一(yi)、供(gong)熱系統與介(jie)質
集(ji)(ji)中供(gong)(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)是(shi)指(zhi)一個(ge)(ge)或多(duo)個(ge)(ge)集(ji)(ji)中的(de)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)，通過供(gong)(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)管網(wang)向多(duo)個(ge)(ge)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)用(yong)戶(hu)供(gong)(gong)(gong)(gong)(gong)應熱(re)(re)(re)(re)(re)(re)(re)(re)(re)能(neng)的(de)系(xi)(xi)統(tong)(tong)(tong)，它主(zhu)要由(you)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)、熱(re)(re)(re)(re)(re)(re)(re)(re)(re)網(wang)和(he)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)用(yong)戶(hu)組(zu)成。其中熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)是(shi)指(zhi)將天(tian)然或人(ren)造(zao)的(de)能(neng)源(yuan)形態轉(zhuan)化為符合供(gong)(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)要求(qiu)的(de)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)能(neng)裝(zhuang)置。熱(re)(re)(re)(re)(re)(re)(re)(re)(re)網(wang)是(shi)指(zhi)由(you)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)向熱(re)(re)(re)(re)(re)(re)(re)(re)(re)用(yong)戶(hu)輸(shu)送和(he)分配(pei)供(gong)(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)介質的(de)管道系(xi)(xi)統(tong)(tong)(tong)，熱(re)(re)(re)(re)(re)(re)(re)(re)(re)用(yong)戶(hu)是(shi)指(zhi)從熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)獲得熱(re)(re)(re)(re)(re)(re)(re)(re)(re)能(neng)的(de)用(yong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)裝(zhuang)置。集(ji)(ji)中供(gong)(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)分類(lei)(lei)方式(shi)有三種，可以根(gen)(gen)據(ju)(ju)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)分類(lei)(lei)、根(gen)(gen)據(ju)(ju)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)媒分類(lei)(lei)、根(gen)(gen)據(ju)(ju)供(gong)(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)管網(wang)分類(lei)(lei)。集(ji)(ji)中供(gong)(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)按(an)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)源(yuan)形式(shi)的(de)不同可分為：熱(re)(re)(re)(re)(re)(re)(re)(re)(re)電廠供(gong)(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)、區域(yu)鍋(guo)爐房供(gong)(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)、地熱(re)(re)(re)(re)(re)(re)(re)(re)(re)供(gong)(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)、工(gong)業余熱(re)(re)(re)(re)(re)(re)(re)(re)(re)供(gong)(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)、核供(gong)(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)堆和(he)太(tai)陽能(neng)供(gong)(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)等(deng)。