1. 伴管(guan)管(guan)徑及(ji)根數的選用
①. 伴(ban)管管徑宜(yi)為10、12、DN15、DN20、DN25,伴(ban)管根數不宜(yi)超過4根。
②. 在不(bu)同環(huan)境(jing)溫(wen)(wen)(wen)度(du)(du)(du)(du)及工藝(yi)操作(zuo)條件下,蒸(zheng)(zheng)汽(qi)伴(ban)(ban)管(guan)(guan)管(guan)(guan)徑(jing)及根數從(cong)SH/T 3040提供的(de)四個表(biao)(biao)(表(biao)(biao)1蒸(zheng)(zheng)汽(qi)伴(ban)(ban)管(guan)(guan)溫(wen)(wen)(wen)度(du)(du)(du)(du)143℃/183℃、環(huan)境(jing)溫(wen)(wen)(wen)度(du)(du)(du)(du)5℃;表(biao)(biao)2蒸(zheng)(zheng)汽(qi)伴(ban)(ban)管(guan)(guan)溫(wen)(wen)(wen)度(du)(du)(du)(du)143℃/183℃、環(huan)境(jing)溫(wen)(wen)(wen)度(du)(du)(du)(du)-5℃;表(biao)(biao)3蒸(zheng)(zheng)汽(qi)伴(ban)(ban)管(guan)(guan)溫(wen)(wen)(wen)度(du)(du)(du)(du)143℃/183℃、環(huan)境(jing)溫(wen)(wen)(wen)度(du)(du)(du)(du)-15℃;表(biao)(biao)4蒸(zheng)(zheng)汽(qi)伴(ban)(ban)管(guan)(guan)溫(wen)(wen)(wen)度(du)(du)(du)(du)143℃/183℃、環(huan)境(jing)溫(wen)(wen)(wen)度(du)(du)(du)(du)-25℃)中(zhong)選擇;熱水伴(ban)(ban)管(guan)(guan)管(guan)(guan)徑(jing)及根數從(cong)SH/T 3040提供的(de)四個表(biao)(biao)(表(biao)(biao)5蒸(zheng)(zheng)汽(qi)伴(ban)(ban)管(guan)(guan)溫(wen)(wen)(wen)度(du)(du)(du)(du)90℃/100℃/110℃、環(huan)境(jing)溫(wen)(wen)(wen)度(du)(du)(du)(du)5℃;表(biao)(biao)6蒸(zheng)(zheng)汽(qi)伴(ban)(ban)管(guan)(guan)溫(wen)(wen)(wen)度(du)(du)(du)(du) 90℃/100℃/110℃、環(huan)境(jing)溫(wen)(wen)(wen)度(du)(du)(du)(du)-5℃;表(biao)(biao)7蒸(zheng)(zheng)汽(qi)伴(ban)(ban)管(guan)(guan)溫(wen)(wen)(wen)度(du)(du)(du)(du)90℃/100℃/110℃、環(huan)境(jing)溫(wen)(wen)(wen)度(du)(du)(du)(du)-15℃;表(biao)(biao)8蒸(zheng)(zheng)汽(qi)伴(ban)(ban)管(guan)(guan)溫(wen)(wen)(wen)度(du)(du)(du)(du)90℃/100℃/110℃、環(huan)境(jing)溫(wen)(wen)(wen)度(du)(du)(du)(du)-25℃)中(zhong)選擇。
③. 環境溫(wen)度、伴管介質(zhi)的操(cao)作條件、保溫(wen)材料(liao)制(zhi)品的熱(re)導(dao)率及傳(chuan)熱(re)系數等數據與表1~表8不同時,伴管管徑及根數(采用硬(ying)質(zhi)或半硬(ying)質(zhi)圓形保溫(wen)材料(liao)制(zhi)品)按(an)下面公式計算。
2. 蒸汽分配(pei)站和疏水(shui)站
