名 称符 号 单 位公 式管道始端压力p1Mpa绝压管道始端温度t1℃蒸汽质量流量Gt/h管道始端蒸汽比容υ 1m3/kg查焓熵图管道始端蒸汽密度ρ 1kg/m3管道始端蒸汽焓值h1kj/kg查焓熵图管道末端允许压力(假定)p2Mpa管道末端允许温度(假定)t2℃管道末端蒸汽比容(假定)υ 2m3/kg查焓熵图管道末端蒸汽密度(假定)ρ 2kg/m3管道末端蒸汽焓值h1kj/kg查焓熵图管道允许焓降Δ Hkj/kgΔ H=H1-H2始末端平均压力ppjMpappj=0.5*（p1+p2）始末端平均比容υ pjm3/kgVpj=0.5*(υ 1+υ 2)管道流速wm/sw=Gυ /(Di/594.5)^2钢管外径(假定)D0mm钢管内径Dimm钢管壁厚δmm管道保温层厚度δ 0mm保温管外径D1mm管道设计温度T℃T=(T1+T2)/2蒸汽管道外表面温度t℃t=T管道保温层平均温度tm℃tm=(t+ta)/2环境温度ta℃取ta=0℃室外常年平均风速wm/s取w=2m/s保温材料导热系数λW/(m.k)离心玻璃棉λ =0.031+0.00017×tm保温层外表面对空气的放热系数αW/（㎡.℃）α =1.163×（10+6√w）介质动力粘度η 1Pa.s查汽规P221~ 224页介质运动粘度γm2/sγ =η 1*υ 1雷诺系数ReRe=w*Di/γ管壁的当量绝对粗糙度Km查汽规P225页管道相对粗糙度εε =K/Di管道摩擦系数λλ =1/(1.14+2lg(Di/K))^2管道沿程阻力长度Lm管道局部阻力当量长度LZLz=0.2*L管道压降Δ P1PaΔ P1=λ (l+lZ)/d×(ρ v^2)/2考虑余量的管道压降Δ PMPa△p=1.1*△p1/1000000(阻力预留10%预量)终端管道实际压力P2MPaP2=P1-Δ P单位长度的散热损失qW/m2q=(T-Ta)/(D1/2λ ln D1/D管道的散热损失QkWpi×D1×L×q/1000蒸汽焓降Δ H'kJ/kgΔ H'=Q/G终端实际焓H2'H2'=H1-Δ H'终端实际温度T2'查表温降ΔT℃Δ T=T2'-T101234568101520计算结果11111.51.51.5250300350400250300350606060606060600.23260.25790.28250.30660.1720.19170.21054.303.883.543.265.815.224.752941.83050.431573263.12921.73036.53146.60.80.80.80.81.31.31.32302803303802302803300.31520.35010.38410.41760.18710.20950.23093.172.862.602.395.344.774.332905.63013.33118.93224.22882.62997.73107.536.237.138.138.939.138.839.10.9000.9000.9000.9001.4001.4001.4000.270.300.330.360.180.200.2234.2237.9841.6445.2429.2232.6435.914284284284283773773774124124124123613613618888888150150150150150150150728728728728677677677240290340390240290340240290340390240290340120145170195120145170000000022222220.05140...