集(ji)(ji)中供(gong)(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)根(gen)(gen)據(ju)(ju)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)媒不同分為蒸汽供(gong)(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)和(he)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)水(shui)供(gong)(gong)(gong)(gong)(gong)熱(re)(re)(re)(re)(re)(re)(re)(re)(re)系(xi)(xi)統(tong)(tong)(tong)。
熱水熱力網(wang)供熱介(jie)(jie)質設計(ji)(ji)壓(ya)力小(xiao)于(yu)或(huo)等于(yu)2.5MPa，設計(ji)(ji)溫度小(xiao)于(yu)或(huo)等于(yu)200℃；蒸(zheng)汽熱力網(wang)供熱介(jie)(jie)質設計(ji)(ji)壓(ya)力小(xiao)于(yu)或(huo)等于(yu)1.6MPa，設計(ji)(ji)溫度小(xiao)于(yu)或(huo)等于(yu)350℃。
對(dui)民(min)用建筑物采(cai)暖、通風、空(kong)調(diao)及生活(huo)熱水熱負荷供(gong)熱的城市熱力網(wang)，宜采(cai)用水作供(gong)熱介質。
對生產(chan)工(gong)(gong)藝(yi)熱(re)(re)負(fu)(fu)荷和采(cai)(cai)暖、通(tong)(tong)風(feng)、空調(diao)、生活熱(re)(re)水(shui)熱(re)(re)負(fu)(fu)荷供(gong)熱(re)(re)的城市熱(re)(re)力網供(gong)熱(re)(re)介(jie)(jie)質(zhi)按下列原則確定(ding)：當生產(chan)工(gong)(gong)藝(yi)熱(re)(re)負(fu)(fu)荷為主要(yao)負(fu)(fu)荷，且必(bi)須采(cai)(cai)用蒸(zheng)(zheng)汽供(gong)熱(re)(re)時(shi)，宜采(cai)(cai)用蒸(zheng)(zheng)汽作供(gong)熱(re)(re)介(jie)(jie)質(zhi)；當以水(shui)位供(gong)熱(re)(re)介(jie)(jie)質(zhi)能夠(gou)滿足生產(chan)工(gong)(gong)藝(yi)需要(yao)（包括在用戶處轉換(huan)為蒸(zheng)(zheng)汽），且技術經濟合(he)理時(shi)，宜采(cai)(cai)用水(shui)作供(gong)熱(re)(re)介(jie)(jie)質(zhi)；當采(cai)(cai)暖、通(tong)(tong)風(feng)、空調(diao)熱(re)(re)負(fu)(fu)荷為主要(yao)負(fu)(fu)荷，生產(chan)工(gong)(gong)藝(yi)又必(bi)須采(cai)(cai)用蒸(zheng)(zheng)汽供(gong)熱(re)(re)，經技術經濟比較(jiao)認為合(he)理時(shi)，可采(cai)(cai)用水(shui)和蒸(zheng)(zheng)汽兩種供(gong)熱(re)(re)介(jie)(jie)質(zhi)。
1. 國家(jia)現(xian)行標準GJJ／T 34《城鎮(zhen)供(gong)(gong)熱(re)(re)(re)(re)管網設計規范》適(shi)用于(yu)(yu)供(gong)(gong)熱(re)(re)(re)(re)熱(re)(re)(re)(re)水介質設計壓力(li)(li)小(xiao)于(yu)(yu)或(huo)(huo)等于(yu)(yu)2.5MPa，設計溫(wen)度小(xiao)于(yu)(yu)或(huo)(huo)等于(yu)(yu)200℃；供(gong)(gong)熱(re)(re)(re)(re)蒸汽介質設計壓力(li)(li)小(xiao)于(yu)(yu)或(huo)(huo)等于(yu)(yu)1.6MPa，設計溫(wen)度小(xiao)于(yu)(yu)或(huo)(huo)等于(yu)(yu)350℃的(de)下列(lie)城鎮(zhen)供(gong)(gong)熱(re)(re)(re)(re)管網的(de)設計：以熱(re)(re)(re)(re)電廠或(huo)(huo)鍋爐房(fang)為熱(re)(re)(re)(re)源，自熱(re)(re)(re)(re)切至建筑物熱(re)(re)(re)(re)力(li)(li)人(ren)口的(de)供(gong)(gong)熱(re)(re)(re)(re)管網，供(gong)(gong)熱(re)(re)(re)(re)管網新建、擴建或(huo)(huo)改建的(de)管道(dao)、中斷泵(beng)站和熱(re)(re)(re)(re)力(li)(li)站等工(gong)藝系統。
2. 國家現行標準GJJ／T 81《城(cheng)鎮供(gong)熱(re)直埋熱(re)水管道技術(shu)規程(cheng)》適用于(yu)新(xin)建(jian)、改建(jian)、擴建(jian)的設(she)計溫(wen)度小于(yu)或等于(yu)150℃、設(she)計壓力小于(yu)或等于(yu)2.5MPa，DN小于(yu)或等于(yu)1200mm的城(cheng)鎮供(gong)熱(re)直埋熱(re)水管道的設(she)計、施工(gong)、驗(yan)收和運行管理。
