分(fen)類、根據供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)管網分(fen)類。集中供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)系統(tong)(tong)(tong)按熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)源形(xing)式(shi)的(de)(de)不(bu)(bu)同可分(fen)為(wei)：熱(re)(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)(re)系統(tong)(tong)(tong)、區域鍋爐(lu)房供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)系統(tong)(tong)(tong)、地熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)系統(tong)(tong)(tong)、工業余熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)系統(tong)(tong)(tong)、核供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)堆和太陽能(neng)供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)系統(tong)(tong)(tong)等(deng)。集中供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)系統(tong)(tong)(tong)根據熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)媒(mei)不(bu)(bu)同分(fen)為(wei)蒸汽供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)系統(tong)(tong)(tong)和熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)水供(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)(re)系統(tong)(tong)(tong)。
熱水(shui)熱力(li)網供熱介質設計壓力(li)小(xiao)于(yu)或(huo)等(deng)(deng)于(yu)2.5MPa，設計溫度(du)小(xiao)于(yu)或(huo)等(deng)(deng)于(yu)200℃；蒸汽熱力(li)網供熱介質設計壓力(li)小(xiao)于(yu)或(huo)等(deng)(deng)于(yu)1.6MPa，設計溫度(du)小(xiao)于(yu)或(huo)等(deng)(deng)于(yu)350℃。
對民(min)用建筑物采暖、通風(feng)、空調及生(sheng)活熱水熱負荷供(gong)熱的城市熱力(li)網，宜采用水作供(gong)熱介(jie)質(zhi)。
對(dui)生(sheng)(sheng)產工藝(yi)(yi)熱(re)(re)(re)(re)負荷和(he)采(cai)(cai)(cai)暖(nuan)、通(tong)(tong)風、空調、生(sheng)(sheng)活熱(re)(re)(re)(re)水(shui)熱(re)(re)(re)(re)負荷供(gong)熱(re)(re)(re)(re)的城(cheng)市熱(re)(re)(re)(re)力網供(gong)熱(re)(re)(re)(re)介質(zhi)按下列原則確定：當(dang)生(sheng)(sheng)產工藝(yi)(yi)熱(re)(re)(re)(re)負荷為主要(yao)負荷，且必(bi)須采(cai)(cai)(cai)用(yong)蒸(zheng)汽(qi)(qi)供(gong)熱(re)(re)(re)(re)時，宜采(cai)(cai)(cai)用(yong)蒸(zheng)汽(qi)(qi)作供(gong)熱(re)(re)(re)(re)介質(zhi)；當(dang)以水(shui)位供(gong)熱(re)(re)(re)(re)介質(zhi)能夠(gou)滿足生(sheng)(sheng)產工藝(yi)(yi)需要(yao)（包括在用(yong)戶處轉換(huan)為蒸(zheng)汽(qi)(qi)），且技術經濟(ji)合理時，宜采(cai)(cai)(cai)用(yong)水(shui)作供(gong)熱(re)(re)(re)(re)介質(zhi)；當(dang)采(cai)(cai)(cai)暖(nuan)、通(tong)(tong)風、空調熱(re)(re)(re)(re)負荷為主要(yao)負荷，生(sheng)(sheng)產工藝(yi)(yi)又(you)必(bi)須采(cai)(cai)(cai)用(yong)蒸(zheng)汽(qi)(qi)供(gong)熱(re)(re)(re)(re)，經技術經濟(ji)比較(jiao)認(ren)為合理時，可(ke)采(cai)(cai)(cai)用(yong)水(shui)和(he)蒸(zheng)汽(qi)(qi)兩(liang)種供(gong)熱(re)(re)(re)(re)介質(zhi)。
1. 國(guo)家現行標準GJJ／T 34《城(cheng)鎮供(gong)熱(re)(re)管(guan)網設計(ji)(ji)(ji)規范》適用于(yu)(yu)供(gong)熱(re)(re)熱(re)(re)水介質(zhi)設計(ji)(ji)(ji)壓力(li)小(xiao)(xiao)于(yu)(yu)或(huo)(huo)等(deng)(deng)于(yu)(yu)2.5MPa，設計(ji)(ji)(ji)溫度小(xiao)(xiao)于(yu)(yu)或(huo)(huo)等(deng)(deng)于(yu)(yu)200℃；供(gong)熱(re)(re)蒸汽介質(zhi)設計(ji)(ji)(ji)壓力(li)小(xiao)(xiao)于(yu)(yu)或(huo)(huo)等(deng)(deng)于(yu)(yu)1.6MPa，設計(ji)(ji)(ji)溫度小(xiao)(xiao)于(yu)(yu)或(huo)(huo)等(deng)(deng)于(yu)(yu)350℃的下列城(cheng)鎮供(gong)熱(re)(re)管(guan)網的設計(ji)(ji)(ji)：以熱(re)(re)電廠或(huo)(huo)鍋爐房為熱(re)(re)源，自熱(re)(re)切至建筑物熱(re)(re)力(li)人口的供(gong)熱(re)(re)管(guan)網，供(gong)熱(re)(re)管(guan)網新(xin)建、擴建或(huo)(huo)改建的管(guan)道、中斷泵站(zhan)和熱(re)(re)力(li)站(zhan)等(deng)(deng)工藝(yi)系統。