①. 對于(yu)蒸(zheng)汽分配站(zhan)(zhan)和疏水站(zhan)(zhan)的(de)管徑(jing)也給出(chu)了下面的(de)公式,計算出(chu)S值,再查詢(xun)SH3040相(xiang)應的(de)表格來獲得蒸(zheng)汽分配站(zhan)(zhan)和疏水站(zhan)(zhan)的(de)管徑(jing)。
S=A+2B+3C 式中(zhong)A-DN15、612、10伴(ban)管根(gen)(gen)數;B-DN20伴(ban)管根(gen)(gen)數;C-DN25伴(ban)管根(gen)(gen)數。
②. 在3m半徑范圍內如有3個或(huo)3個以上的伴(ban)(ban)熱(re)點及回(hui)收點時(shi),蒸汽(qi)伴(ban)(ban)熱(re)系統應設置蒸汽(qi)分(fen)配(pei)站和(he)(he)(he)疏(shu)水(shui)站,熱(re)水(shui)伴(ban)(ban)熱(re)系統應設置熱(re)水(shui)分(fen)配(pei)站和(he)(he)(he)熱(re)水(shui)回(hui)水(shui)站。站的設置應考慮統一考慮,布局(ju)合理,方便操作(zuo)和(he)(he)(he)維修。
3. 蒸汽(qi)伴(ban)管(guan)沿被伴(ban)熱(re)管(guan)的最大允許有效伴(ban)熱(re)長度(du)(包括(kuo)垂直管(guan)道)(表6-34)
凝結水不回收時,最(zui)大允(yun)許有效伴(ban)熱長度(du)可延(yan)長20%;采用(yong)導(dao)熱膠(jiao)泥時,最(zui)大允(yun)許有效伴(ban)熱長度(du)宜(yi)縮短(duan)20%;對于(yu)出現(xian)U形(xing)彎時,在超過(guo)規定數值(蒸(zheng)汽壓(ya)力0.3~0.5MPa,累(lei)計上升4m;蒸(zheng)汽壓(ya)力大于(yu)0.5~0.7MPa,累(lei)計上升5m;蒸(zheng)汽壓(ya)力大于(yu)0.7~1MPa,累(lei)計上升6m)時宜(yi)適當減少最(zui)大允(yun)許有效伴(ban)熱長度(du),但伴(ban)管累(lei)計上升高度(du)不宜(yi)超過(guo)10m。
注(zhu):1. 蒸(zheng)汽(qi)分(fen)配站安裝(zhuang)(zhuang)位置(zhi)高于(yu)蒸(zheng)汽(qi)總管(guan)時,分(fen)配站低(di)點可不(bu)設排放冷(leng)凝水的蒸(zheng)汽(qi)疏水閥系(xi)統,水平安裝(zhuang)(zhuang)的分(fen)配站應(ying)(ying)無袋形并坡向蒸(zheng)汽(qi)總管(guan)。蒸(zheng)汽(qi)分(fen)配站低(di)于(yu)蒸(zheng)汽(qi)總管(guan)時,其上游不(bu)得(de)有(you)下(xia)凹(ao)的袋形彎,分(fen)配站的低(di)點應(ying)(ying)設蒸(zheng)汽(qi)疏水閥組。
2. 蒸(zheng)汽分配站至少(shao)有3根(gen)伴(ban)(ban)管(DN15)送至半(ban)徑為3m范圍內的地點(dian)時才設(she)置,否則伴(ban)(ban)熱供汽管可直接從蒸(zheng)汽總管上引出。
3. 分配站應布置(zhi)(zhi)在不(bu)妨礙(ai)通行、便于操(cao)作(zuo)的地方,布置(zhi)(zhi)應考慮整齊和(he)美觀。
4. 供汽(qi)管的閥門應布置在便于接近的地方。
5. 分配(pei)站的蒸汽應從蒸汽總管的頂部(bu)引出(chu)。
4. 熱水伴管沿(yan)被伴熱管的最大允許有效伴熱長(chang)度(包(bao)括垂直管道)(表6-35)
注:按SH/T 3040,應注意有效伴(ban)熱長(chang)度和其他標(biao)準規定的數值的不同,根據(ju)項目(mu)實際情況選用(yong)。
注(zhu):按 SH/T 3040,應注(zhu)意有效伴(ban)熱長度和(he)其他標(biao)準規(gui)定(ding)的(de)數(shu)值的(de)不(bu)同,根據項目實際(ji)情況選用(yong)。