3. 國(guo)家(jia)現行標準GJJ／T 104《城(cheng)鎮供熱直埋蒸汽管道技術規(gui)程》適用于(yu)工作(zuo)壓力小(xiao)于(yu)或(huo)等于(yu)2.5MPa，溫度小(xiao)于(yu)或(huo)等于(yu)350℃，直接埋地敷設(she)的(de)鋼質外護(hu)蒸汽保溫管道的(de)設(she)計、施工、驗收及運(yun)行維(wei)護(hu)。
二、熱力網的(de)形式
供熱管(guan)(guan)網(wang)(wang)按(an)其(qi)(qi)平面布置形式可分為枝狀(zhuang)管(guan)(guan)網(wang)(wang)、環狀(zhuang)管(guan)(guan)網(wang)(wang)和(he)多(duo)管(guan)(guan)制管(guan)(guan)網(wang)(wang)。其(qi)(qi)特點是：
1. 枝狀管網
從熱(re)(re)源引出主干(gan)線沿城鎮(zhen)道路向各熱(re)(re)用(yong)(yong)(yong)戶(hu)供(gong)熱(re)(re)，形(xing)成(cheng)類(lei)似樹枝(zhi)狀的(de)(de)管(guan)(guan)網(wang)(wang)叫枝(zhi)狀管(guan)(guan)網(wang)(wang)。枝(zhi)狀管(guan)(guan)網(wang)(wang)是目前我(wo)國城鎮(zhen)供(gong)熱(re)(re)中普遍采用(yong)(yong)(yong)的(de)(de)形(xing)式，它形(xing)式簡單(dan)、投資費用(yong)(yong)(yong)低，且運行管(guan)(guan)理方(fang)便，但安全可靠性(xing)較差，當(dang)管(guan)(guan)網(wang)(wang)中距離熱(re)(re)源較近的(de)(de)主干(gan)線發生(sheng)故(gu)障時，會影響較多的(de)(de)熱(re)(re)用(yong)(yong)(yong)戶(hu)用(yong)(yong)(yong)熱(re)(re)。
2. 環狀管(guan)網
供(gong)熱(re)管(guan)網的主干線之間在適當位(wei)置連通構成環(huan)形，環(huan)狀管(guan)網運行較安全可靠(kao)，局部發生(sheng)故(gu)障可通過環(huan)網供(gong)熱(re)。但(dan)投資費用高。
3. 多(duo)管制(zhi)管網
一般用(yong)(yong)于以下情況：不能間斷的熱用(yong)(yong)戶(hu)；供熱系統中熱用(yong)(yong)戶(hu)所需介(jie)質參(can)數(shu)差別較大；熱負荷變化較大：季節(jie)性(xing)熱負荷占全年總負荷比例較大。
三、熱水熱力網形(xing)式的確(que)定
熱(re)(re)水熱(re)(re)力網宜(yi)采(cai)用(yong)閉式(shi)雙管制。以熱(re)(re)電廠為熱(re)(re)源(yuan)的熱(re)(re)水熱(re)(re)力網，同時有工藝(yi)、采(cai)暖(nuan)、通風、空調、生(sheng)活熱(re)(re)水多種(zhong)熱(re)(re)負(fu)荷(he)(he)，在生(sheng)產(chan)工藝(yi)熱(re)(re)負(fu)荷(he)(he)與采(cai)暖(nuan)熱(re)(re)負(fu)荷(he)(he)所需供熱(re)(re)介(jie)質(zhi)參(can)數相(xiang)差(cha)較(jiao)大，或(huo)季(ji)節性熱(re)(re)負(fu)荷(he)(he)占總(zong)熱(re)(re)負(fu)荷(he)(he)比例較(jiao)大，且(qie)技術經濟合(he)理時，可采(cai)用(yong)閉式(shi)多管制。
當(dang)熱(re)水熱(re)力(li)網具有水處理(li)費用較低的(de)豐(feng)富的(de)補給水資源，且(qie)技術經(jing)濟合理(li)時，可采用開(kai)式熱(re)力(li)網。
當(dang)熱水(shui)熱力網具有與生活熱水(shui)熱負荷相適應(ying)的廉價低位能熱源，且技(ji)術經(jing)濟合理時，可采用開式熱水(shui)網。
開式熱(re)水(shui)(shui)熱(re)力網在生活熱(re)水(shui)(shui)熱(re)負荷足夠大(da)且技術經濟合理時，可不設(she)回水(shui)(shui)管。
四、蒸汽熱力網形(xing)式的確定
蒸汽(qi)熱(re)(re)(re)力網宜采用單管制。當(dang)各用戶間所(suo)需蒸汽(qi)參數相差較大或季節性熱(re)(re)(re)負(fu)荷占總熱(re)(re)(re)負(fu)荷比例較大且(qie)技術經濟合理時(shi)，蒸汽(qi)熱(re)(re)(re)力網可采用雙管或多管制。
蒸(zheng)汽熱(re)力網的熱(re)負荷(he)分期增長(chang)時，可采用雙(shuang)管(guan)或多管(guan)制。蒸(zheng)汽供熱(re)系統應創造條件采用間接換熱(re)系統。當被加熱(re)介(jie)質(zhi)泄漏不會產生危害(hai)時，其凝(ning)結水(shui)應全(quan)部回收并(bing)設置凝(ning)結水(shui)管(guan)道。
當凝結水(shui)回(hui)收時，用戶(hu)熱力(li)站應設閉式凝結水(shui)箱，用水(shui)泵(beng)將凝結水(shui)送回(hui)熱源(yuan)。
五、多供(gong)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。