2. 國(guo)家現行標(biao)準GJJ／T 81《城鎮(zhen)供熱直(zhi)埋熱水(shui)管(guan)道技術(shu)規程》適用于(yu)新建、改建、擴建的設(she)計溫(wen)度(du)小(xiao)(xiao)于(yu)或(huo)等于(yu)150℃、設(she)計壓力小(xiao)(xiao)于(yu)或(huo)等于(yu)2.5MPa，DN小(xiao)(xiao)于(yu)或(huo)等于(yu)1200mm的城鎮(zhen)供熱直(zhi)埋熱水(shui)管(guan)道的設(she)計、施工、驗收(shou)和運行管(guan)理(li)。
3. 國家現行標(biao)準GJJ／T 104《城鎮供熱直埋蒸汽管道技術規程》適用于(yu)工作壓(ya)力小于(yu)或(huo)等于(yu)2.5MPa，溫度小于(yu)或(huo)等于(yu)350℃，直接埋地敷設(she)的(de)鋼質外護蒸汽保溫管道的(de)設(she)計、施(shi)工、驗收(shou)及運行維護。
二、熱力網(wang)的形(xing)式
供(gong)熱管網按其平面布置形式可分為枝(zhi)狀(zhuang)管網、環狀(zhuang)管網和多管制(zhi)管網。其特點(dian)是：
1. 枝(zhi)狀管網
從熱(re)(re)源引出(chu)主干(gan)線沿城鎮道路向各熱(re)(re)用戶(hu)供熱(re)(re)，形成(cheng)類似(si)樹枝(zhi)狀(zhuang)的(de)管網(wang)叫(jiao)枝(zhi)狀(zhuang)管網(wang)。枝(zhi)狀(zhuang)管網(wang)是(shi)目前(qian)我國城鎮供熱(re)(re)中(zhong)普遍(bian)采用的(de)形式，它形式簡單、投資(zi)費用低，且運行管理方便，但安全可靠性較差，當(dang)管網(wang)中(zhong)距離熱(re)(re)源較近的(de)主干(gan)線發生故障(zhang)時，會影(ying)響較多(duo)的(de)熱(re)(re)用戶(hu)用熱(re)(re)。
2. 環狀(zhuang)管網
供熱(re)管網的主(zhu)干線之間在適當位置連通(tong)構成環(huan)形(xing)，環(huan)狀管網運(yun)行較安全(quan)可靠，局部(bu)發生故障可通(tong)過(guo)環(huan)網供熱(re)。但投資費用高(gao)。
3. 多管制(zhi)管網
一般用(yong)于以(yi)下(xia)情況：不能間斷的熱(re)用(yong)戶；供(gong)熱(re)系(xi)統(tong)中熱(re)用(yong)戶所需介質參數差別較(jiao)大(da)；熱(re)負(fu)荷(he)變化較(jiao)大(da)：季節性(xing)熱(re)負(fu)荷(he)占全年總負(fu)荷(he)比例較(jiao)大(da)。
三、熱水熱力網形式的(de)確(que)定
熱(re)(re)水(shui)(shui)熱(re)(re)力網宜(yi)采(cai)(cai)用(yong)閉式雙管(guan)制。以熱(re)(re)電廠(chang)為熱(re)(re)源(yuan)的熱(re)(re)水(shui)(shui)熱(re)(re)力網，同時有(you)工藝、采(cai)(cai)暖、通風、空調、生(sheng)活熱(re)(re)水(shui)(shui)多種(zhong)熱(re)(re)負(fu)荷，在生(sheng)產工藝熱(re)(re)負(fu)荷與采(cai)(cai)暖熱(re)(re)負(fu)荷所需供(gong)熱(re)(re)介質參數相(xiang)差較大，或季節(jie)性熱(re)(re)負(fu)荷占總(zong)熱(re)(re)負(fu)荷比例較大，且技術經濟合理(li)時，可采(cai)(cai)用(yong)閉式多管(guan)制。
當熱(re)水(shui)熱(re)力網(wang)具有水(shui)處理費用(yong)較低的豐富(fu)的補給水(shui)資源，且技術經濟合理時，可采用(yong)開式熱(re)力網(wang)。
當熱(re)水熱(re)力(li)網具有與生(sheng)活熱(re)水熱(re)負(fu)荷(he)相適(shi)應的(de)廉價低位能熱(re)源(yuan)，且技術經濟合(he)理時，可采(cai)用開式熱(re)水網。
開(kai)式熱水(shui)熱力網在生(sheng)活(huo)熱水(shui)熱負荷足(zu)夠大且技術經濟(ji)合理時，可不設回水(shui)管。
四、蒸汽(qi)熱(re)力網形式的確定
蒸(zheng)汽熱(re)力(li)網宜采(cai)用單管制(zhi)。當各用戶間所(suo)需蒸(zheng)汽參數相(xiang)差(cha)較大或季節性(xing)熱(re)負荷占總熱(re)負荷比例較大且技術經濟合理(li)時，蒸(zheng)汽熱(re)力(li)網可采(cai)用雙管或多管制(zhi)。
蒸汽熱(re)力(li)網的熱(re)負荷(he)分期增長時(shi)，可采用(yong)雙管或(huo)多管制。蒸汽供熱(re)系統應創造條件采用(yong)間接換熱(re)系統。當被加熱(re)介質泄漏不會產(chan)生危害時(shi)，其凝結(jie)水應全部回(hui)收并設(she)置凝結(jie)水管道。
當凝結(jie)(jie)水(shui)回(hui)收時(shi)，用戶熱力站應(ying)設閉(bi)式(shi)凝結(jie)(jie)水(shui)箱，用水(shui)泵將凝結(jie)(jie)水(shui)送回(hui)熱源。
五、多供熱(re)源熱(re)力網(wang)形(xing)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。
