管道压降计算

名称符号公式管道外径Do管道总长度L管道始端蒸汽焓H1蒸汽始端压力P2蒸汽始端温度T1蒸汽终端允许压力P2管道终端允许温度T2管道终端允许蒸汽焓H2管道蒸汽流量V管道允许焓降ΔHΔH=H1-H2假定保温厚度δ假定假定管道保温外径D1D1=D0+2*δ假定管道外表面积SS=π*D1*L/1000允许散热密度qq=1000*ΔH*V/S允许对流和辐射散热密度q1假定：q1=q环境温度ta假定室外常年平均风速w保温层材料黑度(镀锌铁皮)ε假设管道保温外壁温度ts假定管道对流传热系数acac=72.8*w0.6/D10.4管道保温外表面传热系数anan=(5.67*ε/(ts-ta))/(((273+ts)/100)^4-((273+ta)/100)^4)传热系数aa=ac+an允许保温外表面温度ts'ts'=ta+q1/a管道设计温度TT=(T1+T2)/2管道外表面温度tt=T1管道保温层平均温度tmtm=(t+ta)/2保温材料导热系数λλ=0.035+1.65*0.0001*tm+1.242*E-7*tm^2保温层热传导散热密度q2q2=q1保温层厚度δδ=λ*(t-ts')/q2实际取用保温厚度A实际保温层热传导散热密度q2'q2'=(t-ts)/(A/λ)实际取用保温外径D1'D1'=D0+2*A管道实际总外表面积S'S'=π*D1'*L/1000管道实际损失热量Q'Q'=q2'*S'/1000蒸汽焓降ΔH'ΔH'=Q'/V终端实际焓H2'H2'=H1-ΔH'终端实际温度T2'查表单位管径计算(426x8)管径计算(426x8)管径计算(426x8)mm426426426m160016001600kj/kg303230323032Mpa0.850.850.85290290290Mpa0.50.50.5260260260kj/kg300030003000t/h605030kj/kg323232mm100100100mm626626626m23145.0243145.0243145.024W/m2169.580052141.3167184.79002598w/m2169.580052141.3167184.79002598-30-30-30m/s2220.250.250.250008.3969128058.3969128058.396912805an=(5.67*ε/(ts-ta))/(((273+ts)/100)^4-((273+ta)/100)^4)0.0022850510.0022850510.0022850518.3991978568.3991978568.399197856-9.809970564-13.17497547-19.90498528275275275275275275122.5122.5122.5W/(m.K)0.0570762760.0570762760.057076276w/m2169.580052141.3167184.79002598mm95.85969795116.3907263198.5148396mm100100100w/m2162.5589256164.4795451168.3207841mm626626626m23145.0243145.0243145.024kw511.2517224517.2921168529.3729056kj/kg30.6751033437.2450324163.52474867kj/kg3001.3248972994.7549682968.475251270265250管径计算(426x8)426160030320.852900.5260300020321006263145.02456.5266839956.52668399-3020.2508.3969128050.0022850518.399197856-23.26999019275275122.50.05707627656.52668399301.1699813100170.24140366263145.024535.413396.3743942935.625606240名称符号单位管段始端压力p1Mpa管段始端温度t1℃蒸汽流量Gt/h管段始端蒸汽密度ρ1kg/m3管段始端蒸汽比容υ1m3/kg管段始端蒸汽焓值h1kj/kg管段末端允许压力(假定)p2'Mpa管段末端允许温度(假定)t2℃管段末端蒸汽密度(假定)ρ2kg/m3管段末端蒸汽比容(假定)υ2m3/kg平均压力ppjMpa平均比容υpjm3/kg管道流速计算wm/s抽汽管道管外径(假定)Dwmm抽汽管道管内径Dimm抽汽管道壁厚δmm介质动力粘度η1Pa.s介质运动粘度γm2/s雷诺系数Re管道等值粗糙度ε管道相对粗糙度管道摩擦系数λ管道弯头个数n1管道上阀门个数n2单个弯头局部阻力系数ξj1弯头处局部总阻力系数ξjw止回阀局部阻力系数ξj2闸阀局部阻力系数ξj3ξjf管道局部阻力系数ξj管道沿程阻力系数ξy管道总长Lm管道阻力系数ξt管道压降ΔP1Pa管道压降ΔPMPa终端管道实际压力P2MPa管道压降比值B公式数值1(Φ426x8)0.85290603.74950.26670222730320.52602.43770.4102227510.675Vpj=0.5*(υ1+υ2)0.338462489w=Gυ/(Di*0.001/594.7)^242.725775854264108查汽规P162~165页1.9800E-05γ=η1*υ15.28E-06Re=w*Di/γ3.32E+06查汽规P166页0.3ε/Di0.000731707查汽规P39页莫迪图0.018每90米一个π弯60闸阀1只1ξj1=20*λ(单个弯头阻力系数)0.36ξjw=n1*ξj1(弯头局部阻力系数:r/d=1)21.6查汽规(止回阀门阻力系数：L/Di=50)0查汽规(闸阀阻力系数)0.25ξjf=ξj2+1*ξj30.25ξj=ξjw+ξjf21.85ξy=λ*L/Di70.243902441600ξt=ξj+ζy92.09390244ΔP1=ξt*w2/2*υ248353.4815△p=1.1*△p1/1000000(阻力预留10%预量)0.27318883P2=P1-ΔP0.57681117Δp/p10.321398623数值1(Φ426x8)0.75290503.34550.2989089823034.70.52602.43770.4102227510.6250.35456586737.2988199942641081.9800E-055.92E-062.58E+060.30.0007317070.0186010.3621.600.250.2521.8570.24390244160092.09390244180673.36820.1987407050.5512592950.264987607